阅读说明：本技术 作业机械以及作业机械的控制方法 (Work machine and work machine control method ) 是由 根田知树 岛田健二郎 畠一寻 西乡雄祐 于 2020-05-22 设计创作，主要内容包括：作业机械具备：行驶体；回转体,其以能够回转的方式设置于行驶体；角速度传感器,其安装于回转体,输出回转体的方位角速度；测定装置,其测定回转体的方位；以及控制部,其基于由测定装置测定出的方位信息对方位角速度进行校正,并基于校正后的方位角速度对回转体进行控制。(The work machine is provided with: a traveling body; a revolving body provided to the traveling body so as to be able to revolve; an angular velocity sensor mounted on the revolving body and outputting an azimuth velocity of the revolving body; a measuring device for measuring the orientation of the rotator; and a control unit that corrects the azimuth angular velocity based on the azimuth information measured by the measuring device, and controls the revolving body based on the corrected azimuth velocity.)

1. A working machine, wherein,

the work machine is provided with:

a traveling body;

a revolving body provided to the traveling body so as to be able to revolve;

an angular velocity sensor that is attached to the rotating body and outputs an azimuth velocity of the rotating body;

a measuring device that measures an orientation of the rotator; and

and a control unit that corrects the azimuth velocity based on azimuth information measured by the measuring device, and controls the revolving unit based on the corrected azimuth velocity.

2. The work machine of claim 1,

the control unit calculates a reference turning angle based on the azimuth before the start of turning of the turning body and the azimuth after the end of turning of the turning body measured by the measuring device.

3. The work machine of claim 2,

the control unit calculates an expected turning angle based on the azimuth angle speed output from the angular speed sensor and the turning operation time of the turning body,

the control unit calculates a correction coefficient for correcting the output of the angular velocity sensor based on the reference turning angle and the expected turning angle.

4. The work machine of claim 3,

the correction coefficient is a ratio of the expected turning angle to the reference turning angle.

5. A method of controlling a working machine, wherein,

the method for controlling a working machine includes the steps of:

detecting an azimuth velocity by an angular velocity sensor attached to a revolving body provided to a traveling body so as to be rotatable;

measuring the orientation of the rotator;

correcting the detected azimuth velocity based on the measured azimuth information of the revolving body; and

and controlling the revolving body based on the corrected azimuth angle speed.

Technical Field

The present disclosure relates to swing control of a work machine.

Background

Conventionally, a work vehicle such as a hydraulic excavator is known. For example, in japanese patent application laid-open No. 2017-122602 (patent document 1), an excavator is known in which a rotation angle of a rotation body is derived based on an output of an inertia measurement device such as a gyro sensor attached to the rotation body.

Prior art documents

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-122602

Disclosure of Invention

Problems to be solved by the invention

On the other hand, the inertial measurement unit has high environmental dependency and may have a sensitivity error. In this case, an error may occur in the derivation of the turning angle, and there is a possibility that the turning control cannot be performed with high accuracy.

An object of the present disclosure is to provide a working machine and a method of controlling a working machine, which can perform rotation control with high accuracy.

Means for solving the problems

A work machine according to one aspect of the present disclosure includes: a traveling body; a revolving body provided to the traveling body so as to be able to revolve; an angular velocity sensor mounted on the revolving body and outputting an azimuth velocity of the revolving body; a measuring device for measuring the orientation of the rotator; and a control unit that corrects the azimuth angular velocity based on the azimuth information measured by the measuring device, and controls the revolving body based on the corrected azimuth velocity.

Preferably, the control unit calculates the reference turning angle based on the azimuth before the start of turning of the turning body measured by the measuring device and the azimuth after the end of turning of the turning body.

Preferably, the control unit calculates the expected turning angle based on the azimuth angle speed output from the angular velocity sensor and the turning operation time of the turning body, and the control unit calculates a correction coefficient for correcting the output of the angular velocity sensor based on the reference turning angle and the expected turning angle.

Preferably, the correction coefficient is a ratio of the expected pivot angle to the reference pivot angle.

A control method of a work machine according to an aspect of the present disclosure includes the steps of: detecting an azimuth velocity by an angular velocity sensor attached to a revolving body provided to a traveling body so as to be rotatable; measuring the orientation of the rotator; correcting the detected azimuth velocity based on the measured azimuth information of the rotating body; and controlling the revolving body based on the corrected azimuth velocity.

Effects of the invention

The disclosed work machine and control method for a work machine can perform high-precision rotation control.

Drawings

Fig. 1 is an external view of a working machine according to an embodiment.

Fig. 2 is a diagram schematically illustrating a work machine 100 according to an embodiment.

Fig. 3 is a schematic block diagram illustrating a configuration of a control system of the work machine 100 according to the embodiment.

Fig. 4 is a diagram schematically illustrating a turning operation of the turning body 3 according to the embodiment.

Fig. 5 is a graph illustrating sensitivity errors of the IMU24 according to an embodiment.

Fig. 6 is a block diagram showing the configuration of work implement controller 26 according to the embodiment.

Fig. 7 is a flowchart for explaining calculation of the correction coefficient by the correction unit 104 according to the embodiment.

Detailed Description

Hereinafter, embodiments will be described with reference to the drawings. In the following description, the same components are denoted by the same reference numerals. Their names and functions are the same. Therefore, detailed description thereof will not be repeated.

< overall construction of work machine >

Fig. 1 is an external view of a working machine according to an embodiment.

As shown in fig. 1, a hydraulic excavator including a work implement 2 that is hydraulically operated will be described as an example of a work machine to which the concept of the present disclosure can be applied.

Work machine 100 includes vehicle body 1 and work implement 2.

Vehicle body 1 includes revolving unit 3, cab 4, and traveling device 5.

The revolving unit 3 is disposed above the traveling device 5. The traveling device 5 supports the revolving unit 3. Revolving unit 3 can revolve around revolving axis AX. The cab 4 is provided with an operator seat 4S on which an operator sits. An operator operates the work machine 100 in the cab 4. The traveling device 5 includes a pair of crawler belts 5Cr. The work machine 100 travels by the rotation of the crawler 5Cr. The running gear 5 may be formed of a wheel (tire).

In embodiment 1, the positional relationship of the respective portions will be described with reference to an operator sitting in the driver seat 4S. The front-rear direction refers to the front-rear direction of the operator seated in the driver seat 4S. The left-right direction is a left-right direction with reference to an operator sitting in the driver seat 4S. The left-right direction coincides with the width direction of the vehicle (vehicle width direction). The direction in which the operator sitting in the driver seat 4S faces the front is referred to as the front direction, and the direction opposite to the front direction is referred to as the rear direction. The right and left sides of the operator seated in the driver seat 4S when facing the front are set to the right and left directions, respectively.

Revolving unit 3 has an engine room 9 for housing the engine, and a counterweight provided for the rear portion of revolving unit 3. In revolving unit 3, an armrest 19 is provided in front of engine room 9. An engine, a hydraulic pump, and the like are disposed in the engine room 9.

The working device 2 is supported by the revolving unit 3. Work implement 2 includes boom 6, arm 7, bucket 8, boom cylinder 10, arm cylinder 11, and bucket cylinder 12.

Boom 6 is connected to revolving unit 3 via boom pin 13. Arm 7 is connected to boom 6 via arm pin 14. Bucket 8 is connected to arm 7 via bucket pin 15. Boom cylinder 10 drives boom 6. Arm cylinder 11 drives arm 7. Bucket cylinder 12 drives bucket 8. A base end portion (boom base portion) of boom 6 is connected to revolving unit 3. The tip end portion (boom tip portion) of boom 6 is connected to the base end portion (arm base portion) of arm 7. The tip end portion (arm top portion) of arm 7 is connected to the base end portion of bucket 8. The boom cylinder 10, the arm cylinder 11, and the bucket cylinder 12 are hydraulic cylinders driven by hydraulic oil.

Boom 6 is rotatable about a rotation shaft, i.e., a boom pin 13, with respect to revolving unit 3. Arm 7 is rotatable with respect to boom 6 about arm pin 14 which is a rotation shaft parallel to boom pin 13. Bucket 8 is rotatable with respect to arm 7 about bucket pin 15, which is a rotation shaft parallel to boom pin 13 and arm pin 14.

The traveling device 5 and the revolving unit 3 are examples of the "traveling structure" and the "revolving unit" of the present disclosure.

Fig. 2 is a diagram schematically illustrating a work machine 100 according to an embodiment.

Fig. 2 (a) shows a side view of the work machine 100. Fig. 2 (B) shows a rear view of the work machine 100.

As shown in fig. 2 (a) and 2 (B), a length L1 of boom 6 is a distance between boom pin 13 and arm pin 14. The length L2 of the arm 7 is the distance between the arm pin 14 and the bucket pin 15. The length L3 of bucket 8 is between bucket pin 15 and the cutting edge 8A of bucket 8. Bucket 8 has a plurality of teeth, and in this example, the tip of bucket 8 is referred to as cutting edge 8A.

The bucket 8 may not have a tooth. The front end of bucket 8 may be formed of a straight steel plate.

Work machine 100 includes boom cylinder stroke sensor 16, arm cylinder stroke sensor 17, and bucket cylinder stroke sensor 18. The boom cylinder stroke sensor 16 is disposed in the boom cylinder 10. Arm cylinder stroke sensor 17 is disposed on arm cylinder 11. The bucket cylinder stroke sensor 18 is disposed in the bucket cylinder 12. The boom cylinder stroke sensor 16, the arm cylinder stroke sensor 17, and the bucket cylinder stroke sensor 18 are also collectively referred to as a cylinder stroke sensor.

The stroke length of boom cylinder 10 is determined based on the detection result of boom cylinder stroke sensor 16. The stroke length of arm cylinder 11 is obtained based on the detection result of arm cylinder stroke sensor 17. The stroke length of the bucket cylinder 12 is obtained based on the detection result of the bucket cylinder stroke sensor 18.

In this example, the stroke lengths of the boom cylinder 10, the arm cylinder 11, and the bucket cylinder 12 are also referred to as a boom cylinder length, an arm cylinder length, and a bucket cylinder length, respectively. In this example, the boom cylinder length, the arm cylinder length, and the bucket cylinder length are also collectively referred to as cylinder length data L. Note that a method of detecting the stroke length using an angle sensor may be employed.

The work machine 100 includes a position detection device 20 capable of detecting the position of the work machine 100.

The position detection device 20 includes an antenna 21, a global coordinate calculation unit 23, and an imu (inertial Measurement unit) 24.

The antenna 21 is, for example, an antenna for GNSS (Global Navigation Satellite system). The antenna 21 is, for example, an antenna for RTK-GNSS (Real Time Kinematic-Global Navigation Satellite Systems).

Antenna 21 is provided on revolving unit 3. In this example, antenna 21 is provided on handrail 19 of revolving unit 3. The antenna 21 may be disposed in the rear direction of the engine room 9. For example, antenna 21 may be provided in a counterweight of revolving unit 3. The antenna 21 outputs a signal corresponding to a radio wave (GNSS radio wave) received from a satellite to the global coordinate calculation unit 23.

The global coordinate calculation unit 23 detects the installation position P1 of the antenna 21 in the global coordinate system. The global coordinate system is a three-dimensional coordinate system (Xg, Yg, Zg) having a reference position Pr set in the work area as an origin. In this example, the reference position Pr is the position of the tip of the reference pile set in the work area. The local coordinate system is a three-dimensional coordinate system expressed by (X, Y, Z) with respect to the work machine 100. The reference position of the local coordinate system is data indicating a reference position P2 located at a rotation axis (rotation center) AX of revolving unit 3.

In this example, antenna 21 includes first antenna 21A and second antenna 21B provided on revolving unit 3 so as to be spaced apart from each other in the vehicle width direction.

The global coordinate calculation unit 23 detects the installation position P1A of the first antenna 21A and the installation position P1B of the second antenna 21B. The global coordinate calculation unit 23 acquires reference position data P indicated by global coordinates. In this example, reference position data P is data indicating reference position P2 located at rotation axis (rotation center) AX of revolving unit 3. The reference position data P may be data indicating the installation position P1.

In this example, global coordinate calculation unit 23 generates revolving unit orientation data Q based on both installation position P1a and installation position P1 b. Revolving unit orientation data Q is determined based on an angle formed by a straight line determined by installation position P1a and installation position P1b with respect to a reference orientation (for example, north) of global coordinates. Revolving unit orientation data Q indicates the orientation in which revolving unit 3 (work implement 2) is oriented. The global coordinate calculation unit 23 outputs the reference position data P and the revolving unit orientation data Q to a work implement controller 26, which will be described later. The global coordinate calculation unit 23 can generate and output high-precision revolving unit orientation data when the revolving unit 3 is stationary. In this example, a method of calculating the revolving unit orientation data by the global coordinate calculation unit 23 using GNSS radio waves is described, but the present invention is not particularly limited to this, and the revolving unit orientation data may be calculated by another method. For example, the rotational body orientation data may be calculated by acquiring three-dimensional data using a stereo image. The revolution body orientation data can also be calculated using lidar (light Detection and ranging) technology that irradiates a laser to measure distance. The rotational body orientation data may be obtained by a scan matching method using the scan data.

The IMU24 is one of angular velocity sensors, and is provided to the revolving unit 3. In this example, IMU24 is disposed at the lower portion of cab 4. In revolving unit 3, a highly rigid frame is disposed at a lower portion of cab 4. The IMU24 is disposed on the frame. The IMU24 may be disposed on the side (right side or left side) of the rotation axis AX (reference position P2) of the revolving unit 3.

The IMU24 measures and outputs azimuth velocity data when the revolving unit 3 performs a revolving operation. Slewing control of slewing body 3 is performed based on the azimuth velocity data. The IMU24 can detect the inclination angle θ 4 at which the vehicle body 1 is inclined in the left-right direction and the inclination angle θ 5 at which the vehicle body 1 is inclined in the front-rear direction.

Fig. 3 is a schematic block diagram illustrating a configuration of a control system of the work machine 100 according to the embodiment.

As shown in fig. 3, work machine 100 includes boom cylinder stroke sensor 16, arm cylinder stroke sensor 17, bucket cylinder stroke sensor 18, antenna 21, global coordinate calculation unit 23, IMU24, work implement controller 26, boom cylinder 10, arm cylinder 11, bucket cylinder 12, swing motor 62, and hydraulic device 64.

The hydraulic device 64 includes a hydraulic oil tank, a hydraulic pump, a flow rate control valve, and an electromagnetic proportional control valve, which are not shown. The hydraulic pump is driven by power of an engine, not shown, and supplies hydraulic oil to the boom cylinder 10, the arm cylinder 11, and the bucket cylinder 12 via a flow rate adjustment valve. The hydraulic pump supplies hydraulic oil to the turning motor 62 to perform a turning operation of the turning body 3.

The sensor controller 30 calculates the boom cylinder length based on the detection result of the boom cylinder stroke sensor 16. The boom cylinder stroke sensor 16 outputs a pulse accompanying the turnaround operation to the sensor controller 30. The sensor controller 30 calculates the boom cylinder length based on the pulse output from the boom cylinder stroke sensor 16.

Likewise, the sensor controller 30 calculates the arm cylinder length based on the detection result of the arm cylinder stroke sensor 17. The sensor controller 30 calculates the bucket cylinder length based on the detection result of the bucket cylinder stroke sensor 18.

Sensor controller 30 calculates inclination angle θ 1 of boom 6 in the vertical direction with respect to revolving unit 3, based on the boom cylinder length obtained based on the detection result of boom cylinder stroke sensor 16. Sensor controller 30 calculates an inclination angle θ 2 of arm 7 with respect to boom 6 based on the arm cylinder length obtained based on the detection result of arm cylinder stroke sensor 17. Sensor controller 30 calculates inclination angle θ 3 of cutting edge 8A of bucket 8 with respect to arm 7, based on the bucket cylinder length obtained based on the detection result of bucket cylinder stroke sensor 18.

The attitude of work machine 100 can be controlled by the above-described calculation results, that is, inclination angles θ 1, θ 2, and θ 3, inclination angle θ 4 at which vehicle body 1 is inclined in the left-right direction, inclination angle θ 5 at which vehicle body 1 is inclined in the front-rear direction, reference position data P, and revolving unit orientation data Q.

Sensor controller 30 outputs azimuth velocity data measured by IMU24 when revolving unit 3 performs a revolving operation to work implement controller 26.

Global coordinate calculation unit 23 outputs revolving unit orientation data Q to work implement controller 26.

Work implement controller 26 corrects the azimuth velocity data measured by IMU24 based on the rotation body azimuth data Q from global coordinate operation unit 23, and controls hydraulic device 64 based on the corrected azimuth velocity data to control the rotation operation of rotation body 3.

Fig. 4 is a diagram schematically illustrating a turning operation of the turning body 3 according to the embodiment.

As shown in fig. 4, the rotator 3 is provided with an IMU24, and the IMU24 measures and outputs azimuth velocity data of the rotator 3.

Work implement controller 26 receives input of azimuthal velocity data measured by IMU24 via sensor controller 30.

Work implement controller 26 calculates a turning angle based on the product of the azimuth velocity data measured by IMU24 and the turning operation time of turning body 3.

Fig. 5 is a graph illustrating sensitivity errors of the IMU24 according to an embodiment.

Fig. 5 shows actual azimuth velocity data ω of the turning operation of the turning body 3_IMU(rad/s) and azimuthal velocity data ω measured by IMU24_{IMU_corr}The relationship (2) of (c).

Ideally, the measured azimuthal velocity data ω_{IMU_corr}Relative to actual azimuthal velocity data ω_IMUThe ratio of (A) to (B) is "1".

On the other hand, the IMU24 has high environmental dependence and generates sensitivity errors according to temperature.

In particular, the measured azimuth velocity data ω is shown_{IMU_corr}Relative to actual azimuthal velocity data ω_IMUThe ratio of (a) is greater than 1, or less than 1.

Therefore, in the embodiment, the sensitivity error is measured and the measured azimuth velocity data ω is subjected to the approximate actual azimuth velocity data_{IMU_corr}And (6) carrying out correction. In this example, the calculation is performed so that the measured azimuth velocity data ω_{IMU_corr}Approximate actual azimuthal velocity data ω_IMUThe correction coefficient of (1).

Fig. 6 is a block diagram showing the configuration of work implement controller 26 according to the embodiment.

As shown in fig. 6, work implement controller 26 includes a detection information acquisition unit 102, a correction unit 104, and a revolving unit control unit 106.

The detection information acquisition unit 102 acquires azimuth velocity data from the IMU24 output from the sensor controller 30 and revolving unit azimuth data output from the global coordinate calculation unit 23.

The correction unit 104 calculates a correction coefficient for correcting the azimuth velocity data measured by the IMU24, based on the rotation body azimuth data Q from the global coordinate calculation unit 23 and the azimuth velocity data from the IMU 24.

The revolving unit control unit 106 controls the revolving unit 3 based on the correction coefficient calculated by the correction unit 104 and the azimuth velocity data of the IMU 24.

Fig. 7 is a flowchart for explaining calculation of the correction coefficient by the correction unit 104 according to the embodiment.

As shown in fig. 7, the correcting unit 104 acquires azimuth information before the turning operation of the turning body 3 is started (step S2). For example, slewing body orientation data of work machine 100 during an excavation operation before the start of a slewing operation of slewing body 3 is acquired from global coordinate calculation unit 23.

Next, the correcting unit 104 acquires azimuth information after the end of the turning operation of the turning body 3 (step S4). For example, the work machine 100 rotation direction data during the discharging operation after the end of the rotation operation of the rotation body is acquired from the global coordinate calculation unit 23.

Next, the correcting unit 104 calculates a reference pivot angle (step S6).

Specifically, the correction unit 104 calculates the reference turning angle based on the azimuth information before the turning operation of the turning body 3 is started and the azimuth information after the turning operation of the turning body 3 is ended from the global coordinate calculation unit 23.

As an example, the slewing body azimuth data θ before starting the slewing operation of the slewing body 3 is set_{swing_start}And the rotational body azimuth data θ after the end of the rotational operation of the rotational body 3_{swing_goal}Time, reference rotation angle theta_GNSSCan be calculated as follows.

Reference angle of revolution theta_GNSS＝θ_{swing_goal}-θ_{swing_start}

Next, the correcting unit 104 calculates an expected turning angle (step S8).

Specifically, the correction unit 104 is based on the azimuth velocity data ω from the IMU24_IMUAnd a rotator operation time t_swingTo calculate the expected rotation angle theta_IMU. Predicted pivot angle θ_IMUCan be calculated as follows.

Predicted pivot angle θ_IMU＝∑ω_IMU×Ts

Ts: sampling time

The azimuth angle speed data omega_IMUAt a revolving body operation time t from the beginning of the revolving operation to the end of the revolving operation_swingIntegration is performed.

Next, the correction unit 104 calculates a correction coefficient (step S10).

Specifically, based on the expected rotation angle θ_IMURelative to a reference swivel angle theta_GNSSIs used to calculate the ratio (ω) for the measured azimuthal velocity data (ω)_{IMU_corr}The sensitivity error of (2) is corrected by a correction coefficient p. The correction coefficient p is a ratio of the sensor output of the IMU24 that changes according to the input, and is calculated by the following equation.

Correction coefficient p ═ ω_{IMU_corr}/ω_IMU＝θ_GNSS/θ_IMU

Then, the process is terminated (end).

The revolving unit control unit 106 corrects the azimuth velocity data measured by the IMU24 based on the correction coefficient p calculated by the correction unit 104, and controls the hydraulic machine 64 based on the corrected azimuth velocity data so as to perform the revolving operation of the revolving unit 3. This enables a highly accurate turning operation of the turning body 3.

As described above, work implement controller 26 according to the present embodiment acquires inclination angles θ 1 to θ 5, reference position data P, and revolving unit orientation data Q from sensor controller 30. Therefore, work implement controller 26 can automatically control the attitude of work machine 100 based on the acquired information. Specifically, automatic control of the following actions may be performed: an excavation operation of excavating an excavation object using the bucket 8, a lifting and turning operation of moving the excavation object taken into the bucket 8 by the excavation operation to a soil discharge position, a soil discharge operation of discharging the excavation object taken into the bucket 8 to a cargo bed of a dump truck, and a lowering and turning operation of moving the bucket 8 emptied after the soil discharge operation to the excavation position.

The work implement controller 26 may repeatedly calculate a correction coefficient for correcting the azimuth velocity data measured by the IMU24 used for the raising slewing operation and the lowering slewing operation, based on the above-described manner, using the slewing body azimuth data output from the global coordinate calculation unit 23 during the excavation operation and the discharging operation in the automatic control.

Alternatively, work implement controller 26 may use an average value of the correction coefficients calculated repeatedly as described above. This enables calculation of a highly reliable correction coefficient.

Alternatively, work implement controller 26 may be configured to rotate about reference rotation angle θ_GNSSTo calculate a correction coefficient. Specifically, the reference pivot angle θ may be_GNSSWhen the angle is not less than the predetermined angle, the sensitivity error may become large, and therefore, such a situation may occurUnder the condition of calculating correction coefficient, at reference rotation angle theta_GNSSIf the angle is smaller than the predetermined angle, the sensitivity error is small, and therefore the correction coefficient is not calculated in this case.

Alternatively, work implement controller 26 may perform a test slewing operation in order to calculate a correction coefficient p for correcting the azimuth velocity data from IMU 24. In the test slewing operation, the slewing body azimuth data before the start of slewing of the slewing body 3 and after the end of slewing, which is generated by the global coordinate calculation unit 23, may be used to calculate a correction coefficient for correcting the azimuth acceleration data measured by the IMU24 used in the slewing operation, based on the above-described method.

While the embodiments of the present disclosure have been described above, it should be understood that the embodiments of the present disclosure are illustrative and not restrictive in all respects. The scope of the present disclosure is intended to be indicated by the appended claims, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein.

Description of reference numerals:

a vehicle body; a working device; a revolving body; a cab; a driver seat; a travel device; 5Cr.. tracks; 6.. a boom; a dipper; a bucket; a shovel tip; an engine compartment; a boom cylinder; a dipper handle cylinder; a bucket cylinder; a boom pin; a bucket rod pin; a bucket pin; a boom cylinder stroke sensor; a dipper cylinder travel sensor; a bucket cylinder travel sensor; a handrail; a position detection device; an antenna; a first antenna; a second antenna; a global coordinate operation section; a work device controller; a sensor controller; a rotary motor; a hydraulic device; a work machine; a detection information acquisition unit; a correction section; a rotor control section.