阅读说明：本技术 作业车辆用障碍物检测系统 (Obstacle detection system for work vehicle ) 是由 岩濑卓也 横山和寿 杉田士郎 于 2019-02-26 设计创作，主要内容包括：本发明提供一种作业车辆用障碍物检测系统,其能够实现成本的降低、事先执行作业所需的工时的减少。在作业车辆用障碍物检测系统中,将左右侧各3个的超声波传感器103A～103C、104A～104C以它们的测定范围Na～Nc在前后方向上连续的状态配置于作业车辆1的左右两侧部,测距用控制部105基于测定范围Na～Nc连续的超声波传感器103A～103C、104A～104C的测距动作而执行对物体在前后方向上的相对车身位置进行检测的位置检测处理,并且,基于测定范围Na～Nc连续的超声波传感器103A～103C、104A～104C的测距动作顺序而执行对物体在前后方向上的移动进行检测的位移检测处理。(The invention provides an obstacle detection system for a work vehicle, which can reduce the cost and the man-hour required for executing work in advance. In the obstacle detection system for a working vehicle, 3 ultrasonic sensors 103A to 103C and 104A to 104C on the left and right sides, respectively, are disposed on the left and right sides of the working vehicle 1 in a state where their measurement ranges Na to Nc are continuous in the front-rear direction, the distance measurement control unit 105 performs a position detection process of detecting the relative vehicle body position of an object in the front-rear direction based on the distance measurement operation of the ultrasonic sensors 103A to 103C and 104A to 104C in which the measurement ranges Na to Nc are continuous, and performs a displacement detection process of detecting the movement of the object in the front-rear direction based on the sequence of the distance measurement operation of the ultrasonic sensors 103A to 103C and 104A to 104C in which the measurement ranges Na to Nc are continuous.)

1. An obstacle detection system for a work vehicle, comprising:

a sensor unit having 3 or more ultrasonic sensors and disposed on one of front, rear, left, and right sides of the work vehicle; and

a distance measurement control unit that measures a distance to an object that enters a measurement range of the ultrasonic sensor based on a distance measurement operation of the ultrasonic sensor,

the ultrasonic sensors are arranged on the one side portion in a positional relationship in which the measurement ranges of at least 2 of the ultrasonic sensors are continuous in a direction along the one side portion,

the control unit performs a position detection process of detecting a relative vehicle body position of the object in the direction along the one side portion based on the distance measurement operation of the ultrasonic sensor having the continuous measurement range, and performs a displacement detection process of detecting a movement of the object in the direction along the one side portion based on the sequence of the distance measurement operation of the ultrasonic sensor having the continuous measurement range.

2. The obstacle detection system for a work vehicle according to claim 1, wherein,

the sensor unit has 4 or more of the ultrasonic sensors,

the ultrasonic sensors are arranged in a longitudinal and transverse direction on the one side portion in a positional relationship in which the measurement ranges are continuous in both a direction along the one side portion and the distance and approach direction,

the control unit detects the relative vehicle body position of the object within the measurement range of the sensor unit based on the distance measurement operation of the ultrasonic sensor having the continuous measurement range in the position detection process, and detects the movement of the object within the measurement range of the sensor unit based on the sequence of the distance measurement operation of the ultrasonic sensor having the continuous measurement range in the displacement detection process.

3. The obstacle detection system for a work vehicle according to claim 1 or 2, wherein,

the obstacle detection system for a work vehicle includes a collision avoidance control unit that performs collision avoidance control for avoiding a collision between the work vehicle and the object based on information from the control unit,

the collision avoidance control unit controls traveling of the work vehicle in the collision avoidance control.

Technical Field

The present invention relates to an obstacle detection system for a work vehicle, which can prevent a work vehicle such as a tractor from colliding with an obstacle present at a work site.

Background

As an obstacle detection system provided in a work vehicle such as an agricultural machine, for example, there is a system configured to: a front portion of a working vehicle (agricultural machine) is provided with a stereo camera (stereo camera device) for imaging the front of the working vehicle and a pair of left and right ultrasonic sonar devices for taking the front of the working vehicle as a measurement range, and the stereo camera is used for detecting an obstacle in the traveling direction of the working vehicle and for detecting the distance and size to the obstacle, and the ultrasonic sonar device is used for measuring the distance to an obstacle in a blind spot which cannot be captured by the stereo camera (see, for example, patent document 1).

Disclosure of Invention

That is, the invention described in patent document 1 includes, in a front portion of a work vehicle: a stereo camera adapted to detect a relative vehicle body position of an obstacle or the like; and a set of ultrasonic sonar devices on the left and right sides that measure the distance to an obstacle entering the area near the work vehicle that is a blind spot of the stereo camera. Further, when the stereo camera or the ultrasonic sonar device captures an obstacle existing in the traveling direction (front side) of the work vehicle, it is possible to avoid collision of the work vehicle with the obstacle existing in the traveling direction (front side). Therefore, in the invention described in patent document 1, in order to avoid collision of an obstacle with the front, rear, left, and right side portions of the work vehicle, it is necessary to dispose the ultrasonic sonar devices together with expensive stereo cameras on the front, rear, left, and right side portions of the work vehicle. In addition, in the case of detecting an obstacle using a stereo camera, it is necessary to perform a learning process of learning in advance the shapes of a large number of obstacles as detection targets. As a result, when constructing an obstacle detection system that avoids a collision between a work vehicle and an obstacle, the cost increases, and the number of steps required for work performed in advance, such as learning, increases.

In view of the above circumstances, a main object of the present invention is to provide an obstacle detection system for a work vehicle, which can reduce costs and reduce the number of steps required for a previously performed work.

A 1 st aspect of the present invention is summarized as an obstacle detection system for a work vehicle, including: a sensor unit having 3 or more ultrasonic sensors and disposed on one of front, rear, left, and right sides of the work vehicle; and a distance measurement control unit that measures a distance of an object that has entered a measurement range of the ultrasonic sensor based on a distance measurement operation of the ultrasonic sensor, the ultrasonic sensor being disposed on the one side portion in a positional relationship in which the measurement ranges of at least 2 of the ultrasonic sensors are continuous in a direction along the one side portion, respectively, the control unit performing a position detection process of detecting a relative vehicle body position of the object in the direction along the one side portion based on the distance measurement operation of the ultrasonic sensors in which the measurement ranges are continuous, and performing a displacement detection process of detecting a displacement of the object in the direction along the one side portion based on a sequence of the distance measurement operations of the ultrasonic sensors in which the measurement ranges are continuous.

According to this configuration, for example, when the sensor unit is disposed on the right side portion of the work vehicle, at least 2 ultrasonic sensors are disposed in a line in the vehicle body front-rear direction on the right side portion of the work vehicle.

In this case, for example, when an object enters the measurement range of the 1 st ultrasonic sensor having the front region on the outer side on the right side of the vehicle body as the measurement range, the ultrasonic wave transmitted from the 1 st ultrasonic sensor comes into contact with the object and bounces back to the 1 st ultrasonic sensor. Accordingly, the 1 st ultrasonic sensor performs a ranging operation for receiving a reflected wave in addition to transmitting an ultrasonic wave. The control unit detects that an object is present in the measurement range of the 1 st ultrasonic sensor that has performed the distance measurement operation, that is, in the front region on the outer side on the right side of the vehicle body, by the position detection processing described above, and measures the distance from the 1 st ultrasonic sensor to the object based on the time required from the transmission of the ultrasonic wave from the 1 st ultrasonic sensor to the reception of the ultrasonic wave. As a result, the control unit can detect that an object is present at a position separated from the 1 st ultrasonic sensor in the front region on the right outer side of the vehicle body by the measurement distance based on the distance measurement operation of the 1 st ultrasonic sensor.

Similarly, for example, when the object enters the measurement range of the 2 nd ultrasonic sensor having the rear region on the outer side on the right side of the vehicle body as the measurement range, the 2 nd ultrasonic sensor performs the distance measurement operation, and therefore the control unit can detect that the object is present at a position separated by the measurement distance from the 2 nd ultrasonic sensor in the rear region on the outer side on the right side of the vehicle body based on the distance measurement operation of the 2 nd ultrasonic sensor.

Further, for example, when the object enters the measurement range of the 1 st ultrasonic sensor and then enters the measurement range of the 2 nd ultrasonic sensor, the 2 nd ultrasonic sensor performs the distance measuring operation after the 1 st ultrasonic sensor performs the distance measuring operation, and therefore, the control section can detect that the object is displaced from the front region to the rear region on the outer side on the right side of the vehicle body by the displacement detection processing described above.

Similarly, for example, when the object enters the measurement range of the 1 st ultrasonic sensor after entering the measurement range of the 2 nd ultrasonic sensor, the 1 st ultrasonic sensor performs the distance measuring operation after the 2 nd ultrasonic sensor performs the distance measuring operation, and therefore the control unit can detect that the object is displaced from the rear region to the front region on the outer side on the right side of the vehicle body by the displacement detection processing described above.

On the other hand, when the object is out of the measurement range of the sensor unit, the control unit can detect that there is no object in the measurement range of the sensor unit because each ultrasonic sensor does not perform the distance measurement operation.

Further, since the control unit measures the distance of the object based on the distance measuring operation of the 1 st ultrasonic sensor or the 2 nd ultrasonic sensor, the control unit can detect the displacement of the object in the distance and approach direction with respect to the right side portion of the vehicle body by the measurement distance that changes along with the displacement of the object in the distance and approach direction with respect to the right side portion of the vehicle body when the object located in the measurement range of the 1 st ultrasonic sensor or the 2 nd ultrasonic sensor is displaced in the distance and approach direction with respect to the right side portion of the vehicle body within the measurement range.

Further, when the displacement of the object between the front region and the rear region on the right outer side of the vehicle body is detected by the displacement detection processing, the control unit can detect the displacement of the object in the distance and approach direction with respect to the right side portion of the vehicle body based on the difference in the measurement distances obtained along with the displacement.

That is, the sensor unit including the plurality of ultrasonic sensors, which is less expensive than the stereo camera, the radar sensor instead of the stereo camera, or the like, is disposed at least at one side portion of the front, rear, left, and right sides of the work vehicle, and thus, the relative vehicle body position or displacement in the direction along the one side portion in the vicinity of the one side portion of the object with respect to the direction in which the one side portion is separated from and approaches the object can be detected without providing the stereo camera, the radar sensor, or the like that images the vicinity of the one side portion.

As a result, when constructing the obstacle detection system for a work vehicle, it is possible to reduce the number of expensive stereo cameras, radar sensors, and the like, thereby reducing the cost and the number of man-hours required to perform work in advance.

The 2 nd characteristic structure of the present invention is: the sensor unit includes 4 or more ultrasonic sensors, the ultrasonic sensors are arranged in a vertical and horizontal direction in a positional relationship in which the measurement ranges are continuous in both the direction along the one side portion and the distance and approach direction, the control unit detects the relative vehicle body position of the object within the measurement range of the sensor unit based on the distance measurement operation of the ultrasonic sensors in which the measurement ranges are continuous in the position detection process, and the control unit detects the displacement of the object within the measurement range of the sensor unit based on the sequence of the distance measurement operation of the ultrasonic sensors in which the measurement ranges are continuous in the displacement detection process.

However, in a case where the work vehicle includes an ultrasonic sensor, particularly in a work vehicle such as an agricultural work machine which is often driven in a field where soil is muddy, the ultrasonic sensor needs to be disposed at a high position of the vehicle body in order to prevent adhesion of the mud to the ultrasonic sensor. When the ultrasonic sensor is disposed at a high position of the vehicle body in this way, the higher the ultrasonic sensor is disposed, the larger the depression angle of the ultrasonic sensor needs to be in order to reduce the blind spot of the ultrasonic sensor near the vehicle body. When the depression angle is increased, the measurement range of the ultrasonic sensor needs to be limited so that the ultrasonic sensor detects the ground as an object and does not measure the distance. Therefore, the measurement range of the ultrasonic sensor is limited to a short distance from the working vehicle.

According to the present configuration obtained in view of such a situation, for example, in the case where the sensor unit is disposed on the right side portion of the work vehicle, at least 4 ultrasonic sensors are disposed in the right side portion of the work vehicle in a vertically and horizontally arranged manner in the positional relationship described above.

In this case, for example, when an object enters the measurement range of the 1 st ultrasonic sensor, which has the front outer region on the outer side on the right side of the vehicle body as the measurement range, the ultrasonic wave transmitted from the 1 st ultrasonic sensor contacts the object and bounces back to the 1 st ultrasonic sensor. Accordingly, the 1 st ultrasonic sensor performs a distance measuring operation for receiving a reflected wave in addition to transmitting an ultrasonic wave. The control unit detects that an object is present in a front outer region on the outer side of the right side of the vehicle body, which is a measurement range of the 1 st ultrasonic sensor that has performed the distance measurement operation, by the position detection processing described above, and measures the distance from the 1 st ultrasonic sensor to the object based on the time required for transmission of the ultrasonic wave from the 1 st ultrasonic sensor to the reception of the ultrasonic wave. As a result, the control unit can detect that an object is present at a position separated by the measurement distance from the 1 st ultrasonic sensor in the front outer region on the right outer side of the vehicle body based on the distance measurement operation of the 1 st ultrasonic sensor.

Similarly, for example, when an object enters the measurement range of the 2 nd ultrasonic sensor having the rear outside region on the right outside of the vehicle body as the measurement range, the 2 nd ultrasonic sensor performs the distance measurement operation, and therefore the control unit can detect that the object is present at a position separated by the measurement distance from the 2 nd ultrasonic sensor in the rear outside region on the right outside of the vehicle body based on the distance measurement operation of the 2 nd ultrasonic sensor.

Similarly, for example, when an object enters the measurement range of the 3 rd ultrasonic sensor having the front inner region on the right outer side of the vehicle body as the measurement range, the 3 rd ultrasonic sensor performs the distance measurement operation, and therefore the control unit can detect that the object is present at a position separated by the measurement distance from the 3 rd ultrasonic sensor in the front inner region on the right outer side of the vehicle body based on the distance measurement operation of the 3 rd ultrasonic sensor.

Similarly, for example, when the object enters the measurement range of the 4 th ultrasonic sensor having the measurement range of the rear inner region on the right outer side of the vehicle body, the 4 th ultrasonic sensor performs the distance measurement operation, and therefore the control unit can detect that the object is present at a position separated by the measurement distance from the 4 th ultrasonic sensor in the rear inner region on the right outer side of the vehicle body based on the distance measurement operation of the 4 th ultrasonic sensor.

Further, for example, when the object enters the measurement range of the 1 st ultrasonic sensor and then enters the measurement range of the 2 nd ultrasonic sensor, the 2 nd ultrasonic sensor performs the distance measuring operation after the 1 st ultrasonic sensor performs the distance measuring operation, and therefore, the control unit can detect that the object is displaced from the front outer region to the rear outer region on the right outer side of the vehicle body by the displacement detection processing described above.

That is, when the object enters the measurement range of any one of the ultrasonic sensors and then enters the measurement range of the other ultrasonic sensor, the control unit can detect that the object has shifted from the predetermined region on the outer side on the right side of the vehicle body corresponding to the measurement range of the movement source to the predetermined region on the outer side on the right side of the vehicle body corresponding to the measurement range after the movement by the displacement detection processing described above.

On the other hand, when the object is out of the measurement range of the sensor unit, the control unit can detect that there is no object in the measurement range of the sensor unit because each ultrasonic sensor does not perform the distance measurement operation.

Further, since the control unit measures the distance of the object based on the distance measuring operation of any one of the ultrasonic sensors, the control unit can detect the displacement of the object in the distance and approach direction with respect to the right side portion of the vehicle body based on the measurement distance that changes along with the displacement of the object in the distance and approach direction with respect to the right side portion of the vehicle body when the object located in the measurement range of any one of the ultrasonic sensors is displaced in the distance and approach direction with respect to the right side portion of the vehicle body in the measurement range.

Further, when the displacement of the object between any 2 predetermined regions on the right outer side of the vehicle body is detected by the displacement detection processing, the control unit can detect the displacement of the object in the distance and approach direction with respect to the right side portion of the vehicle body based on the difference in the measurement distances obtained along with the displacement.

Accordingly, the ultrasonic sensors are disposed at a high position where adhesion of mud can be prevented, and the measurement range of the sensor unit can be expanded in the direction of moving away from and approaching the working vehicle with a reduced blind spot near the vehicle body without causing a problem that the ultrasonic sensors measure the distance to the ground. Further, the control unit can detect the position and displacement of the object relative to the vehicle body in a wider area outside one side portion of the work vehicle.

As a result, it is possible to reduce the cost, reduce the number of steps required to perform the work in advance, and the like, and it is possible to ensure a suitably wide measurement range and perform good object detection as an obstacle detection system for a work vehicle.

The 3 rd characteristic structure of the present invention is: the obstacle detection system for a work vehicle includes a collision avoidance control unit that performs collision avoidance control for avoiding a collision between the work vehicle and the object based on information from the control unit, wherein the collision avoidance control unit controls traveling of the work vehicle in the collision avoidance control.

According to this configuration, for example, when the work vehicle travels at the set speed for work, the control unit executes deceleration processing for causing the work vehicle to travel at a speed lower than the set speed based on the detection information when it is detected that an object is present in a far-side area based on the distance measurement operation of the ultrasonic sensor having the far-side area from the work vehicle as the measurement range, and then executes stop processing for stopping the work vehicle based on the detection information in collision avoidance control when it is detected that an object is present in a near-side area based on the distance measurement operation of the ultrasonic sensor having the near-side area from the work vehicle as the measurement range.

Further, for example, when the work vehicle is caused to travel at a speed lower than the set speed by the deceleration processing described above, if the ultrasonic sensors do not perform the distance measuring operation and the presence of the object in the area corresponding to the measurement range of the sensor unit cannot be detected, the control unit can avoid a reduction in work efficiency caused by continuing the low-speed travel in a state where there is no fear of collision between the work vehicle and the obstacle if the speed increasing processing for increasing the vehicle speed of the work vehicle to the set speed is performed based on the detection information in the collision avoidance control.

As a result, it is possible to construct an obstacle detection system for a work vehicle, which can reduce costs, reduce the number of man-hours required to perform work in advance, and the like, and can avoid a collision between the work vehicle and an object, a reduction in work efficiency, and the like.

Drawings

Fig. 1 is a diagram showing a schematic configuration of an automatic traveling system.

Fig. 2 is a block diagram showing a schematic configuration of the automatic traveling system.

Fig. 3 is a diagram showing an example of the target travel route.

Fig. 4 is a diagram showing the measurement ranges of the respective radar sensors and the measurement ranges of the respective ultrasonic sensors in a side view.

Fig. 5 is a view showing the measurement range of each radar sensor and the measurement range of each ultrasonic sensor in a plan view.

Fig. 6 is a block diagram showing a schematic configuration of the sonar system.

Fig. 7 is a perspective view showing the arrangement and structure of the sensor unit.

Fig. 8 is a flowchart showing a control operation of the distance measurement control unit in the position/displacement detection process.

Fig. 9 is a flowchart showing a control operation of the collision avoidance control section in the collision avoidance control.

Fig. 10 is a plan view showing another embodiment in which 3 ultrasonic sensors are arranged so that measurement ranges overlap.

Fig. 11 is a perspective view showing another embodiment in which 4 ultrasonic sensors are arranged vertically and horizontally in a side view such that measurement ranges are vertically and horizontally arranged in a top view.

Fig. 12 is a plan view showing another embodiment in which 4 ultrasonic sensors are arranged vertically and horizontally so that measurement ranges are vertically and horizontally arranged in a plan view.

Fig. 13 is a front view showing another embodiment in which 4 ultrasonic sensors are arranged vertically and horizontally so that measurement ranges are vertically and horizontally arranged in a plan view.

Fig. 14 is a plan view showing another embodiment in which 3 ultrasonic sensors are arranged in a dispersed manner so that measurement ranges are separated at equal intervals in the front-rear direction and are continuous.

Detailed Description

Hereinafter, an embodiment in which the obstacle detection system for a work vehicle according to the present invention is applied to a tractor as an example of a work vehicle will be described as an example for carrying out the present invention with reference to the drawings.

The obstacle detection system for a working vehicle according to the present invention can be applied to a working vehicle such as a riding mower, a riding rice transplanter, a combine harvester, a carrier, a snow sweeper, a wheel loader, and an unmanned working vehicle such as an unmanned mower in addition to a tractor.

As shown in fig. 1 and 2, a tractor 1 according to the present embodiment is configured such that: the work vehicle automatic traveling system automatically travels in a field S (see fig. 3) or the like as an example of a work site. The automatic traveling system includes: an automatic traveling unit 2 mounted on a tractor 1; and a portable communication terminal 3 that performs communication setting so as to be able to communicate with the automatic traveling unit 2. For the portable communication terminal 3, it is possible to adopt: a tablet personal computer, a smartphone, or the like having a display unit 51 (e.g., a liquid crystal panel) or the like capable of performing a touch operation.

The tractor 1 includes a traveling machine body 7, and the traveling machine body 7 includes: left and right front wheels 5 functioning as drivable steered wheels; and left and right rear wheels 6 capable of driving. A front frame 27 and an engine cover 8 are disposed on a front side of the travel machine body 7, and the engine cover 8 includes: an electronically controlled diesel engine (hereinafter, referred to as an engine) 9 having a common rail system. The traveling machine body 7 is provided with, on the rear side of the engine cover 8: a cab 10 forming a riding cab and left and right side rear flaps (rear guards) 28.

A rotary cultivator device as an example of the working device 12 is connected to the rear portion of the traveling machine body 7 via a 3-point link mechanism 11 so as to be able to ascend and descend and to be able to roll. Thus, the tractor 1 is configured to have a rotary tillage specification. Instead of the rotary tillage device, a working device 12 such as a plowing machine, a sowing device, or a spreading device may be connected to the rear portion of the tractor 1.

As shown in fig. 2, the tractor 1 includes the following components: an electronically controlled transmission 13 for changing the speed of power from the engine 9; a full hydraulic power steering mechanism 14 for steering the left and right front wheels 5; left and right side brakes (not shown) for braking the left and right rear wheels 6; an electronically controlled brake operating mechanism 15 capable of hydraulically operating the left and right side brakes; a working clutch (not shown) for turning on/off the power transmission to the working device 12 such as a rotary tiller; an electronically controlled clutch operating mechanism 16 capable of hydraulically operating the working clutch; an electronic hydraulic control type elevation driving mechanism 17 for elevating and driving the working device 12 such as a rotary cultivator; an onboard electronic control unit 18 having various control programs and the like relating to automatic travel and the like of the tractor 1; a vehicle speed sensor 19 for detecting a vehicle speed of the tractor 1; a steering angle sensor 20 that detects a steering angle of the front wheels 5; and a positioning unit 21 that measures the current position and the current orientation of the tractor 1.

An electronically controlled gasoline engine having an electronic governor may be used as the engine 9. The transmission 13 may be a hydro-mechanical continuously variable transmission (HMT), a hydrostatic continuously variable transmission (HST), a belt-type continuously variable transmission, or the like. The power steering mechanism 14 may be an electric power steering mechanism 14 including an electric motor.

As shown in fig. 1 and 4, the following components are provided inside the cab 10: a steering wheel 38 that can manually steer the left and right front wheels 5 by the power steering mechanism 14 (see fig. 2); a driver seat 39 for a rider; a touch panel type display unit; and various operating members. On both lateral side portions of a front portion of the cab 10, there are provided the boarding/alighting pedals 41 and 42 as boarding/alighting portions for the cab 10 (the operator's seat 39).

As shown in fig. 2, the in-vehicle electronic control unit 18 has the following components and the like: a shift control unit 181 that controls the operation of the transmission 13; a brake control unit 182 that controls the operation of the left and right side brakes; a working device control unit 183 for controlling the operation of the working device 12 such as a rotary cultivator; a steering angle setting unit 184 that sets a target steering angle of the left and right front wheels 5 during automatic traveling and outputs the set target steering angle to the power steering mechanism 14; and a nonvolatile in-vehicle storage unit 185 that stores a preset target travel route P for automatic travel (see fig. 3, for example).

As shown in fig. 2, the positioning unit 21 includes the following components: a Satellite Navigation device 22 for measuring the current position and the current azimuth of the tractor 1 using a GPS (Global positioning System) as an example of a Satellite positioning System (NSS); and an Inertial Measurement Unit (IMU) 23 that has a 3-axis gyroscope, a 3-direction acceleration sensor, and the like and measures the posture, orientation, and the like of the tractor 1. Positioning methods using GPS include DGPS (Differential GPS: relative positioning mode), RTK-GPS (Real Time Kinematic GPS: interference positioning mode), and the like. In the present embodiment, an RTK-GPS suitable for positioning of a mobile body is used. Therefore, as shown in fig. 1 and 2, at known positions around the field, there are provided: a base station 4 capable of positioning based on RTK-GPS.

As shown in fig. 2, the tractor 1 and the base station 4 are provided with the following components: GPS antennas 24 and 61 that receive radio waves transmitted from GPS satellites 71 (see fig. 1); and communication modules 25, 62 that enable wireless communication of various data including positioning data between the tractor 1 and the base station 4. Accordingly, the satellite navigation device 22 can measure the current position and the current azimuth of the tractor 1 with high accuracy based on the positioning data obtained by the GPS antenna 24 on the tractor side receiving the radio waves from the GPS satellite 71 and the positioning data obtained by the GPS antenna 61 on the base station side receiving the radio waves from the GPS satellite 71. The positioning unit 21 includes a satellite navigation device 22 and an inertial measurement unit 23, and can measure the current position, the current azimuth, and the attitude angle (yaw angle, roll angle, pitch angle) of the tractor 1 with high accuracy.

As shown in fig. 1, the GPS antenna 24, the communication module 25, and the inertia measurement device 23 of the tractor 1 are housed in the antenna unit 80. The antenna unit 80 is disposed at an upper position on the front surface side of the cab 10.

As shown in fig. 2, the mobile communication terminal 3 includes the following components: a terminal electronic control unit 52 having various control programs and the like for controlling the operations of the display unit 51 and the like; and a communication module 55 that enables wireless communication of various data including positioning data with the tractor-side communication module 25. The terminal electronic control unit 52 has the following components and the like: a travel route generation unit 53 that generates a target travel route P for travel guidance for automatically traveling the tractor 1 (see fig. 3, for example); and a nonvolatile terminal storage unit 54 that stores various input data input by the user, the target travel route P generated by the travel route generation unit 53, and the like.

When the travel route generation unit 53 generates the target travel route P, a user or the like including a driver or a manager inputs vehicle body data such as the type or model of the work vehicle or the work equipment 12 based on the input guide for setting the target travel route displayed on the display unit 51 of the mobile communication terminal 3, and stores the input vehicle body data in the terminal storage unit 54. The travel region R (see fig. 3) to be generated as the target travel route P is set as a work region in the field S, and the terminal electronic control unit 52 of the mobile communication terminal 3 acquires field data including the shape and position of the field and stores the field data in the terminal storage unit 54.

To explain the acquisition of field data, the terminal electronic control unit 52 can acquire position information for specifying the shape, position, and the like of a field from the current position, and the like, of the tractor 1 acquired by the positioning unit 21 by driving by a user or the like so that the tractor 1 actually travels. The terminal electronic control unit 52 specifies the shape and position of the field from the acquired position information, and acquires field data including the travel region R specified from the specified shape and position of the field. Fig. 3 shows an example of determining a rectangular travel region R.

When the field data including the shape, position, and the like of the identified field is stored in the terminal storage unit 54, the travel route generation unit 53 generates the target travel route P using the field data and the vehicle body data stored in the terminal storage unit 54.

As shown in fig. 3, the travel route generation unit 53 sets the travel range R to be divided into a center range R1 and an outer periphery range R2. The center region R1 is set in the center of the travel region R, and is set as a reciprocating work region in which the tractor 1 is automatically caused to travel in a reciprocating direction and a predetermined work (for example, a work such as tilling) is performed. The outer peripheral region R2 is set around the central region R1, and is set as a circular operation region in which the tractor 1 automatically travels in the circular direction immediately after the central region R1 and performs a predetermined operation. The travel path generation unit 53 obtains a space for turning travel required for turning the tractor 1 at the ridge of the field, for example, from the turning radius, the front-rear length, the left-right width, and the like of the tractor 1 included in the vehicle body data. The travel route generation unit 53 divides the travel range R into a center range R1 and an outer periphery range R2 so as to secure a space or the like required in the outer periphery of the center range R1.

As shown in fig. 3, the travel route generation unit 53 generates the target travel route P using vehicle body data, field data, and the like. For example, the target travel path P has: a plurality of work paths P1 arranged in parallel at a fixed interval corresponding to the work width and having the same straight-line distance in the central region R1; a plurality of non-working turning paths P2 formed by connecting the start end and the end of the adjacent working paths P1 in the traveling order; and a circular path P3 (indicated by a broken line in the figure) formed in the outer peripheral region R2. The plurality of work paths P1 are paths for causing the tractor 1 to perform a predetermined work while traveling straight. The turning path P2 is a U-shaped turning path in which the traveling direction of the tractor 1 is changed by 180 degrees without causing the tractor 1 to perform a predetermined operation, and connects the terminal end of the working path P1 to the start end of the next adjacent working path P1. The circulation path P3 is a path for allowing the tractor 1 to perform a predetermined work while circulating in the outer peripheral region R2. In the circular path P3, the path portions located at the four corners of the travel region R are path portions for changing the travel direction of the tractor 1 by 90 degrees while the tractor 1 appropriately performs forward travel and backward travel. The target travel route P shown in fig. 3 is an example, and what kind of target travel route is generated may be changed according to vehicle body data, field data, and the like.

The target travel route P generated by the travel route generation unit 53 can be displayed on the display unit 51, and is stored in the terminal storage unit 54 as route data associated with vehicle body data, field data, and the like. The path data includes: an azimuth of the target travel path P; and a set engine rotation speed, a target travel speed, and the like set according to a travel pattern of the tractor 1 on the target travel path P, and the like.

In this way, when the travel route generating unit 53 generates the target travel route P, the terminal electronic control unit 52 transmits the route data from the portable communication terminal 3 to the tractor 1, and the onboard electronic control unit 18 of the tractor 1 can acquire the route data. The onboard electronic control unit 18 can automatically travel the tractor 1 along the target travel path P while acquiring its own current position (current position of the tractor 1) by the positioning unit 21 based on the acquired path data. As for the current position of the tractor 1 acquired by the positioning unit 21, it is transmitted from the tractor 1 to the portable communication terminal 3 in real time (for example, a period of several seconds), so that the current position of the tractor 1 can be grasped with the portable communication terminal 3.

Regarding the transmission of the path data, all the path data may be transmitted from the terminal electronic control unit 52 to the in-vehicle electronic control unit 18 at once at a stage before the tractor 1 starts the automatic travel. For example, the route data including the target travel route P may be divided into a plurality of route portions each having a predetermined distance and having a small data amount. In this case, at a stage before the tractor 1 starts the automatic travel, only the initial path portion of the path data is transmitted from the terminal electronic control unit 52 to the in-vehicle electronic control unit 18. After the start of the automatic travel, the following method may be adopted: each time the tractor 1 reaches a route acquisition point set according to the data amount or the like, only the route data of the subsequent route portion corresponding to the point is transmitted from the terminal electronic control unit 52 to the in-vehicle electronic control unit 18.

When the tractor 1 starts automatic travel, for example, after the user or the like moves the tractor 1 to a start point and various automatic travel start conditions are satisfied, the user operates the display unit 51 with the mobile communication terminal 3 to issue an instruction to start automatic travel, thereby causing the mobile communication terminal 3 to transmit the start instruction of automatic travel to the tractor 1. Accordingly, in the tractor 1, the in-vehicle electronic control unit 18 receives the start instruction of the automatic travel, and starts the automatic travel control as follows: the tractor 1 is automatically driven along the target driving route P while acquiring its own current position (current position of the tractor 1) by the positioning means 21.

The automatic travel control includes the following controls and the like: automatic shift control for automatically controlling the operation of the transmission 13; automatic brake control for automatically controlling the operation of the brake operating mechanism 15; automatic steering control for automatic steering is performed for the left and right front wheels 5; and automatic control for work for automatically controlling the work of the working device 12 such as a rotary cultivator.

In the automatic shift control, the shift control unit 181 automatically controls the operation of the transmission 13 so that a target travel speed set in accordance with the travel pattern of the tractor 1 on the target travel path P or the like can be obtained as the vehicle speed of the tractor 1 based on the path data of the target travel path P including the target travel speed, the output of the positioning unit 21, and the output of the vehicle speed sensor 19.

In the automatic braking control, the brake control unit 182 automatically controls the operation of the brake operating mechanism 15 so that the left and right side brakes appropriately brake the left and right rear wheels 6 in the braking region included in the path data of the target travel path P, based on the target travel path P and the output of the positioning means 21.

In the automatic steering control, the steering angle setting unit 184 obtains a target steering angle for setting the left and right front wheels 5 based on the route data of the target travel route P and the output of the positioning means 21, and outputs the set target steering angle to the power steering mechanism 14 so that the tractor 1 automatically travels on the target travel route P. The power steering mechanism 14 automatically steers the left and right front wheels 5 based on the target steering angle and the output of the steering angle sensor 20 so that the target steering angle can be obtained as the steering angle of the left and right front wheels 5.

In the automatic control for work, the work implement control unit 183 automatically controls the operations of the clutch operating mechanism 16 and the lift driving mechanism 17 based on the path data of the target travel path P and the output of the positioning unit 21 so that a predetermined work (e.g., a tilling work) is started by the work implement 12 as the tractor 1 reaches a work start point such as the start end of the work path P1 (see fig. 3, for example), and the predetermined work is stopped by the work implement 12 as the tractor 1 reaches a work end point such as the end of the work path P1 (see fig. 3, for example).

In this way, in the tractor 1, the transmission 13, the power steering mechanism 14, the brake operating mechanism 15, the clutch operating mechanism 16, the elevation drive mechanism 17, the in-vehicle electronic control unit 18, the vehicle speed sensor 19, the steering angle sensor 20, the positioning unit 21, the communication module 25, and the like constitute the automatic traveling unit 2.

In this embodiment, the tractor 1 is automatically driven without the user or the like riding on the cab 10, but the tractor 1 may be automatically driven with the user or the like riding on the cab 10. Accordingly, the user or the like can automatically travel the tractor 1 along the target travel path P only by performing the automatic travel control using the in-vehicle electronic control unit 18 without riding on the cab 10, and also, in the case where the user or the like rides on the cab 10, can automatically travel the tractor 1 along the target travel path P by performing the automatic travel control using the in-vehicle electronic control unit 18.

When a user or the like gets on the cab 10, the running state of the tractor can be switched between an automatic running state in which the tractor 1 is automatically run by the in-vehicle electronic control unit 18 and a manual running state in which the tractor 1 is run by the driving of the user or the like. Accordingly, the running state of the tractor can be switched from the automatic running state to the manual running state while the tractor automatically runs on the target running path P in the automatic running state, and conversely, the running state of the tractor can be switched from the manual running state to the automatic running state while the tractor runs on the manual running state. For switching between the manual travel state and the automatic travel state, for example, a switching operation unit for switching between the automatic travel state and the manual travel state may be provided in the vicinity of the driver seat 39, and the switching operation unit may be displayed on the display unit 51 of the mobile communication terminal 3. Further, when the user operates the steering wheel 38 during the automatic travel control by the in-vehicle electronic control unit 18, the travel state of the tractor can be switched from the automatic travel state to the manual travel state.

As shown in fig. 1, 2, and 4 to 6, the tractor 1 includes an obstacle detection system 100, and the obstacle detection system 100 detects whether or not an obstacle is present around the tractor 1 (traveling machine body 7), and avoids collision with the obstacle when the presence of the obstacle is detected. The obstacle detection system 100 includes: 2 radar sensors (lidar Sensor: light detection and Ranging Sensor)101 and 102 on the front and rear sides, which three-dimensionally measure the distance to the measurement object using laser light and generate 3-dimensional images; and a sonar system 106 for measuring a distance to the measurement target object by using ultrasonic waves; and a collision avoidance control unit 107 that performs obstacle determination control, collision avoidance control, and the like based on information from the radar sensors 101 and 102 and the sonar system 106. The collision avoidance control unit 107 is configured to: when the object to be measured is determined to be an obstacle during the obstacle determination control, notification processing for operating a notification device 26 such as a notification buzzer or a notification lamp provided in the tractor 1, deceleration processing for reducing the vehicle speed of the tractor 1, stop processing for stopping the tractor 1, and the like are appropriately executed during the collision avoidance control according to the distance from the obstacle and the like. Here, the measurement target measured by each of the radar sensors 101 and 102 and the sonar system 106 includes: a person or the like who performs work on a field (work site), another work vehicle, a telegraph pole or a tree existing in the field, and an object such as a ridge or a fence existing around the work site.

Each Of the radar sensors 101 and 102 measures a distance to a measurement target object by a TOF (Time Of Flight) method in which a distance to a measurement target object is measured based on a round trip Time Of a laser beam (for example, a pulsed near-infrared laser beam) that comes into contact with and bounces off the measurement target object. Each of the radar sensors 101 and 102 scans laser light at high speed in the vertical direction and the horizontal direction, and measures the distance to the object to be measured at each scanning angle in sequence, thereby measuring the distance to the object to be measured three-dimensionally. Each of the radar sensors 101 and 102 repeatedly measures the distance to the measurement target object in the measurement range in real time. Each of the radar sensors 101 and 102 generates a three-dimensional image from the measurement result and outputs the three-dimensional image to the in-vehicle electronic control unit 18. The three-dimensional images from the respective radar sensors 101 and 102 can be displayed on a display unit of the tractor 1, a display unit 51 of the mobile communication terminal 3, and other display devices, and thereby, a user or the like can visually confirm the front and rear conditions of the tractor 1. Further, in the three-dimensional image, the distance in the approaching distance direction may be shown by color or the like, for example.

As shown in fig. 1, 4, and 5, the front radar sensor 101 of the front and rear radar sensors 101 and 102 is disposed in the center in the left-right direction of the front end portion of the roof 35 of the cab 10 in a posture in which the front of the tractor 1 is low in front and high in rear when viewed from an obliquely upper side in plan view. Accordingly, the front radar sensor 101 sets the front of the tractor 1 to the measurement range C. The rear radar sensor 102 is disposed in a left-right direction center portion of the rear end portion of the roof 35 of the cab 10 in a posture of being high in front and low in rear of the tractor 1 as viewed from an obliquely upper side in plan view. Accordingly, the rear radar sensor 102 sets the rear of the tractor 1 to the measurement range D.

Further, the measurement range C, D of each radar sensor 101, 102 may be subjected to a cutting process for limiting the range in the left-right direction to a set range corresponding to the working width of the working device 12.

As shown in fig. 1 and 4 to 7, sonar system 106 includes: a right sensor unit 103 disposed on the right side of the tractor 1 (travel machine body 7); a left sensor unit 104 disposed on a left side portion of the tractor 1 (travel machine body 7); and a distance measurement electronic control unit 105 as a distance measurement control unit that measures the distance of the object that enters the measurement range N of each sensor unit 103, 104. The right sensor unit 103 is attached to the bottom surface of the upper step portion 41A of the upper and lower 2-step portions 41A of the right entry/exit pedal 41 (see fig. 5) disposed at the lower right of the cab 10 in a posture directed rightward and downward with a small depression angle. Accordingly, the right sensor unit 103 is disposed at a high position between the right front wheel 5 and the right rear wheel 6 with the right outer side of the tractor 1 set as the measurement range N. As shown in fig. 5, the measurement range N of the right sensor unit 103 is set to: the measurement range Na to Nc of the 3 ultrasonic sensors 103A to 103C arranged in the front-rear direction is included in a wide range in the front-rear direction. As shown in fig. 7, the left sensor unit 104 is attached to the bottom surface of the upper step portion 42A of the upper and lower 2- step portions 42A and 42B of the left entry/exit step 42 disposed below the left side of the cab 10 in a posture oriented downward to the left with a small depression angle. Accordingly, the left sensor unit 104 is disposed at a high position between the left front wheel 5 and the left rear wheel 6 with the left outer side of the tractor 1 set as the measurement range N. As shown in fig. 5, the measurement range N of the left sensor unit 104 is set to: the measurement range includes a wide range in the front-rear direction of the measurement ranges Na to Nc of the 3 ultrasonic sensors 104A to 104C arranged in the front-rear direction. The ultrasonic sensors 103A to 103C and 104A to 104C measure the distance to the measurement object by a TOF (Time Of Flight) method in which the distance to the measurement object is measured based on the round trip Time during which the transmitted ultrasonic wave comes into contact with and bounces back from the measurement object. The distance measurement electronic control unit 105 measures the distance of the object entering the measurement ranges Na to Nc of the ultrasonic sensors 103A to 103C and 104A to 104C based on the distance measurement operation of the ultrasonic sensors 103A to 103C and 104A to 104C.

The left and right sensor units 103 and 104 are configured to: the depression angle, the front-rear direction attachment angle, and the like of the ultrasonic sensors 103A to 103C and 104A to 104C can be adjusted. Accordingly, the measurement range N of each sensor unit 103, 104 can be set appropriately.

As shown in fig. 2, the collision avoidance control section 107 is provided in the in-vehicle electronic control unit 18. The in-vehicle electronic control unit 18 is connected to an engine electronic control unit included in the common rail system, the radar sensors 101 and 102, the sonar system 106, and the like so as to be able to communicate via CAN (Controller Area Network).

As shown in fig. 1, 2, and 4, the tractor 1 includes: a front camera 108 for setting the front of the traveling body 7 as an imaging range; and a rear camera 109 for setting the rear of the travel machine body 7 as a shooting range. The front camera 108 is disposed in the center of the front end portion of the roof 35 of the cab 10 in the lateral direction, in a posture in which the front of the tractor 1 is low in the front and high in the rear, as viewed from an obliquely upper side in plan view, similarly to the front radar sensor 101. The rear camera 109 is disposed in a right and left central portion of the rear end portion of the roof 35 of the cab 10 in a front-high rear-low posture in which the rear of the tractor 1 is viewed in a top view from an obliquely upper side, similarly to the rear radar sensor 102. The images captured by the front camera 108 and the rear camera 109 can be displayed on a display unit of the tractor 1, a display unit 51 of the mobile communication terminal 3, or other display devices, and thus the user or the like can visually confirm the situation around the tractor 1.

As shown in fig. 5 and 6, the right ultrasonic sensors 103A to 103C and the left ultrasonic sensors 104A to 104C are disposed on both the left and right sides of the tractor 1 in a positional relationship such that their measurement ranges Na to Nc are continuous in a direction (front-rear direction) along both the left and right sides of the tractor 1. The distance measuring electronic control unit 105 performs a position detection process in which the relative body position of the object in the direction along the left and right side portions (front-rear direction) of the tractor 1 is detected based on the distance measuring operation of the right ultrasonic sensors 103A to 103C or the distance measuring operation of the left ultrasonic sensors 104A to 104C having the continuous measurement ranges Na to Nc, and performs a displacement detection process in which the displacement of the object in the direction along the left and right side portions (front-rear direction) of the tractor 1 is detected based on the sequence of the distance measuring operation of the right ultrasonic sensors 103A to 103C or the sequence of the distance measuring operation of the left ultrasonic sensors 104A to 104C having the continuous measurement ranges Na to Nc.

According to the above configuration, for example, when an object enters the measurement range Na of the 1 st ultrasonic sensor 103A having the front region on the outer side on the right side of the vehicle body as the measurement range, the ultrasonic wave transmitted from the 1 st ultrasonic sensor 103A contacts the object and bounces back toward the 1 st ultrasonic sensor 103A. Accordingly, the 1 st ultrasonic sensor 103A performs a distance measuring operation for receiving a reflected wave in addition to transmitting an ultrasonic wave. The distance measuring electronic control unit 105 detects that an object is present in the measurement range Na of the 1 st ultrasonic sensor 103A that has performed the distance measuring operation, that is, in the front region on the outer side on the right side of the vehicle body, by the position detection processing described above, and measures the distance from the 1 st ultrasonic sensor 103A to the object based on the time required from the transmission of the ultrasonic wave by the 1 st ultrasonic sensor 103A to the reception of the ultrasonic wave. As a result, the electronic control unit 105 for distance measurement can detect that an object is present at a position separated by a measurement distance from the 1 st ultrasonic sensor 103A in the front region on the right outer side of the vehicle body based on the distance measurement operation of the 1 st ultrasonic sensor 103A.

Similarly, for example, when an object enters the measurement range Nb of the 2 nd ultrasonic sensor 103B having the center side region in the front-rear direction of the right outer side of the vehicle body as the measurement range, the 2 nd ultrasonic sensor 103B performs the distance measurement operation, and therefore the electronic control unit 105 for distance measurement can detect that an object is present at a position separated by the measurement distance from the 2 nd ultrasonic sensor 103B in the center side region in the front-rear direction of the right outer side of the vehicle body based on the distance measurement operation of the 2 nd ultrasonic sensor 103B.

Similarly, for example, when an object enters the measurement range Nc of the 3 rd ultrasonic sensor 103C having the rear region on the outer side on the right side of the vehicle body as the measurement range, the 3 rd ultrasonic sensor 103C performs the distance measurement operation, and therefore the distance measurement electronic control unit 105 can detect that the object is present at a position separated by the measurement distance from the 3 rd ultrasonic sensor 103C in the rear region on the outer side on the right side of the vehicle body based on the distance measurement operation of the 3 rd ultrasonic sensor 103C.

Further, for example, when the object enters the measurement range Na of the 1 st ultrasonic sensor 103A and then enters the measurement range Nb of the 2 nd ultrasonic sensor 103B, the 1 st ultrasonic sensor 103A performs the distance measurement operation and then the 2 nd ultrasonic sensor 103B performs the distance measurement operation, and therefore the distance measurement electronic control unit 105 can detect that the object is displaced from the front region on the outer side on the right side of the vehicle body to the front-rear direction center region by the displacement detection processing described above.

Similarly, for example, when the object enters the measurement range Nc of the 3 rd ultrasonic sensor 103C after the measurement range Nb of the 2 nd ultrasonic sensor 103B, the 3 rd ultrasonic sensor 103C performs the distance measuring operation after the 2 nd ultrasonic sensor 103B performs the distance measuring operation, and therefore the distance measuring electronic control unit 105 can detect that the object is shifted from the front-rear direction center side region to the rear side region on the outer side of the right side of the vehicle body by the displacement detection processing described above.

Similarly, for example, when the object enters the measurement range Nb of the 2 nd ultrasonic sensor 103B after the measurement range Nc of the 3 rd ultrasonic sensor 103C, the 2 nd ultrasonic sensor 103B performs the distance measuring operation after the 3 rd ultrasonic sensor 103B performs the distance measuring operation, and therefore the distance measuring electronic control unit 105 can detect that the object is displaced from the rear region on the outer side on the right side of the vehicle body to the front-rear direction center region by the displacement detection processing described above.

Similarly, for example, when the object enters the measurement range Na of the 1 st ultrasonic sensor 103A after the measurement range Nb of the 2 nd ultrasonic sensor 103B, the 1 st ultrasonic sensor 103A performs the distance measuring operation after the 2 nd ultrasonic sensor 103B performs the distance measuring operation, and therefore the distance measuring electronic control unit 105 can detect that the object is displaced from the front-rear direction center side region to the front side region on the outer side of the right side of the vehicle body by the displacement detection processing described above.

On the other hand, when the object is out of the measurement range N of the right sensor unit 103, the right ultrasonic sensors 103A to 103C do not perform the distance measurement operation, and therefore the distance measurement electronic control unit 105 can detect that there is no object in the measurement range N of the right sensor unit 103.

Further, it is a matter of course that the electronic distance measuring control unit 105 measures the distance of the object based on the distance measuring operation of any one of the ultrasonic sensors 103A to 103C and 104A to 104C, and therefore, when the object in the measurement range Na to Nc of any one of the ultrasonic sensors 103A to 103C located on the right side is displaced in the distance and approach direction with respect to the right side portion of the vehicle body within the measurement range Na to Nc, the electronic distance measuring control unit 105 can detect the displacement of the object in the distance and approach direction with respect to the right side portion of the vehicle body by the measurement distance that changes along with this displacement.

Further, when it is detected that the object is displaced between 2 regions adjacent in the front-rear direction on the outer side of the right side of the vehicle body by the displacement detection processing described above, the electronic control unit for distance measurement 105 can detect the displacement of the object in the distance and approach direction with respect to the right side portion of the vehicle body based on the difference in the measurement distance obtained along with this.

The distance measurement electronic control unit 105 can detect the relative vehicle body position and displacement of the object based on the distance measurement operation and the distance measurement operation sequence of the right-side ultrasonic sensors 103A to 103C as described above, based on the distance measurement operation and the distance measurement operation sequence of the left-side ultrasonic sensors 104A to 104C.

That is, the tractor 1 includes a sonar system 106, and the sonar system 106 includes: the 6 ultrasonic sensors 103A to 103C and 104A to 104C, which are cheaper than stereo cameras, radar sensors instead of stereo cameras, and the electronic control unit 105 for distance measurement are not provided with stereo cameras on the left and right sides, radar sensors on the left and right sides, and the like for imaging the vicinities of the left and right sides of the tractor 1, and the relative vehicle body position and displacement in the directions along the left and right sides (front-rear direction) and the directions of approach and separation (left-right direction) to the left and right sides of the object in the vicinities of the left and right sides of the tractor 1 can be detected.

As a result, when constructing the obstacle detection system 100 for a tractor, it is possible to reduce the number of expensive stereo cameras, radar sensors, and the like, thereby reducing the cost and the number of man-hours required for performing the operation in advance.

The control operation of the distance measuring electronic control unit 105 in the above-described position/displacement detection process will be described based on the flowchart shown in fig. 8.

The electronic control unit for ranging 105 executes the following 1 st ranging operation determination process: it is determined whether any of the ultrasonic sensors 103A to 103C and 104A to 104C has performed a distance measurement operation (step # 1).

When the distance measuring operation is not performed in step #1, the electronic distance measuring control unit 105 waits until the distance measuring operation is performed, and when the distance measuring operation is performed in step #1, the electronic distance measuring control unit 105 performs the distance measuring process of measuring the distance of the object and the position detecting process described above, thereby specifying the relative vehicle body position of the object in the direction (front-rear direction) along the left and right side portions of the tractor 1 (steps #2 and # 3).

Next, the electronic control unit for ranging 105 executes the following ranging operation continuation determination process: it is determined whether or not the ultrasonic sensors 103A to 103C and 104A to 104C that have performed the distance measuring operation have continued the distance measuring operation (step # 4).

When the distance measurement operation is continued in step #4, the electronic distance measurement control unit 105 executes the distance measurement processing described above, executes the distance separating/approaching direction displacement detection processing (steps #5 and #6), and returns the processing to step #4, and in the distance separating/approaching direction displacement detection processing, the displacement of the object in the distance separating/approaching direction (left-right direction) with respect to the left and right side portions of the tractor 1 is detected based on the difference between the distance of the object obtained by the current distance measurement processing and the distance of the object obtained by the previous distance measurement processing.

When the distance measuring operation is not continued in step #4, the electronic control unit 105 for distance measuring executes the 2 nd distance measuring operation determination process (step #7) of determining whether or not the ultrasonic sensors 103A to 103C and 104A to 104C having performed the distance measuring operation in step #1 and any of the ultrasonic sensors 103A to 103C and 104A to 104C having continuous measurement ranges Na to Nc have performed the distance measuring operation in the 2 nd distance measuring operation determination process.

When the distance measurement operation is performed in step #7, the electronic distance measurement control unit 105 executes the distance measurement processing and the position detection processing described above to specify the relative body positions of the objects in the direction (front-rear direction) along the left and right side portions of the tractor 1 (steps #8 and #9), and executes the displacement detection processing described above and the distance and approach direction displacement detection processing (steps #10 and #11) based on the difference between the relative body position of the object specified this time and the relative body position of the object specified last time, and then returns the processing to step # 4.

When the distance measurement operation is not performed in step #7, the electronic control unit 105 for distance measurement determines that the object is out of the measurement ranges Na to Nc of the ultrasonic sensors 103A to 103C and 104A to 104C, and returns the process to step # 1.

As shown in fig. 5 and 6, in the obstacle determination control based on the information from the sonar system 106, when any of the ultrasonic sensors 103A to 103C and 104A to 104C detects an object that enters the measurement range N of any of the sensor units 103 and 104 on the left and right sides, the collision avoidance control unit 107 determines that the object is an obstacle. In the collision avoidance control based on the information from the sonar system 106, the collision avoidance control unit 107 controls the traveling of the tractor 1.

The control operation of the collision avoidance control unit 107 in collision avoidance control based on information from the sonar system 106 will be described based on the flowchart shown in fig. 9.

First, the collision avoidance control unit 107 determines the relative vehicle body position of the obstacle based on the information from the distance measuring electronic control unit 105 (steps #20 to # 22).

When the relative vehicle body position of the obstacle is in the front region (measurement range Na) on either the left or right side that is farther from the working device 12 of the tractor 1, the collision avoidance control unit 107 executes 1 st low-speed travel processing (step #23) for causing the tractor 1 to travel at the 1 st speed that is lower than the operation set speed, and then executes approach determination processing (step #24) for determining whether or not the front region (measurement range Na) on either the left or right side of the relative vehicle body position of the obstacle is displaced in the approach direction (vehicle body direction in the left or right direction) in the approach direction. In the approach determination process, when the position of the obstacle relative to the vehicle body is shifted in the approach direction, a stop process for stopping the tractor 1 is executed to end the collision avoidance control (step # 25). And returns to step #20 without shifting in the approaching direction.

When the relative vehicle body position of the obstacle is in the front-rear direction center side region (measurement range Nb) that is closer to either the left or right side of the working device 12 of the tractor 1 than the left or right side front side region (measurement range Na), the collision avoidance control unit 107 executes the 2 nd low speed travel process of causing the tractor 1 to travel at the 2 nd speed lower than the 1 st speed (step #26), and then executes the approach determination process (step # 24). Then, in the approach determination process, when the position of the obstacle relative to the vehicle body is shifted in the approach direction, the above-described stop process is executed to end the collision avoidance control (step # 25). And returns to step #20 without shifting in the approaching direction.

When the position of the obstacle relative to the vehicle body is in a rear region (measurement range Nc) closer to either the left or right of the working device 12 of the tractor 1 than the left or right front-rear direction center side region (measurement range Nb), the collision avoidance control unit 107 executes a stop process of stopping the tractor 1 to terminate the collision avoidance control in order to avoid a collision between the working device 12 and the obstacle (step # 25). When the relative vehicle body position of the obstacle is not in any of the front side region (measurement range Na), the front-rear direction center side region (measurement range Nb), and the rear side region (measurement range Nc), a set speed travel process is executed to cause the tractor 1 to travel at the set speed for work (step #27), and the process returns to step # 20.

The collision avoidance control unit 107 performs such a control operation, and can appropriately control the travel of the tractor 1 based on the relative vehicle body position of the obstacle. As a result, the possibility of collision of the tractor 1 with an obstacle can be avoided, and a reduction in work efficiency due to continuous low-speed travel without fear of collision of the tractor 1 with an obstacle can be avoided.

It is preferable that, as the control operation of the collision avoidance control section 107 in the collision avoidance control, a notification process of operating the notification device 26 is further performed when the relative vehicle body position of the obstacle is in any one of the front side region (measurement range Na), the front-rear direction center side region (measurement range Nb), and the rear side region (measurement range Nc). Further, it is more preferable that the operation of the notification device 26 is made different (for example, the notification sound is increased) as the relative vehicle body position of the obstacle approaches the tractor 1.

In the approach determination process described above, when the position of the obstacle relative to the vehicle body is shifted in the approach direction, the collision avoidance control unit 107 may execute a collision avoidance steering process of steering the left and right front wheels 5 in a direction away from the obstacle, instead of the stopping process.

The collision avoidance control unit 107 can execute map data update processing for determining the position of an object (obstacle) at a work site or the like and adding the position to the map data, based on the map data stored in the in-vehicle storage unit 185, the position information of the object acquired by the sonar system 106, the position information of the ultrasonic sensors 103A to 103C and 104A to 104C (the mounting positions of the ultrasonic sensors 103A to 103C and 104A to 104C to the tractor 1, etc.) that detect the object included in the vehicle body data, and the position information of the tractor 1 included in the positioning information from the positioning unit 21.

Accordingly, when the tractor 1 is driven along the periphery of the work site at the work site such as a field, the positions of fences and ridges existing around the work site (field), or the positions of entrances and exits to the work site can be identified and added to the map data.

When the tractor 1 is stored in a grain barn, the position of an entrance to the grain barn or the position of an object such as a pillar or an agricultural machine tool present inside the grain barn is determined and added to the map data.

[ other embodiments ]

Other embodiments of the present invention will be explained.

The configurations of the embodiments described below are not limited to being applied individually, and may be applied in combination with the configurations of other embodiments.

(1) Another typical embodiment related to the structure of the work vehicle 1 is as follows.

For example, work vehicle 1 may be configured to have a quasi-crawler format having left and right crawlers instead of left and right rear wheels 6.

For example, work vehicle 1 may be configured to have a full track specification having left and right tracks instead of left and right front wheels 5 and left and right rear wheels 6.

For example, work vehicle 1 may be configured to have an electric motor instead of the electric specification of engine 9.

For example, work vehicle 1 may be configured to have a hybrid specification of engine 9 and an electric motor.

For example, the work vehicle 1 may be configured to a rear wheel steering specification in which the right and left rear wheels 6 function as steered wheels.

For example, the work vehicle 1 may be configured to execute work by causing a plurality of work vehicles 1 to run in parallel by an automatic travel system.

For example, work vehicle 1 may be configured such that work implement 12 is coupled to only one of the front and rear sides thereof.

For example, work vehicle 1 may be configured to include a protection frame extending from traveling machine body 7 to above the boarding space, instead of cab 10.

(2) The number and arrangement of the sensor units 103 and 104 may be variously changed.

For example, the left and right sensor units 103 and 104 may be provided at the lower end portions of the left and right side portions of the cab 10.

For example, sensor units 103 and 104 may be provided at both front and rear side portions of work vehicle 1, such as a front end portion of hood 8 and a rear surface portion of cab 10, or may be provided at one front and rear side portions of work vehicle 1.

(3) The number and arrangement of the ultrasonic sensors 103A to 103C and 104A to 104C of the sensor units 103 and 104 may be variously changed.

For example, as shown in fig. 10, 3 ultrasonic sensors 103A to 103C and 104A to 104C may be arranged in the left and right sensor units 103 and 104, respectively: the measurement ranges Na to Nc have measurement ranges Nab and Nbc overlapping in the front-rear direction. In this case, the distance measurement control unit (distance measurement electronic control unit) 105 can execute the position detection process and the displacement detection process described above based on the 5 measurement ranges Na, Nab, Nb, Nbc, and Nc.

For example, as shown in fig. 11 to 13, the 4 ultrasonic sensors 103A to 103D, 104A to 104D may be arranged vertically and horizontally so as to form a positional relationship in which their measurement ranges Na to Nd are continuous in both a direction along the left and right side portions (front-rear direction) and a direction of moving away from and approaching to the left and right side portions (left-right direction), respectively, with respect to the left and right side sensor units 103, 104. In this case, the distance measurement control unit (distance measurement electronic control unit) 105 can execute the above-described position detection processing and displacement detection processing based on the 4 measurement ranges Na, Nb, Nc, and Nd arranged vertically and horizontally in a plan view.

For example, as shown in fig. 14, 3 ultrasonic sensors 103A to 103C and 104A to 104C may be disposed at the left and right side portions of the engine cover 8, the left and right access steps 41 and 42, and the left and right tailgate 28, respectively, so as to be positioned at equal intervals in a direction along the left and right side portions (front-rear direction) and be continuous with respect to the left and right sensor units 103 and 104.

Industrial applicability of the invention

The obstacle detection system for a work vehicle according to the present invention is applicable to, for example, a passenger work vehicle such as a tractor, a passenger lawnmower, a passenger rice transplanter, a combine harvester, a carrier, a snow sweeper, a wheel loader, and an unmanned work vehicle such as an unmanned lawn mower.

Description of the reference numerals

1 working vehicle

103 sensor unit (Right side sensor unit)

103A 1 st ultrasonic sensor

103B 2 nd ultrasonic sensor

103C No. 3 ultrasonic sensor

104 sensor unit (left sensor unit)

104A 1 st ultrasonic sensor

104B 2 nd ultrasonic sensor

104C 3 rd ultrasonic sensor

105 distance measuring control unit (electronic control unit for distance measuring)

107 collision avoidance control section

Na measurement Range

Nb measurement Range

Nc measurement Range