Automatic driving control right smooth transfer method and system based on dynamic gradient amplitude limiting

Abstract

The invention is suitable for the technical field of automobiles, and provides an automatic driving control right smooth transfer method and system based on dynamic gradient amplitude limiting, and the method comprises the steps: detecting the operation intention of a driver, preventing false triggering through double thresholds, and triggering a transfer signal. Dynamic amplitude limiting is calculated according to driver torque, and multi-mode parameter selection is supported to adapt to different scenes. And the torque change rate is subjected to amplitude limiting smoothing, compensation torque is generated, and final torque is output through an attenuation function. According to real-time error dynamic optimization, iterative convergence is achieved, and it is ensured that the switching process is rapid and stable. According to the method, the problem that the torque generated in manual takeover during existing man-machine co-driving is not smooth is solved, and the risk of man-machine co-driving is reduced. According to the method, by designing an iterative optimization scheme, jitter and errors in the whole switching process are reduced, the mastering feeling of a driver is enhanced, the situation that the driver is nervous due to the problems such as steering wheel response is avoided, and the driver feels more comfortable and safer when taking over automatic driving.

Description

Technical Field

[0001] The present invention belongs to the field of automobile technology, and in particular relates to a method and system for smooth transfer of automatic driving control rights based on dynamic gradient limiting. Background Art

[0002] With the rapid development of autonomous driving technology, the safe and smooth switching of vehicle control has become one of the core challenges in achieving human-machine co-driving. Especially during the handover from automatic mode to manual driving mode, sudden changes in steering wheel torque can easily cause vibration, leading to driver tension or misoperation, which directly affects driving experience and safety.

[0003] Existing methods are unable to solve the problem of uneven torque generated during manual takeover of autonomous driving vehicles when humans and machines are co-driving together. The tension and discomfort caused by the sense of frustration can also become a precursor to danger. Summary of the invention

[0004] The purpose of the present invention is to provide a method and system for smooth transfer of automatic driving control rights based on dynamic gradient limiting, aiming to solve the problem of the driver's hand torque frustration caused by the sudden change of system torque when the automatic driving of an automatic driving vehicle switches to manual driving when the driver is performing manual operation.

[0005] The present invention is implemented by a method for smooth transfer of control rights of automatic driving based on dynamic gradient limiting, the method comprising: S1. Read the information collected by the steering wheel torque sensor in real time, identify the steering wheel takeover status, and calculate the torque value applied by the driver and takeover duration , set the torque threshold and time threshold ,judge and When the control transfer is triggered; S2, according to the current torque value , calculate the maximum limit of torque change rate : ; ; in, represents the base rate of change, represents the applied torque at time zero, and All are adjustment parameters; S3. Set the sampling period and limit the torque change rate within the sampling period Do not exceed the maximum limit of torque change rate , and based on the smoothed moment With target torque The error between generates a compensation torque ; S4, combined system torque and compensation torque , the final output torque is calculated by the attenuation function ; S5, according to the smoothed torque With target torque The error between the dynamic adjustment torque change rate maximum limit , calculate the dynamic limit change rate : ; in, To adjust the parameters.

[0006] As a further solution of the present invention, the identification of the steering wheel takeover state in S1 further includes: if the torque value applied by the driver is At time threshold Not continuously satisfied , it is judged as a false trigger and the control transfer is not initiated.

[0007] As a further solution of the present invention, the adjustment parameters described in S2 and The value of is set according to the switching mode, including: Quick switch mode: ; Normal switching mode: ; Slow switching mode: .

[0008] As a further solution of the present invention, the smoothed torque With target torque The error between the two generates a compensation torque , specifically: ; in, Indicates Sampling period, is the adjustment parameter, and .

[0009] As a further solution of the present invention, the final output torque is calculated by the attenuation function , specifically: ; in, , is a constant term.

[0010] As a further solution of the present invention, the method is optimized through dynamic gradient limiting and iterative compensation, comprising: According to the error of the current sampling period, Updated to ; S3 to S5 are repeatedly executed until the total switching time reaches 0.5 seconds.

[0011] As a further solution of the present invention, the method is optimized through dynamic gradient limiting and iterative compensation, comprising: According to the error of the current sampling period, Updated to ; Set the torque error threshold and repeat S3 to S5 until the output torque With target torque The error between them is less than the torque error threshold.

[0012] Another object of the present invention is to provide an automatic driving control authority smooth transfer system based on dynamic gradient limiting, the system comprising: The manual takeover intention recognition module is used to read the information collected by the steering wheel torque sensor in real time, identify the steering wheel takeover status, and calculate the torque value applied by the driver and takeover duration , set the torque threshold and time threshold ,judge and When the control transfer is triggered; The maximum switching rate determination module is used to determine the torque value currently obtained , calculate the maximum limit of torque change rate ; Target gap compensation module, used to set the sampling period and limit the torque change rate within the sampling period Do not exceed the maximum limit of torque change rate , and based on the smoothed moment With target torque The error between the two generates a compensation torque , combined with the system torque and compensation torque , the final output torque is calculated by the attenuation function ; The switching rate dynamic adjustment module is used to adjust the torque according to the smoothed torque. With target torque The error between the dynamic adjustment torque change rate maximum limit , calculate the dynamic limit change rate .

[0013] The beneficial effects of the present invention are: The present invention solves the problem of uneven torque generated during manual takeover when humans and machines are co-driving, and reduces the danger of co-driving. The present invention reduces jitter and error in the entire switching process by designing an iterative optimization scheme, enhances the driver's sense of control, avoids the driver's nervousness due to problems such as steering wheel response, and makes the driver more comfortable and safe when taking over automatic driving. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is a flow chart of the automatic driving control right smooth transfer system based on dynamic gradient limiting according to the present invention; Figure 2 It is the torque variation curve under three switching modes; Figure 3 Schematic diagram of iterative optimization effect. DETAILED DESCRIPTION

[0015] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0016] A method for smooth transfer of control rights for autonomous driving based on dynamic gradient limiting, the method comprising: S1. Read the information collected by the steering wheel torque sensor in real time, identify the steering wheel takeover status, and calculate the torque value applied by the driver and takeover duration , set the torque threshold and time threshold ,judge and When the control transfer is triggered; When the driver manually operates the steering wheel, the takeover intention is recognized. In order to prevent the slight shaking of the steering wheel from causing misrecognition and avoid overly sensitive switching, a torque threshold is introduced. , time threshold ,set up , when judging Manual takeover starts from time to time, the logic is as follows: ; If the torque applied by the driver At time threshold Not continuously satisfied , it is judged as a false trigger and the control transfer is not initiated.

[0017] S2, according to the current torque value , calculate the maximum limit of torque change rate : ; ; (steering wheel turns left for a positive value) Basic change rate The setting ensures that no matter how the torque changes suddenly, the time will be controlled within 0.5s. in, represents the base rate of change, represents the applied torque at time zero, and All are adjustment parameters; The value determines the average smoothing speed of the torque during the entire switching process. The value determines the driver's sense of control over the steering wheel when applying a sudden torque, that is, The larger the value, the faster the driver's torque applied by the automated driving system will decrease at the beginning of the switching process.

[0018] like Figure 2 As shown, the adjustment parameters and The value of is set according to the switching mode, including: Quick switch mode: ; Normal switching mode: ; Slow switching mode: .

[0019] S3. Set the sampling period. According to the torque data collected by the torque sensor, calculate the real-time change rate of the torque with a sampling period of 0.01 seconds, and limit the torque change rate within the sampling period. Do not exceed the maximum limit of torque change rate , i.e. limit At this time, the rate of change presents a nonlinear step line in the time span of 0.5s.

[0020] Since the rate of change of the instantaneous mutation of the torque is very large, although the limit R max The smoothing purpose is achieved to a certain extent, but there is also a certain error. The target gap compensation method is adopted: and based on the smoothed moment With target torque The error between the two generates a compensation torque ; Specifically: ; in, Indicates Sampling period, is the adjustment parameter, and .

[0021] S4, combined system torque and compensation torque , the final output torque is calculated by the attenuation function ; Specifically: ; ; ; ; in, is the optimized system torque modulated by the decay function, which acts through The attenuation characteristics optimize the final output torque The calculation process speeds up the convergence speed, improves the smoothness of the torque curve, and alleviates the steering wheel shaking problem during the switching process. , As a constant term, take , that is, it is hoped that the entire conversion process will be completed in about 0.5s. At this time, the optimized torque curve is both smooth and accurate, and greatly reduces the steering wheel vibration during the switching process.

[0022] S5, in order to further enhance the smoothing effect, dynamic Adjustment, according to the smoothed torque With target torque The error between the dynamic adjustment torque change rate maximum limit , calculate the dynamic limit change rate : ; in, To adjust the parameters, take =0.2.

[0023] The method is optimized through dynamic gradient limiting and iterative compensation, and includes: According to the error of the current sampling period, Updated to ; Repeat S3 to S5 until the total switching time reaches 0.5 seconds or the output torque With target torque The error between them is less than the torque error threshold.

[0024] like Figure 3 As shown, the optimized and , from the entire 0.5s optimization process, we can know that when When the value is 0~25, the more optimization times, the faster the response speed. When the value is 25-50, the cumulative error is slightly reduced, the smoothness is better, and the manual takeover is softer in the later stage. Through this step, the steering wheel torque felt by the driver during manual takeover is smoother, the response is faster, and the accuracy is also better, which meets the driver's comfort expectations.

[0025] like Figure 1 As shown, a system for smooth transfer of control rights of an automatic driving system based on dynamic gradient limiting comprises: The manual takeover intention recognition module is used to read the information collected by the steering wheel torque sensor in real time, identify the steering wheel takeover status, and calculate the torque value applied by the driver and takeover duration , set the torque threshold and time threshold ,judge and When the control transfer is triggered; The maximum switching rate determination module is used to determine the torque value currently obtained , calculate the maximum limit of torque change rate ; Target gap compensation module, used to set the sampling period and limit the torque change rate within the sampling period Do not exceed the maximum limit of torque change rate , and based on the smoothed moment With target torque The error between the two generates a compensation torque , combined with the system torque and compensation torque , the final output torque is calculated by the attenuation function ; The switching rate dynamic adjustment module is used to adjust the torque according to the smoothed torque. With target torque The error between the dynamic adjustment torque change rate maximum limit , calculate the dynamic limit change rate .

[0026] It should be understood that, although each step in the flow chart of each embodiment of the present invention is shown in sequence according to the indication of the arrow, these steps are not necessarily performed in sequence according to the order indicated by the arrow. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be performed in other orders. Moreover, at least a portion of the steps in each embodiment may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these sub-steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of other steps or sub-steps or stages of other steps.

[0027] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application may include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0028] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0029] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

[0030] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for smooth transfer of control rights for autonomous driving based on dynamic gradient limiting, characterized in that: The method comprises: S1. Read the information collected by the steering wheel torque sensor in real time, identify the steering wheel takeover status, and calculate the torque value applied by the driver and takeover duration , set the torque threshold and time threshold ,judge and When the control transfer is triggered; S2, according to the current torque value , calculate the maximum limit of torque change rate : ； ； in, represents the base rate of change, represents the applied torque at time zero, and All are adjustment parameters; S3. Set the sampling period and limit the torque change rate within the sampling period Do not exceed the maximum limit of torque change rate , and based on the smoothed moment With target torque The error between the two generates a compensation torque ; S4, combined system torque and compensation torque , the final output torque is calculated by the attenuation function ; S5, according to the smoothed torque With target torque The error between the dynamic adjustment torque change rate maximum limit , calculate the dynamic limit change rate : ； in, To adjust the parameters.

2. The method according to claim 1, characterized in that: The identification of the steering wheel takeover state described in S1 also includes if the torque value applied by the driver At time threshold Not continuously satisfied , it is judged as a false trigger and the control transfer is not initiated.

3. The method according to claim 1, characterized in that The adjustment parameters described in S2 and The value of is set according to the switching mode, including: Quick switch mode: ; Normal switching mode: ; Slow switching mode: .

4. The method according to claim 1, characterized in that: The smoothed moment With target torque The error between the two generates a compensation torque , specifically: ； in, Indicates Sampling period, is the adjustment parameter, and .

5. The method according to claim 1, characterized in that The final output torque is calculated by the attenuation function , specifically: ； in, , is a constant term.

6. The method according to claim 1, characterized in that The method is optimized through dynamic gradient limiting and iterative compensation, and includes: According to the error of the current sampling period, Updated to ; S3 to S5 are repeatedly executed until the total switching time reaches 0.5 seconds.

7. The method according to claim 1, characterized in that The method is optimized through dynamic gradient limiting and iterative compensation, and includes: According to the error of the current sampling period, Updated to ; Set the torque error threshold and repeat S3 to S5 until the output torque With target torque The error between them is less than the torque error threshold.

8. The automatic driving control smooth transfer system based on dynamic gradient limiting is characterized by: The system comprises: The manual takeover intention recognition module is used to read the information collected by the steering wheel torque sensor in real time, identify the steering wheel takeover status, and calculate the torque value applied by the driver and takeover duration , set the torque threshold and time threshold ,judge and When the control transfer is triggered; The maximum switching rate determination module is used to determine the torque value currently obtained , calculate the maximum limit of torque change rate ; Target gap compensation module, used to set the sampling period and limit the torque change rate within the sampling period Do not exceed the maximum limit of torque change rate , and based on the smoothed moment With target torque The error between the two generates a compensation torque , combined with the system torque and compensation torque , the final output torque is calculated by the attenuation function ; The switching rate dynamic adjustment module is used to adjust the torque according to the smoothed torque. With target torque The error between the dynamic adjustment torque change rate maximum limit , calculate the dynamic limit change rate .

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