CN115817639A - Vehicle steering control method, device, equipment and storage medium - Google Patents
Vehicle steering control method, device, equipment and storage medium Download PDFInfo
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Abstract
The invention provides a vehicle steering control method, a device, equipment and a storage medium, wherein the method comprises the following steps: collecting current running data of a vehicle, calculating a feedback error according to the current running data, wherein the feedback error comprises a transverse error and a course angle error, and performing feedback control processing on the feedback error to obtain a first steering control parameter: the method comprises the steps of obtaining expected driving data of a vehicle, conducting feedforward control processing on the expected driving data to obtain a second steering control parameter, fusing the first steering control parameter and the second steering control parameter to obtain a target steering control parameter, and sending a steering control command based on the target steering control parameter. The embodiment can improve the vehicle steering control precision and greatly reduce the consumption of computing resources.
Description
Technical Field
The invention relates to the technical field of automatic driving, in particular to a vehicle steering control method, device, equipment and storage medium.
Background
In the technical field of automatic driving, automatic vehicle control is to apply some automatic control technologies to a traffic system, and the traditional improvement of mechanical performance is developed into assistance or partial or complete replacement of human operation, so that accidents caused by human limitation are reduced, the driving intensity is reduced, and the traffic efficiency is improved.
Among them, the vehicle lateral control is one of the vehicle controls, and the lateral control refers to a control in a direction perpendicular to the moving direction, and for the automobile, that is, the steering control, the object is to control the automobile to automatically maintain a desired running course. In the field of automatic driving tracking control, the requirement on the control precision of vehicle steering is high.
It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the invention and therefore may include information that does not constitute prior art that is already known to a person of ordinary skill in the art.
Disclosure of Invention
In view of the problems in the prior art, the present invention aims to provide a method, an apparatus, a device and a storage medium for controlling vehicle steering, which overcome the difficulties in the prior art and can improve the accuracy of vehicle steering control.
The disclosed embodiment provides a vehicle steering control method, which includes:
acquiring current running data of a vehicle, and calculating a feedback error according to the current running data, wherein the feedback error comprises a transverse error and a course angle error;
performing feedback control processing on the feedback error to obtain a first steering control parameter;
obtaining expected driving data of the vehicle, and carrying out feedforward control processing on the expected driving data to obtain a second steering control parameter;
fusing the first steering control parameter and the second steering control parameter to obtain a target steering control parameter;
and issuing a steering control instruction based on the target steering control parameter.
Optionally, calculating a feedback error from the current driving data comprises:
and extracting the current pose and the planned path of the vehicle from the current running data, and calculating the transverse error and the heading angle error by using the current pose and the planned path of the vehicle.
Optionally, performing feedback control processing on the feedback error to obtain a first steering control parameter, including:
in the case where the vehicle is a two-axle steering vehicle, the following feedback control model is obtained:
δ feedback_front ＝(k 1 ×e lateral +k 2 ×e yaw )/v
δ feedback_rear ＝(k 1 ×e lateral -k 2 ×e yaw )/v
wherein k is 1 As a transverse feedback coefficient, k 2 Is a course angle feedback coefficient, delta feedback_front Is the front wheel slip angle, delta feedback_rear Is rear wheel slip angle, e lateral As a lateral error, e yaw Is the yaw error;
transverse error e lateral And heading angle error e yaw And inputting a feedback control model to obtain a first steering control parameter comprising a front wheel deflection angle and a rear wheel deflection angle.
Optionally, the first steering control parameter further comprises a steering mode;
wherein, under the feedforward that the lateral error is not less than the first error threshold, the steering mode is crab steering;
and under the feedforward that the heading angle error is not less than the second error threshold value, the steering mode is splay steering.
Optionally, the acquiring of the expected running data of the vehicle comprises:
acquiring a vehicle planned path and a vehicle head expected orientation angle;
obtaining a tracking point according to a planned path of the vehicle, obtaining a tangential angle and a curvature of the tracking point, and making a difference between the tangential angle and an expected heading angle of the vehicle head to obtain a crab running angle of the vehicle;
and obtaining expected driving data of the vehicle according to the crab running angle and the curvature of the vehicle.
Optionally, obtaining the tracking point according to the planned path of the vehicle includes:
and acquiring a pre-aiming distance on a planned path of the vehicle, and taking a pre-aiming point of the pre-aiming distance as a tracking point.
Optionally, performing feed-forward control processing on the expected driving data to obtain a second steering control parameter, including:
in the case of a vehicle with two-axis steering, the following feed-forward control model is obtained:
δ feedforward_front ＝kappa×l f +θ crabbing
δ feedforward_rear ＝-kappa×l r +θ crabbing
where kappa is the path curvature, θ crabbing Is crab angle, delta feedforward_front Is the front wheel slip angle, delta feedforward_rear Is a rear wheel slip angle;
and inputting expected driving data into the feedforward control model to obtain a second steering control parameter.
Optionally, before the first steering control parameter and the second steering control parameter are fused to obtain the target steering control parameter, the vehicle steering control method further includes:
under the condition that the increasing rate of the feedback error in a set time period exceeds a threshold value, carrying out error compensation on the feedback error, and obtaining a compensation steering control parameter according to the error compensation;
fusing the first steering control parameter and the second steering control parameter to obtain a target steering control parameter, including;
and fusing the first steering control parameter, the second steering control parameter and the compensation steering control parameter to obtain a target steering control parameter.
The disclosed embodiment also provides a vehicle steering control device, which includes:
the acquisition module is used for acquiring the current running data of the vehicle and calculating a feedback error according to the current running data, wherein the feedback error comprises a transverse error and a course angle error;
the feedback control module is used for carrying out feedback control processing on the feedback error to obtain a first steering control parameter;
the feedforward control module is used for acquiring expected driving data of the vehicle and carrying out feedforward control processing on the expected driving data to obtain a second steering control parameter;
the fusion module is used for fusing the first steering control parameter and the second steering control parameter to obtain a target steering control parameter;
and the instruction sending module is used for sending a steering control instruction based on the target steering control parameter.
An embodiment of the present invention also provides a vehicle steering control apparatus including:
a processor;
a memory having stored therein executable instructions of the processor;
wherein the processor is configured to perform the steps of the vehicle steering control method described above via execution of executable instructions.
Embodiments of the present invention also provide a computer-readable storage medium storing a program that, when executed, implements the steps of the above-described vehicle steering control method.
According to the vehicle steering control method, the vehicle steering control device, the vehicle steering control equipment and the vehicle steering control storage medium, feedforward control and feedback control are decoupled, so that the feedforward control and the feedback control are independent and independent of each other. The method is convenient for respectively debugging and analyzing the feedforward control and the feedback control, for example, the effect of the feedback control is only influenced by adjusting the parameters of the feedback control, and the effect of the rest part is unchanged, so that the result is analyzed more efficiently and accurately, the steering control precision of the vehicle is further improved, and the consumption of computing resources is also greatly reduced. In addition, one of the feedforward control and the feedback control is wrong without influencing the other parts, thereby reducing the error propagation range and enhancing the reusability of the code of each part
Drawings
Other features, objects and advantages of the present invention will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, with reference to the accompanying drawings.
Fig. 1 is one of flowcharts of a vehicle steering control method of an embodiment of the present disclosure.
Fig. 2 is a second flowchart of a vehicle steering control method according to an embodiment of the disclosure.
Fig. 3 is a schematic diagram of a specific process of a vehicle steering control method of the embodiment of the present disclosure.
Fig. 4 is a schematic structural diagram of a vehicle steering control apparatus of an embodiment of the present disclosure.
Fig. 5 is a schematic structural diagram of a vehicle steering control apparatus according to another embodiment of the present disclosure.
Fig. 6 is a schematic configuration diagram of a vehicle steering control apparatus of the invention. And
fig. 7 is a schematic structural diagram of a computer-readable storage medium according to an embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present application is provided by way of specific examples, and other advantages and effects of the present application will be readily apparent to those skilled in the art from the disclosure herein. The present application is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present application. It should be noted that, in the present application, the embodiments and features of the embodiments may be combined with each other without conflict.
Embodiments of the present application will be described in detail below with reference to the accompanying drawings so that those skilled in the art to which the present application pertains can easily carry out the present application. The present application may be embodied in many different forms and is not limited to the embodiments described herein.
Reference throughout this specification to "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," or the like, means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present application. Furthermore, the particular features, structures, materials, or characteristics shown may be combined in any suitable manner in any one or more embodiments or examples. Moreover, various embodiments or examples and features of different embodiments or examples presented in this application can be combined and combined by those skilled in the art without contradiction.
Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or to implicitly indicate the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the expressions of the present application, "plurality" means two or more unless specifically defined otherwise.
In order to clearly explain the present application, components that are not related to the description are omitted, and the same reference numerals are given to the same or similar components throughout the specification.
Throughout the specification, when a device is referred to as being "connected" to another device, this includes not only the case of being "directly connected" but also the case of being "indirectly connected" with other components interposed therebetween. In addition, when a device "includes" a certain component, unless otherwise stated, the device does not exclude other components, but may include other components.
When a device is said to be "on" another device, this may be directly on the other device, but may also be accompanied by other devices in between. When a device is said to be "directly on" another device, there are no other devices in between.
Although the terms first, second, etc. may be used herein to denote various components in some instances, these components should not be limited by these terms. These terms are only used to distinguish one element from another. For example, the first interface and the second interface are represented. Furthermore, as used in this application, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes" and/or "including," when used in this specification, specify the presence of stated features, steps, operations, components, items, species, and/or groups, but do not preclude the presence, or addition of one or more other features, steps, operations, components, items, species, and/or groups thereof. The terms "or" and/or "as used herein are to be construed as inclusive or meaning any one or any combination. Thus, "a, B or C" or "a, B and/or C" means "any of the following: a; b; c; a and B; a and C; b and C; A. b and C ". An exception to this definition will occur only when a combination of components, functions, steps or operations are inherently mutually exclusive in some way.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the singular forms "a", "an" and "the" include plural forms as long as the words do not expressly indicate a contrary meaning. The term "comprises/comprising" when used in this specification is taken to specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but does not exclude the presence or addition of other features, regions, integers, steps, operations, elements, and/or components.
Although not defined differently, including technical and scientific terms used herein, all terms have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terms defined in commonly used dictionaries are to be interpreted as having meanings consistent with those of the related art documents and the present prompts, and must not be excessively interpreted as having ideal or very formulaic meanings unless defined otherwise.
The related technology of vehicle steering control is searched to find that the mainstream automatic driving tracking steering control algorithm in the market at present comprises feedback control and feedforward control, wherein part of algorithms take feedback errors as input in the feedforward control algorithm. Due to the fact that the feedforward control and the feedback control are coupled, accurate source tracing attribution and debugging are difficult to conduct according to results, and further accuracy of vehicle steering control is difficult to improve.
Fig. 1 is a flowchart of a vehicle steering control method of an embodiment of the present disclosure. The execution subject of the method can be a vehicle-mounted terminal or a cloud server. As shown in fig. 1, an embodiment of the present disclosure provides a vehicle steering control method, including the steps of:
step 110: acquiring current running data of a vehicle, and calculating a feedback error according to the current running data, wherein the feedback error comprises a transverse error and a course angle error;
step 120: performing feedback control processing on the feedback error to obtain a first steering control parameter;
step 130: acquiring expected driving data of a vehicle, and performing feedforward control processing on the expected driving data to obtain a second steering control parameter;
step 140: fusing the first steering control parameter and the second steering control parameter to obtain a target steering control parameter;
step 150: and issuing a steering control instruction based on the target steering control parameter.
In the embodiment, the input of the feedforward control is the expected running data of the vehicle, and the feedback error is obtained according to the current running data of the vehicle, so the expected running data of the vehicle is different from the feedback error, and the feedback error is excluded from the input of the feedforward control, so that the feedforward control and the feedback control are decoupled, and the feedforward control and the feedback control are independent and independent.
The method is convenient for respectively debugging and analyzing the feedforward control and the feedback control, for example, the effect of the feedback control is only influenced by adjusting the parameters of the feedback control, and the effect of the rest part is unchanged, so that the result is analyzed more efficiently and accurately, and the steering control precision of the vehicle is further improved.
Therefore, the technical scheme of the embodiment can efficiently debug the feedforward control and the feedback control, and further remarkably improve the steering control precision of the vehicle. In addition, the error of one of the feedforward control and the feedback control does not affect the rest parts, so that the risk (error) propagation range is reduced, and the reusability of the code of each part is enhanced.
In addition, compared with steering control algorithms based on models such as LQR and MPC, the embodiment of the disclosure decouples feedforward control and feedback control, so that the calculation process of feedback control is direct and simple, and does not involve a large number of iteration steps existing in LQR and MPC, thereby greatly reducing the consumption of calculation resources. Therefore, the calculation efficiency of the scheme of the embodiment is much higher than that of the mainstream algorithm, and the method is more suitable for the characteristics and requirements of high real-time performance of automatic driving.
In the embodiment of the present disclosure, the sequence indicated in fig. 1 does not exist between the above steps 120 and 130, and may be a parallel process.
In the disclosed embodiment, the lateral error characterizes the degree to which the vehicle deviates from the planned trajectory, and the heading angle error characterizes the degree to which the vehicle's direction of travel deviates from the desired direction of travel. The method comprises the following steps of calculating a feedback error according to current running data of a vehicle, and specifically comprises the following steps:
and extracting the current pose and the planned path of the vehicle from the vehicle running data, and calculating the transverse error and the heading angle error by using the current pose and the planned path of the vehicle.
The current driving data of the vehicle may include a current pose of the vehicle and a planned path, where the vehicle pose may refer to a position and a posture of the vehicle during driving, and the planned path is a current set pre-driving track. The specific driving data can be obtained through a sensor or a module deployed on a vehicle-mounted end or a cloud end.
Specifically, the information issued by the vehicle positioning module and the planning module is subscribed to receive information such as vehicle pose and planning path. And secondly, analyzing the track of the planned path, and calculating a transverse error and a course angle error by combining the current pose information of the vehicle to be used as feedback control input. The current pose of the vehicle can be acquired through a sensor, and the planned path is a pre-planned driving path.
This embodiment has considerable feasibility.
In this disclosure, performing feedback control processing on the feedback error to obtain a first steering control parameter includes:
in the case where the vehicle is a two-axle steering vehicle, the following feedback control model is obtained:
δ feedback_front ＝(k 1 ×e lateral +k 2 ×e yaw )/v
δ feedback_rear ＝(k 1 ×e lateral -k 2 ×e yaw )/v
wherein k is 1 As a transverse feedback coefficient, k 2 Is the course angle feedback coefficient, delta feedback_front Is the front wheel slip angle, delta feedback_rear Is rear wheel slip angle, e lateral As a lateral error, e yaw Is the yaw error;
will transverse error e lateral And heading angle error e yaw And inputting a feedback control model to obtain a first steering control parameter comprising a front wheel deflection angle and a rear wheel deflection angle.
In this embodiment, the wheel slip angle refers to an included angle formed between a wheel and a longitudinal direction of the vehicle when the vehicle is steered, and corresponds to a front wheel slip angle and a rear wheel slip angle, respectively. Thus, according to the lateral error (e) fed back lateral ) And course angle error (e) yaw ) A closed loop control system is formed. The feedback control model is designed based on the following principle:
starting from two special conditions (when the transverse error and the course angle error are respectively equal to 0), the transverse feedback coefficient k is adjusted by combining the Lyapunov stability theorem 1 And course angle feedback coefficient k 2 And the variable of the speed is added, so that the wheel deflection angle can be self-adaptive to the vehicle speed (mainly the change rate of steering is self-adaptively adjusted according to the vehicle speed, and the stability and the comfort degree are improved), and an expression of the feedback control model is designed.
According to the feedback control model, the vehicle speed and the wheel slip angle are in an approximately inverse proportion relation, and the faster the speed is, the smaller the wheel slip angle is correspondingly, and the more conservative the steering is realized. Therefore, the feedback control of the embodiment can adaptively adjust the steering size according to the vehicle speed, and the stability and the comfort of the vehicle under different vehicle speeds are improved.
Further, k is 1 As a transverse feedback coefficient, k 2 Is a course angle feedback coefficient, k 1 And k 2 Respectively representing the lateral error e of the feedback control lateral And heading angle error e yaw Is assigned a weight.
The feedback control model of the embodiment is applied to a double-shaft steering vehicle, and realizes the control of the deflection angles of the front wheels and the rear wheels. The double-shaft steering vehicle is characterized in that one shaft is arranged from the front wheel to the mass center of the vehicle, and one shaft is arranged from the rear wheel to the mass center of the vehicle, so that the front wheel and the rear wheel can be steered at will without the need of mutual opposite numbers, for example, the front wheel can be turned to the right by 30 degrees, and the rear wheel can be turned to the right by 20 degrees or turned to the left by 10 degrees.
Wherein, the transverse feedback coefficient k of the front and rear wheels 1 And the same sign indicates that when the transverse error is large, the crab steering mode is favored. In this case, the steering mode set in the first steering control parameter is the crab steering bias in the feed-forward where the lateral error is not less than the first error threshold value.
Wherein, the course angle feedback coefficient k of the front and rear wheels 2 And (3) the abnormal sign indicates that the heading angle is biased to the splayed steering mode when the error is large. In this case, the steering mode set in the first steering control parameter is biased toward the splay steering in the feed-forward in which the rudder angle error is not less than the second error threshold value.
By the above-mentioned same sign and different sign setting, it is possible to prevent an infinite number from being calculated when the vehicle speed v is extremely small, and generally set a minimum value of v, for example, 1.
Therefore, the present embodiment can flexibly select which steering mode is biased according to the feedback error, thereby allowing the error to quickly converge.
In further embodiments of the present disclosure, in the lateral feedback coefficient k 1 When the steering angle is 0, the feedback control model of the embodiment can also be used for a single-axle steering vehicle, namely, only one axle connecting the front wheel and the rear wheel is used, and the steering is front-rear symmetric steering, namely, the steering angles of the front wheel and the rear wheel are opposite numbers. For example, the front wheel equivalent steering angle is 30 degrees to the right, and then the rear wheel equivalent steering angle must be 30 degrees to the left.
In an optional embodiment of the present disclosure, acquiring the expected driving data of the vehicle specifically includes the following steps:
acquiring a planned path of a vehicle and an expected heading angle of a vehicle head;
obtaining a tracking point according to a planned path of the vehicle, obtaining a tangential angle and a curvature of the tracking point, and making a difference between the tangential angle and an expected heading angle of the vehicle head to obtain a crab running angle of the vehicle;
and obtaining expected driving data of the vehicle according to the crab running angle and the curvature of the vehicle.
The planned vehicle path is a track to be tracked in vehicle control, for example, the vehicle is currently near the origin of coordinates (0, 0), and the planned vehicle path may be a path between (-5, 0) and (25, 0).
As for the crab-walking angle concept, as understood from the perspective of the planned path, the planned path gives two angles, one is the tangential angle (course angle) of the path, one is the heading angle (heading angle) expected by the nose, and the difference (course-heading) is the crab-walking angle. And the two angles can be calculated according to the path information of the planned path of the vehicle.
By introducing the crab-walking angle, the degree of freedom of double-shaft control is increased, so that the double-shaft steering vehicle can steer more flexibly without being limited to the traditional splay steering.
In alternative embodiments of the present disclosure, the tracking point may be the current position of the vehicle or other point on the planned path of the vehicle that is not far from the current position of the vehicle.
In an embodiment of the present disclosure, obtaining a tracking point according to a planned path of a vehicle includes:
acquiring a projection point of a current point of a vehicle on the vehicle planned path;
calculating the Look ahead distance (Look ahead distance) of the vehicle, adding the Look ahead distance by taking the projection point as a starting point to obtain a Look ahead point, and taking the Look ahead point as the tracking point.
In the embodiment, the pre-aiming distance is introduced into the feedforward control to compensate the time delay existing between the issuing of the steering control command and the execution of the command, so that the accurate steering control is achieved.
Preview distance, i.e. predicting a distance ahead and determining a preview point, then determining a tracking point according to the preview point to determine some reference input information of feedforward control, such as curvature kappa and crab angle theta crabbing ). The preview distance is mainly determined by the vehicle speed v, and the faster the vehicle speed is, the longer the preview distance is, and the formula is as follows:
Look ahead distance＝delay_time*v
the delay-time is a delay response coefficient, and a general value can be obtained through actual tests on a specific vehicle, the delay time is represented, and the delay time is multiplied by the current vehicle speed, so that the pre-aiming distance is obtained. Therefore, the size of the pre-aiming distance can be adjusted reasonably according to the vehicle speed.
In one embodiment of the present disclosure, performing feed-forward control processing on the expected driving data to obtain a second steering control parameter includes:
in the case of a vehicle with two-axis steering, the following feed-forward control model is obtained:
δ feedforward_front ＝kappa×l f +θ crabbing
δ feedforward_rear ＝-kappa×l r +θ crabbing
where kappa is the path curvature, θ crabbing Is crab angle, delta feedforward_front Is the front wheel slip angle, delta feedforward_rear Is a rear wheel slip angle;
and inputting expected driving data into a feedforward control model to obtain a second steering control parameter comprising a front wheel deflection angle and a rear wheel deflection angle.
Based on the expression of the feedforward control model, the front and rear wheel slip angles obtained based on the feedforward control processing can be calculated.
The crab angle is understood from the perspective of a vehicle, and as can be seen from the expression of the feedforward control model, the first terms of the front wheel and the rear wheel are mutually opposite numbers and represent splay steering, namely symmetric steering, and then the crab angle is respectively added to form the feedforward expression. Thus, the feed forward control represents the desired steering of the vehicle's planned path.
The expression of the feedforward control model as above can be designed by the following principle:
calculating a crab running angle theta according to the tangential angle of the tracking point and the expected heading angle of the head crabbing And combining the curvatures of the tracking points kappa and then combining a kinematic model formula of the four-wheel drive steering vehicle (wherein the angular velocity of the center of mass of the vehicle, delta, is represented by feedforward_front And delta feedforward_rear Equivalent wheel slip angles for the front and rear wheels, respectively):
the feedforward control expression as above is designed. In the process, kappa and theta are here crabbing The data are all data corresponding to the preview point obtained by adding a preview distance on the planned path of the vehicle.
In the embodiment of the present disclosure, the target steering control parameter may be obtained by fusing the first steering control parameter and the second steering control parameter, and in a dual-axle steering vehicle, the target steering control parameter includes a front-wheel slip angle and a rear-wheel slip angle.
And the specific gravity of the first steering control parameter is subjected to weight distribution through a transverse feedback coefficient and a course angle feedback coefficient, and then is directly added with the second steering control parameter. As can be seen from the above, the second steering control parameter is the wheel slip angle calculated from the planned path of the vehicle, and its physical meaning represents the steering that should be taken in the case of an ideal tracking trajectory of the vehicle (i.e. in the ideal case, without lateral error and heading angle error). It is, of course, practically impossible to have no error at all, and therefore feedback control is required to perform steering adjustment on the real-time feedback error, so that the first steering control parameter and the second steering control parameter can be directly added to form the final target steering control parameter.
Fig. 2 is a flowchart of a vehicle steering control method provided in an embodiment of the present disclosure, and as shown in fig. 2, the method may include the following steps:
step 210: acquiring current running data of a vehicle, and calculating a feedback error according to the current running data, wherein the feedback error comprises a transverse error and a course angle error;
step 220: performing feedback control processing on the feedback error to obtain a first steering control parameter;
step 230: acquiring expected driving data of a vehicle, and performing feedforward control processing on the expected driving data to obtain a second steering control parameter;
step 240: under the condition that the increasing rate of the feedback error in a set time period exceeds a threshold value, carrying out error compensation on the feedback error, and obtaining a compensation steering control parameter according to the error compensation;
step 250: fusing the first steering control parameter, the second steering control parameter and the compensation steering control parameter to obtain a target steering control parameter;
step 260: and issuing a steering control instruction based on the target steering control parameter.
The present embodiment considers that in some extreme cases, if the vehicle continuously deviates from the planned path, i.e. the lateral error and the heading angle error continuously increase, the lateral error and the heading angle can be converged back quickly by adding an integral term for error compensation. Wherein the error compensation can be characterized by the following expression:
wherein k is 3 And k 4 The weight values of the error compensation of the transverse error and the course angle error are respectively.
In this case, the first steering control parameter, the second steering control parameter, and the compensation steering control parameter are fused by the following expressions:
δ lateral_control ＝δ feedback +δ feedforward +δ error_integral
wherein, in a two-axle-steered vehicle, δ feedback And delta feedforward Each of which includes a control parameter for a toe-out angle of the front wheel and a control parameter for a toe-out angle of the rear wheel.
Specifically, the three items are fused to form the complete steering control expression, amplitude limiting is performed according to some mechanical structure limitations of the vehicle, such as parameters of a maximum wheel slip angle, a maximum angular speed, a maximum crab angle and the like, and finally a steering control instruction issued by final control is obtained by multiplying the steering control instruction (advance 1, reverse-1 or parking state 0) by an upper direction variable.
Fig. 3 is a flowchart of a vehicle steering control method in a specific scenario provided in the embodiment of the present disclosure, and as shown in fig. 3, the method includes the following steps:
step 310: receiving a vehicle planned path and vehicle positioning information;
step 320: calculating a feedback error based on the vehicle planned path and the vehicle positioning information, and obtaining the curvature and the crab angle of the tracking point according to the vehicle planned path;
step 330: processing the feedback error according to the feedback control model to obtain a feedback control quantity, wherein the feedback control quantity corresponds to the first steering control parameter;
step 340: processing the curvature and the crab running angle by using a feedforward control model to obtain a feedforward control quantity, wherein the feedforward control quantity corresponds to the second steering control parameter;
step 350: calculating compensation control quantity according to the feedback error increase change in the set time, wherein the compensation control quantity corresponds to the compensation steering control parameter;
step 360: fusing the feedforward control quantity, the feedback control quantity and the compensation control quantity to obtain a final steering control parameter;
step 370: determining a steering control instruction by combining the vehicle self-vehicle parameter and the steering control parameter;
step 380: and issuing steering control commands for the deflection angles of the front wheels and the rear wheels.
Fig. 4 is a schematic configuration diagram of a vehicle steering control apparatus of the present invention. As shown in fig. 4, a vehicle steering control device 400 according to the present invention includes:
the acquisition module 410 acquires current driving data of the vehicle and calculates a feedback error according to the current driving data, wherein the feedback error comprises a transverse error and a course angle error;
the feedback control module 420 is used for performing feedback control processing on the feedback error to obtain a first steering control parameter;
the feedforward control module 430 is used for acquiring expected driving data of the vehicle and performing feedforward control processing on the expected driving data to obtain a second steering control parameter;
the fusion module 430 is used for fusing the first steering control parameter and the second steering control parameter to obtain a target steering control parameter;
the command issuing module 440 issues a steering control command based on the target steering control parameter.
In an alternative embodiment, the acquisition module 410 is specifically configured to:
and extracting the current pose and the planned path of the vehicle from the vehicle running data, and calculating the transverse error and the heading angle error by using the current pose and the planned path of the vehicle.
In an alternative embodiment, the feedback control module 420 is specifically configured to:
in the case where the vehicle is a two-axle steering vehicle, the following feedback control model is obtained:
δ feedback_front ＝(k 1 ×e lateral +k 2 ×e yaw )/v
δ feedback_rear ＝(k 1 ×e lateral -k 2 ×e yaw )/v
wherein k is 1 As a transverse feedback coefficient, k 2 Is the course angle feedback coefficient, delta feedback_front Is the front wheel slip angle, delta feedback_rear Is rear wheel slip angle, e lateral As a lateral error, e yaw Is the yaw error;
the lateral error e is measured lateral And heading angle error e yaw And inputting the feedback control model to obtain a first steering control parameter comprising a front wheel deflection angle and a rear wheel deflection angle.
In an alternative embodiment, the first steering control parameter further comprises a steering mode;
wherein, under the feedforward that the lateral error is not less than the first error threshold, the steering mode is crab steering;
and under the feedforward that the heading angle error is not less than the second error threshold value, the steering mode is splay steering.
In an alternative embodiment, the feedforward control module 430 is specifically configured to:
acquiring a vehicle planned path and a vehicle head expected orientation angle;
obtaining a tracking point according to a planned path of the vehicle, obtaining a tangential angle and a curvature of the tracking point, and making a difference between the tangential angle and an expected heading angle of the vehicle head to obtain a crab running angle of the vehicle;
and obtaining expected driving data of the vehicle according to the crab running angle and the curvature of the vehicle.
In an alternative embodiment, the feedforward control module 430 is specifically configured to:
acquiring a projection point of a current point of a vehicle on a planned path of the vehicle;
and calculating the pre-aiming distance of the vehicle, adding the pre-aiming distance by taking the projection point as a starting point to obtain a pre-aiming point, and taking the pre-aiming point as the tracking point.
In an alternative embodiment, the feedforward control module 430 is specifically configured to:
in the case of a vehicle with two-axis steering, the following feed-forward control model is obtained:
δ feedforward_front ＝kappa×l f +θ crabbing
δ feedforward_rear ＝-kappa×l r +θ crabbing
where kappa is the path curvature, θ crabbing Is crab angle, delta feedforward_front Is the front wheel slip angle, delta feedforward_rear Is a rear wheel slip angle;
and inputting expected driving data into the feedforward control model to obtain a second steering control parameter.
In an alternative embodiment, compared to fig. 4, the vehicle steering control device 500 shown in fig. 5 further includes:
an error compensation module 510, configured to perform error compensation on the feedback error under a condition that an increase rate of the feedback error within a set time period exceeds a threshold before the first steering control parameter and the second steering control parameter are fused to obtain a target steering control parameter, and obtain a compensated steering control parameter according to the error compensation;
the fusion module 520 is specifically configured to;
and fusing the first steering control parameter, the second steering control parameter and the compensation steering control parameter to obtain a target steering control parameter.
The vehicle steering control device can decouple feedforward control and feedback control, so that the feedforward control and the feedback control are independent and independent. This is convenient for debug analysis respectively to feedforward control and feedback control to more high-efficient and accurately carry out the analysis to the result, further promote vehicle steering control accuracy. Therefore, the technical scheme of the embodiment can be used for efficiently debugging the feedforward control and the feedback control respectively, and further remarkably improving the steering control precision of the vehicle.
The embodiment of the invention also provides vehicle steering control equipment which comprises a processor. A memory having stored therein executable instructions of the processor. Wherein the processor is configured to perform the steps of the vehicle steering control method via execution of executable instructions.
As described above, the vehicle steering control apparatus of the present invention can efficiently debug the feedforward control and the feedback control, respectively, thereby significantly improving the vehicle steering control accuracy and reducing the consumption of computing resources.
As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or program product. Thus, various aspects of the invention may be embodied in the form of: an entirely hardware embodiment, an entirely software embodiment (including firmware, microcode, etc.) or an embodiment combining hardware and software aspects that may all generally be referred to herein as a "circuit," module "or" platform.
Fig. 6 is a schematic configuration diagram of a vehicle steering control apparatus of the invention. An electronic device 600 according to this embodiment of the invention is described below with reference to fig. 6. The electronic device 600 shown in fig. 6 is only an example, and should not bring any limitation to the functions and the scope of use of the embodiments of the present invention.
As shown in fig. 6, the electronic device 600 is embodied in the form of a general purpose computing device. The components of the electronic device 600 may include, but are not limited to: at least one processing unit 610, at least one memory unit 620, a bus 630 connecting the different platform components (including the memory unit 620 and the processing unit 610), a display unit 640, etc.
Wherein the memory unit stores program code which is executable by the processing unit 610 such that the processing unit 610 performs the steps according to various exemplary embodiments of the present invention as described in the above-mentioned vehicle steering control method section of the present specification. For example, processing unit 610 may perform the steps as shown in fig. 1.
The storage unit 620 may include readable media in the form of volatile memory units, such as a random access memory unit (RAM) 621 and/or a cache memory unit 622, and may further include a read only memory unit (ROM) 623.
The storage unit 620 may also include a program/utility 624 having a set (at least one) of program modules 625, such program modules 625 including, but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which, or some combination thereof, may comprise an implementation of a network environment.
Bus 630 can be any bus representing one or more of several types of bus structures, including a memory unit bus or memory unit controller, a peripheral bus, an accelerated graphics port, a processing unit, or a local bus using any of a variety of bus architectures.
The electronic device 600 may also communicate with one or more external devices 700 (e.g., keyboard, pointing device, bluetooth device, etc.), with one or more devices that enable a user to interact with the electronic device 600, and/or with any device (e.g., router, modem, etc.) that enables the electronic device 600 to communicate with one or more other computing devices. Such communication may occur via an input/output (I/O) interface 650. Also, the electronic device 600 may communicate with one or more networks (e.g., a Local Area Network (LAN), a Wide Area Network (WAN), and/or a public network such as the Internet) via the network adapter 660. The network adapter 660 may communicate with other modules of the electronic device 600 via the bus 630. It should be appreciated that although not shown in the figures, other hardware and/or software modules may be used in conjunction with the electronic device 600, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage platforms, to name a few.
Embodiments of the present invention also provide a computer-readable storage medium storing a program, which when executed, implements the steps of the vehicle steering control method. In some possible embodiments, the various aspects of the invention may also be implemented in the form of a program product comprising program code means for causing a terminal device to carry out the steps according to various exemplary embodiments of the invention described in the above-mentioned vehicle steering control method section of the present description, when the program product is run on the terminal device.
As described above, the program of the computer-readable storage medium of this embodiment, when executed, can greatly reduce the hardware configuration cost of container detection, reduce CPU and GPU occupation, and improve the accuracy of container attitude detection.
Fig. 7 is a schematic structural diagram of a computer-readable storage medium of the present invention. Referring to fig. 7, a program product 700 for implementing the above method according to an embodiment of the present invention is described, which may employ a portable compact disc read only memory (CD-ROM) and include program code, and may be run on a terminal device, such as a personal computer. However, the program product of the present invention is not limited in this regard and, in the present document, a readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
The program product may employ any combination of one or more readable media. The readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the foregoing. More specific examples (a non-exhaustive list) of the readable storage medium include: an electrical connection having one or more wires, a portable diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.
A computer readable storage medium may include a propagated data signal with readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated data signal may take many forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A readable storage medium may also be any readable medium that is not a readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. Program code embodied on a readable storage medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
Program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, C + + or the like and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code may execute entirely on the user's computing device, partly on the user's device, as a stand-alone software package, partly on the user's computing device and partly on a remote computing device, or entirely on the remote computing device or server. In the case of a remote computing device, the remote computing device may be connected to the user computing device through any kind of network, including a Local Area Network (LAN) or a Wide Area Network (WAN), or may be connected to an external computing device (e.g., through the internet using an internet service provider).
In summary, the vehicle steering control method, the vehicle steering control device, the vehicle steering control equipment and the storage medium of the invention respectively carry out efficient debugging on feedforward control and feedback control, thereby significantly improving the vehicle steering control precision and reducing the consumption of computing resources.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.
Claims (11)
1. A vehicle steering control method, characterized by comprising:
acquiring current running data of a vehicle, and calculating a feedback error according to the current running data, wherein the feedback error comprises a transverse error and a course angle error;
performing feedback control processing on the feedback error to obtain a first steering control parameter;
acquiring expected driving data of a vehicle, and performing feedforward control processing on the expected driving data to obtain a second steering control parameter;
fusing the first steering control parameter and the second steering control parameter to obtain a target steering control parameter;
and issuing a steering control instruction based on the target steering control parameter.
2. The vehicle steering control method according to claim 1, wherein the calculating a feedback error from the current running data includes:
and extracting the current pose and the planned path of the vehicle from the current running data, and calculating the transverse error and the course angle error by using the current pose and the planned path of the vehicle.
3. The vehicle steering control method according to claim 2, wherein the feedback control processing of the feedback error to obtain a first steering control parameter includes:
in the case where the vehicle is a two-axle steering vehicle, a feedback control model is obtained as follows:
δ feedback_front ＝(k 1 ×e lateral +k 2 ×e yaw )/v
δ feedback_rear ＝(k 1 ×e lateral -k 2 ×e yaw )/v
wherein k is 1 As a transverse feedback coefficient, k 2 Is a course angle feedback coefficient, delta feedback_front Is the front wheel slip angle, delta feedback_rear Is rear wheel slip angle, e lateral As a lateral error, e yaw Is the yaw error;
the lateral error e is measured lateral And heading angle error e yaw And inputting the feedback control model to obtain a first steering control parameter comprising a front wheel deflection angle and a rear wheel deflection angle.
4. The vehicle steering control method according to claim 3, characterized in that the first steering control parameter further includes a steering mode;
wherein the steering mode is crab steering under feed forward with the lateral error not less than a first error threshold;
and under the feedforward that the course angle error is not less than a second error threshold value, the steering mode is splay steering.
5. The vehicle steering control method according to claim 1, wherein the acquiring vehicle expected travel data includes:
acquiring a vehicle planned path and a vehicle head expected orientation angle;
obtaining a tracking point according to the planned path of the vehicle, obtaining a tangential angle and a curvature of the tracking point, and making a difference between the tangential angle and an expected heading angle of the vehicle head to obtain a crab running angle of the vehicle;
and obtaining the expected driving data of the vehicle according to the crab running angle and the curvature of the vehicle.
6. The vehicle steering control method according to claim 5, wherein the obtaining tracking points according to the vehicle planned path includes:
acquiring a projection point of a current point of a vehicle on the vehicle planned path;
and calculating the pre-aiming distance of the vehicle, adding the pre-aiming distance by taking the projection point as a starting point to obtain a pre-aiming point, and taking the pre-aiming point as the tracking point.
7. The vehicle steering control method according to claim 5, wherein the feed-forward control processing of the desired travel data to obtain a second steering control parameter includes:
in the case of the vehicle with two-axis steering, the following feed-forward control model is obtained:
δ feedforward_front ＝kappa×l f +θ crabbing
δ feedforward_rear ＝-kappa×l r +θ crabbing
where kappa is the path curvature, θ crabbing Is crab angle, delta feedforward_front Is the front wheel slip angle, delta feedforward_rear Is a rear wheel slip angle;
and inputting the expected running data into the feedforward control model to obtain the second steering control parameter.
8. The vehicle steering control method according to claim 1, wherein before the first steering control parameter and the second steering control parameter are fused to obtain a target steering control parameter, the vehicle steering control method further comprises:
under the condition that the increasing rate of the feedback error in a set time period exceeds a threshold value, carrying out error compensation on the feedback error, and obtaining a compensation steering control parameter according to the error compensation;
fusing the first steering control parameter and the second steering control parameter to obtain a target steering control parameter, wherein the target steering control parameter comprises;
and fusing the first steering control parameter, the second steering control parameter and the compensation steering control parameter to obtain a target steering control parameter.
9. A vehicle steering control apparatus, characterized by comprising:
the system comprises an acquisition module, a feedback module and a feedback module, wherein the acquisition module acquires current running data of a vehicle and calculates a feedback error according to the current running data, and the feedback error comprises a transverse error and a course angle error;
the feedback control module is used for carrying out feedback control processing on the feedback error to obtain a first steering control parameter;
the feedforward control module is used for acquiring expected driving data of a vehicle and carrying out feedforward control processing on the expected driving data to obtain a second steering control parameter;
the fusion module is used for fusing the first steering control parameter and the second steering control parameter to obtain a target steering control parameter;
and the instruction sending module is used for sending a steering control instruction based on the target steering control parameter.
10. A vehicular steering control apparatus, characterized by comprising:
a processor;
a memory having stored therein executable instructions of the processor;
wherein the processor is configured to perform the steps of the vehicle steering control method of any one of claims 1 to 8 via execution of the executable instructions.
11. A computer-readable storage medium storing a program, characterized in that the program when executed implements the steps of the vehicle steering control method according to any one of claims 1 to 8.
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| CN118092405A (en) * | 2024-04-29 | 2024-05-28 | 成都赛力斯科技有限公司 | Decoupling debugging method and device for vehicle controller, computer equipment and medium |
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| CN118092405A (en) * | 2024-04-29 | 2024-05-28 | 成都赛力斯科技有限公司 | Decoupling debugging method and device for vehicle controller, computer equipment and medium |
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