CN113022555B

CN113022555B - Target following control method and device for differential slip steering vehicle

Info

Publication number: CN113022555B
Application number: CN202110225309.0A
Authority: CN
Inventors: 宋彬; 王肖; 张德兆; 李晓飞; 霍舒豪; 张放
Original assignee: Chongqing Landshipu Information Technology Co ltd
Current assignee: Chongqing Landshipu Information Technology Co ltd
Priority date: 2021-03-01
Filing date: 2021-03-01
Publication date: 2023-01-20
Anticipated expiration: 2041-03-01
Also published as: CN113022555A

Abstract

The embodiment of the invention relates to a target following control method of a speed difference slipping steering vehicle, which is characterized by comprising the following steps of receiving a control instruction sent by an interaction device; the control instructions include transport protocol information; determining whether the vehicle enters a following mode or not according to the transmission protocol information; when the vehicle enters a following mode, acquiring the distance between the vehicle and a preset target following object; comparing the distance with a preset distance threshold, and determining that the following mode is the pivot steering mode when the distance is between a preset first distance threshold and a preset second distance threshold; wherein the first distance threshold is less than the second distance threshold; and when the pivot steering mode is adopted, acquiring first movement angle information of the target following object, generating a first pivot steering control signal according to the first movement angle information, and performing pivot steering through the first pivot steering control signal.

Description

Target following control method and device for differential slip steering vehicle

Technical Field

The invention relates to the technical field of automatic driving, in particular to a target following control method and device for a differential slip steering vehicle.

Background

In recent years, with rapid development of robotics and unmanned driving, unmanned ground vehicles have been widely used in various fields. The target obstacle following is one of common functions of the unmanned ground vehicle, and the unmanned ground vehicle detects the position and the speed of the target obstacle in real time by depending on a sensor of the unmanned ground vehicle, so that the speed and the turning angle of the unmanned ground vehicle are adjusted, and the target obstacle is followed. The differential speed slip steering vehicle is widely applied to the field of unmanned ground vehicles due to the characteristics of reliable control, capability of in-situ steering and the like.

The application environment of the unmanned ground vehicle is complex, and the common target obstacle following control method cannot turn on the spot when passing through a narrow road section and a road section with dense obstacles, so that the trafficability of the unmanned ground vehicle is limited.

Disclosure of Invention

The invention aims to provide a target following control method and device of a differential slip-steering vehicle, aiming at the defects in the prior art, so that the differential slip-steering vehicle can be adaptively adjusted in the process of following a preset target following object to drive, the pivot steering is realized, and the vehicle is convenient to pass through a narrow and obstacle-dense complex road section.

To achieve the above object, a first aspect of the present invention provides a target following control method of a differential skid steer vehicle, the target following control method including:

receiving a control instruction sent by an interaction device; the control instruction comprises transmission protocol information;

determining whether the vehicle enters a following mode or not according to the transmission protocol information;

when the vehicle enters a following mode, calculating the distance between the vehicle and a preset target following object;

comparing the distance with the preset distance threshold, and determining that the following mode is the pivot steering mode when the distance is between the preset first distance threshold and the preset second distance threshold; wherein the first distance threshold is less than the second distance threshold;

and when the target is in the pivot steering mode, acquiring first movement angle information of the target following object, generating a first pivot steering control signal according to the first movement angle information, and performing pivot steering through the first pivot steering control signal.

Preferably, when the vehicle enters the following mode, the calculating a distance between the vehicle and a preset target following object specifically includes:

acquiring image information of the preset target tracking object acquired by the vehicle-mounted camera;

acquiring environment perception data of the preset target tracking object acquired by the vehicle-mounted laser radar;

processing the environmental perception data to generate laser point cloud data;

performing fusion processing on the image information according to the laser point cloud data;

and calculating the distance between the vehicle and the preset target following object through the vehicle-mounted laser radar according to the image information after the fusion processing.

Preferably, after comparing the distance with the preset distance threshold, the method further includes:

generating an emergency stop signal when the distance equals the second distance threshold;

and performing emergency stop according to the emergency stop signal.

when the distance is larger than a preset third distance threshold value, determining that the following mode is a common steering mode; the third distance threshold is greater than the second distance threshold;

and when the following mode is a common steering mode, acquiring first moving speed information and second moving angle information of the target following object, generating a first common steering control signal according to the first moving speed information and the second moving angle information, and controlling a steering angle and a steering speed through the first common steering control signal.

Further preferably, the method further comprises:

acquiring a following mode of the vehicle at a previous moment;

when the following mode of the vehicle at the previous moment is the pivot steering mode and the distance is between the second distance threshold and the third distance threshold, determining that the following mode of the vehicle at the current moment is the pivot steering mode;

and acquiring third movement angle information of the target following object, generating a second pivot steering control signal according to the third movement angle information, and carrying out pivot steering through the first pivot steering control signal.

Further preferably, the method further comprises:

acquiring a following mode of the vehicle at a previous moment;

when the following mode of the vehicle at the previous moment is a common steering mode and the distance is between the second distance threshold and the third distance threshold, determining that the following mode of the vehicle at the current moment is the common steering mode;

and acquiring second moving speed information and fourth moving angle information of the target following object, generating a second common steering control signal according to the second moving speed information and the fourth moving angle information, and controlling a steering angle and a steering speed through the second common steering control signal.

A second aspect of the present invention provides a target following control apparatus for a differential skid steer vehicle, comprising:

the processing module is used for receiving a control instruction sent by the interactive device; the control instruction comprises transmission protocol information; and the number of the first and second groups,

comparing the distance with the preset distance threshold, and determining that the following mode is an in-place steering mode when the distance is between the preset first distance threshold and a preset second distance threshold; wherein the first distance threshold is less than the second distance threshold;

and when the pivot steering mode is adopted, acquiring first movement angle information of the target following object, generating a first pivot steering control signal according to the first movement angle information, and performing pivot steering through the first pivot steering control signal.

A third aspect of an embodiment of the present invention provides an electronic device, including: a memory, a processor, and a transceiver;

the processor is configured to be coupled to the memory, read and execute instructions in the memory, so as to implement the method steps of the first aspect;

the transceiver is coupled to the processor, and the processor controls the transceiver to transmit and receive messages.

A fourth aspect of embodiments of the present invention provides a computer-readable storage medium storing computer instructions that, when executed by a computer, cause the computer to perform the method of the first aspect.

The embodiment of the invention provides a target following control method of a differential slip steering vehicle, a target following control device of the differential slip steering vehicle, an electronic device and a computer readable storage medium, so that the differential slip steering vehicle can be adaptively adjusted in the process of following a preset target to follow an object to drive, the pivot steering is realized, and the differential slip steering vehicle can conveniently pass through a narrow and dense obstacle complex road section.

Drawings

FIG. 1 is a flowchart of a target following control method for a differential slip-steered vehicle according to an embodiment of the present invention;

FIG. 2 is a block diagram of a target follow control apparatus of a differential slip-steered vehicle according to a second embodiment of the present invention;

fig. 3 is a schematic structural diagram of an electronic device according to a third embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail with reference to the accompanying drawings. 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 invention.

The technical solution of the present invention is further described in detail by the accompanying drawings and embodiments.

The target following control method of the differential slip steering vehicle is executed in the differential slip steering unmanned ground vehicle, hereinafter referred to as the unmanned ground vehicle or the vehicle for short, can realize free switching between a pivot steering control mode and a common steering control mode of the differential slip steering unmanned ground vehicle, and is convenient for passing through a narrow and dense obstacle complex road section.

Fig. 1 is a flowchart of a target following control method for a differential slip steered vehicle according to an embodiment of the present invention, and the method is described below with reference to fig. 1.

The embodiment of the invention provides a target following control method of a differential slip steering vehicle, which mainly comprises the following steps:

step 110, receiving a control instruction sent by an interactive device; the control instructions include transport protocol information;

specifically, the interaction device may be a human-computer interface or a remote controller, and the unmanned ground vehicle may perform information interaction with the user through the human-computer interface or the remote controller. The transmission protocol information comprises a transmission protocol code so as to facilitate the identification of different control commands by the unmanned ground vehicle.

Step 120, determining whether the vehicle enters a following mode according to the transmission protocol information;

step 130, when the vehicle enters a following mode, calculating the distance between the vehicle and a preset target following object;

specifically, an in-vehicle sensor, such as an in-vehicle laser radar, an in-vehicle camera, or the like, is mounted in the unmanned ground vehicle. The preset target following object may be a person or a vehicle, and facial features of the person or a license plate number of the vehicle may be prestored in the memory of the vehicle without the vehicle. After the unmanned ground vehicle is switched to the unmanned ground vehicle following mode through a code of a designated protocol, the vehicle can match and confirm the image information acquired by the vehicle-mounted camera with the prestored license plate number or facial features through an image feature comparison method, and a target following object is locked.

Further, acquiring preset image information of a target tracking object acquired by a vehicle-mounted camera; acquiring environmental perception data of a preset target tracking object acquired by a vehicle-mounted laser radar; processing the environmental perception data to generate laser point cloud data; fusing the image information according to the laser point cloud data; and calculating the distance between the vehicle and a preset target following object through the vehicle-mounted laser radar according to the image information after the fusion processing. The fusion processing here can be regarded as a process of correcting image information acquired by the vehicle-mounted camera, and then the corresponding distance is calculated according to the corrected image information by using the ranging principle of the vehicle-mounted laser radar.

Step 140, comparing the distance with a preset distance threshold, and determining that the following mode is the pivot steering mode when the distance is between a preset first distance threshold and a preset second distance threshold; wherein the first distance threshold is less than the second distance threshold;

specifically, the following mode includes a pivot steering mode and a normal steering mode. The distance between the unmanned ground vehicle and the target following object calculated by the vehicle-mounted sensor can be compared with a preset distance threshold value through a processing module on the vehicle to obtain a comparison result, so that whether the vehicle meets corresponding following mode judgment conditions or not is judged according to the comparison result, and free switching between different following modes is realized. The preset distance threshold may be a distance between the vehicle coordinate origin and the target following object. The vehicle origin of coordinates may be the intersection of the front wheel axis and the median plane of symmetry. The second distance threshold may be understood as a safe distance between the vehicle and the target following object before the vehicle switches to the pivot steering mode, i.e. a stopping distance of the vehicle.

Therefore, as a preferred scheme, when the vehicle follows the target to travel to a narrow and obstacle-dense complex road section or the end of a dead end, the processing module compares the distance with a preset distance threshold, and when the distance is equal to a second distance threshold, firstly generates an emergency stop signal and sends the emergency stop signal to the control module; and the control module carries out sudden stop according to the sudden stop signal, at the moment, the speed of the vehicle is zero, and the vehicle stops following the target to follow the object.

And then, the target following object moves towards the vehicle direction, so that the distance between the vehicle and the target following object is gradually reduced, when the distance is between the first distance threshold and the second distance threshold, the pivot steering mode judgment condition is met, and the following mode of the vehicle is determined to be the pivot steering mode. The first distance threshold may be understood as a safe distance between the vehicle and the moving target following object.

Step 150, when the mode is the pivot steering mode, obtaining first movement angle information of the target following object, generating a first pivot steering control signal according to the first movement angle information, and performing pivot steering through the first pivot steering control signal.

Specifically, the first movement angle information is an included angle formed by a connection line between the target following object and the vehicle after the vehicle suddenly stops and a connection line between the target following object and the vehicle after the vehicle enters the pivot steering mode and moves, with the vehicle coordinate origin as an origin. The first movement angle information can be calculated in real time through the preset tracking path and the position information. After the first movement angle information is obtained, a processing module of the vehicle can calculate by combining the following mode and the movement angle of the target following object, generate a first control signal comprising gear adjustment, motor rotating speed and rotating turns, and enter a control mode of vehicle pivot steering through the first control signal. Thus, the vehicle may be steered in situ through narrow, obstacle-dense complex road sections, "dead-end" or narrow quarter-turns.

It can be understood that when the vehicle enters the following mode, the vehicle not only includes the pivot steering mode, but also can steer under the condition that the vehicle speed is not zero, and the specific judgment process is as follows:

the processing module compares the distance with a preset distance threshold value, and when the distance is greater than a preset third distance threshold value, the following mode is determined to be a common steering mode; the third distance threshold is greater than the second distance threshold.

When the following mode is the common steering mode, first moving speed information and second moving angle information of the target following object are obtained, a first common steering control signal is generated according to the first moving speed information and the second moving angle information, and the steering angle and the steering speed are controlled through the first common steering control signal.

In particular, the third distance threshold may be understood as a safe distance between the moving vehicle and the target following object after the vehicle enters the following mode. The second moving angle information is similar to the first moving angle information in the obtaining process, and is not described herein again. The first moving speed information is obtained by acquiring the position information of the target moving object within a preset time and then calculating according to the position information, the preset time and the like.

In order to maintain the stability of the control mode, besides the adaptive switching between different following modes, the vehicle needs to determine the current following mode of the vehicle in combination with the following mode at the previous moment, and enter the corresponding control mode.

Specifically, a following mode of the vehicle at a previous time is acquired.

And when the following mode of the vehicle at the previous moment is the pivot steering mode and the distance is between the second distance threshold and the third distance threshold, determining that the following mode of the vehicle at the current moment is the pivot steering mode.

And obtaining third movement angle information of the target following object, generating a second pivot steering control signal according to the third movement angle information, and carrying out pivot steering through the first pivot steering control signal.

That is to say, when the vehicle is in the pivot steering mode at the previous moment, after the vehicle is turned around, and the distance between the vehicle and the target preset object enters the range between the second distance threshold and the third distance threshold from the first distance threshold and the second distance threshold, the vehicle is still in the pivot steering mode, that is, the vehicle speed is zero when the vehicle enters the pivot steering control mode, and the gear is the neutral gear.

Further specifically, when the vehicle is in the pivot steering mode, a following mode of the vehicle at the previous moment is obtained;

and when the following mode of the vehicle at the previous moment is the common steering mode and the distance is between the second distance threshold and the third distance threshold, acquiring second moving speed information and fourth moving angle information of the target following object, generating a second common steering control signal according to the second moving speed information and the fourth moving angle information, and controlling the steering angle and the steering speed through the second common steering control signal.

That is, when the vehicle is in the normal steering mode at a time immediately before, the vehicle enters between the second distance threshold and the third distance threshold from being greater than the third distance threshold, and the vehicle is still in the normal steering mode. Therefore, the fuzzy control area is formed between the second distance threshold and the third distance threshold, and the stability of the control mode is realized.

Of course, it is understood that the unmanned ground vehicle may exit the following mode by receiving a control command, and the process is similar to entering the following mode, and will not be described in detail herein.

The target following control method for the differential slip steering vehicle provided by the embodiment of the invention enables the differential slip steering vehicle to be self-adaptively adjusted in the process of driving along with a preset target following object, realizes free switching between an in-situ steering mode and a common steering mode, and is convenient for passing through a narrow and obstacle-intensive complex road section.

Fig. 2 is a block diagram of a target following control device of a differential slip-steered vehicle according to a second embodiment of the present invention, which may be a device capable of implementing the method according to the first embodiment of the present application, such as a target following control device or a chip system of a differential slip-steered vehicle. As shown in fig. 2, the apparatus includes:

a processing module 201, configured to receive a control instruction sent by an interaction apparatus; the control instructions include transport protocol information.

The processing module 201 is further configured to determine whether the vehicle enters a following mode according to the transmission protocol information;

comparing the distance with a preset distance threshold, and determining that the following mode is the pivot steering mode when the distance is between a preset first distance threshold and a preset second distance threshold; wherein the first distance threshold is less than the second distance threshold;

when the target is in the pivot steering mode, first movement angle information of the target following object is obtained, a first pivot steering control signal is generated according to the first movement angle information, and pivot steering is carried out through the first pivot steering control signal.

In a specific implementation manner provided in this embodiment, when the vehicle enters the following mode, the processing module 201 is specifically configured to:

and calculating the distance between the vehicle and a preset target following object through the vehicle-mounted binocular camera.

In another specific implementation manner provided in this embodiment, when the distance is equal to the second distance threshold, the processing module 201 is further configured to:

generating an emergency stop signal;

and performing emergency stop according to the emergency stop signal.

In another specific implementation manner provided in this embodiment, when the distance is greater than the preset third distance threshold, the processing module 201 is further configured to:

determining that the following mode is a common steering mode; the third distance threshold is greater than the second distance threshold;

In another specific implementation manner provided in this embodiment, the processing module 201 is further configured to:

acquiring a following mode of a vehicle at a previous moment;

when the following mode of the vehicle at the previous moment is the common steering mode and the distance is between the second distance threshold and the third distance threshold, determining that the following mode of the vehicle at the current moment is the common steering mode;

and acquiring second moving speed information and fourth moving angle information of the target following object, generating a second common steering control signal according to the second moving speed information and the fourth moving angle information, and controlling the steering angle and the steering speed through the second common steering control signal.

The target following control device for the differential slip steering vehicle provided by the embodiment of the invention can execute the method steps in the method embodiment, and the implementation principle and the technical effect are similar, so that the detailed description is omitted.

It should be noted that the division of the modules of the above apparatus is only a logical division, and the actual implementation may be wholly or partially integrated into one physical entity, or may be physically separated. And these modules can be realized in the form of software called by processing element; or may be implemented entirely in hardware; and part of the modules can be realized in the form of calling software by the processing element, and part of the modules can be realized in the form of hardware. For example, the determining module may be a processing element separately set up, or may be implemented by being integrated in a chip of the apparatus, or may be stored in a memory of the apparatus in the form of program code, and the function of the determining module is called and executed by a processing element of the apparatus. The other modules are implemented similarly. In addition, all or part of the modules can be integrated together or can be independently realized. The processing element described herein may be an integrated circuit having signal processing capabilities. In implementation, each step of the above method or each module above may be implemented by an integrated logic circuit of hardware in a processor element or an instruction in the form of software.

For example, the above modules may be one or more integrated circuits configured to implement the above methods, such as: one or more Application Specific Integrated Circuits (ASICs), or one or more microprocessors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs), etc. For another example, when some of the above modules are implemented in the form of a Processing element scheduler code, the Processing element may be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor that can call the program code. As another example, these modules may be integrated together and implemented in the form of a System-on-a-chip (SOC).

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, digital Subscriber Line (DSL)), or wireless (e.g., infrared, wireless, bluetooth, microwave, etc.).

Fig. 3 is a schematic structural diagram of an electronic device according to a third embodiment of the present invention. As shown in fig. 3, the electronic device 300 may include: a processor 31 (e.g., CPU), a memory 32, a transceiver 33; the transceiver 33 is coupled to the processor 31, and the processor 31 controls the transceiving operation of the transceiver 33. Various instructions may be stored in memory 32 for performing various processing functions and implementing method steps performed by the electronic device of embodiments of the present invention. Preferably, the electronic device according to an embodiment of the present invention may further include: a power supply 34, a system bus 35, and a communication port 36. The system bus 35 is used to implement communication connections between the elements. The communication port 36 is used for connection communication between the electronic device and other peripherals.

The system bus mentioned in fig. 3 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The system bus may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown, but this does not mean that there is only one bus or one type of bus. The communication interface is used for realizing communication between the database access device and other equipment (such as a client, a read-write library and a read-only library). The Memory may include a Random Access Memory (RAM) and may also include a Non-Volatile Memory (Non-Volatile Memory), such as at least one disk Memory.

The Processor may be a general-purpose Processor, including a central processing unit CPU, a Network Processor (NP), and the like; but also a digital signal processor DSP, an application specific integrated circuit ASIC, a field programmable gate array FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components.

It should be noted that the embodiment of the present invention also provides a computer-readable storage medium, which stores instructions that, when executed on a computer, cause the computer to execute the method and the processing procedure provided in the above-mentioned embodiment.

The embodiment of the invention also provides a chip for running the instructions, and the chip is used for executing the method and the processing procedure provided in the embodiment.

Embodiments of the present invention also provide a program product, which includes a computer program stored in a storage medium, from which the computer program can be read by at least one processor, and the at least one processor executes the methods and processes provided in the embodiments.

Those of skill would further appreciate that the various illustrative components and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative components and steps have been described above generally in terms of their functionality in order to clearly illustrate this interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be embodied in hardware, a software module executed by a processor, or a combination of the two. A software module may reside in Random Access Memory (RAM), memory, read Only Memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, a removable disk, a CD-ROM powertrain control method, or any other form of storage medium known in the art.

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

Claims

1. A target following control method of a differential slip steered vehicle, characterized by comprising:

receiving a control instruction sent by an interactive device; the control instruction comprises transmission protocol information;

when the target is in the pivot steering mode, acquiring first movement angle information of the target following object, generating a first pivot steering control signal according to the first movement angle information, and performing pivot steering through the first pivot steering control signal;

wherein after comparing the distance to the preset distance threshold, the method further comprises:

when the following mode is a common steering mode, acquiring first moving speed information and second moving angle information of the target following object, generating a first common steering control signal according to the first moving speed information and the second moving angle information, and controlling a steering angle and a steering speed through the first common steering control signal;

wherein the method further comprises:

acquiring a following mode of the vehicle at a previous moment;

when the following mode of the vehicle at the previous moment is the pivot steering mode and the distance is between the second distance threshold and a preset third distance threshold, determining that the following mode of the vehicle at the current moment is the pivot steering mode;

and acquiring third movement angle information of the target following object, generating a second pivot steering control signal according to the third movement angle information, and carrying out pivot steering through the second pivot steering control signal.

2. The target following control method according to claim 1, wherein the calculating a distance between the vehicle and a preset target following object when the vehicle enters a following mode specifically includes:

fusing the image information according to the laser point cloud data;

3. The target following control method according to claim 1, wherein after comparing the distance to the preset distance threshold, the method further comprises:

and performing emergency stop according to the emergency stop signal.

4. The target following control method according to claim 1, characterized in that the method further comprises:

acquiring a following mode of the vehicle at a previous moment;

5. A target following control apparatus of a differential skid steer vehicle, characterized by comprising:

the processing module is used for receiving a control instruction sent by the interaction device; the control instruction comprises transmission protocol information; and the number of the first and second groups,

when the vehicle enters a following mode, acquiring the distance between the vehicle and a preset target following object;

a processing module further configured to:

a processing module further configured to: acquiring a following mode of the vehicle at a previous moment;

6. An electronic device, comprising: a memory, a processor, and a transceiver;

the processor is used for being coupled with the memory, reading and executing the instructions in the memory to realize the method steps of any one of claims 1-4;

7. A computer-readable storage medium having stored thereon computer instructions which, when executed by a computer, cause the computer to perform the method of any of claims 1-4.