Control method of vehicle accelerator pedal fault-tolerant control system

Abstract

The invention discloses a control method of a vehicle accelerator pedal fault-tolerant control system. The fault-tolerant control system comprises a first-path sensor signal and a second-path sensor. According to the control method, sensor signals are obtained in real time, fault diagnosis is carried out, and a stroke strategy is output; performing consistency fault judgment through a preset multiple relation and a preset error range; fault-tolerant output logic is adopted, including stroke percentage conversion, stroke percentage minimum value and stroke percentage maximum value determination, and a final output stroke is obtained through a weighted fusion formula based on stroke intervals. By the adoption of the technical scheme, the optimal balance between safety and drivability is achieved, and smooth transition driving experience is provided; diagnosis and fault tolerance are closely combined, and the system robustness is extremely high; and finally, the driving experience is improved through smooth processing of the output travel.

Description

Technical Field

[0001] This invention belongs to the technical field of combining vehicle driving safety control and driving experience. More specifically, this invention relates to a vehicle accelerator pedal fault-tolerant control system. Background Technology

[0002] In vehicle electronic control systems, the accelerator pedal typically employs a dual-sensor design to enhance safety. When one sensor fails, the system can switch to the other, functioning sensor. However, existing technology has a significant drawback: when both sensors experience a "consistency failure" (i.e., both signals are valid, but their relationship does not conform to preset logic), the traditional handling method is overly simplistic and crude.

[0003] For example, existing technologies might directly report an error and limit power, or force an output to a fixed value (such as zero or a minimum value). While this approach ensures safety, it severely sacrifices the vehicle's drivability and controllability, potentially leading to sudden loss of speed while driving and creating new safety hazards.

[0004] Deficiencies of existing technology:

[0005] Existing technologies employ a single handling strategy when inconsistencies occur in the dual-channel accelerator pedal sensors, leading to a sharp decline in vehicle drivability. Specifically:

[0006] 1. It directly reports an error and limits power, causing the vehicle to suddenly lose speed;

[0007] 2. Forcing a fixed value (such as zero or the minimum value) to be output affects the normal operation of the vehicle;

[0008] 3. Lacking intelligent signal fusion algorithms, it is unable to output a safe, reliable accelerator pedal travel signal that reflects the driver's intentions under fault conditions.

[0009] Using keywords such as "vehicle; accelerator pedal; fault tolerance; control; system; method", a search was conducted on existing publicly available technical literature, yielding the following results:

[0010] 1. Chinese patent document: "Automobile throttle fault-tolerant safety control method and device", patent (application) number: 201910615872.1; the technical solution described therein is:

[0011] "The automotive accelerator pedal fault-tolerant safety control method includes the following steps: S1: The sensor unit detects the pressure on the pedal; S2: The sensor converts the pressure on the accelerator pedal into an electrical signal and outputs it to the control unit; S3: The control unit determines whether the driver has pressed the pedal based on the above signal; S4: If pressure is detected on the pedal, the accelerator pedal signal is output, and the control unit then determines whether the pedal lock signal is output normally; S5: If the pedal lock signal is output normally, the accelerator pedal signal is output normally; if the pedal lock signal is output abnormally, the accelerator pedal signal is output abnormally and the output stops."

[0012] The technical effects described are:

[0013] "It can provide timely and effective protection when the accelerator pedal is stuck due to incorrect external force, even though the driver has released the accelerator pedal, causing both the accelerator pedal signal and the accelerator pedal lock signal to be incorrect. Moreover, the installation method is simple and diverse, the control is simple, and it is easy to implement."

[0014] 2. Chinese patent document: "Functional Fault Tolerance Testing Device and Testing Method for New Energy Vehicles", Patent (Application) No.: 202010821568.5; the technical solution described therein is:

[0015] "The new energy vehicle functional fault-tolerant testing device uses a vehicle controller CAN bus, resolver, current sensor, voltmeter, displacement sensor, hydraulic sensor and data acquisition module to synchronously collect key signals such as ignition status current, voltage, displacement and pressure from the vehicle controller, actuators and other key components, and uploads the signals to the host computer for display and processing."

[0016] The technical effects described are:

[0017] "It can comprehensively monitor the functional fault tolerance status of new energy vehicles, and then be used for functional fault tolerance testing and R&D verification of new energy vehicles."

[0018] However, the technical solutions described in the aforementioned technical documents, as well as the existing publicly available technical solutions, have not been able to solve the problems and defects in the existing technology, such as "single processing strategy during consistent failures, leading to a sudden drop in vehicle drivability", "direct error reporting causing sudden vehicle stall", "affecting normal vehicle operation" and "inability to output a safe, reliable accelerator pedal travel signal that reflects the driver's intentions in a fault state".

[0019] Therefore, there is an urgent need for an intelligent fault-tolerant control scheme that can maintain normal vehicle operation to the greatest extent possible while ensuring safety. Summary of the Invention

[0020] This invention provides a vehicle accelerator pedal fault-tolerant control system, the purpose of which is to maintain normal vehicle operation to the maximum extent while ensuring safety and achieving intelligent fault tolerance.

[0021] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0022] The present invention discloses a control method for a vehicle accelerator pedal fault-tolerant control system, wherein the fault-tolerant control system includes a first sensor signal and a second sensor; the control method acquires the sensor signal in real time, performs fault diagnosis, and outputs a travel strategy; performs consistency fault judgment through a predetermined multiple relationship and a preset error range; and adopts fault-tolerant output logic, including travel percentage conversion, determination of minimum and maximum travel percentage, and obtaining the final output travel through a weighted fusion formula based on travel interval.

[0023] The control method includes the following steps:

[0024] Step S100: Acquire the first sensor signal and the second sensor signal in real time;

[0025] Step S200: Perform fault diagnosis on the two sensor signals, wherein the fault diagnosis includes at least consistency fault judgment;

[0026] Step S300: Based on the results of the fault diagnosis, execute the corresponding travel output strategy.

[0027] The consistency fault determination in step S200 is specifically as follows: under the premise that neither of the two sensor signals reports an over-range, open circuit, or short circuit fault, determine whether the voltage value of the first sensor is a predetermined multiple of the voltage value of the second sensor, and whether the difference between the two is within a first preset error range; if not, then a consistency fault is determined to have occurred.

[0028] The predetermined multiple relationship is a 2x relationship, and the first preset error range is ±0.5V.

[0029] In step S300, when a consistency failure is determined to have occurred, the following fault-tolerant output logic is executed:

[0030] S310: Convert the first and second channel sensor signals into first stroke percentage Perc1 and second stroke percentage Perc2 respectively;

[0031] S320: Determine the minimum value X1=min(Perc1,Perc2) and the maximum value X2=max(Perc1,Perc2);

[0032] S330: Based on the numerical range of X1, selectively calculate the final output stroke:

[0033] If both Perc1 and Perc2 are greater than or equal to 50%, the final output will be the following:

[0034] Perc = (Perc1 + Perc2) / 2;

[0035] If both Perc1 and Perc2 are less than 50%, the final output travel is calculated using the following weighted fusion formula: Final output travel:

[0036] Perc=[(X1-A) / (BA)]×[(X1+X2) / 2]+[(B-X1) / (BA)]×X1.

[0037] Where A is the first preset lower limit threshold; B is the second preset switching threshold.

[0038] The first preset lower threshold A is 3%; the second preset switching threshold B is 50%.

[0039] After step S300, add step S400:

[0040] Step S400: Smooth the final output stroke, specifically by: calculating the absolute value of the difference between the current output stroke and the output stroke at the previous moment; if the difference is greater than the first rate of change threshold, then directly output the current value; if the difference is between the second rate of change threshold and the first rate of change threshold, then approximate the current value with a fixed gradient based on the value at the previous moment.

[0041] The first rate of change threshold is 0.3%; the second rate of change threshold is 0.1%; and the fixed gradient value is 0.1%.

[0042] The present invention adopts the above-mentioned technical solution to achieve the optimal balance between safety and drivability: providing a smooth driving experience; the close integration of diagnosis and fault tolerance makes the system extremely robust; and the smooth processing of the final output stroke enhances the driving experience. Attached Figure Description

[0043] The following is a brief explanation of the contents shown in the attached figure and the markings therein:

[0044] Figure 1 This is a control flow diagram of the present invention;

[0045] Figure 2 This is a flowchart of the specific process of S300 in this invention.

[0046] The diagram shows the process step numbers:

[0047] S100, Acquire sensor signal; S200, Fault diagnosis; S300, Stroke output; 310, Signal conversion; S320, Determine minimum and maximum values; S330, Final stroke output; S400, Smoothing. Detailed Implementation

[0048] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0049] like Figure 1 , Figure 2 The technical solution of the present invention shown is a fault-tolerant control system for a vehicle accelerator pedal. The fault-tolerant control system includes a first sensor signal and a second sensor.

[0050] The primary objective of this invention is to address the problem that existing technologies suffer from a single processing strategy when the dual-channel accelerator pedal sensors experience a consistent failure, leading to a sharp decline in vehicle drivability.

[0051] To address the problems and shortcomings of existing technologies, and to achieve the invention's objective of maintaining normal vehicle operation to the greatest extent possible while ensuring safety and realizing intelligent fault tolerance, the technical solution adopted by this invention is as follows:

[0052] like Figure 1 , Figure 2 As shown, the control method of the vehicle accelerator pedal fault-tolerant control system of the present invention acquires sensor signals in real time, performs fault diagnosis, and outputs a travel strategy; performs consistency fault judgment through a predetermined multiple relationship and a preset error range; and adopts fault-tolerant output logic, including travel percentage conversion, determination of minimum and maximum travel percentage, and obtaining the final output travel through a weighted fusion formula based on the travel interval.

[0053] This invention provides a hierarchical, intelligent fault-tolerant control method, which aims to accurately diagnose faults while using an innovative signal fusion algorithm to output a safe, reliable accelerator pedal travel signal that reflects the driver's intentions under fault conditions.

[0054] The control method includes the following steps:

[0055] Step S100: Acquire the first sensor signal and the second sensor signal in real time;

[0056] Step S200: Perform fault diagnosis on the two sensor signals, wherein the fault diagnosis includes at least consistency fault judgment;

[0057] Step S300: Based on the results of the fault diagnosis, execute the corresponding travel output strategy.

[0058] The consistency fault determination in step S200 is specifically as follows: under the premise that neither of the two sensor signals reports an over-range, open circuit, or short circuit fault, determine whether the voltage value of the first sensor is a predetermined multiple of the voltage value of the second sensor, and whether the difference between the two is within a first preset error range; if not, then a consistency fault is determined to have occurred.

[0059] As a further optimization of the present invention, the predetermined multiple relationship is a 2-fold relationship, and the first preset error range is ±0.5V.

[0060] In step S300, when a consistency failure is determined to have occurred, the following fault-tolerant output logic is executed:

[0061] S310: Convert the first and second channel sensor signals into first stroke percentage Perc1 and second stroke percentage Perc2 respectively;

[0062] S320: Determine the minimum value X1=min(Perc1,Perc2) and the maximum value X2=max(Perc1,Perc2);

[0063] S330: Based on the numerical range of X1, selectively calculate the final output stroke:

[0064] If both Perc1 and Perc2 are greater than or equal to 50%, the final output will be the following:

[0065] Perc = (Perc1 + Perc2) / 2;

[0066] If both Perc1 and Perc2 are less than 50%, the final output travel is calculated using the following weighted fusion formula: Final output travel:

[0067] Perc=[(X1-A) / (BA)]×[(X1+X2) / 2]+[(B-X1) / (BA)]×X1.

[0068] Where A is the first preset lower limit threshold; B is the second preset switching threshold.

[0069] This weighted fusion formula breaks through the traditional linear fusion logic, achieving an adaptive balance between safety and drivability by dynamically adjusting the weights, rather than simply applying existing fusion algorithms.

[0070] The beneficial effects of this invention are:

[0071] 1. Achieves the optimal balance between safety and drivability: This invention breaks through the traditional "either 0 or 1" mindset in fault handling. By introducing an intelligent weighted fusion formula based on the travel range, in the low travel range (X1<50%), when the sensor may have a fault that leads to a low reading, the output result is biased towards the safer smaller value X1, effectively preventing the vehicle from accelerating unexpectedly; in the high travel range, it is biased towards the average value of the two signals, making full use of the sensor's higher reliability at high travel, ensuring smooth power output;

[0072] 2. Provides a smooth driving experience: The weighted fusion formula is essentially a linear interpolation process. When X1 changes between A and B, the output value will smoothly transition between X1 and the average value, completely avoiding the signal jump and vehicle jerking caused by traditional switching strategies, and greatly improving the driving experience in fault conditions;

[0073] 3. Diagnosis and fault tolerance are closely integrated, resulting in extremely robust system: This invention seamlessly integrates quantitative and precise consistency diagnosis with multi-mode and adaptive fault-tolerant output, forming a complete closed-loop solution; the system can not only "detect problems" but also "intelligently solve problems", ensuring that the vehicle can still drive safely and controllably when some sensor systems fail.

[0074] As a further optimization of the present invention, the first preset lower limit threshold A is 3%; the second preset switching threshold B is 50%.

[0075] Experiments have shown that when A=3%, it can effectively filter out false outputs caused by slight sensor drift; when B=50%, it can accurately distinguish between low-stroke (idling, slow) and high-stroke (acceleration, high-speed) operating conditions, ensuring control effectiveness in different scenarios.

[0076] As a further optimization of the present invention, step S400 is added after step S300:

[0077] Step S400: Smooth the final output stroke, specifically by: calculating the absolute value of the difference between the current output stroke and the output stroke at the previous moment; if the difference is greater than the first rate of change threshold, then directly output the current value; if the difference is between the second rate of change threshold and the first rate of change threshold, then approximate the current value with a fixed gradient based on the value at the previous moment.

[0078] As a further optimization of the present invention, the first rate of change threshold is 0.3%; the second rate of change threshold is 0.1%; and the fixed gradient value is 0.1%.

[0079] The fixed gradient value of 0.1% enables a seamless transition, avoiding driving jerks caused by signal abrupt changes. Meanwhile, the first rate of change threshold of 0.3% sets a critical value for power response in emergency situations (such as rapid overtaking or hazard avoidance), ensuring timely response and avoiding safety hazards caused by smooth processing.

[0080] In summary, the technological innovations and advantages of this invention are reflected in the following aspects:

[0081] 1. A fault-tolerant control method for vehicle accelerator pedal, including steps such as real-time acquisition of sensor signals, fault diagnosis, and stroke output strategy;

[0082] 2. The consistency fault judgment method is based on a predetermined multiple relationship and a preset error range;

[0083] 3. Fault-tolerant output logic, including travel percentage conversion, minimum and maximum value determination, and weighted fusion formula based on travel interval;

[0084] 4. The final output stroke is smoothed to improve the driving experience.

[0085] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A control method for a vehicle accelerator pedal fault-tolerant control system, wherein the fault-tolerant control system includes a first sensor signal and a second sensor; characterized in that: The control method described herein acquires sensor signals in real time, performs fault diagnosis, and outputs a travel strategy. Consistency faults are determined by using a predetermined multiple relationship and a preset error range; fault-tolerant output logic is adopted, including stroke percentage conversion, determination of the minimum and maximum stroke percentages, and obtaining the final output stroke through a weighted fusion formula based on the stroke interval.

2. The control method of the vehicle accelerator pedal fault-tolerant control system according to claim 1, characterized in that: The control method includes the following steps: Step S100: Acquire the first sensor signal and the second sensor signal in real time; Step S200: Perform fault diagnosis on the two sensor signals, wherein the fault diagnosis includes at least consistency fault judgment; Step S300: Based on the results of the fault diagnosis, execute the corresponding travel output strategy.

3. The control method of the vehicle accelerator pedal fault-tolerant control system according to claim 2, characterized in that: The consistency fault judgment in step S200 is specifically as follows: under the premise that neither of the two sensor signals reports an over-range, open circuit or short circuit fault, it is determined whether the voltage value of the first sensor is a predetermined multiple of the voltage value of the second sensor, and whether the difference between the two is within the first preset error range. If not, then a consistency failure is determined to have occurred.

4. The control method of the vehicle accelerator pedal fault-tolerant control system according to claim 3, characterized in that: The predetermined multiple relationship is a 2x relationship, and the first preset error range is ±0.5V.

5. The control method of the vehicle accelerator pedal fault-tolerant control system according to claim 1, characterized in that: In step S300, when a consistency failure is determined to have occurred, the following fault-tolerant output logic is executed: S310: Convert the first and second channel sensor signals into first stroke percentage Perc1 and second stroke percentage Perc2 respectively; S320: Determine the minimum value X1=min(Perc1,Perc2) and the maximum value X2=max(Perc1,Perc2); S330: Based on the numerical range of X1, selectively calculate the final output stroke: If both Perc1 and Perc2 are greater than or equal to 50%, the final output will be the following: Perc = (Perc1 + Perc2) / 2; If both Perc1 and Perc2 are less than 50%, the final output travel is calculated using the following weighted fusion formula: Final output travel: Perc=[(X1-A) / (BA)]×[(X1+X2) / 2]+[(B-X1) / (BA)]×X1.

6. The control method of the vehicle accelerator pedal fault-tolerant control system according to claim 5, characterized in that: in, A is the first preset lower threshold; B is the second preset switching threshold.

7. The control method of the vehicle accelerator pedal fault-tolerant control system according to claim 6, characterized in that: The first preset lower threshold A is 3%; the second preset switching threshold B is 50%.

8. The control method of the vehicle accelerator pedal fault-tolerant control system according to claim 2, characterized in that: After step S300, add step S400: Step S400: Smooth the final output stroke, specifically by: calculating the absolute value of the difference between the current output stroke and the output stroke at the previous moment; if the difference is greater than the first rate of change threshold, then directly output the current value; if the difference is between the second rate of change threshold and the first rate of change threshold, then approximate the current value with a fixed gradient based on the value at the previous moment.

9. The control method of the vehicle accelerator pedal fault-tolerant control system according to claim 8, characterized in that: The first rate of change threshold is 0.3%; the second rate of change threshold is 0.1%; and the fixed gradient value is 0.1%.

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