Unexpected torque fault judgment method, system and equipment and storage medium

Abstract

The invention provides an unexpected torque fault judgment method, system and device and a storage medium. The method comprises the steps that vehicle request torque and vehicle actual torque are compared and judged; when the electric drive controller and the vehicle control unit lose communication or the feedback vehicle actual torque is invalid, the vehicle actual torque is estimated and compared with the vehicle request torque for judgment; brake pedal and accelerator pedal information fed back by the pedal signal collector is judged, and whether short circuit, open circuit and synchronous faults exist or not is judged; and performing fault judgment on the battery manager and the electric drive controller. According to the method, the unexpected torque fault is timely and accurately judged and pre-warned through the actual torque and the request torque of the vehicle, abnormal acceleration or deceleration of the vehicle is effectively prevented, the accident risk is reduced, and the safety of a driver and passengers is guaranteed. The vehicle driving torque estimated based on the vehicle acceleration can be independent of a vehicle torque control loop, a reliable comparison reference is provided, and unexpected torque faults are effectively recognized and judged.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicle control, and particularly relates to a method, system, device and storage medium for judging unexpected torque faults. Background Art

[0002] In the prior art, there is a lack of an effective real-time monitoring and judgment mechanism for unexpected torque problems that may occur during vehicle driving. Although the current vehicle control system has a predetermined fault diagnosis ability, its rapid response and precise processing for unexpected torque are not perfect enough. For example, when there is a communication fault between the vehicle's electric drive (MCU) and the vehicle control unit (VCU), or when the battery management system (BMS) has a high fault level, it is impossible to judge and take measures in a timely and accurate manner to make the vehicle enter a safe state. On the other hand, in terms of vehicle acceleration estimation, the accuracy and reliability of the prior art need to be improved. Relying solely on the rate of change of vehicle speed to estimate acceleration may be interfered by external factors, resulting in inaccurate estimation results, thus affecting the judgment of vehicle driving force and the determination of fault levels. Summary of the Invention

[0003] In view of the deficiencies of the prior art, the present invention provides a method for judging unexpected torque faults, which includes,

[0004] Determine the vehicle requested torque and the vehicle actual torque;

[0005] Compare and judge the vehicle requested torque and the vehicle actual torque; at different vehicle speed segments, when the torque difference between the vehicle requested torque and the vehicle actual torque exceeds a predetermined threshold and exceeds the time threshold, it is determined that a fault has occurred;

[0006] Output the judged fault as fault information.

[0007] Furthermore, the method further includes, when the electric drive controller loses communication with the vehicle controller or the feedback of the vehicle actual torque is invalid, estimating the vehicle actual torque and comparing and judging it with the vehicle requested torque; when the difference between the estimated vehicle actual torque and the vehicle requested torque exceeds a predetermined threshold and exceeds the time threshold, it is determined that a fault has occurred.

[0008] Furthermore, the estimation of the vehicle actual torque includes,

[0009] Collect the vehicle speed within a predetermined period and calculate the first acceleration based on this;

[0010] Collect the second acceleration through an acceleration sensor;

[0011] Sum the first acceleration and the second acceleration to obtain the average acceleration;

[0012] Calculate the rolling resistance by estimating the vehicle weight and road adhesion coefficient;

[0013] Estimate the actual torque of the vehicle by multiplying the vehicle mass by the average acceleration and adding the rolling resistance.

[0014] Furthermore, the method further includes,

[0015] Judge the information of the brake pedal and accelerator pedal fed back by the pedal signal collector to judge whether there are short - circuit, open - circuit and synchronization faults; when the judgment result is a fault and exceeds the time threshold, it is judged that a fault has occurred;

[0016] Judge the faults of the battery manager and the electric drive controller. When faults occur in the battery manager and the electric drive controller and exceed the time threshold, it is judged that a fault has occurred and fault information is output.

[0017] An unexpected torque fault judgment system, the system includes: a torque determination module, a fault judgment module and a fault information output module;

[0018] The torque determination module is used to determine and obtain the vehicle requested torque and the vehicle actual torque;

[0019] The fault judgment module is used to compare and judge the vehicle requested torque and the vehicle actual torque. When the torque difference between the vehicle requested torque and the vehicle actual torque exceeds a predetermined threshold and exceeds the time threshold at different vehicle speed segments, it is judged that a fault has occurred;

[0020] The fault information output module is used to output the judged fault as fault information.

[0021] Furthermore, the fault judgment module is also used to estimate the vehicle actual torque and compare and judge it with the vehicle requested torque when the electric drive controller loses communication with the vehicle controller or the feedback of the vehicle actual torque is invalid; when the difference between the estimated vehicle actual torque and the vehicle requested torque exceeds a predetermined threshold and exceeds the time threshold, it is judged that a fault has occurred.

[0022] Furthermore, the fault judgment module is specifically used for,

[0023] Collect the vehicle speed within a predetermined period and calculate the first acceleration based on this;

[0024] Collect the second acceleration through an acceleration sensor;

[0025] Sum the first acceleration and the second acceleration to obtain the average acceleration;

[0026] Calculate the rolling resistance by estimating the vehicle weight and road adhesion coefficient;

[0027] Multiply the vehicle curb weight by the average acceleration and add the rolling resistance to estimate the actual torque of the vehicle.

[0028] Furthermore, the fault judgment module is further configured to judge the information of the brake pedal and the accelerator pedal fed back by the pedal signal collector to determine whether there are short circuit, open circuit and synchronization faults; when the judgment result is a fault and exceeds the time threshold, it is determined that a fault has occurred.

[0029] Perform fault judgment on the battery management unit and the electric drive controller. When a fault occurs in the battery management unit and the electric drive controller and exceeds the time threshold, it is determined that a fault has occurred.

[0030] An electronic device includes a processor, a communication interface, a memory, and a communication bus. Among them, the processor, the communication interface, and the memory complete mutual communication through the communication bus.

[0031] The memory is used to store a computer program.

[0032] When the processor is used to execute the program stored in the memory, it implements the steps of any of the above-mentioned non-expected torque fault judgment methods.

[0033] A computer program product includes a computer program / instructions. When the computer program / instructions are executed by a processor, it implements the steps of any of the above-mentioned non-expected torque fault judgment methods.

[0034] Compared with the prior art, the present invention has the following advantages:

[0035] 1. The present invention proposes to timely and accurately judge and warn of non-expected torque faults through the actual torque of the vehicle and the requested torque of the vehicle, effectively preventing abnormal acceleration or deceleration of the vehicle, reducing the accident risk, and ensuring the safety of the driver and passengers.

[0036] 2. The vehicle drive torque estimated based on the vehicle acceleration in the present invention can be independent of the vehicle torque control loop, providing a reliable comparison benchmark and effectively identifying and judging non-expected torque faults.

[0037] Other features and advantages of the present invention will be described in the subsequent specification, and part of them will become obvious from the specification or be understood by implementing the present invention. The objectives and other advantages of the present invention can be achieved and obtained through the structures pointed out in the specification, the claims, and the drawings. Description of the Drawings

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the accompanying drawings required in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on these drawings.

[0039] Figure 1 Shows a schematic flowchart of a method for judging an unexpected torque fault.

[0040] Figure 2 Shows a schematic flowchart of the actual vehicle driving force estimation in the embodiment of the present invention.

[0041] Figure 3 Shows the vehicle system involved in the embodiment of the present invention. Detailed implementation manners

[0042] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0043] To improve the driving safety of the vehicle, the present invention proposes a method for judging an unexpected torque fault, as Figure 1 shown, which includes:

[0044] 1. Judge the absolute value of the difference between the requested torque of the vehicle and the actual torque of the vehicle, and obtain the threshold value by looking up the table according to the vehicle speed. When the absolute value of the torque difference exceeds the predetermined threshold and lasts for a certain period of time, exceeding the time threshold, it is judged that the fault is mature. Control the vehicle to enter a safe state.

[0045] 2. When the electric drive controller loses communication or the feedback of the actual torque of the vehicle is invalid, estimate the actual torque of the vehicle based on the actual state of the whole vehicle, and compare it with the requested torque of the vehicle for judgment; when the absolute value of the difference between the estimated actual torque of the vehicle and the requested torque exceeds the predetermined threshold and exceeds the time threshold, it is judged that a fault has occurred, and control the vehicle to enter a safe state.

[0046] Optionally, as Figure 2 shown, estimate the actual torque of the vehicle through the vehicle acceleration, and its steps include:

[0047] S1. Collect the vehicle speed within a predetermined period, and calculate the first acceleration a1 based on this;

[0048] S2. Collect the second acceleration a2 through the acceleration sensor;

[0049] S3. Sum the first acceleration a1 and the second acceleration a2 to obtain the average acceleration a3;

[0050] S4. Calculate the rolling resistance by estimating the vehicle mass m and the road adhesion coefficient;

[0051] S5. Multiply the vehicle mass m by the average acceleration value a3 and add the rolling resistance to estimate the actual torque of the vehicle.

[0052] In another embodiment of the present invention, to improve the robustness of the acceleration fusion algorithm, a dynamic compensation method is also adopted, which includes:

[0053] Apply a sliding window variance filter to the first acceleration a1, and its formula is expressed as,

[0054]

[0055] where σ 2 represents the speed sample variance, and its unit is (m / s) 2 ; N represents the number of sample data; v i represents the actual driving speed of the vehicle at the i-th time, and its unit is m / s; represents the average vehicle speed, and its unit is m / s; when the speed variance within the window exceeds 0.5 (m / s) 2 , it is determined as an abnormal fluctuation, and the first acceleration a1 needs to be recalculated;

[0056] Optionally, the method for recalculating the first acceleration a1 is to re-collect the actual driving speed of the vehicle based on the speed data within the window, and then use the re-collected actual driving speed of the vehicle to estimate the first acceleration a1.

[0057] Apply a frequency domain notch filter to the second acceleration a2 to eliminate the 4 - 8 Hz resonance interference caused by road excitation.

[0058] In another embodiment of the present invention, an Extended Kalman Filter (EKF) is also used to estimate the road slope θ, and the road slope estimation error is controlled within ±0.5° through this model. Its state equation is expressed as,

[0059]

[0060] where θ k+1 is the road slope at the time step k + 1; is the angular velocity of the road slope at the time step k + 1; θ k is the road slope at the time step k; is the road slope angular velocity at time step k; Δt is the time step, which is the time interval between two consecutive time steps; w k is the random noise caused by system uncertainty, external interference or modeling error at time step k.

[0061] Its observation equation is expressed as

[0062] z k = sin(θ k ) + v k

[0063] where z k represents the observed value at time step k; θ k represents the true road slope at time step k; v k represents the observation noise at time step k.

[0064] 3. Judge the information of the brake pedal and the accelerator pedal fed back by the pedal signal collector to determine whether there are short circuits, open circuits and synchronization failures; when the judgment result is a failure and exceeds the time threshold, it is determined that a failure has occurred, and the vehicle is controlled to enter a safe state.

[0065] Optionally, the pedal signal collector ensures the reliability of the pedal signal by collecting two-way pedal signals. When a short circuit or open circuit occurs in one of the pedal signals, observe whether a short circuit or open circuit also occurs in the other signal; if the difference between the two-way pedal signals is large, it is set as a synchronization failure.

[0066] 4. Judge the faults of the battery manager and the electric drive controller. When the battery manager and the electric drive controller fail and exceed the time threshold, it is determined that a failure has occurred, and the vehicle is controlled to enter a safe state.

[0067] Optionally, when it is determined that the failure is that the battery manager and the electric drive controller fail, the severity of the failure and the vehicle acceleration need to be considered, the torque is reduced in a gradient manner, and when the vehicle enters a safe state, it is requested to disconnect the main positive and negative relays to ensure driving safety.

[0068] In another embodiment of the present invention, the vehicle system involved in the present invention, as Figure 3 shown, includes: a vehicle control unit (VCU), an instrument cluster (ICM), a battery management system (BMS), an electric drive controller (MCU), an anti-lock braking system (ABS), a pedal signal collector, and an acceleration sensor.

[0069] The vehicle control unit (VCU) is used to receive the vehicle information fed back by the vehicle information collection unit, perform fault judgment based on the fed-back vehicle information, and send fault information to the instrument cluster.

[0070] The vehicle instrument (ICM) is used to receive fault information, turn on the corresponding fault indicator light, perform fault judgment, and alert the driver;

[0071] The battery management system (BMS) is used to collect the states of the main positive and main negative relays and determine the fault level;

[0072] The electric drive controller (MCU) is used to collect the torque and speed of the vehicle motor and determine the fault level;

[0073] The anti-lock braking system (ABS) is used to collect the vehicle speed signal;

[0074] The pedal signal collector is used to collect the signals of the accelerator pedal and the brake pedal;

[0075] The acceleration sensor is used to collect the vehicle acceleration.

[0076] Optionally, the pedal signal collector ensures the reliability of the pedal signal by collecting two-way pedal signals. When one of the pedal signals shows a short circuit or an open circuit, observe whether the other signal also shows a short circuit or an open circuit; if the difference between the two-way pedal signals is large, it is set as a synchronous fault.

[0077] In another embodiment of the present invention, in order to improve the accuracy of non-expected torque fault judgment, the present invention sets different torque difference thresholds and time thresholds according to different vehicle speed ranges. The implementation steps include:

[0078] 1. Vehicle speed range division:

[0079] The vehicle driving speed is divided into three ranges: low speed range: 0 - 20 km / h; medium speed range: 20 - 80 km / h; high speed range: above 80 km / h.

[0080] 2. Torque difference threshold and time threshold setting:

[0081] Different torque difference thresholds and time thresholds are set for each vehicle speed range:

[0082] Low speed range: torque difference threshold: 25 Nm; time threshold: 0.5 seconds

[0083] Medium speed range: torque difference threshold: 20 Nm; time threshold: 1 second

[0084] High speed range: torque difference threshold: 15 Nm; time threshold: 1 second

[0085] 3. Torque difference calculation and judgment:

[0086] Torque difference calculation: Calculate the difference between the vehicle requested torque Trequest and the vehicle actual torque Tactual in real time:

[0087] ΔT = |Trequest - Tactual|

[0088] Vehicle speed range determination: Determine the current vehicle speed range based on the current vehicle speed v.

[0089] Threshold comparison: Within the determined vehicle speed range, determine whether the torque difference ΔT exceeds the corresponding torque difference threshold and whether the duration exceeds the corresponding time threshold.

[0090] 4. Fault judgment logic:

[0091] Low-speed range: When ΔT > 25 Nm and the duration exceeds 0.5 seconds, it is judged as an unexpected torque fault.

[0092] Medium-speed range: When ΔT > 20 Nm and the duration exceeds 1 second, it is judged as an unexpected torque fault.

[0093] High-speed range: When ΔT > 15 Nm and the duration exceeds 1 second, it is judged as an unexpected torque fault.

[0094] In another embodiment of the present invention, assume that when a new energy vehicle is driving at different speeds on the road surface, the communication between the electric drive controller (MCU) and the vehicle control unit (VCU) is suddenly interrupted; the judgment method in different vehicle speed sections includes:

[0095] 1. When the vehicle is driving at a speed of 20 km / h; it is judged that the vehicle is in the low-speed range, and the actual torque of the vehicle is estimated through the vehicle acceleration; when the difference between the estimated torque and the vehicle request torque exceeds 25 Nm and the duration exceeds 0.5 seconds; it is judged as an unexpected torque fault and a safety response is triggered.

[0096] 2. When the vehicle is driving at a speed of 60 km / h; it is judged that the vehicle is in the medium-speed range, and the actual torque of the vehicle is estimated through the vehicle acceleration; when the difference between the estimated torque and the vehicle request torque exceeds 20 Nm and the duration exceeds 1 second; it is judged as an unexpected torque fault and a safety response is triggered.

[0097] 3. When the vehicle is driving at a speed of 100 km / h; it is judged that the vehicle is in the high-speed range, and the actual torque of the vehicle is estimated through the vehicle acceleration; when the difference between the estimated torque and the vehicle request torque exceeds 15 Nm and the duration exceeds 1 second; it is judged as an unexpected torque fault and a safety response is triggered.

[0098] In another embodiment of the present invention, in order to judge the unexpected torque fault of the vehicle in real time and more accurately, the present invention proposes an unexpected torque fault judgment system, which includes: a torque determination module, a fault judgment module, and a fault information output module;

[0099] The torque determination module is used to determine and obtain the vehicle requested torque and the vehicle actual torque;

[0100] The fault judgment module is used to compare and judge the vehicle requested torque and the vehicle actual torque. When the torque difference between the vehicle requested torque and the vehicle actual torque exceeds a predetermined threshold and exceeds the time threshold at different vehicle speed ranges, it is determined that a fault has occurred;

[0101] The fault information output module is used to output the judged fault as fault information;

[0102] The fault judgment module is used to compare and judge the vehicle requested torque and the vehicle actual torque. When the torque difference between the vehicle requested torque and the vehicle actual torque exceeds a predetermined threshold and exceeds the time threshold at different vehicle speed ranges, it is determined that a fault has occurred and the fault information is output.

[0103] In another embodiment of the present invention, the fault judgment module is further used to estimate the vehicle actual torque and compare and judge it with the vehicle requested torque when the electric drive controller loses communication with the vehicle controller or the feedback of the vehicle actual torque is invalid; when the difference between the estimated vehicle actual torque and the vehicle requested torque exceeds a predetermined threshold and exceeds the time threshold, it is determined that a fault has occurred and the fault information is output.

[0104] Optionally, the vehicle actual torque is estimated by the vehicle acceleration, and the steps include:

[0105] S1. Collect the vehicle speed within a predetermined period and calculate the first acceleration therefrom;

[0106] S2. Collect the second acceleration through the acceleration sensor;

[0107] S3. Sum the first acceleration and the second acceleration to obtain the average acceleration;

[0108] S4. Calculate the rolling resistance by estimating the vehicle weight and the road adhesion coefficient;

[0109] S5. Multiply the vehicle mass by the average acceleration and add the rolling resistance to estimate the vehicle actual torque.

[0110] In another implementation of the present invention, the fault judgment module is further used to judge the information of the brake pedal and the accelerator pedal fed back by the pedal signal collector to judge whether there are short circuit, open circuit and synchronization faults; when the judgment result is a fault and exceeds the time threshold, it is determined that a fault has occurred and the fault information is output; and to judge the faults of the battery manager and the electric drive controller, when the battery manager and the electric drive controller have faults and exceed the time threshold, it is determined that a fault has occurred and the fault information is output.

[0111] Based on the above disclosed content, correspondingly, the present invention further provides an electronic device. The electronic device according to an embodiment of the present invention includes at least one processor and at least one storage medium that are electrically connected, the storage medium being electrically connected to the processor, wherein the storage medium stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the method as described above.

[0112] Based on the same inventive concept, the present invention further provides a storage medium that stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the method as described above.

[0113] The above description and the drawings fully illustrate the embodiments of the present invention, enabling those skilled in the art to practice them. Other embodiments may include structural and other changes. The embodiments only represent possible variations. Unless explicitly required, the individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The embodiments of the present invention are not limited to the structures already described and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present invention is only limited by the appended claims.

Claims

1. A method for judging an unexpected torque fault, characterized in that The method includes: Determine the vehicle requested torque and the vehicle actual torque; Compare and judge the vehicle requested torque with the vehicle actual torque; Under different vehicle speed ranges, when the torque difference between the vehicle requested torque and the vehicle actual torque exceeds a predetermined threshold and exceeds the time threshold, it is determined that a fault has occurred; Output the determined fault as fault information.

2. The non-expected torque fault judgment method according to claim 1, wherein The method further includes, when the electric drive controller loses communication with the vehicle controller or the feedback of the vehicle actual torque is invalid, estimating the vehicle actual torque and comparing and judging it with the vehicle requested torque; When the difference between the estimated vehicle actual torque and the vehicle requested torque exceeds a predetermined threshold and exceeds the time threshold, it is determined that a fault has occurred.

3. The non-expected torque fault judgment method according to claim 2, characterized in that The estimating of the vehicle actual torque includes: Collect the vehicle speed within a predetermined period and calculate the first acceleration based on this; Collect the second acceleration through an acceleration sensor; Sum the first acceleration and the second acceleration to obtain the average acceleration; Calculate the rolling resistance by estimating the vehicle weight and the road adhesion coefficient; Multiply the vehicle mass by the average acceleration and add the rolling resistance to estimate the vehicle actual torque.

4. The method for judging an unexpected torque fault according to claim 1, wherein, The method further includes: Judge the information of the brake pedal and the accelerator pedal feedback by the pedal signal collector to determine whether there are short circuit, open circuit and synchronization faults; when the judgment result is a fault and exceeds the time threshold, it is determined that a fault has occurred; Judge the faults of the battery manager and the electric drive controller. When faults occur in the battery manager and the electric drive controller and exceed the time threshold, it is determined that a fault has occurred and fault information is output.

5. A non-expected torque fault judgment system, characterized in that, The system includes: a torque determination module, a fault judgment module and a fault information output module; The torque determination module is used to determine and obtain the vehicle requested torque and the vehicle actual torque; The fault judgment module is used to compare and judge the vehicle requested torque with the vehicle actual torque. Under different vehicle speed ranges, when the torque difference between the vehicle requested torque and the vehicle actual torque exceeds a predetermined threshold and exceeds the time threshold, it is determined that a fault has occurred; The fault information output module is used to output the determined fault as fault information.

6. The non-expected torque fault judgment system according to claim 5, wherein The fault judgment module is further used to estimate the vehicle actual torque and compare and judge it with the vehicle requested torque when the electric drive controller loses communication with the vehicle controller or the feedback of the vehicle actual torque is invalid; when the difference between the estimated vehicle actual torque and the vehicle requested torque exceeds a predetermined threshold and exceeds the time threshold, it is determined that a fault has occurred.

7. The non-expected torque fault judgment system according to claim 6, wherein The fault judgment module specifically includes: Collect the vehicle speed within a predetermined period and calculate the first acceleration based on this; Collect the second acceleration through an acceleration sensor; Sum the first acceleration and the second acceleration to obtain the average acceleration; Calculate the rolling resistance by estimating the vehicle weight and the road adhesion coefficient; Multiply the vehicle mass by the average acceleration and add the rolling resistance to estimate the vehicle actual torque.

8. The unexpected torque fault judgment system according to claim 5, characterized in that The fault judgment module is further used to judge the information of the brake pedal and the accelerator pedal feedback by the pedal signal collector to determine whether there are short circuit, open circuit and synchronization faults; when the judgment result is a fault and exceeds the time threshold, it is determined that a fault has occurred; Fault judgment is performed on the battery management unit and the electric drive controller. When a fault occurs in the battery management unit and the electric drive controller and exceeds the time threshold, it is determined that a fault has occurred.

9. An electronic device, characterized in that, It includes a processor, a communication interface, a memory, and a communication bus. Among them, the processor, the communication interface, and the memory complete mutual communication through the communication bus; The memory is used to store computer programs; When the processor is used to execute the program stored on the memory, it implements the steps of the unexpected torque fault judgment method described in any one of claims 1-4.

10. A computer program product, comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, it implements the steps of the unexpected torque fault judgment method described in any one of claims 1-4.

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