Lateral adaptive control method and apparatus used for emergency lane keeping

Abstract

A lateral adaptive control method used for emergency lane keeping, comprising: determining that an emergency lane keeping function has been activated; acquiring the yaw velocity of a vehicle, performing integral operation on same to obtain a yaw angle, and inputting the yaw angle into a yaw angle PID controller to obtain a first steering angle; determining a heading angle of the vehicle, and inputting the heading angle into an adaptive PID controller to obtain a second steering angle; superposing the first steering angle and the second steering angle and performing amplitude limiting to obtain a target steering angle, and outputting the target steering angle to a vehicle steering mechanism to control the vehicle to steer; and when determining that an adjustment condition of an adaptive control parameter is satisfied, a parameter observer acquiring an actual response steering angle, the lateral velocity and the steering wheel torque of the vehicle, and, on the basis of the actual response steering angle, the lateral velocity and the steering wheel torque of the vehicle, adaptively adjusting the control parameter of the adaptive PID controller. Also provided is a lateral adaptive control apparatus used for emergency lane keeping. The method can improve the adaptability of control parameters to actual disturbances and mechanical deviations.

Description

A lateral adaptive control method and device applied to emergency lane keeping

[0001] Cross-reference to Related Applications

[0002] The embodiments of the present application are based on and claim priority to Chinese Patent Application No. CN202410437101.9, filed on April 12, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0003] The present application belongs to the technical field of vehicle control, and particularly relates to a lateral adaptive control method and device applied to emergency lane keeping. BACKGROUND

[0004] The emergency lane keeping (ELK) function detects lane lines, lane edges, oncoming vehicles and rearward vehicles through cameras and radars, and provides steering control of a steering wheel for a driver in advance within an adjustable speed range. One scenario of the emergency lane keeping function is that a vehicle deviates to the left side of a lane, and when there is an oncoming vehicle on the left side and a risk of collision, the vehicle is controlled laterally to keep the vehicle in the lane.

[0005] At present, various control parameters of the emergency lane keeping function are calibrated by manual operation multiple times, and then are uniformly applied to all vehicles. However, in actual use, actual disturbances or actuator deviations can cause scenarios that cannot be covered by pre-manual calibration, so there is a problem of poor adaptability of using fixed control parameters to actual disturbances and mechanical deviations. SUMMARY

[0006] In view of the above defects or improvement needs of the prior art, the present application provides a lateral adaptive control method and device applied to emergency lane keeping, to solve the problem of poor adaptability of using fixed control parameters of the emergency lane keeping function to actual disturbances and mechanical deviations.

[0007] To achieve the above-mentioned purpose, according to the first aspect of the present application, a lateral adaptive control method applied to emergency lane keeping is provided, which comprises:

[0008] determining that the emergency lane keeping function is activated;

[0009] obtaining a yaw angular velocity of the vehicle and integrating the yaw angular velocity to obtain a yaw angle, and inputting the yaw angle to a yaw angle PID controller to obtain a first steering angle;

[0010] determining a heading angle of the vehicle, inputting the heading angle to an adaptive PID controller to obtain a second steering angle; and

[0011] The first steering angle and the second steering angle are superimposed and limited to obtain a target steering angle, and the target steering angle is output to a vehicle steering mechanism to control the vehicle steering;

[0012] The adjustment condition of the adaptive control parameter is determined to be satisfied, the parameter observer acquires the actual response steering angle, the lateral velocity and the steering wheel torque of the vehicle, and the control parameter of the adaptive PID controller is adaptively adjusted according to the actual response steering angle, the lateral velocity and the steering wheel torque of the vehicle.

[0013] According to the second aspect of the present application, a lateral adaptive control device applied to emergency lane keeping is provided for implementing the lateral adaptive control method applied to emergency lane keeping in any of the above aspects, and the device comprises:

[0014] A yaw angle PID controller is configured to obtain a first steering angle according to the yaw angle;

[0015] An adaptive PID controller is configured to obtain a second steering angle according to the heading angle;

[0016] A limiting module is configured to superimpose and limit the first steering angle and the second steering angle to obtain a target steering angle;

[0017] A vehicle steering mechanism is configured to control the vehicle steering according to the target steering angle;

[0018] and a parameter observer is configured to acquire the actual response steering angle, the lateral velocity and the steering wheel torque of the vehicle, and to adaptively adjust the control parameter of the adaptive PID controller according to the actual response steering angle, the lateral velocity and the steering wheel torque of the vehicle.

[0019] According to the third aspect of the present application, a computer device is provided, comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the method in any of the above aspects when executing the computer program.

[0020] According to the fourth aspect of the present application, a computer readable storage medium is provided, which stores a computer program, wherein the computer program is executable on a processor to implement the steps of the method in any of the above aspects.

[0021] In general, the above technical solutions conceived by the present application can achieve the following beneficial effects compared with the prior art:

[0022] The first rotation angle is obtained through a yaw angle PID controller, the second rotation angle is obtained through an adaptive PID controller, then the first rotation angle and the second rotation angle are superimposed and limited to obtain a target rotation angle, and the target rotation angle is output to a vehicle steering mechanism to control vehicle steering, so as to realize the lateral control of emergency lane keeping; in addition, when the adjustment condition of the adaptive control parameter is determined to be met, the actual response rotation angle, the lateral speed and the steering wheel torque of the vehicle are obtained by using a parameter observer, and the control parameters of the adaptive PID controller are adaptively adjusted according to the actual response rotation angle, the lateral speed and the steering wheel torque of the vehicle, so as to solve the problem of poor adaptability caused by the use of fixed control parameters of the emergency lane keeping function to actual disturbance and mechanical deviation, compensate for the scenes that cannot be covered by the pre-artificial calibration due to actual disturbance or actuator deviation, and avoid manual calibration multiple times. BRIEF DESCRIPTION OF DRAWINGS

[0023] Fig. 1 is a flow chart of a lateral adaptive control method for emergency lane keeping provided by an embodiment of the present application;

[0024] Fig. 2 is a schematic diagram of a scene of emergency lane keeping provided by an embodiment of the present application;

[0025] Fig. 3 is a whole control block diagram of emergency lane keeping provided by an embodiment of the present application;

[0026] Fig. 4 is a schematic diagram of an activation timing provided by an embodiment of the present application;

[0027] Fig. 5 is a rotation angle response curve provided by an embodiment of the present application;

[0028] Fig. 6 is a lateral speed and lateral distance change diagram provided by an embodiment of the present application;

[0029] Fig. 7 is a structural schematic diagram of a computer device provided by an embodiment of the present application. Embodiment of the present application

[0030] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application, and are not used to limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0031] In the description of the application, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0032] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the application, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise explicitly specified and limited.

[0033] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0034] In the present application, unless otherwise explicitly specified and limited, the first feature "on" or "under" the second feature can be direct contact between the first and second features, or indirect contact between the first and second features through intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0035] One scenario of the emergency lane keeping (ELK) function is that the ego vehicle deviates to the left side of the lane, and there is a risk of collision with an oncoming vehicle on the left side, so the ego vehicle is controlled in the lateral direction to keep the ego vehicle in the lane. For this purpose, the application provides a lateral control method applied to emergency lane keeping, a determination method of different control methods according to the specific position of the vehicle and the collision time with the oncoming vehicle, and an adaptive lateral control method that automatically observes the characteristics of the controlled object EPS (electric power steering) and the whole vehicle, and automatically adjusts the control parameters, thereby solving the problem of poor adaptability caused by the use of fixed control parameters in traditional lateral control to actual disturbances and mechanical deviations, and reducing the number of manual calibration.

[0036] Embodiment one

[0037] The embodiment provides a lateral adaptive control method applied to emergency lane keeping, as shown in FIG. 1, which comprises the following steps:

[0038] Determine the activation of the emergency lane keeping function. This method is applicable to the state where the emergency lane keeping function is activated.

[0039] Obtain the yaw angular velocity of the vehicle and integrate it to obtain the yaw angle, and input the yaw angle into the yaw angle PID controller to obtain a first steering angle.

[0040] Determine the heading angle of the vehicle, and input the heading angle into the adaptive PID controller to obtain a second steering angle.

[0041] Superimpose the first steering angle and the second steering angle and limit the amplitude to obtain a target steering angle, and output the target steering angle to the vehicle steering mechanism to control the steering of the vehicle.

[0042] Determine that the adjustment condition of the adaptive control parameter is met, and the parameter observer obtains the actual response steering angle, the lateral velocity and the steering wheel torque of the vehicle, and adaptively adjusts the control parameters of the adaptive PID controller according to the actual response steering angle, the lateral velocity and the steering wheel torque of the vehicle.

[0043] FIG. 2 is a schematic diagram of a typical oncoming vehicle collision risk condition, three virtual control auxiliary lines are fixed, L1 is a lane center line fitted according to the real lane line, L2 is the earliest activation line when the ego vehicle deviates from the ego lane, the specific value is artificially set according to the vehicle model, and L3 is a performance index line representing the maximum deviation distance of the typical working condition defined by the host factory, the typical working condition is generally used in the Encap scene, the X-Y coordinate system is the ego vehicle coordinate system, the direction is shown in FIG. 2, and the origin is the center of the rear axle.

[0044] In this embodiment, the activation mode of the emergency lane keeping function includes: the self-vehicle forms a left heading angle with L1, the left edge of the self-vehicle reaches the L2 earliest activation line, and the collision time threshold (TTC) of the self-vehicle and the target vehicle meets the trigger threshold. If all the three conditions are met, the emergency lane keeping function is activated.

[0045] Fig. 3 is a control block diagram of the emergency lane keeping of the present application, which is a combination of a PID controller with Yaw (yaw angle) as input after integration of Yawrate (yaw rate) and an adaptive PID controller with HeadAngle (heading angle) as input. The control outputs of the two controllers are superimposed, and then output SW-target (target steering angle) to the actuator EPS (steering motor) through a limiting module. The EPS controls the steering of the vehicle.

[0046] At the same time, the adaptive PID controller also accepts the input of the parameter observer to automatically adjust the parameters of the controller. The input of the parameter observer is the signal of the EPS and the sensors of the whole vehicle (described below), and the output is given to the adaptive PID and the limiting module.

[0047] HeadAngle (heading angle) controller: the heading angle of the self-vehicle with respect to L1 in the X-Y coordinate system is controlled. Since the heading angle is usually small, the calculation method of the heading angle is simplified as the lateral distance from the preview point to L1 divided by the preview distance. The preview distance is obtained by multiplying the current vehicle speed by the preview time.

[0048] Yaw (yaw angle) controller: when the vehicle deviates from the lane line, there may be a yaw rotation motion in addition to the normal lateral motion. Therefore, a yaw angle controller is designed to solve the lateral deviation caused by yaw.

[0049] The Yaw (yaw angle) controller is a PID controller, and the input is the current yaw angle of the self-vehicle. The yaw angle is calculated by integrating the Yawrate (yaw rate) sent by the sensor of the vehicle chassis. The discretization is shown in equation (1), and the control calculation is shown in equation (2). The output is the initial target steering angle 。

[0050] (1)

[0051] (2)

[0052] In the formula, is the yaw angle, is the yaw rate at time k, is the time interval, is the initial target steering angle at time k, , and Kp, Ki and Kd are the proportional coefficient, integral coefficient and differential coefficient respectively.

[0053] The amplitude limiting module: the controller may cause the output yaw angle to be too large due to abnormal sensor bias input, and the lateral motion needs to be comfortable, so the initial target yaw angle is limited by the amplitude limiting module. The upper and lower limits of the amplitude limiting are usually fixed values, and the upper and lower limit values of the amplitude limiting cannot excessively limit the control ability.

[0054] The parameter observer: the actual response yaw angle SW, steering wheel torque SWTrq, vehicle sensor output vehicle speed V (i.e. vehicle lateral speed), lane line coefficient C0 (i.e. the distance of the vehicle from the left lane line) output by the camera, and other vehicle response parameter are observed, and output to the adaptive controller of the heading angle control, to adaptively adjust the control parameters, and save the process of manually calibrating new control parameters.

[0055] The control parameters of the yaw angle PID controller and the adaptive PID controller are calibrated by the basic calibration method. The basic control parameters Kp, Ki and Kd of the adaptive PID controller are calibrated, and the calculation formula is shown in formula (3).

[0056] The calibration method is based on the typical test scene of FIG. 2. The steering wheel requires zero position return state, i.e. SW=0 degrees, and the fixed angle with the left lane line, i.e. HeadAngle is a constant value set as , at this time the lateral speed Vy of the ego vehicle to the left lane line is a constant value, and the TTC of the ego vehicle to the target vehicle at the earliest activation line L2 reaches the activation threshold set as , the calculation formula is shown in formula (4), at this time the ego vehicle is pulled back to the lane, and the ego vehicle does not exceed the performance index line L3 during the pulling back process.

[0057] (3)

[0058] (4)

[0059] In the formula, is the distance to the target vehicle; is the relative speed of the ego vehicle to the target vehicle; is the heading angle at the sampling time.

[0060] In the embodiment, the control parameters of the yaw angle PID controller and the adaptive PID controller are calibrated together. In addition, the heading angle PID controller can be calibrated first, and then the yaw angle PID controller can be calibrated.

[0061] The adaptive control parameter adjustment method is shown in formula (5):

[0062] (5)

[0063] where Kp is the parameter determined under the condition of basic calibration, K is the parameter adjusted adaptively according to the result of the observer, the adjusted K replaces Kp in equation (3), is the adjusted weight parameter, is the adjusted compensation parameter, and are determined by the parameter observer. The initial value =1, =0, that is, k is Kp.

[0064] and Before the determination method, first determine whether to enable the adjustment of the adaptive control parameter by the activation timing of the emergency lane keeping. The determination method is to determine according to the distance d3 from the performance index line L3, the TTC of the oncoming target vehicle, and the distance d2 from the earliest activation line L2. d2 and d3 are calculated by C0, as shown in equations (6) and (7), is the vehicle width, L2 and L3 are set values, both are positive values, and are the distances of the earliest activation line L2 and the performance index line L3 from the left lane line, respectively.

[0065] (6)

[0066] (7)

[0067] According to the determination result, the control purpose is divided into two kinds, (a) the left edge of the ego vehicle does not exceed the performance index line L3, and (b) the left edge of the ego vehicle can exceed the performance index line L3, and the rear axle center point of the ego vehicle does not exceed L3. One of them can be selected as needed.

[0068] As shown in FIG. 4, it is assumed that the left edge of the ego vehicle is on the left side of L2, then d2 0, the ego vehicle is left biased >0; the ego vehicle is on the right side of L3 d3>0, and the specific determination process is as follows:

[0069] 1) If TTC is greater than the set threshold , there is no risk of collision, and the emergency lane keeping function does not intervene.

[0070] 2) If TTC is less than the set threshold , d2 , is the set threshold for determining the activation position of the ego vehicle, then the adaptive adjustment method of equation (5) is not enabled.

[0071] 3) If TTC is less than the set threshold , d2> , d3 , 3 is the set threshold for judging the activation position of the ego vehicle, and the adaptive adjustment method of formula (5) is enabled.

[0072] 4) If TTC is less than the set threshold ,d2> , d3 , then the adaptive adjustment method of formula (5) is not enabled.

[0073] In this embodiment, the working method of the parameter observer is:

[0074] When the emergency lane keeping function is activated in accordance with the above 3), that is, the adjustment conditions of the adaptive control parameters are met, the two methods of observing the change of the steering angle SW and the lateral speed Vy are used to adjust the and , initial value =1, =0.

[0075] First, calculate the time t for the steering angle response, detect the steering wheel angle value SW, and the steering wheel torque value SWTrq, as shown in Figure 5. The steering angle response curve consists of three curves from top to bottom: the top one is the requested steering angle curve, the middle one is the normal steering angle response curve, which is also the basic calibration response curve in the standard scenario, and the bottom one is the actual response curve value. Weight adjustment parameters , compensation parameters It is determined by the corner response time t and response value SW in Figure 5.

[0076] ①When the difference between the actual response time and the basic response time (t2-t1) is greater than the set threshold When t increases and value, thereby increasing , speeding up the system's response.

[0077] ② When the maximum value of the actual response angle SWreal is smaller than the requested value, and the difference SWtarget-SWreal is greater than the threshold When SW, increase Value and value, thereby increasing , increasing the response strength of EPS.

[0078] ③ In the case of ① and ②, the steering wheel torque SWTrq is opposite to the direction of the current steering angle SW and is greater than the set torque threshold SWTrq, the set torque threshold is used to judge that the current steering wheel resistance is too large, then increase value and value.

[0079] Since case ③ contains case ① and case ②, case ③ has higher priority. In order to reflect this containing situation, when case ① and ② are satisfied, the counter is added a first number of times, for example, 1; when case ③ is satisfied, the counter is added a second number of times, for example, 2.

[0080] When timing is performed in the presence of the above three cases ①, ② and ③, if the number of times the counter is increased is more than a set number of threshold values, for example, more than 5 times within a set time, the new K value is taken as the final value of the p value.

[0081] At the same time, the clipping value of the clipping module is adjusted, and the clipping limit value is increased. The limit value before clipping adjustment is SW_Limit_Init, and the limit value after clipping is SW_Limit_Final. The calculation method is shown in formula (8).

[0082] SW_Limit_Final=SW_Limit_Init+ SW_Limit (8)

[0083] In the formula, SW_Limit is the adjustment amount.

[0084] According to the size of the actual response time t2, the clipping value can be adjusted first, and then the control gain can be adjusted, or they can be adjusted at the same time.

[0085] Further, as shown in FIG. 6, Vy is the lateral velocity change graph of the ego vehicle when the maximum offset distance is just d3=0 at Vy=0 in the scene of basic calibration, Vy_Real is the actual lateral velocity change graph, d3_Real is the actual distance change graph, Vy can be obtained by Vy=V , V is the current vehicle speed.

[0086] By observing the actual Vy_Real change, comparing the size of Vy_Real and Vy at the same d3, and calculating the differential value of Vy_Real, that is, the change rate , it can be predicted whether the vehicle will exceed the performance line L3, that is, d3<0.

[0087] (9)

[0088] If the prediction result is exceeded, that is, when the same d3, Vy_Real>Vy, is less than the set threshold Vy, the vehicle will exceed the performance line L3, at this time, the , so that the control of the EPS is increased, Vy decays faster, and the offset of the vehicle is reduced.

[0089] In some embodiments, , the value of is set to increase by 0.1, such as 1.1, 1.2, and so on; similarly, the increasing method of is set to increase by 1, such as 1, 2, and so on; the amplitude limit is set to increase by 2, such as 2, 4, and so on.

[0090] When , and SW_Limit increases, the difference between the steering angle response time t and the steering angle response value SW and the base case will be less than the threshold value, and the decay of Vy will also be accelerated, ensuring that the ego vehicle will not exceed the performance line L3, i.e. , the current adjustment method is stopped, and the value of at the current time is used as the control parameter for lateral control.

[0091] Embodiment Two

[0092] The embodiment provides a lateral adaptive control device for emergency lane keeping, which is used for implementing the lateral adaptive control method for emergency lane keeping in the embodiment one, and the device comprises:

[0093] A yaw angle PID controller is configured to obtain a first steering angle according to a yaw angle; the specific method for obtaining the first steering angle is the same as that in the embodiment one, and thus is not repeated here.

[0094] An adaptive PID controller is configured to obtain a second steering angle according to a heading angle; the specific method for obtaining the second steering angle is the same as that in the embodiment one, and thus is not repeated here.

[0095] An amplitude limiting module is configured to superimpose the first steering angle and the second steering angle and limit the amplitude to obtain a target steering angle; the specific method for obtaining the target steering angle is the same as that in the embodiment one, and thus is not repeated here.

[0096] A vehicle steering mechanism is configured to control vehicle steering according to the target steering angle; the specific control method is the same as that in the embodiment one, and thus is not repeated here.

[0097] and a parameter observer, used to obtain the actual response turning angle, lateral velocity and steering wheel torque of the vehicle, and to adaptively adjust the control parameters of the adaptive PID controller according to the actual response turning angle, lateral velocity and steering wheel torque of the vehicle. The adaptive adjustment mode is the same as that of Embodiment One, and is not repeated here.

[0098] Embodiment Three

[0099] As shown in FIG. 7 is a structural schematic diagram of a computer device provided by the embodiment of the present application, such as a smartphone, a tablet computer, a notebook computer, a desktop computer, a rack server, a blade server, a tower server or a cabinet server (including a single server or a server cluster composed of multiple servers) that can execute programs. The computer device 20 of the embodiment at least includes but is not limited to a memory 21 and a processor 22 that can be connected to each other in communication through a system bus, as shown in FIG. 7. It should be noted that FIG. 7 only shows the computer device 20 with components 21-22, but it should be understood that it is not required to implement all the shown components, and more or fewer components can be alternatively implemented.

[0100] In the embodiment, the memory 21 (i.e., a readable storage medium) includes a flash memory, a hard disk, a multimedia card, a card-type memory (for example, an SD or DX memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM) The memory 21 can also be an external storage device of the computer device 20, such as a plug-in hard disk, a smart media card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card, etc. equipped on the computer device 20. Of course, the memory 21 can also include both the internal storage unit and the external storage device of the computer device 20. In the embodiment, the memory 21 is usually used to store the operating system and various application software installed on the computer device 20, such as the program code of the lateral adaptive control method for emergency lane keeping in the method embodiment. In addition, the memory 21 can also be used to temporarily store various data that have been output or will be output.

[0101] The processor 22 can be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chip in some embodiments. The processor 22 is generally used to control the overall operation of the computer device 20. In the present embodiment, the processor 22 is used to run program codes or process data stored in the memory 21, such as the lateral adaptive control device for emergency lane keeping described in Embodiment Two, to implement the lateral adaptive control method for emergency lane keeping described in Embodiment One.

[0102] Embodiment Four

[0103] The present application also provides a computer readable storage medium, such as a flash memory, a hard disk, a multimedia card, a card memory (e.g., an SD or DX memory, etc.), a random access memory (RAM), a static random access memory (SRAM), a read-only memory (ROM), an electrically erasable programmable read-only memory (EEPROM), a programmable read-only memory (PROM), a magnetic memory, a magnetic disk, an optical disk, a server, an App application store, etc., on which a computer program is stored, and the program is executed by a processor to implement a corresponding function. The computer readable storage medium of the present embodiment implements the lateral adaptive control device for emergency lane keeping described in Embodiment Two, and when executed by a processor, implements the lateral adaptive control method for emergency lane keeping described in Embodiment One.

[0104] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0105] The present application is described with reference to flowcharts and / or block diagrams according to the methods, devices (systems), and computer program products of the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices produce the functions specified in one or more flows in the flowcharts and / or one or more blocks in the block diagrams.

[0106] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart block or blocks and / or block or blocks of the block diagram.

[0107] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart block or blocks and / or block or blocks of the block diagram.

[0108] In summary, the present application uses different emergency lane keeping control methods through the information of the self-vehicle position and the collision time with the oncoming vehicle; through adaptive control, the sensor information of the self-vehicle is used to automatically adjust the control parameters, to compensate for the scenes that cannot be covered by the pre-manual calibration due to actual disturbances or actuator deviations, without manual multiple calibration, the problem of poor adaptability caused by the use of solidified control parameters of the emergency lane keeping function to actual disturbances and mechanical deviations is solved.

[0109] It should be noted that the size of the serial number of each step in the above embodiment does not mean the order of execution, the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiment of the present application.

[0110] It should be pointed out that according to the needs of implementation, each step / component described in the present application can be split into more steps / components, or two or more steps / components or part of the operation of the steps / components can be combined into a new step / component to achieve the purpose of the present application.

[0111] Those skilled in the art will readily understand that the above is only a preferred embodiment of the present application, and is not intended to limit the present application, any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A lateral adaptive control method for emergency lane keeping, characterized in that: The method includes: Confirm that the emergency lane keeping function is activated; Obtaining the vehicle's yaw angular velocity and integrating it to obtain a yaw angle, and inputting the yaw angle into a yaw angle PID controller to obtain a first turning angle; Determine the heading angle of the vehicle and input the heading angle into the adaptive PID controller to obtain the second turning angle; The first turning angle and the second turning angle are superimposed and limited to obtain a target turning angle, and the target turning angle is output to a vehicle steering mechanism to control the vehicle steering; After determining that the adjustment conditions of the adaptive control parameters are met, the parameter observer obtains the actual response angle, lateral speed and steering wheel torque of the vehicle, and adaptively adjusts the control parameters of the adaptive PID controller according to the actual response angle, lateral speed and steering wheel torque of the vehicle.

2. The lateral adaptive control method for emergency lane keeping according to claim 1, characterized in that: The activation conditions for the emergency lane keeping function include: The vehicle and the lane form a leftward heading angle; The left edge of the vehicle reaches the earliest activation line when the vehicle deviates from its lane; The collision time between the vehicle and the oncoming vehicle reaches the preset collision time threshold; When all three of the above conditions are met, the emergency lane keeping function is activated.

3. The lateral adaptive control method for emergency lane keeping according to claim 1 or 2, characterized in that: Determine the vehicle's heading angle, including: Determine the preview distance based on the current vehicle speed and the preset preview time; Determine the preview point based on the preview distance and the current vehicle orientation; Based on the preview point, determine the lateral distance between the preview point and the center line of the lane where the vehicle is located; The lateral distance divided by the preview distance is the heading angle of the vehicle.

4. The lateral adaptive control method for emergency lane keeping according to claim 1, characterized in that: The calibration method of the control parameters of the yaw angle PID controller and the adaptive PID controller is as follows: Based on a typical test scenario, the steering wheel is in the zero-position return state, the vehicle forms a fixed angle with the left lane line, the lateral speed of the vehicle relative to the left lane line is constant, and the collision time of the vehicle with the oncoming vehicle at the location of the earliest activated line reaches the preset collision time threshold; At this time, the vehicle is pulled back to its own lane, and during the pulling back process, the vehicle does not exceed the performance indicator line; the performance indicator line is the maximum deviation distance under typical working conditions.

5. The lateral adaptive control method for emergency lane keeping according to claim 1, characterized in that: Determine whether the adjustment conditions of the adaptive control parameters are met, including: Determine the collision time between the vehicle and the oncoming vehicle; Determine the second distance between the ego vehicle and the earliest activated line; Determine the third distance between the ego vehicle and the performance index line; Determine that the vehicle has formed a leftward heading angle with the lane; When the collision time between the vehicle and the oncoming vehicle does not reach the preset collision time threshold, there is no collision risk, the emergency lane keeping function is not activated, and the adjustment condition is not met; When the collision time between the vehicle and the oncoming vehicle reaches the preset collision time threshold, and the second distance is less than the second preset activation distance threshold, the emergency lane keeping function is activated, but the adjustment condition is not met; When the collision time between the vehicle and the oncoming vehicle reaches the preset collision time threshold, the second distance is greater than the second preset activation distance threshold, and the third distance is greater than the third preset activation distance threshold, the emergency lane keeping function is activated and the adjustment condition is met; When the collision time between the vehicle and the oncoming vehicle reaches the preset collision time threshold, the second distance is greater than the second preset activation distance threshold, and the third distance is less than the third preset activation distance threshold, the emergency lane keeping function is activated, but the adjustment condition is not met.

6. The lateral adaptive control method for emergency lane keeping according to claim 5, characterized in that: The collision time between the ego vehicle and the oncoming vehicle is determined based on the relative distance and relative speed between the ego vehicle and the oncoming vehicle; the second distance between the ego vehicle and the earliest activation line is determined based on the distance between the ego vehicle and the left lane line, the width of the ego vehicle, and the distance between the earliest activation line and the left lane line; the third distance between the ego vehicle and the performance index line is determined based on the distance between the ego vehicle and the left lane line, the width of the ego vehicle, and the distance between the performance index line and the left lane line.

7. The lateral adaptive control method for emergency lane keeping according to claim 1, characterized in that: The control parameters of the adaptive PID controller are adaptively adjusted according to the actual vehicle response angle, lateral speed, and steering wheel torque, including: Multiplying a proportional parameter of the adaptive PID controller by a weight parameter and then adding the new proportional parameter to a compensation parameter; wherein the weight parameter and the compensation parameter can be adaptively adjusted; The adaptive adjustment method of the weight parameter and the compensation parameter is as follows: Obtaining a requested turning angle curve, a normal response turning angle curve, and an actual response turning angle curve, and determining a maximum requested turning angle; Determine the normal response time, the actual response time and the maximum value of the actual response angle according to the request angle curve, the normal response angle curve and the actual response angle curve; ① When the difference between the actual response time and the normal response time is greater than the preset time threshold, the counter increases the first number; ② When the maximum actual response angle is less than the maximum requested angle, and the difference between the two is greater than the preset angle threshold, the counter increases the first number; ③ In the case of ① and ②, when the current steering wheel torque is opposite to the current steering angle and the current steering wheel torque is greater than the preset torque threshold, the counter is incremented by a second number; the second number is greater than the first number; When the above three situations occur, timing is performed. If the number of times the counter increases within the set time exceeds the preset number threshold, the weight parameter and the compensation parameter are increased, thereby increasing the proportion parameter.

8. The lateral adaptive control method for emergency lane keeping according to claim 7, characterized in that: The method further includes: If the number of times the counter is incremented exceeds a preset number threshold, the limit value of the limit is increased.

9. The lateral adaptive control method for emergency lane keeping according to claim 8, characterized in that: The method further includes: Obtain the lateral speed change graph and lateral distance change graph during calibration; Determine the actual lateral velocity change graph and lateral distance change graph; At the same lateral distance, if the actual lateral speed is greater than the lateral speed during calibration, and the actual lateral speed change rate is less than the preset change rate threshold, the weight parameter is directly increased; After the weight parameter increases, if the difference between the actual response time and the normal response time is less than a preset time threshold, the difference between the actual maximum response angle and the requested maximum angle is less than a preset angle threshold, and the actual lateral speed change rate increases, so that the vehicle does not exceed the performance indicator line, all adjustments are stopped.

10. A lateral adaptive control device for emergency lane keeping, for implementing the lateral adaptive control method for emergency lane keeping according to any one of claims 1 to 9, characterized in that: The device includes: A yaw angle PID controller, used for obtaining a first turning angle according to the yaw angle; An adaptive PID controller is used to obtain a second turning angle according to the heading angle; A clipping module, configured to superimpose the first angle and the second angle and clip them to obtain a target angle; A vehicle steering mechanism, used to control the vehicle steering according to a target turning angle; and a parameter observer for obtaining the actual response angle, lateral speed, and steering wheel torque of the vehicle, and adaptively adjusting the control parameters of the adaptive PID controller according to the actual response angle, lateral speed, and steering wheel torque of the vehicle.

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