CN115303262A

CN115303262A - Vehicle control method, device, terminal device and computer readable storage medium

Info

Publication number: CN115303262A
Application number: CN202210956407.6A
Authority: CN
Inventors: 蒋拯民; 李慧云; 张明宇; 桑明
Original assignee: Shenzhen Institute of Advanced Technology of CAS
Current assignee: Shenzhen Zhongke Xunlian Technology Co ltd; Shenzhen Institute of Advanced Technology of CAS
Priority date: 2022-08-10
Filing date: 2022-08-10
Publication date: 2022-11-08

Abstract

The application is applicable to the technical field of control, and provides a vehicle control method, a device, terminal equipment and a computer-readable storage medium, wherein the vehicle control method comprises the following steps: recording a parking path of a vehicle into a target area in the process of parking the vehicle into the target area; acquiring the parking-out position of the vehicle in real time in the process of parking out the target area; determining a steering wheel angle based on a position deviation between the berthing-out position and the berthing-in path; and controlling the vehicle to park out of the target area along the parking path according to the steering wheel rotating angle. By the method, the vehicle can be automatically controlled to return along the original path, and the intelligent degree of automatic driving is improved.

Description

Vehicle control method, device, terminal device and computer readable storage medium

Technical Field

The present application relates to the field of control technologies, and in particular, to a vehicle control method and apparatus, a terminal device, and a computer-readable storage medium.

Background

With the development of intelligent control technology, the automatic driving function of the vehicle is more and more perfect, and the frequency of application of users to the automatic driving function is higher and higher. The existing automatic driving function is generally to control the vehicle to travel according to a fixed route or to automatically plan a travel route in a wide area. However, when the vehicle enters an unknown narrow area and cannot exit by turning around, the conventional automatic driving function becomes ineffective. In this case, the driver usually switches to a manual driving mode, and operates the vehicle to move backward. The mode greatly depends on the control capability of a driver on the vehicle, and when the experience of the driver is insufficient or the driver is in mental stress, collision accidents are easy to happen. Therefore, the existing automatic driving function has lower intelligent degree.

Disclosure of Invention

The embodiment of the application provides a vehicle control method, a vehicle control device, terminal equipment and a computer readable storage medium, and the intelligent degree of automatic driving can be effectively improved.

In a first aspect, an embodiment of the present application provides a vehicle control method, including:

recording a parking path of a vehicle into a target area in the process of parking the vehicle into the target area;

acquiring the parking-out position of the vehicle in real time in the process of parking out the target area;

determining a steering wheel angle based on a position deviation between the berthing position and the berthing path;

and controlling the vehicle to park out of the target area along the parking path according to the steering wheel rotation angle.

In the embodiment of the application, since the parking path of the vehicle into the target area is a completed path, which indicates that the path is capable of guaranteeing the traffic, the path is recorded, which is equivalent to a reference path being saved. When the vehicle needs to park out of the target area, the recorded parking path is taken as a reference path, and the vehicle is controlled to park in the target area. When the vehicle enters an unknown narrow area and cannot exit by turning around, the vehicle can be automatically controlled to return along the original path by the method, and the intelligent degree of automatic driving is improved.

In one possible implementation manner of the first aspect, the target area includes a plurality of first location points, and the recording a parking path of the vehicle into the target area during the parking of the vehicle into the target area includes:

when the vehicle is parked in the target area, acquiring a three-dimensional point cloud representing the environment where the first position point is located and position coordinates of the first position point every time when one first position point is reached;

calculating pose transformation data of the vehicle between every two adjacent first position points according to the three-dimensional point clouds of the first position points;

and generating the parking path according to the pose transformation data of the vehicle between each two adjacent first position points and the position coordinates of each first position point.

In one possible implementation manner of the first aspect, the obtaining the parking-out position of the vehicle during the process of parking out the target area includes:

calculating the pose information of the vehicle in real time in the process that the vehicle is parked out of the target area;

and carrying out data filtering processing on the pose information to obtain the berthing position.

In one possible implementation manner of the first aspect, the determining a steering wheel angle according to a position deviation between the berthing position and the berthing path includes:

acquiring gear information corresponding to the parking position of the vehicle, wherein the gear information represents a gear when the vehicle passes through the parking position in the process of parking in the target area;

if the gear information represents forward movement, determining the steering wheel angle according to the position deviation between a pre-aiming point and the parking position, wherein the pre-aiming point is a position point in the parking path;

and if the gear information represents backward movement, determining the steering wheel angle according to the position deviation between the berthing-out position and the berthing path.

In one possible implementation manner of the first aspect, the determining the steering wheel angle according to a position deviation between the preview point and the pull-out position includes:

calculating a first lateral tracking error, wherein the first lateral tracking error represents a lateral distance of a rear axle center of the vehicle at the parked position to the home sight point;

calculating a first front wheel corner according to the first lateral tracking error and a first control law, wherein the first control law represents a functional relationship between the first lateral tracking error and a front wheel corner of the vehicle;

the steering wheel angle is determined based on the first front wheel angle.

In one possible implementation manner of the first aspect, the determining the steering wheel angle according to a position deviation between the berthing position and the berthing path includes:

calculating a second lateral tracking error, wherein the second lateral tracking error represents a distance from a front axle center of the vehicle at the parked position to the parked path;

calculating an angle tracking error, wherein the angle tracking error represents an angle difference between a heading angle of the vehicle at the parked position and a heading angle of the vehicle at the second position point;

calculating a second front wheel steering angle according to the second lateral tracking error, the angle tracking error and a second control law, wherein the second control law represents a functional relationship among the second lateral tracking error, the angle tracking error and a front wheel steering angle of the vehicle;

and determining the steering wheel angle according to the second front wheel steering angle.

In a possible implementation manner of the first aspect, the method further includes:

and in the process of parking the vehicle out of the target area, if the gear information corresponding to the current position of the vehicle is different from the gear information corresponding to the previous position, switching the gear of the vehicle according to the gear information corresponding to the current position of the vehicle.

In a second aspect, an embodiment of the present application provides a vehicle control apparatus, including:

the route recording unit is used for recording a parking route of the vehicle into a target area in the process of parking the vehicle into the target area;

the position acquisition unit is used for acquiring the parking-out position of the vehicle in real time in the process of parking out the target area;

an angle calculation unit for determining a steering wheel angle according to a position deviation between the berthing-out position and the berthing-in path;

and the vehicle control unit is used for controlling the vehicle to park out of the target area along the parking path according to the steering wheel rotation angle.

In a third aspect, an embodiment of the present application provides a terminal device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor, when executing the computer program, implements the vehicle control method according to any one of the first aspect.

In a fourth aspect, embodiments of the present application provide a computer-readable storage medium, and embodiments of the present application provide a computer-readable storage medium, which stores a computer program that, when executed by a processor, implements the vehicle control method according to any one of the first aspects.

In a fifth aspect, the present application provides a computer program product, when the computer program product runs on a terminal device, the terminal device is caused to execute the vehicle control method according to any one of the first aspect.

It is to be understood that, for the beneficial effects of the second aspect to the fifth aspect, reference may be made to the relevant description in the first aspect, and details are not described herein again.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a schematic diagram of a vehicle control system provided in an embodiment of the present application;

FIG. 2 is a schematic flow chart diagram of a vehicle control method provided by an embodiment of the present application;

FIG. 3 is a geometric schematic diagram of a back preview tracking algorithm provided by an embodiment of the present application;

FIG. 4 is a geometric schematic diagram of a forward error feedback tracking algorithm provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of an application scenario provided in an embodiment of the present application;

fig. 6 is a block diagram of a vehicle control device according to an embodiment of the present application;

fig. 7 is a schematic structural diagram of a terminal device according to an embodiment of the present application.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. It will be apparent, however, to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It should also be understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

As used in this specification and the appended claims, the term "if" may be interpreted contextually as "when", "upon" or "in response to" determining "or" in response to detecting ". Similarly, the phrase "if it is determined" or "if a [ described condition or event ] is detected" may be interpreted contextually to mean "upon determining" or "in response to determining" or "upon detecting [ described condition or event ]" or "in response to detecting [ described condition or event ]".

Furthermore, in the description of the present application and the appended claims, the terms "first," "second," "third," and the like are used for distinguishing between descriptions and not necessarily for describing or implying relative importance.

Reference throughout this specification to "one embodiment" or "some embodiments," or the like, means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the present application. Thus, appearances of the phrases "in one embodiment," "in some embodiments," "in other embodiments," or the like, in various places throughout this specification are not necessarily all referring to the same embodiment, but rather "one or more but not all embodiments" unless specifically stated otherwise.

The background of the application of the embodiments of the present application will first be described. When a vehicle enters an unknown narrow area and cannot turn around to exit, such as parking in a garage or a parking space, driving into the same, or passing through a narrow gap between two workshops, the automatic driving function is often disabled. In this case, the driver usually switches to a manual driving mode, and operates the vehicle to move backward. The mode greatly depends on the control capability of a driver on the vehicle, and when the experience of the driver is insufficient or visual dead angles exist, collision accidents are easy to happen. The existing automatic driving function has low intelligent degree and cannot meet the driving requirement of an unknown narrow area.

In order to solve the above problem, an embodiment of the present application provides a vehicle control method. In the method, a parking path is recorded in the process of parking a vehicle in an unknown narrow area; and in the process that the vehicle needs to be parked out of the unknown narrow area, calculating the steering wheel angle in real time according to the position deviation between the parking-out position and the recorded parking path, and controlling the vehicle to move out of the unknown narrow area along the parking path in real time according to the steering wheel angle. The method can realize automatic driving under complex road conditions, has high control precision, effectively reduces the driving load of drivers, improves the intelligent degree of vehicles, and does not need to increase additional hardware equipment.

The following describes a vehicle control system according to an embodiment of the present application. Referring to fig. 1, a schematic diagram of a vehicle control system according to an embodiment of the present application is shown. As shown in FIG. 1, a vehicle control system may include an information acquisition layer, a control layer, and an execution layer. And the layers CAN be in communication connection through a CAN bus. In the application process, the information acquisition layer sends the acquired data about vehicle running to the control layer, the control layer plans a running path (such as a parking path and a parking path) and a required control quantity according to the received data, and the execution layer controls the vehicle related devices to execute the planned control quantity.

The information acquisition layer may include various sensors such as a wheel speed sensor, a transmission control unit, a steering wheel angle sensor, an obstacle detection sensor, a vision sensor, and the like. The wheel speed sensor is used for acquiring the rotating speeds of the non-driving wheels on the two sides of the vehicle and obtaining the midpoint speed of the rear axle after averaging. The transmission control unit is used for acquiring the forward/backward gear of the vehicle. The steering wheel angle sensor is used for acquiring a steering wheel angle. Obstacle detection sensors (e.g., cameras, radar, etc.) are used to detect obstacles around the vehicle. The vision sensor is used for acquiring environmental information (such as three-dimensional point cloud, two-dimensional image and the like) in the driving process.

The control layer can comprise a positioning calculation module, a power-off storage module, a data recording module, a man-machine interaction module, a forward control module, a backward control module, an actuator handshake module, an obstacle alarm module and the like. The position calculation module is used for calculating the parking-out position of the vehicle, and comprises a parking-in positioning unit and a parking-out positioning unit, and the details are shown in the following embodiments. The forward control module is used to calculate a forward control strategy, such as the forward error feedback tracking strategy described in the embodiments described below. The back-off control module is used to calculate a back-off control strategy, such as the back-off preview tracking strategy described in the embodiments described below.

The executive layer may include a Power Steering (EPS), a Human Machine Interface (HMI), and a driving operation device (e.g., a gearshift, a brake, a throttle, etc.).

Referring to fig. 2, which is a schematic flow chart of a vehicle control method provided in the embodiment of the present application, by way of example and not limitation, the method may include the following steps:

s101, recording a parking path of the vehicle into a target area in the process of parking the vehicle into the target area.

The target area in the embodiment of the present application may refer to an area which is narrow and in which the vehicle cannot turn around.

In the embodiment of the present application, the parking positioning unit of the positioning calculation module in the control layer described in the above embodiments may be used for executing the above-described method.

In some embodiments, the driving path may be recorded in real time after the vehicle is started. When the storage space is full, the latest record overwrites the original record. The backing-off path (i.e. the parking-out path) of the vehicle is the latest parking-in path, so that the method can ensure that the driving data is not lost and the recorded parking-in path can be called when the vehicle backs off.

In other embodiments, the logging function may be turned on by the user through the HMI. For example, a user sends an opening instruction to the execution layer through the HMI, the execution layer sends the opening instruction to the control layer, and after receiving the opening instruction, the human-computer interaction module in the control layer instructs the data recording module to record the driving data received from the information acquisition layer.

Of course, the two recording modes may alternate. For example, after the vehicle is started, the driving path is recorded in real time; and when the user closes the recording function through the HMI, the control layer stops recording the driving path. For another example, after the vehicle is started, the driving path is not recorded by default; and when the user starts the recording function through the HMI, the control layer starts to record the driving path.

In some embodiments, the target area includes a plurality of first location points. The manner of recording the parking path may include:

when the vehicle is parked in the target area, acquiring a three-dimensional point cloud representing the environment where a first position point is located and a position coordinate of the first position point when the first position point is reached; calculating pose transformation data of the vehicle between every two adjacent first position points according to the three-dimensional point cloud; and generating the parking path according to the pose transformation data of the vehicle between every two adjacent first position points and the position coordinates of each first position point.

One way to set the first location point is: when the driving distance of the vehicle reaches the preset distance, a first position point is reached. For example, when the vehicle travels over 10cm, namely a first position point is reached, the effective position coordinates of the first position point and the three-dimensional point cloud are recorded, and the current gear information is stored.

Another way to set the first location point is: a recording period is preset, and a first position point is recorded every other recording period when the vehicle runs. For example, when the vehicle running speed is more than 10 steps and less than 20 steps, a first position point is recorded every 10 s; when the vehicle running speed is more than 20 steps and less than 30 steps, recording a first position point every 5 s; and by analogy, different recording periods are set for different vehicle speeds.

In the embodiment of the present application, the three-dimensional point cloud may be obtained by a laser radar. The three-dimensional point cloud may also be acquired by a camera mounted on the vehicle. For example, a camera (or a binocular camera or a depth camera) with an intersecting view field on the vehicle body is selected, and parameter calibration is performed on the camera in advance; and in the driving process, acquiring the three-dimensional point cloud of the environment by using the calibrated camera. When a first position point is reached, a frame of three-dimensional point cloud is obtained, namely two adjacent frames of three-dimensional point cloud correspond to two adjacent first position points.

In the embodiment of the present application, the way of calculating pose transformation data between every two adjacent first position points may be: matching ORB characteristics of two adjacent frames of three-dimensional point clouds, and assuming that a group of characteristic points matched according to the two frames are as follows:

and calculating pose transformation data P '= R.P + t of P and P' by using matrix decomposition (such as SVD decomposition), wherein R is a rotation matrix and t is a displacement matrix.

By the method, the parking track can be obtained according to the sequentially obtained pose transformation data between the adjacent position points as long as the coordinate of the initial position is obtained.

It should be noted that, in the embodiment of the present application, the recorded parking path may refer to recorded discrete data, including position coordinates of each of the plurality of first position points and pose transformation data between every two adjacent position points. The recorded parking path may also be a curve which is fitted according to the position coordinates of each of the plurality of first position points and the pose transformation data between every two adjacent position points.

Optionally, while the pose data of each first position point is acquired, the gear information of the vehicle at each first position point may also be recorded. If the reverse gear is recorded as-1, the non-reverse gear is recorded as 1. Of course, it is also possible to record different forward gears as different data, such as 1 for first gear, 2 for second gear, etc. The recording form of the gear position information is not particularly limited herein. The gear information is recorded so as to adjust different control strategies in the process of subsequently parking the vehicle out of the target area.

S102, acquiring the parking-out position of the vehicle in real time in the process of parking out the target area.

In this embodiment, the positioning may be executed by the pull-out positioning unit of the positioning calculation module in the control layer described in the above embodiments.

In some embodiments, during the process of parking the vehicle out of the target area, the pose information of the vehicle is calculated in real time, and the pose information is marked as the parking-out position of the vehicle. The specific method comprises the following steps:

(1) First, the vehicle motion satisfies the ackermann steering and rigid circular motion formulas:

in the formula: v. of _r Is the rear axle midpoint velocity, ω is the yaw rate, R is the turning radius, δ _f The turning radius of the front wheel and the axle distance L. Where ω is unknown data, R and L are known parameters of the vehicle, δ _f And v _r Is data that can be acquired by a sensor. The above equation can be simplified to calculate the yaw rate as:

in the formula: i is the angular gear ratio of the steering wheel.

(2) Secondly, further obtaining the longitudinal and horizontal coordinates of the midpoint of the rear axle according to the vehicle motion geometrical relationship

In the formula: t is _s For discrete calculation periods (time interval between every two adjacent position points), ω _k 、θ _k Yaw angular velocity and course angle, x, at time k, respectively _k 、y _k Respectively a vertical coordinate and a horizontal coordinate of the k moment relative to the starting point; v. of _l 、v _r Left and right non-driving wheel speeds, respectively.

In practical applications, the vehicle speed is not constant during the process of parking the vehicle out of the target area, and certain noise exists in data of the vehicle speed and the yaw rate. If the calculated park-out position is less accurate, as calculated above. In order to improve the precision of real-time positioning, in the embodiment of the application, data filtering processing is performed on the calculated pose information, and the pose information after filtering is recorded as a pull-in position. Optionally, an extended kalman filter may be used to perform the data filtering process. Specifically, on the basis of the steps (1) and (2), the filtering process of the step (3) is added as follows:

(3) Extended Kalman filter

In the formula: v. of _x,k+1 、v _y,k+1 The transverse and longitudinal speeds at time k +1, a _x 、a _y Respectively, the transverse acceleration and the longitudinal acceleration, and the W and the V respectively represent process noise and measurement noise. Where W is given data and V corresponds to a matrix made up of ω calculated by the above steps.

Through the data filtering processing, noise data can be effectively filtered, and the positioning precision is effectively improved.

S103, determining the steering wheel rotation angle according to the position deviation between the berthing-out position and the berthing path.

In this step, the recorded parking path may be regarded as a reference path. The position deviation between the parked position and the reference path can be calculated using existing navigation methods to determine the steering wheel angle, thereby enabling control of the vehicle.

And S104, controlling the vehicle to park out of the target area along the parking path according to the steering wheel rotating angle.

In some embodiments, the vehicle control method further includes, during the process of parking the vehicle out of the target area: and if the gear information corresponding to the current position of the vehicle is different from the gear information corresponding to the previous position, switching the gear of the vehicle according to the gear information corresponding to the current position of the vehicle.

For example, as shown in fig. 5, during the parking of the vehicle into the target area, the vehicle moves forward from the parking start point to the reverse position; from the shift position to the parking end point, the vehicle is moving backwards. Correspondingly, the vehicle moves forward and then moves backward when the vehicle is parked out of the target area. When the vehicle reaches the shift position, the vehicle gear is shifted from the forward gear to the reverse gear.

In the embodiment described in fig. 2, since the parking route of the vehicle into the target area is a completed route, which indicates that the route is capable of ensuring traffic, the route is recorded, which is equivalent to saving a reference route. When the vehicle needs to park out of the target area, the recorded parking path is taken as a reference path, and the vehicle is controlled to park in the target area. When the vehicle enters an unknown narrow area and cannot exit by turning around, the vehicle can be automatically controlled to return along the original path by the method, and the intelligent degree of automatic driving is improved.

With respect to step S103 above, in some embodiments, the same algorithm may be used to calculate the steering wheel angle during the process of parking the vehicle out of the target area, whether forward or reverse.

However, in the process of forward and backward movement of the vehicle, the geometric relationship between the vehicle and the parking path is actually different, and if the steering wheel angle is calculated according to the same algorithm, the accuracy of the calculation result is possibly low, so that the vehicle cannot be accurately returned along the original path.

To improve control accuracy, in one embodiment, the parking path is divided into forward and backward piecewise paths, and different algorithms are set for different piecewise paths. Specifically, S103 may include the following steps:

I. and acquiring gear information corresponding to the parking position of the vehicle, wherein the gear information represents a gear when the vehicle passes through the parking position in the process of parking in the target area.

As described in the above embodiments, the recorded docking path may refer to the recorded discrete data, or may be a curve fitted. When the docking path refers to discrete data, the corresponding location point in the docking path that matches the docking location in step I may be the first location point closest to the docking location. When the docked path refers to the fitted curve, the location point in the docked path that matches the docked location may be the location point closest to the fitted curve (the location point is not necessarily the first location point).

And when the position point matched with the berthing position in the berthing path is the first position point, the gear information corresponding to the berthing position is the gear information of the first position point. When the position point in the parking path matching with the parking-out position is not the first position point, the parking path may be divided into a forward sub-path and a backward sub-path according to the gear information corresponding to each first position point, and then it is determined whether the parking-out position belongs to the forward sub-path or the backward sub-path, so as to determine the gear information corresponding to the parking-out position.

II. And if the gear information indicates forward movement, determining the steering wheel angle according to the position deviation between a pre-aiming point and the parking position, wherein the pre-aiming point is a position point in the parking path.

In this step, the shift information indicates forward movement, that is, a forward movement state when the current position is reached while the vehicle is parked in the target area. Accordingly, when the vehicle is parked out of the target area, the vehicle should be in a reverse state when reaching the current position. In this case, the steering geometry between the vehicle and the parking path is satisfied and the steering wheel angle is determined using a back-off preview tracking algorithm. Specifically, step II may include:

calculating a first front wheel steering angle based on the first lateral tracking error and a first control law, wherein the first control law represents a functional relationship between the first lateral tracking error and a front wheel steering angle of the vehicle;

and determining a steering wheel angle according to the first front wheel steering angle.

Referring to fig. 3, it is a geometric schematic diagram of a back-off preview tracking algorithm provided in an embodiment of the present application. As shown in fig. 3, from the wheel turning angle and the point of preaction (g) in the parking path _x 、g _y ) The relationship betweenConsider a point of pre-aim at a distance l from the center of the rear axle of the vehicle to the parking path _d (preset value). Defining the center of the rear axle of the vehicle to the preview point (g) _x 、g _y ) Is a first lateral tracking error e _ld The triangular geometric relationship comprises:

pre-aiming distance l _d Positive correlation with rear axle midpoint v velocity:

l _d ＝k·v

in the formula: and k is a calibration parameter. The front wheel turning angle of the vehicle is as follows:

δ＝tan ^-1 (L/R)

the above equations are combined to obtain the first control law of

In the formula: delta. For the preparation of a coating ₁ A first front wheel steering angle of the vehicle is indicated.

Based on the first control law, the vehicle front wheel rotation angle can be calculated in real time according to the first transverse tracking error and the related data. Since there is a definite conversion relationship between the vehicle front wheel rudder angle and the steering wheel rudder angle, the steering wheel rudder angle can be determined from the calculated vehicle front wheel rudder angle.

Illustratively, the information acquisition layer sends the rear axle midpoint speed, the position coordinates of the current position and the vehicle attitude data acquired in real time to the control layer; the control layer calculates a first transverse tracking error in real time according to the received data, calculates a first front wheel corner in real time according to the first transverse tracking error and a first control law, converts the first front wheel corner into a steering wheel corner and sends the steering wheel corner to the execution layer; the execution layer controls the steering wheel to rotate according to the received steering wheel angle, and judges whether the steering wheel rotates in place or not according to steering wheel angle data fed back by the information acquisition layer in real time.

And III, if the gear information represents backward movement, determining the steering wheel angle according to the position deviation between the parking position and the parking path.

In this step, the shift position information indicates reverse, that is, a reverse state when the vehicle reaches the current position while the vehicle is parked in the target region. Accordingly, the vehicle should be in a forward state when reaching the current position during the process of parking out of the target area. Under the condition, the ideal Ackerman steering relation is satisfied between the vehicle and the parking path, and the steering wheel rotation angle is determined by utilizing a forward error feedback tracking algorithm. Specifically, step III may include:

and determining a steering wheel angle according to the second front wheel angle.

Referring to fig. 4, a geometric schematic diagram of a forward error feedback tracking algorithm provided in the embodiment of the present application is shown. As shown in fig. 4, an ideal ackermann steering relationship tan (δ) = L/R is satisfied between the vehicle and the parking path. Defining a distance from a center of a front axle of the vehicle to the desired track as a second lateral tracking error e _f The angular tracking error at the front wheel of the vehicle may be expressed as θ _e ＝θ-θ _c In the formula: theta, theta _c And (3) respectively establishing the two formulas to obtain a second control law for the course angle in the exit process and the course angle recorded in the entry path:

in the formula, delta ₂ Is the second front wheel angle of the vehicle.

Note that the XY coordinate system shown in fig. 4 may be set based on the exit start position point. In other words, the subsequent real-time calculated data is based on the outbound starting location. E.g. theta _c Corresponding to the change value of the heading angle of the vehicle at the current position relative to the exit starting position.

Based on the second control law, a second front wheel rotation angle can be calculated in real time according to the second lateral tracking error, the angle tracking error and the related data. Since there is a definite conversion relationship between the front wheel steering angle of the vehicle and the steering wheel steering angle, the steering wheel steering angle can be determined from the calculated front wheel steering angle of the vehicle.

Illustratively, the information acquisition layer sends the rear axle midpoint speed, the position coordinates of the current position and the vehicle attitude data acquired in real time to the control layer; the control layer calculates a second transverse tracking error and an angle tracking error in real time according to the received data, calculates a second front wheel corner in real time according to the second transverse tracking error, the angle tracking error and a first control law, converts the second front wheel corner into a steering wheel corner and sends the steering wheel corner to the execution layer; the execution layer controls the steering wheel to rotate according to the received steering wheel angle, and judges whether the steering wheel rotates in place or not according to steering wheel angle data fed back by the information acquisition layer in real time.

In the above-described embodiment, the parking path is divided into the forward sub-path and the reverse sub-path according to the change of the gear. Through the subsection control of different sub paths, the steering wheel rotating angle can be calculated more accurately, and the accurate control of the vehicle is realized.

Exemplarily, refer to fig. 5, which is a schematic diagram of an application scenario provided in the embodiment of the present application. An application scenario as shown in fig. 5 (a), in which the vehicle is back-parked into the target area. And controlling the vehicle to call a forward strategy to park out in the process of parking out of the target area. An application scenario is shown in fig. 5 (b), in which, during parking of the vehicle into the target area, the vehicle is first parked into the shift position from the parking start point, then is switched to the reverse gear, and then is continuously backed from the shift position to the parking end point. Correspondingly, in the process of parking out the vehicle, a forward strategy is called to control the vehicle to park out from the parking ending point to the gear shifting position, the gear is switched to a reverse gear at the gear shifting position, and then a reverse strategy is called to control the vehicle to park out from the gear shifting position to the parking starting point.

In some applications, when the vehicle successfully returns to the point of initiation of parking, the control system may prompt the user through the HMI to complete parking out to instruct the user to switch to manual driving mode.

Further, in the embodiment of the present application, the parking path is divided into forward and backward segment paths, and different control algorithms are set for different segment paths. The calculation precision of the steering wheel angle is effectively improved, and the control precision of the vehicle is further improved.

It should be understood that, the sequence numbers of the steps in the foregoing embodiments do not imply an execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

Fig. 6 is a block diagram of a vehicle control device according to an embodiment of the present application, which corresponds to the vehicle control method according to the foregoing embodiment, and only a part related to the embodiment of the present application is shown for convenience of description.

Referring to fig. 6, the apparatus includes:

a path recording unit 61 for recording a parking path of a vehicle into a target area in a process of parking the vehicle into the target area;

the position acquisition unit 62 is used for acquiring the parking-out position of the vehicle in real time in the process of parking out the target area;

an angle calculation unit 63 for determining a steering wheel angle from a position deviation between the berthing-out position and the berthing-in path;

a vehicle control unit 64 for controlling the vehicle to park out of the target area along the parking path according to the steering wheel angle.

Optionally, the target area includes a plurality of first location points, and the path recording unit 61 is further configured to:

when the vehicle is parked in the target area, acquiring a three-dimensional point cloud representing the environment where a first position point is located and a position coordinate of the first position point when the first position point is reached;

Optionally, the position obtaining unit 62 is further configured to:

Optionally, the angle calculating unit 63 is further configured to:

calculating a second lateral tracking error, wherein the second lateral tracking error represents a distance of a front axle center of the vehicle at the berthed position to the berthed path;

calculating a second front wheel steering angle according to the second lateral tracking error, the angular tracking error and a second control law, wherein the second control law represents a functional relationship among the second lateral tracking error, the angular tracking error and a front wheel steering angle of the vehicle;

Optionally, the vehicle control unit 64 is further configured to:

It should be noted that, for the information interaction, execution process, and other contents between the above-mentioned devices/units, the specific functions and technical effects thereof are based on the same concept as those of the embodiment of the method of the present application, and specific reference may be made to the part of the embodiment of the method, which is not described herein again.

The vehicle control device shown in fig. 6 may be a software unit, a hardware unit, or a combination of software and hardware unit built in an existing terminal device, may be integrated as a separate pendant into the terminal device, or may exist as a separate terminal device.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions. Each functional unit and module in the embodiments may be integrated in one processing unit, or each unit may exist alone physically, or two or more units are integrated in one unit, and the integrated unit may be implemented in a form of hardware, or in a form of software functional unit. In addition, specific names of the functional units and modules are only for convenience of distinguishing from each other, and are not used for limiting the protection scope of the present application. The specific working processes of the units and modules in the system may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

Fig. 7 is a schematic structural diagram of a terminal device according to an embodiment of the present application. As shown in fig. 7, the terminal device 7 of this embodiment includes: at least one processor 70 (only one shown in fig. 7), a memory 71, and a computer program 72 stored in the memory 71 and operable on the at least one processor 70, the processor 70 implementing the steps in any of the various vehicle control method embodiments described above when executing the computer program 72.

The terminal device can be a desktop computer, a notebook, a palm computer, a cloud server and other computing devices. The terminal device may include, but is not limited to, a processor, a memory. Those skilled in the art will appreciate that fig. 7 is only an example of the terminal device 7, and does not constitute a limitation to the terminal device 7, and may include more or less components than those shown, or may combine some components, or different components, and may further include, for example, an input/output device, a network access device, and the like.

The Processor 70 may be a Central Processing Unit (CPU), and the Processor 70 may be other general-purpose Processor, 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 device, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 71 may in some embodiments be an internal storage unit of the terminal device 7, such as a hard disk or a memory of the terminal device 7. The memory 71 may also be an external storage device of the terminal device 7 in other embodiments, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), and the like, provided on the terminal device 7. Further, the memory 71 may also include both an internal storage unit and an external storage device of the terminal device 7. The memory 71 is used for storing an operating system, an application program, a Boot Loader (Boot Loader), data, and other programs, such as program codes of the computer programs. The memory 71 may also be used to temporarily store data that has been output or is to be output.

An embodiment of the present application further provides a computer-readable storage medium, where a computer program is stored, and when the computer program is executed by a processor, the computer program implements the steps in the foregoing method embodiments.

The embodiments of the present application provide a computer program product, which when running on a terminal device, enables the terminal device to implement the steps in the above method embodiments when executed.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, all or part of the processes in the methods of the embodiments described above may be implemented by instructing relevant hardware by a computer program, which may be stored in a computer-readable storage medium, and when the computer program is executed by a processor, the steps of the embodiments of the methods described above may be implemented. Wherein the computer program comprises computer program code, which may be in the form of source code, object code, an executable file or some intermediate form, etc. The computer readable medium may include at least: any entity or device capable of carrying computer program code to an apparatus/terminal device, recording medium, computer Memory, read-Only Memory (ROM), random Access Memory (RAM), electrical carrier signals, telecommunications signals, and software distribution medium. Such as a usb-disk, a removable hard disk, a magnetic or optical disk, etc. In certain jurisdictions, computer-readable media may not be an electrical carrier signal or a telecommunications signal in accordance with legislative and patent practice.

In the above embodiments, the description of each embodiment has its own emphasis, and reference may be made to the related description of other embodiments for parts that are not described or recited in any embodiment.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. 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 application.

In the embodiments provided in the present application, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other ways. For example, the above-described embodiments of the apparatus/terminal device are merely illustrative, and for example, the division of the modules or units is only one logical division, and there may be other divisions when actually implemented, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims

1. A vehicle control method characterized by comprising:

determining a steering wheel angle based on a position deviation between the berthing-out position and the berthing-in path;

2. The vehicle control method according to claim 1, wherein the target area includes a plurality of first position points, and the recording of the parking path of the vehicle into the target area during parking of the vehicle into the target area includes:

3. The vehicle control method according to claim 1, wherein the acquiring a parked position of the vehicle in real time during parking of the vehicle out of the target area includes:

4. The vehicle control method according to claim 1, wherein the determining a steering wheel angle according to a position deviation between the parked position and the parked path includes:

5. The vehicle control method of claim 4, wherein said determining the steering wheel angle based on a position deviation between a home address and the park out position comprises:

and determining the steering wheel angle according to the first front wheel steering angle.

6. The vehicle control method according to claim 4, wherein the determining the steering wheel angle according to the position deviation between the parked position and the parked path includes:

7. The vehicle control method according to claim 4, characterized in that the method further comprises:

8. A vehicle control apparatus characterized by comprising:

an angle calculation unit for determining a steering wheel angle according to a position deviation between the berthing position and the berthing route;

9. A terminal device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the method according to any of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, in which a computer program is stored which, when being executed by a processor, carries out the method according to any one of claims 1 to 7.