Method and device for lateral control of vehicle, controller, vehicle and computer readable storage medium

Abstract

The invention relates to a method for the lateral control of a vehicle, comprising the following steps: ascertaining the position of a reference vehicle traveling in front of the vehicle at a plurality of times; ascertaining a movement trajectory of the reference vehicle as a desired trajectory of the vehicle on the basis of the ascertained position of the reference vehicle; calculating the curvature, the curvature change rate and the course angle of the expected track at a predefined position; a control signal for lateral control of the vehicle is determined on the basis of the ascertained curvature, the rate of curvature change and the course angle. The invention also relates to a device for lateral control of a vehicle. The invention also relates to a controller for a vehicle. The invention also relates to a vehicle and a computer readable storage medium.

Description

Technical Field

[0001] The present invention relates to a method and a device for lateral control of a vehicle. The present invention also relates to a controller for a vehicle. The present invention also relates to a vehicle having the device or the controller. The present invention also relates to a computer-readable storage medium. Background Art

[0002] At present, vehicle lateral control is an important aspect of vehicle automatic driving. For example, in the lane keeping function, the desired trajectory to be followed by the vehicle to achieve lane keeping is usually obtained based on the lane lines on the road surface. However, in some scenarios, there are no relevant lane lines or the relevant lane lines are incomplete, so that the desired trajectory cannot be obtained. In addition to the lack of relevant lane lines due to unexpected circumstances, there are typically no relevant lane lines for obtaining the desired trajectory in scenarios such as intersections. In these scenarios, the conventional lane keeping function is at least temporarily ineffective. Summary of the invention

[0003] The purpose of the present invention is to provide a method for lateral control of a vehicle and a device for lateral control of a vehicle. The method and device for lateral control of a vehicle according to the present invention can still achieve a lane keeping function when a desired trajectory cannot be obtained based on a lane line on a road surface in front of the vehicle.

[0004] To this end, according to a first aspect of the present invention, a method for lateral control of a vehicle is provided. The method is particularly used for a lane keeping function of the vehicle or is integrated into a lane keeping function of the vehicle. The method can be part of a traffic jam assist function (Traffic Jam Assist), for example.

[0005] The method comprises at least the following steps: respectively determining the position of a reference vehicle traveling in front of the vehicle at multiple times; determining the motion trajectory of the reference vehicle as the desired trajectory of the vehicle based on the determined position of the reference vehicle; determining the curvature, the rate of change of curvature and the heading angle of the desired trajectory at a predefined position; and determining a control signal for lateral control of the vehicle based on the determined curvature, the rate of change of curvature and the heading angle.

[0006] The solution according to the present invention is particularly based on the following considerations: In the case where the desired trajectory of the vehicle cannot be obtained based on the lane line, in order to continue to implement the lane keeping function, according to the present invention, the vehicle traveling in front of the own vehicle is used as a reference vehicle, and the motion trajectory of the reference vehicle is obtained as the desired trajectory of the own vehicle, and then the own vehicle tracks the desired trajectory to achieve lane keeping. By making full use of the sensors already installed on the vehicle according to the solution of the present invention, the implementation of the lane keeping function in a specific scenario is ensured without adding additional hardware overhead.

[0007] Preferably, the method for lateral control of a vehicle according to the present invention is implemented in the vehicle's own vehicle coordinate system, wherein, unless otherwise specified, the method steps or technical features described below all refer to the vehicle's own vehicle coordinate system.

[0008] It can be understood that the horizontal coordinate and the vertical coordinate of the vehicle coordinate system can be defined, for example, as needed.

[0009] It is understood that the method for lateral control of a vehicle according to the present invention can also be implemented in any other suitable coordinate system. It is also understood that during the implementation of the method for lateral control of a vehicle according to the present invention, conversion between different coordinate systems can be performed as needed.

[0010] According to the present invention, a “desired trajectory” may be understood or should be understood as a trajectory that the vehicle should follow or track during the implementation of lateral control.

[0011] In a preferred embodiment of the first aspect of the present invention, the position of a reference vehicle traveling in front of the vehicle relative to the vehicle is respectively determined at the multiple time points. Preferably, the multiple positions determined are represented by their coordinates in the vehicle's own vehicle coordinate system.

[0012] According to the present invention, “a reference vehicle traveling in front of the vehicle” may be understood or should be understood as no other vehicle being between the vehicle and the reference vehicle.

[0013] In a preferred embodiment of the first aspect of the present invention, the position of a reference vehicle traveling in front of the vehicle is ascertained based on sensor data of onboard sensors of the vehicle.

[0014] In a preferred embodiment of the first aspect of the present invention, the vehicle-mounted sensor includes one or more of the following sensor types: radar sensor; laser radar sensor; image sensor. It is understood that the vehicle-mounted sensor may include any other suitable sensor type, and the position of a reference vehicle traveling in front of the vehicle may be obtained based on sensor data of one or more sensors.

[0015] In a preferred embodiment of the first aspect of the present invention, the plurality of time points, for example, relate to or may also be referred to as measurement time points or detection time points.

[0016] In a preferred embodiment of the first aspect of the present invention, the selection or determination of the multiple moments depends on the sampling frequency of the onboard sensors of the vehicle. Alternatively or additionally, the selection or determination of the multiple moments depends on the calculation cycle of the controller or calculation unit for implementing the method for lateral control of the vehicle according to the present invention. Alternatively or additionally, the selection or determination of the multiple moments depends on the current speed of the vehicle and / or the reference vehicle.

[0017] In a preferred embodiment of the first aspect of the present invention, the motion trajectory of the reference vehicle can be obtained from the obtained multiple positions of the reference vehicle by any suitable mathematical method as the desired trajectory of the vehicle. For example, the motion trajectory of the reference vehicle can be obtained by least square fitting of the obtained multiple positions of the reference vehicle as the desired trajectory of the vehicle.

[0018] In a preferred embodiment of the first aspect of the present invention, the position of a reference vehicle traveling ahead of the vehicle is determined at at least three times, and at least three positions of the reference vehicle traveling ahead of the vehicle are obtained therefrom.

[0019] Preferably, the position of a reference vehicle travelling ahead of the vehicle is determined at at least five times in each case, and at least five positions of the reference vehicle travelling ahead of the vehicle are obtained from this.

[0020] In a preferred embodiment of the first aspect of the present invention, the selection or determination of the predefined position may depend on the current speed of the vehicle.

[0021] In a preferred embodiment of the first aspect of the present invention, the predefined position may be selected or determined by the following formula: x=v*t const , y=T(x), where x and y are the ordinate and abscissa of the predefined position in the ego-vehicle coordinate system of the vehicle, respectively, v is the current speed of the vehicle, t const is the predetermined time constant, and T is a functional representation of the desired trajectory in the ego-vehicle coordinate system of the vehicle.

[0022] In a preferred embodiment of the first aspect of the present invention, the predetermined time constant t const It can be equal to 0.7.

[0023] In a preferred embodiment of the first aspect of the present invention, the curvature change rate C of the desired trajectory at the predefined position can be obtained by the following formula:c :

[0024]

[0025] Wherein, x and y are respectively the ordinate and abscissa of the predefined position in the vehicle's own vehicle coordinate system.

[0026] Preferably, C c Not equal to 0.

[0027] In a preferred embodiment of the first aspect of the present invention, the lateral offset of the desired trajectory at the predefined position, i.e., the horizontal coordinate of the predefined position in the vehicle's own vehicle coordinate system, can be additionally taken into account when determining the control signal for the lateral control of the vehicle.

[0028] In addition, according to a second aspect of the present invention, there is provided a device for lateral control of a vehicle, which is particularly configured to implement the method for lateral control of a vehicle according to the first aspect of the present invention. The device for lateral control of a vehicle at least comprises a position determination module, a desired trajectory determination module, a lateral control parameter determination module and a lateral control signal generation module.

[0029] The position determining module may be configured to respectively determine the position of a reference vehicle traveling in front of the vehicle at a plurality of time instants.

[0030] The expected trajectory determination module may be configured to determine the motion trajectory of the reference vehicle as the expected trajectory of the vehicle based on the determined position of the reference vehicle.

[0031] The lateral control parameter obtaining module may be configured to obtain the curvature, curvature change rate and heading angle of the desired trajectory at a predefined position.

[0032] The lateral control signal generation module may be configured to determine a control signal for lateral control of the vehicle based on the obtained curvature, curvature change rate, and heading angle.

[0033] The corresponding technical features and technical effects of the method for lateral control of a vehicle according to the first aspect of the present invention described above are also applicable to the device for lateral control of a vehicle according to the second aspect of the present invention.

[0034] The device for lateral control of a vehicle according to the second aspect of the present invention may be implemented in a software form, a hardware form, or a software / hardware hybrid form, for example.

[0035] In addition, according to a third aspect of the present invention, a controller for a vehicle is provided, wherein the controller can particularly realize lateral control of the vehicle.

[0036] Here, the controller for a vehicle includes:

[0037] processor;

[0038] A memory stores a computer program thereon, which, when executed by a processor, implements the steps of the method for lateral control of a vehicle according to the first aspect of the present invention.

[0039] In addition, according to a fourth aspect of the present invention, a vehicle is provided. The vehicle comprises the device for lateral control of the vehicle according to the second aspect of the present invention or the controller according to the third aspect of the present invention. The vehicle may also comprise an actuator for lateral control of the vehicle.

[0040] In addition, according to a fifth aspect of the present invention, there is provided a computer-readable storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps of the method for lateral control of a vehicle according to the first aspect of the present invention are implemented.

[0041] In addition, according to a sixth aspect of the present invention, a computer program product is provided, which includes a computer program, wherein when the computer program is executed by a processor, the steps of the method for lateral control of a vehicle according to the first aspect of the present invention are implemented.

[0042] The above technical solution according to the present invention has the following advantages:

[0043] 1. The technical solution according to the present invention can improve the semi-automatic driving or fully automatic driving of the vehicle, for example, in terms of the lane keeping assist function, and in particular can still realize the lane keeping function when the desired trajectory cannot be obtained based on the lane line on the road surface in front of the vehicle;

[0044] 2. The technical solution according to the present invention does not require large-scale changes to existing algorithms or deployment of new complex control strategies;

[0045] 3. The technical solution according to the present invention does not require additional hardware overhead;

[0046] 4. The technical solution according to the present invention can be easily combined with other driving assistance functions or driving safety functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The preferred embodiments of the present invention are described in detail below according to the accompanying drawings. It should be understood by those skilled in the art that these preferred embodiments are merely exemplary and are not intended to limit the present invention in any way.

[0048] Figure 1 A schematic flow chart of a method according to the present invention for lateral control of a vehicle is shown.

[0049] Figure 2 A schematic block diagram of a device for lateral control of a vehicle according to the present invention is shown. DETAILED DESCRIPTION

[0050] Figure 1 A schematic flow chart of a method for lateral control of a vehicle according to the present invention is shown. The vehicle is in particular a vehicle with semi-automatic driving capability or fully automatic driving capability. The method for lateral control of a vehicle according to the present invention is implemented in particular in a semi-automatic driving state or in a fully automatic driving state of the vehicle. The method according to the present invention is in particular used for a lane keeping function of the vehicle or is integrated in a lane keeping function of the vehicle. The method according to the present invention can be part of a traffic jam assistance function, for example. The method according to the present invention is based on, for example, an ego-vehicle coordinate system of the vehicle.

[0051] In a first method step 101 , the position of a reference vehicle travelling ahead of the vehicle is determined at a plurality of times.

[0052] Here, for example, the position of a reference vehicle traveling in front of the vehicle relative to the vehicle is determined at a plurality of times. Preferably, the plurality of determined positions are represented by their coordinates in the vehicle's own vehicle coordinate system.

[0053] Preferably, the position of a reference vehicle travelling in front of the vehicle is ascertained using sensor data from onboard sensors of the vehicle.

[0054] Preferably, the vehicle-mounted sensors include one or more of the following sensor types: radar sensor; lidar sensor; image sensor.

[0055] Preferably, the selection or determination of the multiple moments depends on the sampling frequency of the onboard sensor of the vehicle. Alternatively or additionally, the selection or determination of the multiple moments depends on the calculation cycle of the controller or calculation unit for implementing the method for lateral control of the vehicle according to the present invention. Alternatively or additionally, the selection or determination of the multiple moments depends on the current speed of the vehicle and / or the current speed of the reference vehicle.

[0056] In a second method step 102 , a movement trajectory of the reference vehicle is ascertained as a desired trajectory of the vehicle based on the ascertained position of the reference vehicle.

[0057] Preferably, a movement trajectory of the reference vehicle is ascertained from the ascertained plurality of positions of the reference vehicle by means of a suitable mathematical method, and the ascertained movement trajectory is used as the desired trajectory T of the vehicle.

[0058] For example, the movement trajectory of the reference vehicle is determined as the expected trajectory of the vehicle by least square fitting of the determined position(s) of the reference vehicle.

[0059] In a third method step 103 , the curvature, the curvature change rate and the heading angle of the desired trajectory at a predefined position are determined.

[0060] Preferably, the selection or determination of the predefined position may be dependent on the current speed of the vehicle.

[0061] For example, the predefined position is selected or determined by the following formulas (1) and (2):

[0062] x = v*t const (1)

[0063] y = T(x) (2)

[0064] Wherein, x and y are the ordinate and abscissa of the predefined position in the vehicle's own vehicle coordinate system, v is the current speed of the vehicle, and t const is the predetermined time constant, and T is a functional representation of the desired trajectory in the ego-vehicle coordinate system of the vehicle.

[0065] Preferably, the predetermined time constant t const Equal to 0.7.

[0066] For example, the curvature C of the desired trajectory at the predefined position is obtained by the following formula (3):

[0067]

[0068] Wherein, x and y are respectively the ordinate and abscissa of the predefined position in the vehicle's own vehicle coordinate system.

[0069] Preferably, C is not equal to zero.

[0070] For example, the curvature change rate C of the desired trajectory at the predefined position is obtained by the following formula (4): c :

[0071]

[0072] Wherein, x and y are respectively the ordinate and abscissa of the predefined position in the vehicle's own vehicle coordinate system.

[0073] Preferably, C c Not equal to 0.

[0074] For example, the heading angle θ of the desired trajectory at the predefined position is obtained by the following formula (5):

[0075] θ=arctan(y′(x)) (5)

[0076] Wherein, x and y are respectively the ordinate and abscissa of the predefined position in the vehicle's own vehicle coordinate system.

[0077] In a fourth method step 104 , a control signal for lateral control of the vehicle is determined based on the ascertained curvature, the rate of change of the curvature and the heading angle.

[0078] Preferably, a control signal for lateral control of the vehicle, such as a steering wheel torque target value, is determined based on the obtained curvature, curvature change rate and heading angle. The control signal can especially control or trigger a corresponding actuator, such as an actuator of an electric power steering system, to achieve lateral control of the vehicle.

[0079] Optionally, a lateral offset of the desired trajectory at the predefined position, ie the abscissa of the predefined position in the ego-vehicle coordinate system of the vehicle, is additionally taken into account when determining the control signal for the lateral control of the vehicle.

[0080] For example, a control signal for lateral control of the vehicle, such as a steering wheel torque target value, is determined based on the obtained curvature, curvature change rate, heading angle, and (possibly) the lateral offset of the desired trajectory at the predefined position. The control signal can especially control or trigger a corresponding actuator, such as an actuator of an electric power steering system, to achieve lateral control of the vehicle.

[0081] The sequence of the method steps described above according to the present invention is merely exemplary, and the sequence may be adjusted without departing from the overall technical concept of the present invention.

[0082] Figure 2 A schematic block diagram of a device 2 for lateral control of a vehicle according to the present invention is shown. The device 2 for lateral control of a vehicle according to the present invention is particularly configured to implement the above-mentioned Figure 1 A method according to the invention for lateral control of a vehicle is described.

[0083] Here, the device 2 for lateral control of a vehicle according to the present invention comprises at least a position determination module 201 , a desired trajectory determination module 202 , a lateral control parameter determination module 203 and a lateral control signal generation module 204 .

[0084] The position determining module 201 may be configured to respectively determine the position of a reference vehicle traveling in front of the vehicle at a plurality of time instants.

[0085] The expected trajectory determining module 202 may be configured to determine the motion trajectory of the reference vehicle as the expected trajectory of the vehicle based on the determined position of the reference vehicle.

[0086] The lateral control parameter obtaining module 203 may be configured to obtain the curvature, curvature change rate and heading angle of the desired trajectory at a predefined position.

[0087] The lateral control signal generating module 204 may be configured to determine a control signal for lateral control of the vehicle based on the obtained curvature, curvature change rate, and heading angle.

[0088] Preferably, the device 2 for lateral control of a vehicle may further include an input module (not shown). The input module may be configured to receive sensor data of a vehicle-mounted sensor of the vehicle. Here, the vehicle-mounted sensor of the vehicle may include, for example, one or more of the following sensor types: a radar sensor; a lidar sensor; an image sensor.

[0089] Preferably, the expected trajectory obtaining module 202 may be configured to obtain the motion trajectory of the reference vehicle as the expected trajectory of the vehicle by least square fitting of the obtained position(s) of the reference vehicle.

[0090] Preferably, the lateral control parameter obtaining module 203 may be configured to obtain the curvature C of the desired trajectory at the predefined position by using the following formula (6) (same as formula (3)):

[0091]

[0092] Wherein, x and y are respectively the ordinate and abscissa of the predefined position in the vehicle's own vehicle coordinate system.

[0093] Preferably, the lateral control parameter obtaining module 203 may be configured to obtain the curvature change rate C of the desired trajectory at the predefined position by the following formula (7) (same as formula (4)): c :

[0094]

[0095] Wherein, x and y are respectively the ordinate and abscissa of the predefined position in the vehicle's own vehicle coordinate system.

[0096] Preferably, C c Not equal to 0.

[0097] Preferably, the lateral control parameter obtaining module 203 may be configured to obtain the heading angle θ of the desired trajectory at the predefined position by using the following formula (8) (same as formula (5)):

[0098] θ=arctan(y′(x)) (8)

[0099] Wherein, x and y are respectively the ordinate and abscissa of the predefined position in the vehicle's own vehicle coordinate system.

[0100] Preferably, the device 2 for lateral control of a vehicle may further include an output module (not shown). The output module may be configured to output a control signal for lateral control of the vehicle, in particular to an actuator for lateral control of the vehicle.

[0101] The device 2 according to the invention for lateral control of a vehicle can be realized, for example, in software form or in hardware form or in a software / hardware hybrid form.

[0102] It is apparent to those skilled in the art that various variations or modifications may be made to the above preferred embodiments without departing from the spirit of the present invention, and these variations or modifications do not depart from the scope of the present invention.

Claims

1. A method for lateral control of a vehicle, the method comprising the following steps: determining the position of a reference vehicle traveling in front of the vehicle at a plurality of times; Determining a motion trajectory of the reference vehicle as a desired trajectory of the vehicle based on the determined position of the reference vehicle; Obtaining the curvature, curvature change rate and heading angle of the desired trajectory at a predefined position; A control signal for lateral control of the vehicle is determined based on the ascertained curvature, the rate of change of the curvature and the heading angle.

2. The method according to claim 1, characterized in that Determining the position of a reference vehicle traveling in front of the vehicle using sensor data from an onboard sensor of the vehicle, The vehicle-mounted sensors include one or more of the following sensor types: Radar sensor; LiDAR sensor; Image sensor.

3. The method according to claim 1 or 2, characterized in that: The curvature of the desired trajectory at a predefined position is obtained by the following formula: Wherein, x is the ordinate of the predefined position in the vehicle's own-vehicle coordinate system, and y is the abscissa of the predefined position in the vehicle's own-vehicle coordinate system.

4. The method according to any one of claims 1 to 3, characterized in that The curvature change rate of the desired trajectory at a predefined position is calculated using the following formula: Wherein, x is the ordinate of the predefined position in the vehicle's own-vehicle coordinate system, and y is the abscissa of the predefined position in the vehicle's own-vehicle coordinate system.

5. The method according to any one of claims 1 to 4, characterized in that The heading angle of the desired trajectory at a predefined position is obtained by the following formula: θ = arctan(y′(x)). Wherein, x is the ordinate of the predefined position in the vehicle's own-vehicle coordinate system, and y is the abscissa of the predefined position in the vehicle's own-vehicle coordinate system.

6. The method according to any one of claims 1 to 5, characterized in that The movement trajectory of the reference vehicle is ascertained as the expected trajectory of the vehicle by least squares fitting of the ascertained position of the reference vehicle.

7. The method according to any one of claims 1 to 6, characterized in that When determining the control signal for the lateral control of the vehicle, a lateral deviation of the desired trajectory at the predefined position is additionally taken into account.

8. The method according to any one of claims 1 to 7, characterized in that The predefined position depends on the current speed of the vehicle.

9. A device for lateral control of a vehicle, the device comprising at least the following modules: a position obtaining module configured to obtain the position of a reference vehicle traveling in front of the vehicle at a plurality of time instants; an expected trajectory obtaining module, configured to obtain a motion trajectory of the reference vehicle as an expected trajectory of the vehicle based on the obtained position of the reference vehicle; A lateral control parameter obtaining module, configured to obtain the curvature, curvature change rate and heading angle of the desired trajectory at a predefined position; A lateral control signal generating module is configured to determine a control signal for lateral control of the vehicle based on the obtained curvature, curvature change rate and heading angle.

10. A controller for a vehicle, characterized in that: The controller comprises: processor; A memory having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of the method according to any one of claims 1 to 8.

11. A vehicle, characterized in that: The vehicle comprises: The device for lateral control of a vehicle according to claim 9 or the controller according to claim 10; An actuator for lateral control of the vehicle.

12. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for lateral control of a vehicle according to any one of claims 1 to 8 are implemented.

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