阅读说明：本技术 一种自动驾驶牵引车与飞机对接方法及系统 (Method and system for docking automatic driving tractor and airplane ) 是由 于海洋 余航 任毅龙 王吉祥 付翔 兰征兴 于 2021-09-15 设计创作，主要内容包括：本发明属于飞机牵引作业技术领域,具体而言涉及一种自动驾驶牵引车与飞机对接方法及系统。其对接方法为：牵引车通过高精度定位模块到达与自动驾驶牵引车对接作业的起点位置,并调整其航向角与飞机的航向角一致；自动牵引车开始向飞机靠近,牵引车通过相机传感器调整位姿至牵引车托架与飞起前起落架对齐,车载激光雷达测量牵引车托架末端与飞机前起落架距离；当牵引车达到预设位置时,调整车速,与飞机前起落架接触；最后完成对接。其对接系统包括多种传感器、自动驾驶平台以及车机通信系统,系统中的各个器件相互配合。本发明意在实现自动驾驶牵引车与待牵引飞机的全自动对接,保证作业人员安全以及降低人工劳动量的同时,提高作业效率。(The invention belongs to the technical field of airplane traction operation, and particularly relates to a method and a system for butting an automatic driving tractor and an airplane. The butt joint method comprises the following steps: the tractor reaches the starting point position of the butt joint operation with the automatic driving tractor through the high-precision positioning module, and the course angle of the tractor is adjusted to be consistent with that of the airplane; the automatic tractor starts to approach the airplane, the tractor adjusts the pose through a camera sensor until a tractor bracket is aligned with the flying nose landing gear, and a vehicle-mounted laser radar measures the distance between the tail end of the tractor bracket and the nose landing gear of the airplane; when the tractor reaches a preset position, adjusting the speed of the tractor to be in contact with the nose landing gear of the airplane; and finally, completing the butt joint. The docking system comprises various sensors, an automatic driving platform and a vehicle-mounted machine communication system, and all devices in the system are matched with each other. The invention aims to realize the full-automatic butt joint of the automatic driving tractor and the airplane to be towed, ensure the safety of operators, reduce the amount of manual labor and improve the operation efficiency.)

1. A method for docking an autopilot tractor with an aircraft, comprising:

s1, the automatic piloting platform obtains the position information and the attitude information of the airplane to be towed through the high-precision positioning module, and the control module controls the automatic piloting tractor to reach the starting point of the butt joint operation with the airplane to be towed; meanwhile, controlling the automatic driving tractor to adjust the course angle to be consistent with the course angle of the airplane to be towed;

s2, when the automatic driving tractor reaches a butt joint operation starting point and the course angle of the automatic driving tractor is consistent with that of the airplane to be pulled, the automatic driving tractor starts to approach the airplane to be pulled, a camera sensor on the automatic driving tractor identifies the nose landing gear of the airplane to be pulled, whether the bracket of the automatic driving tractor is aligned with the nose landing gear of the airplane to be pulled is judged, the distance between the tail end of the bracket of the automatic driving tractor and the nose landing gear of the airplane to be pulled is respectively detected through a plurality of vehicle-mounted laser radars in real time, and whether obstacles exist around the bracket of the automatic driving tractor, and the method for identifying the nose landing gear through the camera sensor comprises the following steps: firstly, training a recognition model of a nose landing gear of an airplane to be towed, inputting a captured image into an algorithm network by an automatic driving platform in the butt joint process of an automatic towing vehicle and the airplane to be towed so as to realize recognition of the nose landing gear of the airplane, and simultaneously, installing 5 feature points on the nose landing gear of the airplane, wherein 4 edges of the landing gear are circular, 1 center of the landing gear is rectangular, and obtaining the relative position posture between the nose landing gear of the airplane and a bracket of the automatic towing vehicle by positioning the feature points so as to realize the positioning and posture recognition of the nose landing gear of the airplane;

s3, when the automatic driving tractor reaches a preset position, the automatic driving system adjusts the speed of the automatic driving tractor and drives in a uniform speed reduction mode, so that the speed is 0 when the tail end of the bracket of the automatic driving tractor is contacted with the nose landing gear of the airplane to be towed;

and S4, after the tail end of the automatic driving tractor bracket is contacted with the front landing gear of the airplane to be pulled, the front landing gear of the airplane is clamped by the wheel holding clamping mechanism, the front landing gear of the airplane is lifted by the wheel holding jacking mechanism, and the butt joint is completed.

2. A method of docking an autonomous towing vehicle with an aircraft as claimed in claim 1 wherein, when the autonomous towing vehicle reaches the start of the docking operation, it is docked at v₁m/s speed is backed to be close to the nose landing gear of the airplane to be towed, the nose landing gear of the airplane to be towed is identified through the camera sensor during backing, the position and the posture are adjusted until the tractor bracket is aligned with the nose landing gear of the airplane, and the speed v₁Can be expressed as:wherein L is the distance between the starting point position of the docking operation and the nose landing gear of the airplane, and L₀The distance between the tractor and the nose landing gear of the aircraft is preset.

3. The method as claimed in claim 1, wherein the vehicle-mounted lidar includes a first vehicle-mounted lidar and a second vehicle-mounted lidar, and the first vehicle-mounted lidar is used to calculate the position of the tail end of the tractor bracket and the nose landing gear of the airplane to be towedAnd the distance l between the first vehicle-mounted laser radar and the nose landing gear of the airplane to be towed is extracted by combining the first vehicle-mounted laser radar data with the camera sensor data₁Calculating the distance l between the tail end of the bracket of the automatic driving tractor and the nose landing gear of the airplane to be towed₂Is shown as l₂＝l₁-a, wherein a is the distance of the first onboard lidar from the end of the autopilot chassis.

4. The method of claim 1, wherein the autopilot tractor adjusts the autopilot speed to v when the autopilot reaches a tractor preset position₂m/s, in the process that the tractor is in contact with the nose landing gear of the airplane to be towed from the preset position of the tractor to the tail end of the tractor bracket, the tractor performs uniform deceleration motion, and the acceleration is a₀Expressed as:

5. an autopilot tractor and aircraft docking system, comprising:

the system comprises a plurality of sensors, a control module and a control module, wherein the sensors comprise a high-precision positioning module and are used for acquiring the position information of the airplane to be towed and the course angle information of the airplane to be towed; a camera sensor for identifying the nose landing gear of the aircraft to be towed; the vehicle-mounted laser radar is used for measuring the distance between the tail end of a tractor bracket and the nose landing gear of the airplane to be towed and obstacles around the travel of the tractor;

the automatic driving platform comprises a sensing module, a driving module and a driving module, wherein the sensing module is used for receiving and processing information acquired by various sensors; the decision module is used for generating a tractor advancing track meeting a specific constraint condition according to the information processed by the sensing module; the control module is used for controlling an internal execution device of the tractor according to the actual situation by combining the information of the decision module;

and the vehicle-machine communication equipment is used for information interaction between the tractor and the airplane to be towed.

6. The system of claim 5, wherein the decision module comprises a path planning layer, a behavior decision layer and a motion planning layer, the path planning layer generates a global path, the behavior decision layer makes a specific behavior decision by combining information received from the sensing module after receiving the global path, and the motion planning layer plans and generates a trajectory meeting specific constraints according to the specific behavior decision.

7. An autonomous tractor and aircraft docking system according to claim 6 wherein the trajectory planned by the motion planning layer is transmitted as an input to the control module as the final path of travel of the vehicle.

8. The automatic piloting tractor and aircraft docking system as claimed in claim 5, wherein the sensing module is configured to receive information obtained by multiple sensors and perform distributed fusion on the information, perform local processing on raw data obtained by each individual sensor, and then send the result to the information fusion center for intelligent optimization and combination to obtain a final result.

Technical Field

The invention belongs to the technical field of airplane traction operation, and particularly relates to a method and a system for butting an automatic driving tractor and an airplane.

Background

The aircraft tractor is important equipment for guaranteeing the ground movement of the aircraft, and is divided into rod traction and rodless traction according to different traction modes, wherein the rod traction means that the aircraft tractor is connected with a nose landing gear of the aircraft through a traction rod to realize the traction or pushing of the aircraft. The rodless tractor is an airplane tractor which carries the nose landing gear of the airplane, and the tractor and the airplane form a whole to realize the traction or pushing of the airplane. The rodless traction device is simple in operation, small in turning radius, few in guarantee personnel and good in universality.

In the prior art, an aircraft tractor generally adopts a manual driving tractor, and a tractor driver needs to be responsible for driving the tractor on the basis of knowing various aircraft traction technical requirements (such as a turning angle, a traction speed, a wing span, a height and the like in a maintenance manual). The tractor and the airplane are in butt joint operation, a driver drives the tractor to aim at the nose landing gear of the airplane to approach slowly, and the nose landing gear of the airplane is clamped through a wheel holding clamping mechanism on the tractor after the nose landing gear of the airplane contacts with the tractor, so that the airplane is pulled or pushed. Due to the limited visual field of the driver of the tractor, at least two persons of a traction guide are required to be equipped to observe the clear distance between the tractor and the towed aircraft, between the towed aircraft and the surrounding aircraft or between the towed aircraft and the surrounding buildings, and the driver of the tractor is given an early warning prompt through voice communication.

In addition, in the prior art, for improving the operation safety of the tractor and optimizing the butt joint process of the tractor and the airplane, a sensor is additionally arranged on the tractor to acquire traffic situation information around the tractor and provide information influencing the operation safety for a tractor driver through a visual interface. However, the method still cannot solve the problems of strict requirements of tractor drivers, personal danger of operators, requirement of cooperation of multiple persons and low efficiency.

Disclosure of Invention

This patent is just proposed based on prior art's above-mentioned demand, and the technical problem that this patent will be solved provides an autopilot tractor and aircraft butt joint method and system in order to realize the full-automatic butt joint of autopilot tractor and treating the traction aircraft, when guaranteeing operation personnel safety and reducing the hand labor volume, improves the operating efficiency.

In order to solve the above problem, the technical scheme provided by the patent comprises:

the method for docking the automatic driving tractor with the airplane comprises the following steps: s1, the automatic piloting platform obtains the position information and the attitude information of the airplane to be towed through the high-precision positioning module, and the control module controls the automatic piloting tractor to reach the starting point of the butt joint operation with the airplane to be towed; meanwhile, controlling the automatic driving tractor to adjust the course angle to be consistent with the course angle of the airplane to be towed; s2, when the automatic driving tractor reaches a butt joint operation starting point and the course angle of the automatic driving tractor is consistent with that of the airplane to be pulled, the automatic driving tractor starts to approach the airplane to be pulled, a camera sensor on the automatic driving tractor identifies the nose landing gear of the airplane to be pulled, whether the bracket of the automatic driving tractor is aligned with the nose landing gear of the airplane to be pulled is judged, the distance between the tail end of the bracket of the automatic driving tractor and the nose landing gear of the airplane to be pulled is respectively detected through a plurality of vehicle-mounted laser radars in real time, and whether obstacles exist around the bracket of the automatic driving tractor, and the method for identifying the nose landing gear through the camera sensor comprises the following steps: firstly, training a recognition model of a nose landing gear of an airplane to be towed, inputting a captured image into an algorithm network by an automatic driving platform in the butt joint process of an automatic towing vehicle and the airplane to be towed so as to realize recognition of the nose landing gear of the airplane, and simultaneously, installing 5 feature points on the nose landing gear of the airplane, wherein 4 edges of the landing gear are circular, 1 center of the landing gear is rectangular, and obtaining the relative position posture between the nose landing gear of the airplane and a bracket of the automatic towing vehicle by positioning the feature points so as to realize the positioning and posture recognition of the nose landing gear of the airplane; s3, when the automatic driving tractor reaches a preset position, the distance between the tail end of the bracket of the automatic driving tractor and the nose landing gear of the airplane to be pulled reaches a specified value, the automatic driving system adjusts the speed of the automatic driving tractor, the automatic driving tractor runs in a uniform speed reduction mode, and the speed is 0 when the tail end of the bracket of the automatic driving tractor is contacted with the nose landing gear of the airplane to be pulled; and S4, after the tail end of the automatic driving tractor bracket is contacted with the front landing gear of the airplane to be pulled, the front landing gear of the airplane is clamped by the wheel holding clamping mechanism, the front landing gear of the airplane is lifted by the wheel holding jacking mechanism, and the butt joint is completed. The aircraft nose landing gear is provided with 5 characteristic points, the characteristic points are fixed, the structure is short, the identification is easy, and the identification accuracy is stable.

Preferably, v is the value of v after the autonomous tractor reaches the start of the docking operation₁m/s speed is backed to be close to the nose landing gear of the airplane to be towed, the nose landing gear of the airplane to be towed is identified through the camera sensor during backing, the position and the posture are adjusted until the tractor bracket is aligned with the nose landing gear of the airplane, and the speed v₁Can be expressed as:wherein L is the distance between the starting point position of the docking operation and the nose landing gear of the airplane, and L₀The distance between the tractor and the nose landing gear of the aircraft is preset.

Preferably, the vehicle-mounted laser radar comprises a first vehicle-mounted laser radar and a second vehicle-mounted laser radar, the distance between the tail end of the tractor bracket and the nose landing gear of the airplane to be pulled can be calculated through the first vehicle-mounted laser radar, the first vehicle-mounted laser radar data is combined with the camera sensor data, and the distance l between the first vehicle-mounted laser radar and the nose landing gear of the airplane to be pulled is extracted₁Calculating the distance l between the tail end of the bracket of the automatic driving tractor and the nose landing gear of the airplane to be towed₂Is shown as l₂＝l₁-a, wherein a is the distance of the first onboard lidar from the end of the autopilot chassis.

Preferably, when the automatic driving tractor reaches the tractor preset position, the automatic driving platform adjusts the speed of the automatic driving tractor to be v₂m/s from a tractor preset position toIn the contact process of the tail end of the tractor bracket to the nose landing gear of the airplane to be towed, the tractor performs uniform deceleration motion, and the acceleration of the tractor is a₀Expressed as:

the invention also provides a system for docking the autopilot tractor with the airplane, which comprises: the system comprises a plurality of sensors, a control module and a control module, wherein the sensors comprise a high-precision positioning module and are used for acquiring the position information of the airplane to be towed and the course angle information of the airplane to be towed; a camera sensor for identifying the nose landing gear of the aircraft to be towed; the vehicle-mounted laser radar is used for measuring the distance between the tail end of a tractor bracket and the nose landing gear of the airplane to be towed and obstacles around the travel of the tractor; the automatic driving platform comprises a sensing module, a driving module and a driving module, wherein the sensing module is used for receiving and processing information acquired by various sensors; the decision module is used for generating a tractor advancing track meeting a specific constraint condition according to the information processed by the sensing module; the control module is used for controlling an internal execution device of the tractor according to the actual situation by combining the information of the decision module; and the vehicle-machine communication equipment is used for information interaction between the tractor and the airplane to be towed.

Preferably, the decision module includes a path planning layer, a behavior decision layer and a motion planning layer, the path planning layer generates a global path, the behavior decision layer makes a specific behavior decision by combining with information received from the sensing module after receiving the global path, and the motion planning layer plans and generates a track meeting a specific constraint condition according to the specific behavior decision.

Preferably, the trajectory planned by the motion planning layer is transmitted to the control module as an input, and is used as a final driving path of the vehicle.

Preferably, the sensing module is configured to receive information obtained by the multiple sensors, perform distributed fusion on the information, perform local processing on raw data obtained by each independent sensor, and send a result to the information fusion center to perform intelligent optimization and combination to obtain a final result.

Compared with the prior art, the full-automatic butt joint device can realize full-automatic butt joint of the automatic driving tractor and the airplane to be towed, ensure the safety of operators, reduce the amount of manual labor and improve the operation efficiency.

Drawings

In order to more clearly illustrate the embodiments of the present specification or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the embodiments of the present specification, and other drawings can be obtained by those skilled in the art according to the drawings.

FIG. 1 is a flow chart illustrating the steps of a method of docking an autopilot tractor with an aircraft according to the present invention;

FIG. 2 is a top view of various sensor placement locations on an autonomous tractor in one embodiment of the invention;

FIG. 3 is a side view of various sensor placement locations on an autonomous tractor in one embodiment of the invention;

figure 4 is an architectural diagram of an autopilot tractor and aircraft docking system in one embodiment of the invention.

Reference numerals:

1. a high-precision positioning module; 2. a camera sensor; 3. a first vehicle-mounted laser radar; 4. and a second vehicle-mounted laser radar.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

For the purpose of facilitating understanding of the embodiments of the present application, the following description will be made in terms of specific embodiments with reference to the accompanying drawings, which are not intended to limit the embodiments of the present application.

Example 1

The embodiment provides a method for docking an autopilot tractor with an airplane, and refers to fig. 1.

S1, the automatic piloting platform obtains the position information and the attitude information of the airplane to be towed through the high-precision positioning module, and the control module controls the automatic piloting tractor to reach the starting point of the butt joint operation with the airplane to be towed; and simultaneously controlling the automatic driving tractor to adjust the course angle so that the course angle is consistent with the course angle of the airplane to be towed.

The automatic piloting platform acquires the position information of the airplane to be towed, and simultaneously calculates the position information of the starting point of the butt joint operation by combining the information provided by the high-precision positioning module, and the control module controls the automatic piloting tractor to reach the starting point position of the butt joint operation.

The starting point for the docking operation is at L m directly in front of the nose landing gear of the aircraft.

L is determined according to the requirements of butt joint operation and the size of the field, and can be 10-15 m.

The high-precision positioning module comprises but is not limited to a satellite antenna, an inertia/satellite combined navigation host, upper computer software and the like, and the high-precision positioning module is respectively used for receiving satellite signals, calculating and providing multi-parameter navigation information, assisting positioning, analyzing data and the like.

After the automatic driving tractor reaches the starting point of the butt joint operation, the automatic driving platform controls the automatic driving tractor to adjust the course angle to be consistent with the course angle of the airplane to be pulled through the control module under the assistance of the high-precision positioning module according to the acquired airplane attitude information.

And S2, when the automatic driving tractor reaches a butt joint operation starting point and the course angle of the automatic driving tractor is consistent with that of the airplane to be pulled, the automatic driving tractor starts to approach the airplane to be pulled, a camera sensor on the automatic driving tractor identifies the nose landing gear of the airplane to be pulled, whether the bracket of the automatic driving tractor is aligned with the nose landing gear of the airplane to be pulled is judged, and the distance between the tail end of the bracket of the automatic driving tractor and the nose landing gear of the airplane to be pulled and whether obstacles exist around are respectively detected through a plurality of vehicle-mounted laser radars in real time.

The automatic driving tractor is provided with a camera sensor which can identify the nose landing gear of the airplane to be pulled and is used for judging whether the bracket of the automatic driving tractor is aligned with the nose landing gear of the airplane or not. Referring to fig. 2 and 3, it can be seen that the camera sensor is located on the centerline of the end of the autopilot tractor carriage.

The camera sensor identifies the nose landing gear of the airplane to be towed and adopts a computer vision measurement technology based on a CCD camera, namely, feature points with limited quantity and known geometric dimension and shape are installed on the nose landing gear of the airplane, the CCD camera is installed on the automatic piloting tractor, and the sensing module of the automatic piloting platform obtains the relative position posture of the airplane and the automatic piloting towing workshop through the analysis and processing of images formed by the feature points on the CCD camera.

The CCD (charge coupled device) is a charge coupled device, and may be referred to as a CCD image sensor. A CCD is a semiconductor device that can convert an optical image into a digital signal. The tiny photosensitive substances implanted on the CCD are called pixels. The larger the number of pixels contained in a CCD, the higher the resolution of the picture it provides. The CCD acts like a film, but it converts the image pixels into digital signals. The CCD has many capacitors arranged in order to sense light and convert the image into digital signal. Each small capacitor can transfer its charged charge to its neighboring capacitor under the control of an external circuit.

The camera sensor identifies the nose landing gear of the aircraft using the YOLOv2 algorithm.

The YOLO algorithm solves the target detection as a regression problem, and completes the input of the original image to the output of the object position and type based on an individual end-to-end network. The YOLOv2 introduces the idea of anchor box in the Faster R-CNN on the basis of YOLO, improves the design of each network structure and each layer, uses a convolutional layer to replace a full connection layer of the YOLO in an output layer, jointly uses coco object detection labeling data and imagenet object classification labeling data to train an object detection model, and greatly improves the aspects of identification precision, speed, positioning accuracy and the like.

The flow of identifying the nose landing gear of the airplane by the camera sensor comprises the following steps: the training of the airplane nose landing gear recognition model is completed in advance through a combined training method of target classification and detection, and in the butt joint operation process, the automatic driving platform inputs images captured by a camera sensor into a YOLOv2 algorithm to complete the recognition and positioning of the airplane nose landing gear. Meanwhile, the nose landing gear of the airplane is provided with a limited number of characteristic points with known geometric dimensions and shapes, and the relative position attitude between the nose landing gear of the airplane and the automatic steering tractor bracket is obtained by positioning the characteristic points. Install 5 characteristic points on the aircraft nose landing gear, wherein 4 undercarriage edges are circular, and 1 undercarriage central authorities are the rectangle, install 5 characteristic points on the aircraft nose landing gear, the fixed and structure of characteristic point is brief, and easily discernment and discernment rate of accuracy are stable.

The automatic driving tractor bracket, namely the device for carrying the nose landing gear of the airplane by the automatic driving tractor, comprises a wheel holding mechanism and a wheel holding jacking mechanism.

Automatic driving tractor with v₁And backing at the speed of m/s to be close to the nose landing gear of the airplane to be towed, and identifying the nose landing gear of the airplane through the camera sensor during the backing process to adjust the pose until the automatic driving tractor bracket is aligned with the nose landing gear of the airplane.

Wherein L is₀The distance between the position and the nose landing gear of the aircraft is preset for the autopilot tractor.

The automatic piloting platform comprises a sensing module and a decision-making module, in the process that the automatic piloting tractor approaches to the nose landing gear of the airplane to be towed, the sensing module of the automatic piloting platform sends the relative position posture of the airplane and the automatic piloting towing workshop to the decision-making module, the decision-making module sends a motion instruction to the control module by analyzing the relative position posture, and the control module controls the automatic piloting tractor to adjust the posture until the bracket is aligned with the nose landing gear of the airplane.

In this embodiment, the autonomous driving tractor has two vehicle-mounted lidar, a first vehicle-mounted lidar and a second vehicle-mounted lidar respectively.

The first vehicle-mounted laser radar is used for measuring the distance between the tail end of the automatic driving tractor bracket and the nose landing gear of the airplane to be towed, and continuously feeding back the measured distance to the automatic driving platform; and the second vehicle-mounted laser radar is used for detecting whether any obstacles exist around.

The first on-vehicle laser radar uses a solid-state laser radar having a horizontal angle of view and a vertical angle of view of 120 ° and 25 °, respectively, the horizontal angle of view being in a range of [ -60 °, +60 ° ], and the vertical angle of view being in a range of [ -12.5 °, +12.5 ° ]. And a PTOF (proportional to integral) distance measurement method is adopted for measuring the distance between the tail end of the automatic driving tractor bracket and the nose landing gear of the airplane to be towed. The core principle of the PTOF distance measurement method is that a beam of laser with extremely short time is shot to a detection object, and the distance from the detector to the detected object is reversely deduced by directly measuring the flight time of the laser which is emitted, shot to the detection object and then returned to the detector.

The first vehicle-mounted laser radar transmits laser beams to the front of the first vehicle-mounted laser radar, calculates and analyzes the distance of the obstacle, and feeds the distance back to the automatic driving platform. The automatic driving platform extracts the distance l between the first vehicle-mounted laser radar and the nose landing gear of the airplane to be towed by analyzing and combining the data of the camera sensor₁So as to calculate the distance l between the tail end of the bracket of the automatic driving tractor and the nose landing gear of the airplane to be towed₂。

l₂＝l₁-a

Wherein a is the distance between the first vehicle-mounted laser radar and the tail end of the automatic driving tractor bracket, and a can be determined according to the size of the automatic driving tractor and is 0.2m-0.5 m.

The second vehicle-mounted laser radar uses 32-line laser radars with a horizontal field angle and a vertical field angle of 360 ° and 40 °, respectively, that is, the second vehicle-mounted laser radar can emit 32 laser beams to scan the surrounding environment. And the second vehicle-mounted laser radar emits laser beams to the periphery, detects the obstacles by processing the generated point cloud and using the three-dimensional boundary box, divides the travelable area in real time and feeds back information to the automatic driving platform.

S3, when the automatic driving tractor reaches the preset position, the distance between the tail end of the bracket of the automatic driving tractor and the nose landing gear of the airplane to be pulled reaches the specified value, the automatic driving system adjusts the speed of the automatic driving tractor to drive in a uniform speed reduction mode, and simultaneously, the speed of the tail end of the bracket of the automatic driving tractor and the contact time of the nose landing gear of the airplane to be pulled are 0.

The distance between the tail end of the automatic driving tractor bracket and the nose landing gear of the airplane to be towed reaches a specified value, namely, the automatic driving tractor reaches a preset position. The preset position is just ahead L of the nose landing gear of the airplane₀m, the control module of the automatic driving platform adjusts the speed of the automatic driving tractor to v₂m/s。

Due to the set v₁And v₂Are all very small and have little difference, the deceleration process in the conversion can be ignored

L₀The length of the butt joint operation platform is 2-3m according to the butt joint operation requirement and the field size.

v₂According to the butt joint operation requirement and the determination of L0, the thickness of the material can be 0.5-0.6 m/s.

When the tail end of the bracket of the automatic driving tractor is contacted with the nose landing gear of the airplane to be towed, the automatic driving tractor is just decelerated until the speed is 0, and the acceleration is a₀。

And S4, after the tail end of the automatic driving tractor bracket is contacted with a front landing gear of the airplane to be towed, the front landing gear of the airplane is clamped by the wheel holding clamping mechanism, the front landing gear of the airplane is lifted by the wheel holding jacking mechanism, and the butt joint is completed.

Example 2

The present embodiment provides an autopilot tractor to aircraft docking system, see fig. 4.

The automatic piloting tractor and airplane docking system comprises various sensors, an automatic piloting platform and a vehicle-machine communication device.

The sensor comprises a high-precision positioning module, a camera sensor and a vehicle-mounted laser radar.

The high-precision positioning module comprises but is not limited to a satellite antenna, an inertia/satellite combined navigation host, upper computer software and the like, and the high-precision positioning module is respectively used for receiving satellite signals, calculating and providing multi-parameter navigation information, assisting positioning, analyzing data and the like.

The camera sensor is used for identifying the nose landing gear of the airplane to be towed.

The camera sensor identifies the nose landing gear of the airplane to be towed and adopts a computer vision measurement technology based on a CCD camera, namely, feature points with limited quantity and known geometric dimension and shape are arranged on the nose landing gear of the airplane, the CCD camera is arranged on the automatic piloting tractor, and the sensing module of the automatic piloting platform obtains the relative position posture of the airplane and the automatic piloting tractor through the analysis and the processing of images formed by the feature points on the CCD camera.

The CCD (charge coupled device) is a charge coupled device, and may be referred to as a CCD image sensor. A CCD is a semiconductor device that can convert an optical image into a digital signal. The tiny photosensitive substances implanted on the CCD are called pixels. The larger the number of pixels contained in a CCD, the higher the resolution of the picture it provides. The CCD acts like a film, but it converts the image pixels into digital signals. The CCD has many capacitors arranged in order to sense light and convert the image into digital signal. Each small capacitor can transfer its charged charge to its neighboring capacitor under the control of an external circuit.

The CCD camera sensor has small volume and light weight, and is not influenced by a magnetic field and is resistant to vibration and impact.

The vehicle-mounted laser radar comprises a vehicle-mounted laser radar A and a vehicle-mounted laser radar B.

The vehicle-mounted laser radar A is used for measuring the distance between the tail end of the automatic driving tractor bracket and the nose landing gear of the airplane to be towed, and continuously feeding back the measured distance to the automatic driving platform; and the vehicle-mounted laser radar B is used for detecting whether any obstacles exist around.

The on-vehicle laser radar a uses a solid-state laser radar having a horizontal angle of view and a vertical angle of view of 120 ° and 25 °, respectively, the horizontal angle of view being in the range of [ -60 °, +60 ° ], and the vertical angle of view being in the range of [ -12.5 °, +12.5 ° ]. And a PTOF (proportional to integral) distance measurement method is adopted for measuring the distance between the tail end of the automatic driving tractor bracket and the nose landing gear of the airplane to be towed. The core principle of the PTOF distance measurement method is that a beam of laser with extremely short time is shot to a detection object, and the distance from the detector to the detected object is reversely deduced by directly measuring the flight time of the laser which is emitted, shot to the detection object and then returned to the detector.

The vehicle-mounted laser radar B uses 32-line laser radars with horizontal and vertical field angles of 360 degrees and 40 degrees respectively, namely the vehicle-mounted laser radar B can emit 32 laser beams to scan the surrounding environment. And the laser radar B emits laser beams to the periphery, detects the obstacles by processing the generated point cloud and using the three-dimensional boundary box, divides the travelable area in real time and feeds back information to the automatic driving platform.

The automatic driving platform mainly comprises a sensing module, a decision-making module and a control module.

The sensing module is used for receiving the information acquired by the multiple sensors and performing distributed fusion on the information, namely, the original data acquired by each independent sensor is locally processed, and then the result is sent to the information fusion center to perform intelligent optimization combination to obtain a final result.

The decision module is divided into three levels: path planning, behavior decision making, and motion planning. Firstly, a path planning layer generates a global path, after the global path is received, a behavior decision layer combines information received from a sensing module to make a specific behavior decision, and finally, a motion planning layer plans and generates a track meeting specific constraint conditions according to the specific behavior decision, and the track is used as the input of a control module to decide the final driving path of the vehicle.

And the control module adopts PID control to generate control commands for a bottom layer accelerator, a brake, a steering wheel and a gear lever of the automatic driving tractor according to the planned driving track and speed and the current position, posture and speed, so that the automatic driving tractor drives at a target speed and acceleration along the target track.

The vehicle-mounted communication equipment comprises a vehicle-mounted terminal installed on an airplane and a vehicle-mounted terminal installed on an automatic driving tractor, and a communication network between the vehicle-mounted terminal and the vehicle-mounted terminal is established through 5G aeroMACS.

In the automatic piloting tractor and airplane butt joint system, a sensing module of an automatic piloting platform respectively receives information about position information and attitude information of an airplane to be towed, the distance between the front landing gear of the airplane to be towed and the tail end of a bracket of the automatic piloting tractor and the front landing gear of the airplane to be towed and whether any barriers exist at the periphery, which are acquired by a plurality of sensors including a high-precision positioning module, a camera sensor and a vehicle-mounted laser radar, and respectively independently processes original data information acquired by the plurality of sensors, and then inputs the processed results into an information fusion center for intelligent optimization combination to acquire final results.

The decision module is divided into three levels: path planning, behavior decision making, and motion planning.

The path planning layer generates a global path.

After receiving the generated global path, the behavior decision layer reads information from the perception module:

and obtaining the starting point position of the butt joint operation of the automatic driving tractor and the airplane to be towed and the course angle of the airplane to be towed by the high-precision positioning module.

The method comprises the steps that a camera sensor identifies the nose landing gear of the airplane to be towed, the relative position and the attitude of the airplane and an automatic driving towing workshop are obtained through image analysis and processing on the camera sensor, and whether an automatic driving towing vehicle bracket is aligned with the nose landing gear of the airplane to be towed or not is checked.

And measuring the distance between the tail end of the automatic driving tractor bracket and the nose landing gear of the airplane to be towed by using the vehicle-mounted laser radar A, and feeding back the distance in real time.

And detecting whether any obstacles exist around the driving path of the automatic driving tractor by a vehicle-mounted laser radar B.

After the starting position of the butt joint operation of the automatic driving tractor and the airplane to be towed and the course angle information of the airplane to be towed are obtained, the behavior decision layer makes a specific behavior decision, approaches the starting position of the butt joint operation, and adjusts the course angle of the automatic driving tractor and the course angle of the airplane to be towed in the approaching process. And the motion planning layer generates a track meeting a specific constraint condition according to the specific behavior decision plan, and the track is used as the input of the control module to determine the final driving path of the vehicle.

After the automatic driving tractor reaches the starting position of the butt joint operation, the automatic driving tractor approaches the nose landing gear of the airplane to be pulled, in the approaching process, the nose landing gear of the airplane to be pulled is identified through a camera sensor, whether the bracket of the automatic driving tractor is aligned with the nose landing gear of the airplane to be pulled is observed in real time, and the bracket of the automatic driving tractor and the nose landing gear of the airplane to be pulled are continuously adjusted to be aligned. And the motion planning layer generates a track meeting a specific constraint condition according to the specific behavior decision plan, and the track is used as the input of the control module to determine the final driving path of the vehicle. And enabling the automatic driving tractor to approach the airplane to be pulled in a uniform speed reduction mode, and finally enabling the speed of the automatic driving tractor to be 0 when the automatic driving tractor bracket is in contact with the front landing frame of the airplane to be pulled.

In the approach process, the vehicle-mounted laser radar A measures the distance between the tail end of the automatic driving tractor bracket and the nose landing gear of the airplane to be towed in real time and feeds back the distance to the automatic driving platform continuously, and the vehicle-mounted laser radar B detects whether any barriers exist around. And planning a path by the motion planning layer to avoid the obstacle, and timely adjusting physical quantities such as the travelling speed and the travelling angle of the automatic driving tractor.

And the control module processes the data information transmitted by the motion planning layer, and generates control commands for a bottom accelerator, a brake, a steering wheel and a gear lever of the automatic driving tractor according to the planned driving track and speed and the current position, posture and speed, so that the automatic driving tractor drives at a target speed and acceleration along the target track.

The aircraft is provided with an airborne terminal, and the vehicle-mounted terminal is arranged on the automatic driving tractor and is communicated with the automatic driving tractor through 5G aeroMACS. The AeroMACS is an Aero-acoustic Mobile Airport Communications System, namely an aviation Airport Mobile communication System.

The above-mentioned embodiments, objects, technical solutions and advantages of the present application are described in further detail, it should be understood that the above-mentioned embodiments are merely exemplary embodiments of the present application, and are not intended to limit the scope of the present application, and any modifications, equivalent substitutions, improvements and the like made within the spirit and principle of the present application should be included in the scope of the present application.