A method and system for handling redundant communication failure of a steer-by-wire system

Abstract

This invention provides a method and system for handling redundant communication faults in a steer-by-wire system, relating to the field of steer-by-wire technology. The method includes: acquiring the original communication status parameters of independently configured first and second communication channels; the first and second communication channels are two independent communication channels between the main control unit and the redundant control unit in the steer-by-wire system; verifying the original communication status parameters based on a preset multi-dimensional verification strategy, and determining the current fault level of the system by combining preset fault level judgment rules and a dynamically adjustable fault judgment cycle, wherein the fault level is based on the communication channel status combination and fault severity; and executing matching fault handling, signal switching, and current regulation strategies based on the fault level, combining hierarchical signal control logic and a motor current gradient limiting mechanism to achieve precise switching between system signals and motor current.

Description

Technical Field

[0001] This invention relates to the field of steer-by-wire technology, specifically a method and system for handling redundant communication faults in a steer-by-wire system. Background Technology

[0002] With the rapid development of automotive electrification and intelligentization technologies, steer-by-wire systems, with their flexible spatial layout, superior handling performance, and potential for deep integration with autonomous driving systems, are becoming a key core technology for intelligent vehicles. Steer-by-wire systems achieve steering control by replacing traditional mechanical connections with electronic signals, and their safety highly depends on the reliability of the control system. To ensure that the system can maintain basic steering function even in the event of a single failure, a dual-redundancy architecture, including a main control unit and redundant control units, is typically adopted. These two units interact with each other and synchronize their states through independent communication channels.

[0003] In existing technologies, fault handling of redundant communication channels often employs a binary diagnostic mechanism based on simple threshold judgments. For example, it directly determines whether the channel is "normal" or "faulty" based on packet loss counts or checksum error flags, and then performs a switching operation. This method has significant shortcomings: On the one hand, it is difficult to identify gradual degradation or intermittent abnormalities in communication quality, which can easily lead to delayed fault response or frequent erroneous handover. On the other hand, the lack of fine-grained assessment of the impact of faults makes it impossible to implement differentiated handling strategies based on fault levels, which may cause sudden changes or unstable degradation in system performance, affecting the smoothness and safety of vehicle handling.

[0004] Therefore, a method and system for handling redundant communication faults in a steer-by-wire system are provided. This method can perform multi-dimensional comprehensive analysis of the communication status and accurately classify the fault levels, thereby improving the reliability and safety of fault handling operations and enhancing the robustness, safety, and driving experience of the steer-by-wire system under abnormal communication conditions. Summary of the Invention

[0005] To address the aforementioned technical problems, the present invention aims to provide a method and system for handling redundant communication faults in a steer-by-wire system. This method and system can perform multi-dimensional comprehensive analysis of the communication status and accurately classify fault levels, thereby improving the reliability and safety of fault handling operations and enhancing the robustness, safety, and driving experience of the steer-by-wire system under abnormal communication conditions.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a method for handling redundant communication faults in a steer-by-wire system, the method comprising: Obtain the original communication status parameters of the independently configured first and second communication channels; the first and second communication channels are two independent communication channels between the main control unit and the redundant control unit in the steer-by-wire system; The original communication status parameters are verified based on a preset multi-dimensional verification strategy. Combined with preset fault level judgment rules and a dynamically adjustable fault judgment cycle, the current fault level of the system is determined. The fault level is based on the combination of communication channel status and the severity of the fault. Based on the fault level, matching fault handling, signal switching, and current regulation strategies are executed. By combining hierarchical signal control logic and motor current gradient limiting mechanism, precise switching between system signals and motor current is achieved.

[0007] Preferably, the original communication status parameters are verified based on a preset multi-dimensional verification strategy, and the current system fault level is determined by combining preset fault level judgment rules and a dynamically adjustable fault judgment period. The fault level is based on the combination of communication channel status and the severity of the fault, including: Based on the original communication status parameters corresponding to the first communication channel and the original communication status parameters corresponding to the second communication channel, the two communication channels are verified in multiple dimensions to obtain the corresponding verification result data; the verification result data includes CRC verification result, amplitude detection result, frame status detection result and second communication status; Based on the verification results data, combined with the preset fault level judgment rules and the dynamically adjustable fault judgment cycle, the corresponding fault level is determined. The fault level includes sub-health, level 1 fault, level 2 fault and level 3 fault.

[0008] Preferably, the determination of the corresponding fault level based on the verification result data, combined with preset fault level determination rules and a dynamically adjustable fault determination cycle, includes: Based on one or more of the CRC check result, amplitude detection result, frame status detection result, and second communication status, a preset inspection-fault level association table is queried to determine the corresponding fault level. The inspection-fault level association table contains a set of judgment conditions for corresponding level 1 faults, level 2 faults, and level 3 faults. The set of conditions for determining the first-level fault includes any one of the following conditions: the CRC check of the communication signal of the first communication channel fails, the amplitude of the communication signal of the first communication channel exceeds the preset amplitude range, or the communication signal frame of the first communication channel is lost or an error frame is detected. The set of criteria for determining a level-two fault, assuming the communication status of the second communication channel is normal, includes any one of the following conditions: The communication signal of the first communication channel enters. Status: The amplitude of the communication signal of the first communication channel exceeds the preset amplitude range for N consecutive transmission cycles or the communication signal of the first communication channel is not received for N consecutive transmission cycles; The set of criteria for determining the Level 3 fault, under the premise that the communication status of the second communication channel is abnormal, includes any one of the following conditions: The communication signal of the first communication channel enters the busoff state, the amplitude of the communication signal of the first communication channel exceeds the preset amplitude range for N consecutive transmission cycles, or the communication signal of the first communication channel is not received for N consecutive transmission cycles, where N is a dynamically adjustable fault determination cycle, which is adjusted based on a preset dynamic adjustment strategy.

[0009] Preferably, N is a dynamically adjustable fault determination period, which is adjusted based on a preset dynamic adjustment strategy as follows: Acquire real-time operating status parameters that characterize the dynamic needs of the vehicle, as well as historical quality parameters that characterize the reliability of the communication channel; The real-time operating status parameters are mapped to a first type of adjustment factor, and the historical quality parameters are mapped to a second type of adjustment factor; Multiple vehicle mission profiles are predefined, each of which is associated with a threshold range of a set of real-time operating status parameters, and a fault determination cycle benchmark value is preset for each vehicle mission profile. ; The real-time operating status parameters are matched with the threshold range to determine and switch the vehicle mission profile to which the current vehicle belongs, and the dedicated reference value corresponding to the vehicle mission profile is set. Set as the current fault determination cycle benchmark value. ; Coupling the first type of adjustment factor and the second type of adjustment factor with respect to the benchmark value Perform coordinated modulation and output in real time. .

[0010] Preferably, the step of switching the vehicle mission profile to which the current vehicle belongs involves changing the dedicated reference value corresponding to the vehicle mission profile. Set as the current fault determination cycle benchmark value. include: After determining the vehicle mission profile to which the current vehicle belongs, the vehicle mission profile is switched. If a switch is detected as imminent or has already occurred, the reference value is not immediately changed from the current reference value. Updated to the dedicated reference value corresponding to the target vehicle mission profile. ; At this point, based on the preset transition function and dynamic transition time, the reference value is adjusted. From the current value Gradual change to The dynamic transition time is dynamically adjusted based on the real-time detected vehicle lateral stability parameters and the difference between the dedicated reference values ​​between the two vehicle mission profiles involved in the switching.

[0011] Preferably, the preset fault determination cycle benchmark value is specifically for the vehicle mission profile. The setup process is as follows: For each predefined vehicle mission profile, a unique damage tolerance envelope is defined, which is composed of the maximum permissible cumulative damage value. Quantitative description of the natural recovery rate of damage; Simultaneously acquire typical communication interference statistical characteristics corresponding to the vehicle mission profile; Based on the aforementioned damage tolerance envelope and interference statistical characteristics, a damage dynamic evolution model is constructed for simulation. In this model, instantaneous damage occurs when the amplitude exceeds the limit or a CRC error occurs, and the system accumulates damage. The calculation, update, and iteration are performed based on a preset damage accumulation calculation formula; the core safety constraint of the simulation is the cumulative damage of the system over the entire simulation time series. Must always be lower than ; During the simulation, a search algorithm is used to address and output a specific fault determination cycle value. If the fault determination cycle value is the largest among all candidate values ​​that satisfy the core safety constraints, then the fault determination cycle value is designated as the fault determination cycle benchmark value specific to the vehicle mission profile. .

[0012] Preferably, the precise switching of the system signal includes: When the fault level is a Level 1 fault, the main control unit and the redundant control unit use the values ​​before the Level 1 fault was detected for control. When the fault level is level 2, the main control unit and the redundant control unit switch to the second communication channel to communicate. When the fault level is level three, the main control unit and the redundant control unit use their own collected signals for independent control, and the steer-by-wire system immediately sends an emergency warning signal to the vehicle controller via the CAN bus indicating that the redundant communication has completely failed.

[0013] Preferably, the precise switching of motor current includes: When the fault level is Level 1 or Level 2, the current of the main control unit and the redundant control unit is directly output; When the fault level is three, the redundant signal verification is turned off, and the redundant control unit calculates the signal switching compensation amount of the signals collected by the key sensors. Based on the signal switching compensation amount and the historical main control angle signal value of the main control unit, the corresponding angle signal after signal switching is calculated. Based on the angle signal, the vehicle's current speed, and the preset current gradient calibration parameters, the current change gradient limit is calculated. Based on the current change gradient limit, the total motor current output after the switching signal is gradient-limited to obtain the final motor current output value.

[0014] A second aspect of the present invention also provides a redundant communication fault handling system for a steer-by-wire system, comprising: The acquisition module is used to acquire the original communication status parameters of the independently configured first and second communication channels; the first and second communication channels are two independent communication channels between the main control unit and the redundant control unit in the steer-by-wire system; The determination module is used to verify the original communication status parameters based on a preset multi-dimensional verification strategy, and determine the current fault level of the system by combining preset fault level judgment rules and a dynamically adjustable fault judgment cycle. The fault level is based on the combination of communication channel status and the severity of the fault. The processing module is used to execute matching fault handling, signal switching and current regulation strategies based on the fault level, and combine hierarchical signal control logic and motor current gradient limiting mechanism to complete the precise switching of system signals and motor current.

[0015] Compared with the prior art, the beneficial effects of the present invention are: This solution performs a multi-dimensional comprehensive analysis of the dual-redundant communication channels by acquiring various raw parameters such as CRC check results, amplitude detection results, frame status detection results, and second channel status. Based on a preset set of judgment conditions, it accurately classifies system faults into four levels: "sub-healthy," "Level 1 fault," "Level 2 fault," and "Level 3 fault." This achieves continuous and accurate diagnosis of communication faults, from minor anomalies to complete failures. This hierarchical mechanism avoids the lag and insufficient robustness of traditional "normal / fault" binary judgments, laying a precise judgment foundation for subsequent implementation of differentiated and appropriate fault handling strategies, and significantly improving the system's ability to perceive and classify complex communication anomalies.

[0016] This solution introduces a dynamic adjustment strategy to set the critical fault determination cycle parameter N. This strategy involves defining multiple "vehicle task profiles" associated with vehicle operating states (such as vehicle speed and steering angular velocity), and pre-setting a dedicated benchmark determination cycle for each profile. Based on damage tolerance envelope ( Based on the characteristics of typical communication interference, and through simulation using a damage dynamic evolution model, the optimal solution that satisfies the full life-cycle safety constraints is derived in reverse. During vehicle mission profile switching, a dynamic transition mechanism based on the difference between vehicle lateral stability and a baseline value is employed to achieve a smooth and safe switching of the N value. Intelligent adaptive adjustment of fault detection sensitivity is implemented. While ensuring system safety (within the damage tolerance limit), this mechanism can optimize the fault detection threshold based on the actual dynamic needs of the vehicle and the historical quality of the communication channel. This avoids erroneous switching or disturbances due to excessive sensitivity in low-risk conditions, while ensuring rapid and reliable fault detection in high-risk or channel-degraded situations, thus achieving the optimal balance between system robustness, safety, and driving smoothness.

[0017] This solution employs a progressively tiered signal and current processing approach for different fault levels. At the signal level: Level 1 faults maintain the previous value; Level 2 faults switch to a backup channel; and Level 3 faults involve independent operation of both control units and reporting a vehicle-wide alarm. At the current level: For the most severe Level 3 faults, a combined strategy of signal switching compensation and current gradient limiting is specifically designed. By calculating the compensation amount, reconstructing the angle signal, and dynamically limiting the current gradient based on vehicle speed and calibration parameters, a stable and safe motor current output is ultimately achieved. This achieves a high degree of synergy between fault handling and system function assurance. This strategy ensures that the system can execute optimal fault-tolerant operations across the entire fault spectrum, from minor anomalies to dual-channel failures. Especially under the most severe Level 3 faults, not only is the basic steering function maintained through independent control of both units, but precise current gradient control also minimizes torque spikes or jumps that may occur due to signal source switching, effectively ensuring vehicle lateral stability and driver experience. Ultimately, this comprehensively improves the functional safety and driving experience continuity of the steer-by-wire system under extreme communication failure conditions. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0019] Figure 1 This is a schematic diagram of a method for handling redundant communication faults in a steer-by-wire system. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0022] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0023] Example 1 like Figure 1 As shown in the figure, this embodiment discloses a method for handling redundant communication faults in a steer-by-wire system, the method comprising: Obtain the original communication status parameters of the independently configured first and second communication channels; the first and second communication channels are two independent communication channels between the main control unit and the redundant control unit in the steer-by-wire system; in this embodiment, the main control unit (T1) and the redundant control unit (T2) of the steer-by-wire system communicate via inter-board communication. and To achieve redundant communication, the first communication channel is between boards. The second communication channel is In the specific signal transmission process: • The main control unit (T1) passes through The communication vector is transmitted to the redundant control unit (T2), denoted as... ; • Redundant control unit (T2) via Transmit the communication vector to the main control unit (T1), denoted as ; • The main control unit (T1) passes through The communication vector is transmitted to the redundant control unit (T2), denoted as... ; • Redundant control unit (T2) via Transmit the communication vector to the main control unit (T1), denoted as ; • Redundant control unit (T2) detects the angle of the steering wheel or steering actuator. ; • Maximum limit of motor current output of control unit When the steer-by-wire system is operating normally, the main control unit and the redundant control unit employ... Communication signals.

[0024] The original communication status parameters are verified based on a preset multi-dimensional verification strategy. Combined with preset fault level judgment rules and a dynamically adjustable fault judgment cycle, the current fault level of the system is determined. The fault level is based on the combination of communication channel status and the severity of the fault. It should be noted that the verification of the original communication status parameters based on the preset multi-dimensional verification strategy, combined with the preset fault level judgment rules and the dynamically adjustable fault judgment period, determines the current fault level of the system. The fault level is divided based on the communication channel status combination and the severity of the fault, including: Based on the original communication status parameters corresponding to the first communication channel and the original communication status parameters corresponding to the second communication channel, the two communication channels are verified in multiple dimensions to obtain the corresponding verification result data; the verification result data includes CRC verification result, amplitude detection result, frame status detection result and second communication status; Based on the verification results data, combined with the preset fault level judgment rules and the dynamically adjustable fault judgment cycle, the corresponding fault level is determined. The fault level includes sub-health, level 1 fault, level 2 fault and level 3 fault.

[0025] In this embodiment, determining the corresponding fault level based on the verification result data, combined with preset fault level determination rules and a dynamically adjustable fault determination cycle, includes: Based on one or more of the CRC check result, amplitude detection result, frame status detection result, and second communication status, a preset inspection-fault level association table is queried to determine the corresponding fault level. The inspection-fault level association table contains a set of judgment conditions for corresponding level 1 faults, level 2 faults, and level 3 faults. The set of conditions for determining the first-level fault includes any one of the following conditions: the CRC check of the communication signal of the first communication channel fails, the amplitude of the communication signal of the first communication channel exceeds the preset amplitude range, or the communication signal frame of the first communication channel is lost or an error frame is detected. The set of criteria for determining a level-two fault, assuming the communication status of the second communication channel is normal, includes any one of the following conditions: The communication signal of the first communication channel enters. Status: The amplitude of the communication signal of the first communication channel exceeds the preset amplitude range for N consecutive transmission cycles or the communication signal of the first communication channel is not received for N consecutive transmission cycles; The set of criteria for determining the Level 3 fault, under the premise that the communication status of the second communication channel is abnormal, includes any one of the following conditions: The communication signal of the first communication channel enters. The status is determined by the fact that the amplitude of the communication signal of the first communication channel exceeds the preset amplitude range for N consecutive transmission cycles or the communication signal of the first communication channel is not received for N consecutive transmission cycles, where N is a dynamically adjustable fault determination cycle, which is adjusted based on a preset dynamic adjustment strategy.

[0026] Specifically, N is a dynamically adjustable fault determination period, which is adjusted based on a preset dynamic adjustment strategy as follows: Acquire real-time operating status parameters that characterize the dynamic needs of the vehicle, as well as historical quality parameters that characterize the reliability of the communication channel; The real-time operating status parameters are mapped to a first type of adjustment factor, and the historical quality parameters are mapped to a second type of adjustment factor. In this embodiment, the real-time operating status parameters include the current vehicle speed, data from the vehicle CAN network, the absolute steering angle velocity of the steering wheel, the vehicle lateral acceleration, and the steering mode from the driving mode selector.

[0027] Type I Adjustment Factor To construct a comprehensive dynamic risk field model, the tolerance window for steering system failures of a vehicle under its current motion state is quantified. The first step is to develop a dynamic risk index. The specific calculation formula is as follows: In the formula, This is a lookup table function related to the vehicle brakes, based on the steering angular velocity, representing the maximum speed at the current vehicle speed. Below, the system's maximum permissible or typical steering angular velocity, This is a dimensionless weighted coefficient. Based on the dynamic risk index, the specific calculation of the first type of adjustment factor is as follows: In the formula, and These are the upper and lower thresholds for the first type of adjustment factor. The corresponding risk index threshold, This is the curve steepness coefficient.

[0028] Second type of adjustment factor It is obtained by normalizing the number of communication errors per unit time as a first error rate ratio, normalizing the intensity of the deterioration trend obtained from trend analysis of historical error interval sequences as a second trend ratio, and normalizing the intensity of sudden error events as a third burst ratio, and then linearly superimposing the first, second, and third ratios onto a baseline value according to preset weights. The intensity of a sudden error event can be defined as (number of errors within the burst window) / (burst window duration × baseline error rate).

[0029] Multiple vehicle mission profiles are predefined, each of which is associated with a threshold range of a set of real-time operating status parameters, and a fault determination cycle benchmark value is preset for each vehicle mission profile. ; The real-time operating status parameters are matched with the threshold range to determine and switch the vehicle mission profile to which the current vehicle belongs, and the dedicated reference value corresponding to the vehicle mission profile is set. Set as the current fault determination cycle benchmark value. .

[0030] Specifically, the step of switching the vehicle mission profile to which the current vehicle belongs involves changing the dedicated reference value corresponding to the vehicle mission profile. Set as the current fault determination cycle benchmark value. include: After determining the vehicle mission profile to which the current vehicle belongs, the vehicle mission profile is switched. If a switch is detected as imminent or has already occurred, the reference value is not immediately changed from the current reference value. Updated to the dedicated reference value corresponding to the target vehicle mission profile. ; At this point, based on the preset transition function and dynamic transition time, the reference value is adjusted. From the current value Gradual change to Wherein, the dynamic transition time The system dynamically adjusts based on the real-time detected vehicle lateral stability parameters and the difference between the dedicated reference values ​​between the two vehicle mission profiles involved in the switch.

[0031] In this embodiment, the formula for calculating the dynamic transition time is: , In the formula, The constraint is a dynamic constraint, which is based on the maximum permissible rate of change of the fault determination benchmark value dynamically adjusted according to the real-time vehicle lateral stability parameters. The maximum permissible rate of change based on The dynamic adjustment coefficient that is negatively correlated with the vehicle's lateral stability is specifically the normalized yaw angle: , This is a reference threshold.

[0032] The transition function includes one of the following: first-order inertial filtering, linear interpolation, S-curve function, and acceleration-constrained uniform acceleration model.

[0033] For the first time, the fault determination period N is explicitly elevated from a fixed parameter to a dynamic variable jointly determined by the vehicle's real-time state (such as vehicle speed and yaw rate) and historical channel quality (such as historical bit error rate). The concept of a vehicle mission profile is creatively proposed, mapping complex real-time state parameters to finite, predefined typical operating conditions. This solves the complexity problem of directly mapping continuous dynamics to decision-making, achieving dimensionality reduction from complex problems to simple decision logic through operating condition classification, making the dynamic adjustment strategy engineering-feasible. Furthermore, for the critical moment of vehicle mission profile switching, a smooth switching mechanism based on a transition function and dynamic transition time is designed, accurately identifying switching risks. Secondly, the transition time is dynamically correlated with "vehicle lateral stability parameters" (key indicators directly affecting safety) and "baseline value difference" (switching amplitude), reflecting real-time perception and protection of the system's dynamic safety boundary—a refined safety enhancement design.

[0034] Specifically, the preset fault determination cycle benchmark value is specifically for the vehicle mission profile. The setup process is as follows: For each predefined vehicle mission profile, a unique damage tolerance envelope is defined, which is composed of the maximum permissible cumulative damage value. Quantitative analysis of natural recovery rate of injury describe; Simultaneously acquire typical communication interference statistical characteristics corresponding to the vehicle mission profile; Based on the aforementioned damage tolerance envelope and interference statistical characteristics, a damage dynamic evolution model is constructed for simulation. In the damage dynamic evolution model, instantaneous damage is generated when an amplitude exceeds the limit or a CRC error occurs. System cumulative damage The calculation, update, and iteration are performed based on a preset damage accumulation calculation formula; the core safety constraint of the simulation is the cumulative damage of the system over the entire simulation time series. Must always be lower than The preset formula for calculating cumulative damage is as follows: ; During the simulation, a search algorithm is used to address and output a specific fault determination cycle value. If the fault determination cycle value is the largest among all candidate values ​​that satisfy the core safety constraints, then the fault determination cycle value is designated as the fault determination cycle benchmark value specific to the vehicle mission profile. .

[0035] The search algorithm described in this embodiment is the golden section method, and the specific steps are as follows: in the feasible interval Inside, select two interior points according to the golden ratio. , .

[0036] Test in simulation respectively and The corresponding evaluation function for the decision period is as follows: if the simulation passes, the function value equals the candidate period value itself (larger values ​​are encouraged); if it fails, the function value is set to 0 or negative infinity (indicating unacceptable performance). (Comparison) and The objective function is defined for candidate periodic values. Perform damage tolerance simulation and define This is the difference between the maximum cumulative damage and the upper limit of damage during the simulation. A value always greater than 0 indicates a pass, and a larger value indicates a more sufficient safety margin.

[0037] like Then discard the interval. ,make new And calculate the new proportions. Conversely, the interval is discarded. ,make new Calculate the new .

[0038] When the interval length is less than the precision When the interval is in its minimum value, the average of the two endpoints of the current interval is taken as the optimal value. The calibration value is determined. Specifically, a damage tolerance envelope is set for each vehicle mission profile, incorporating typical communication interference statistics for that profile to simulate real-world fault impacts. Under the core safety constraint that cumulative damage never exceeds the limit, the maximum value that satisfies this constraint is derived through simulation and search algorithms. The goal of searching for the largest candidate value among all candidates that satisfy the safety constraints as the baseline value directly serves the core requirement of improving the robustness and smoothness of the system. This means that, while ensuring absolute safety, the system provides itself with the maximum fault tolerance and anti-interference margin, thereby minimizing false triggering caused by noise or transient interference.

[0039] Coupling the first type of adjustment factor and the second type of adjustment factor with respect to the benchmark value Perform coordinated modulation and output in real time. .

[0040] Specifically, the signal switching operation includes: When the fault level is Level 1, the main control unit and the redundant control unit use the values ​​before the Level 1 signal failure is detected for control. In this embodiment, when a Level 1 fault is detected, the control unit continues to use the values ​​before the Level 1 signal failure is detected for control; that is, at this time, the main control unit and the redundant control unit still use the values ​​before the Level 1 signal failure is detected. Signals and To take control.

[0041] When the fault level is level two, the main control unit and the redundant control unit switch to the second communication channel for communication; in this embodiment, the control unit switches to using the SPI communication signal, and the main control unit uses... replace Signal, redundant control unit use replace It continuously monitors whether SPI communication is normal and whether CANFD communication has recovered. If CANFD communication is recovered, it switches back to normal use of the CANFD signal. If CANFD is not recovered and SPI communication is abnormal, it enters a level three fault state.

[0042] When the fault level is level three, the main control unit and the redundant control unit use their own collected signals for independent control, and the steer-by-wire system immediately sends an emergency warning signal to the vehicle controller via the CAN bus indicating that the redundant communication has completely failed.

[0043] The process of switching the current includes: When the fault level is Level 1 or Level 2, the current of the main control unit and the redundant control unit is directly output; When the fault level is three, the redundant signal verification is turned off, and the redundant control unit calculates the signal switching compensation amount of the signals collected by the key sensors. Based on the signal switching compensation amount and the historical main control angle signal value of the main control unit, the corresponding angle signal after signal switching is calculated. Based on the angle signal, the vehicle's current speed, and the preset current gradient calibration parameters, the current change gradient limit is calculated. Based on the current change gradient limit, the total motor current output after the switching signal is gradient-limited to obtain the final motor current output value. .

[0044] Specifically, redundant signal verification is disabled, and the redundant control unit calculates the signal switching compensation amount for key sensor signals such as the steering wheel and steering actuator angles and angular velocities. For example, to calculate the compensation amount for angle signals, the specific steps are as follows: In the formula, Before the failure occurred Historical master control angle signal value within each sampling period and the angle signal value collected by the redundant control unit , This is the compensation amount for angle signal switching. To calibrate the preset compensation angle gain coefficient, and after switching redundant angle signals 2 It decays rapidly to 0 within a few cycles.

[0045] Angle signal after signal switching ; Specifically, the redundant control unit calculates the total motor current output after the switching signal. and current change gradient limit And by comparing the motor current of the previous cycle The output is obtained by limiting the gradient of the current change: In the formula, The current gradient calibration parameter is typically between 0.05 and 0.1. For vehicle speed. It is dynamically calibrated.

[0046] like ,but ; Conversely, Furthermore, once the current reaches the target value, the current gradient is no longer restricted.

[0047] This embodiment also discloses a redundant communication fault handling system for a steer-by-wire system, which implements the above-mentioned method for handling redundant communication faults in a steer-by-wire system, including: The acquisition module is used to acquire the original communication status parameters of the independently configured first and second communication channels; the first and second communication channels are two independent communication channels between the main control unit and the redundant control unit in the steer-by-wire system; The determination module is used to verify the original communication status parameters based on a preset multi-dimensional verification strategy, and determine the current fault level of the system by combining preset fault level judgment rules and a dynamically adjustable fault judgment cycle. The fault level is based on the combination of communication channel status and the severity of the fault. The processing module is used to execute matching fault handling, signal switching and current regulation strategies based on the fault level, and combine hierarchical signal control logic and motor current gradient limiting mechanism to complete the precise switching of system signals and motor current.

[0048] Optionally, in this embodiment, those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing the hardware related to the terminal device. The program can be stored in a computer-readable storage medium, which may include: flash drive, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0049] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0050] If the integrated units in the above embodiments are implemented as software functional units and sold or used as independent products, they can be stored in the aforementioned computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause one or more electronic devices to execute all or part of the steps of the methods described in the various embodiments of this application.

[0051] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0052] In the several embodiments provided in this application, it should be understood that the disclosed application can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection of units or modules may be electrical or other forms.

[0053] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0054] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0055] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A method for handling redundant communication faults in a steer-by-wire system, characterized in that, The method includes: Obtain the original communication status parameters of the independently configured first and second communication channels; the first and second communication channels are two independent communication channels between the main control unit and the redundant control unit in the steer-by-wire system; The original communication status parameters are verified based on a preset multi-dimensional verification strategy. Combined with preset fault level judgment rules and a dynamically adjustable fault judgment cycle, the current fault level of the system is determined. The fault level is based on the combination of communication channel status and the severity of the fault. Based on the fault level, matching fault handling, signal switching, and current regulation strategies are executed. By combining hierarchical signal control logic and motor current gradient limiting mechanism, precise switching between system signals and motor current is achieved.

2. The method for handling redundant communication faults in a steer-by-wire system according to claim 1, characterized in that, The original communication status parameters are verified based on a preset multi-dimensional verification strategy. Combined with preset fault level determination rules and a dynamically adjustable fault determination cycle, the current fault level of the system is determined. The fault level is based on the communication channel status combination and fault severity, including: Based on the original communication status parameters corresponding to the first communication channel and the original communication status parameters corresponding to the second communication channel, the two communication channels are verified in multiple dimensions to obtain the corresponding verification result data; the verification result data includes CRC verification result, amplitude detection result, frame status detection result and second communication status; Based on the verification results data, combined with the preset fault level judgment rules and the dynamically adjustable fault judgment cycle, the corresponding fault level is determined. The fault level includes sub-health, level 1 fault, level 2 fault and level 3 fault.

3. The method for handling redundant communication faults in a steer-by-wire system according to claim 2, characterized in that, The determination of the corresponding fault level based on the verification result data, combined with the preset fault level determination rules and the dynamically adjustable fault determination cycle, includes: Based on one or more of the CRC check result, amplitude detection result, frame status detection result, and second communication status, a preset inspection-fault level association table is queried to determine the corresponding fault level. The inspection-fault level association table contains a set of fault level judgment rules corresponding to level 1, level 2, and level 3 faults. The set of rules for determining the first-level fault includes any one of the following conditions: the CRC check of the communication signal of the first communication channel fails, the amplitude of the communication signal of the first communication channel exceeds the preset amplitude range, or the communication signal frame of the first communication channel is lost or an error frame is detected. The set of rules for determining level two faults, assuming the communication status of the second communication channel is normal, includes any one of the following conditions: The communication signal of the first communication channel enters. Status: The amplitude of the communication signal of the first communication channel exceeds the preset amplitude range for N consecutive transmission cycles or the communication signal of the first communication channel is not received for N consecutive transmission cycles; The set of rules for determining level three faults, under the premise that the communication status of the second communication channel is abnormal, includes any one of the following conditions: The communication signal of the first communication channel enters. The status is determined by the fact that the amplitude of the communication signal of the first communication channel exceeds the preset amplitude range for N consecutive transmission cycles or the communication signal of the first communication channel is not received for N consecutive transmission cycles, where N is a dynamically adjustable fault determination cycle, which is adjusted based on a preset dynamic adjustment strategy.

4. The method for handling redundant communication faults in a steer-by-wire system according to claim 3, characterized in that, The N is a dynamically adjustable fault determination period, which is adjusted based on a preset dynamic adjustment strategy as follows: Acquire real-time operating status parameters that characterize the dynamic needs of the vehicle, as well as historical quality parameters that characterize the reliability of the communication channel; The real-time operating status parameters are mapped to a first type of adjustment factor, and the historical quality parameters are mapped to a second type of adjustment factor; Multiple vehicle mission profiles are predefined, each of which is associated with a threshold range of a set of real-time operating status parameters, and a fault determination cycle benchmark value is preset for each vehicle mission profile. ; The real-time operating status parameters are matched with the threshold range to determine and switch the vehicle mission profile to which the current vehicle belongs, and the dedicated reference value corresponding to the vehicle mission profile is set. Set as the current fault determination cycle benchmark value. ; Coupling the first type of adjustment factor and the second type of adjustment factor with respect to the benchmark value Perform coordinated modulation and output in real time. This serves as the adjusted fault diagnosis cycle.

5. The method for handling redundant communication faults in a steer-by-wire system according to claim 4, characterized in that, The process of switching the vehicle mission profile to which the current vehicle belongs involves changing the dedicated reference value corresponding to that vehicle mission profile. Set as the current fault determination cycle benchmark value. include: After determining the vehicle mission profile to which the current vehicle belongs, the vehicle mission profile is switched. If a switch is detected as imminent or has already occurred, the reference value is not immediately changed from the current reference value. Updated to the dedicated reference value corresponding to the target vehicle mission profile. ; At this point, based on the preset transition function and dynamic transition time, the reference value is adjusted. From the current value Gradual change to The dynamic transition time is dynamically adjusted based on the real-time detected vehicle lateral stability parameters and the difference between the dedicated reference values ​​between the two vehicle mission profiles involved in the switching.

6. The method for handling redundant communication faults in a steer-by-wire system according to claim 5, characterized in that, The preset fault determination cycle benchmark value is specifically for the vehicle mission profile. The setup process is as follows: For each predefined vehicle mission profile, a unique damage tolerance envelope is defined, which is composed of the maximum permissible cumulative damage value. Quantitative description of the natural recovery rate of damage; Simultaneously acquire typical communication interference statistical characteristics corresponding to the vehicle mission profile; Based on the aforementioned damage tolerance envelope and interference statistical characteristics, a damage dynamic evolution model is constructed for simulation. In this model, instantaneous damage occurs when the amplitude exceeds the limit or a CRC error occurs, and the system accumulates damage. The calculation, update, and iteration are performed based on a preset damage accumulation calculation formula; the core safety constraint of the simulation is the cumulative damage of the system over the entire simulation time series. Must always be lower than ; During the simulation, a search algorithm is used to address and output a specific fault determination cycle value. If the fault determination cycle value is the largest among all candidate values ​​that satisfy the core safety constraints, then the fault determination cycle value is designated as the fault determination cycle benchmark value specific to the vehicle mission profile. .

7. A method for handling redundant communication faults in a steer-by-wire system according to claim 2, characterized in that, The precise switching of system signals includes: When the fault level is a Level 1 fault, the main control unit and the redundant control unit use the values ​​before the Level 1 fault was detected for control. When the fault level is level 2, the main control unit and the redundant control unit switch to the second communication channel to communicate. When the fault level is level three, the main control unit and the redundant control unit use their own collected signals for independent control, and the steer-by-wire system immediately sends an emergency warning signal to the vehicle controller via the CAN bus indicating that the redundant communication has completely failed.

8. A method for handling redundant communication faults in a steer-by-wire system according to claim 7, characterized in that, The precise switching of motor current includes: When the fault level is Level 1 or Level 2, the current of the main control unit and the redundant control unit is directly output; When the fault level is three, the redundant signal verification is turned off, and the redundant control unit calculates the signal switching compensation amount of the signals collected by the key sensors. Based on the signal switching compensation amount and the historical main control angle signal value of the main control unit, the corresponding angle signal after signal switching is calculated. Based on the angle signal, the vehicle's current speed, and the preset current gradient calibration parameters, the current change gradient limit is calculated. Based on the current change gradient limit, the total motor current output after the switching signal is gradient-limited to obtain the final motor current output value.

9. A system for handling redundant communication faults in a steer-by-wire system, implementing the method for handling redundant communication faults in a steer-by-wire system as described in any one of claims 1 to 8, characterized in that, include: The acquisition module is used to acquire the original communication status parameters of the independently configured first and second communication channels; The first communication channel and the second communication channel are two independent communication channels between the main control unit and the redundant control unit in the steer-by-wire system; The determination module is used to verify the original communication status parameters based on a preset multi-dimensional verification strategy, and determine the current fault level of the system by combining preset fault level judgment rules and a dynamically adjustable fault judgment cycle. The fault level is based on the combination of communication channel status and the severity of the fault. The processing module is used to execute matching fault handling, signal switching and current regulation strategies based on the fault level, and combine hierarchical signal control logic and motor current gradient limiting mechanism to complete the precise switching of system signals and motor current.

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