New energy vehicle torque protection method and system

Abstract

The application discloses a new energy automobile torque protection method and system, and belongs to the field of torque control. The method comprises the following steps: issuing a torque request under a vehicle controller, and establishing a torque protection mechanism to control the safe output of torque in the process of corresponding response of a motor controller to the torque request. The torque protection mechanism comprises one or more of a torque response multi-condition access protection mechanism, a torque request priority protection mechanism, an invalid torque request protection mechanism, an abnormal torque request protection mechanism, a slipping working condition protection mechanism and a torque response abnormality protection mechanism. The application realizes the whole-process safety protection of the torque output of the new energy automobile, and improves the driving safety and reliability of the vehicle.

Description

Technical Field

[0001] This invention belongs to the field of torque control, specifically, this invention relates to a torque protection method and system for new energy vehicles. Background Technology

[0002] With the rapid development of the new energy vehicle industry, torque interaction between the vehicle control unit (VCU) and the motor control unit (MCU) has become a core component of vehicle power output.

[0003] In existing technologies, torque control strategies for new energy vehicles suffer from problems such as imprecise torque response logic, lack of effective verification of torque requests, inability to identify abnormal torque in a timely manner, and lack of corresponding protection mechanisms for conditions such as slippage and torque response deviation. These issues can easily lead to abnormal vehicle power output, reduced driving safety, and in severe cases, can cause safety accidents such as loss of vehicle control and component damage.

[0004] In summary, existing technologies suffer from insufficient safety in torque control and inadequate protection mechanisms for abnormal operating conditions in new energy vehicles. Therefore, this invention proposes a torque protection method and system for new energy vehicles. Summary of the Invention

[0005] This invention aims to overcome the shortcomings of existing technologies and proposes a torque protection method and system for new energy vehicles to achieve the following objectives: realize full-process safety protection of torque output of new energy vehicles, and improve vehicle driving safety and reliability.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a torque protection method for new energy vehicles. The method includes: establishing a torque protection mechanism to control the safe output of torque during the process of the vehicle controller issuing a torque request and the motor controller responding to the torque request. The torque protection mechanism includes one or more of the following: a torque response multi-condition access protection mechanism, a torque request priority protection mechanism, an invalid torque request protection mechanism, an abnormal torque request protection mechanism, a slippage condition protection mechanism, and an abnormal torque response protection mechanism.

[0007] Furthermore, the torque response multi-condition access protection mechanism includes setting the following three linkage conditions: (1) The vehicle is in the READY state; (2) The vehicle is in D or R gear; (3) The vehicle controller enables the motor controller; The motor controller is only allowed to respond to the torque request issued by the vehicle controller and perform torque output operation when all three conditions are met; if any one of the three conditions is not met, the motor controller will prohibit the output of torque.

[0008] Furthermore, the torque request priority protection mechanism includes: the vehicle controller determines whether to send a torque request to the motor controller based on preset priority logic. The preset priority logic includes the following priority order from high to low: brake signal > handbrake or electronic parking brake signal > regular torque request. (1) When a braking signal is detected, the vehicle controller does not issue any torque request; (2) In the absence of a braking signal, if the mechanical handbrake is detected to be engaged, the vehicle controller will not issue a torque request; (3) In the absence of a braking signal, if the vehicle is detected to be in electronic parking mode, the vehicle controller will not issue a torque request; (4) The vehicle controller is only allowed to send a torque request to the motor controller when there is no braking signal and the mechanical handbrake is released or the electronic parking mode is disengaged.

[0009] Furthermore, the invalid torque request protection mechanism includes: After receiving the torque request from the vehicle controller, the motor controller parses out the torque request value and determines whether the torque request value is greater than the preset peak torque of the motor controller. If the requested torque value is greater than the preset peak torque of the motor controller, the duration T1 is timed. During the timed period, the motor controller maintains the current torque output and does not respond to the torque request of the vehicle controller; otherwise, the motor controller responds to the torque request of the vehicle controller. Determine whether the duration T1 is greater than the preset duration threshold T1max; if it is, the current torque request of the vehicle controller is regarded as an invalid torque request, and the system enters a fault state and performs a torque limiting operation; otherwise, the motor controller resumes normal response to the torque request of the vehicle controller. After entering a fault state and performing a torque limiting operation, it is determined whether the preset fault recovery conditions are met. If they are met, the fault state is exited and the current torque limiting operation is lifted. At this time, the motor controller is allowed to respond normally to the torque request of the vehicle controller. Otherwise, the current torque limiting operation is maintained.

[0010] Furthermore, the abnormal torque request protection mechanism includes: After receiving the torque request from the vehicle controller, the motor controller parses the slope of the torque loading and determines whether the slope of the torque loading is greater than N times the maximum slope of the motor controller's torque loading, where N is a preset value and N≥1. If the slope of the torque loading is greater than N times the maximum slope of the motor controller torque loading, then the duration T2 is obtained by timing. During the timing, the motor controller maintains the current torque output and does not respond to the torque request of the vehicle controller; otherwise, the motor controller responds to the torque request of the vehicle controller. Determine whether the duration T2 is greater than the preset duration threshold T2max; if it is, treat the current torque request of the vehicle controller as an abnormal torque request, enter a fault state and perform torque limiting operation; otherwise, the motor controller resumes normal response to the torque request of the vehicle controller. After entering a fault state and executing a torque limiting operation, it checks whether the preset fault recovery conditions are met. If met, the fault state is exited and the current torque limiting operation is released, allowing the motor controller to respond normally to the torque request from the vehicle controller. Otherwise, the current torque limiting operation is maintained.

[0011] Furthermore, the preset fault recovery conditions include: when the vehicle controller requests the torque value to be restored to 0 and this remains so for a preset period of time, and the torque output of the motor controller has been set to 0, the current torque limiting operation is released, allowing the motor controller to respond normally to the torque request of the vehicle controller; otherwise, the current torque limiting operation is maintained.

[0012] Furthermore, the slippage protection mechanism includes: When the wheel speed sensor detects a wheel slippage signal, the ABS or ESC system activates and issues a torque request: The vehicle controller directly forwards the torque request sent by the ABS or ESC to the motor controller. At this time, the motor controller disables the invalid torque request protection mechanism and the abnormal torque request protection mechanism to quickly respond to the torque request forwarded by the vehicle controller.

[0013] Furthermore, the torque response anomaly protection mechanism includes: (1) Fault diagnosis: A. The deviation of the actual output torque of the motor controller from the torque value requested by the vehicle controller is greater than a preset threshold and continues for a preset period of time. B. The motor controller's response torque is opposite to the vehicle controller's requested torque, and this continues for a preset period of time; C. When the vehicle controller does not request torque, the motor controller will output torque uncontrollably for a preset period of time. (2) Fault triggering: When any one of A, B, or C is detected to be satisfied, the vehicle controller enters a fault lock state, triggers a fault alarm, and executes emergency avoidance measures: (3) Fault recovery: The current fault is not self-recoverable. It can only be restored after the vehicle is powered back on with high and low voltage and the vehicle controller detects that the fault has been eliminated.

[0014] This invention also provides a torque protection system for new energy vehicles, using the aforementioned torque protection method for new energy vehicles, the system comprising: The torque response multi-condition access protection module is used to execute the torque response multi-condition access protection mechanism; The torque request priority protection module is used to execute the torque request priority protection mechanism; The invalid torque request protection module is used to execute the invalid torque request protection mechanism; The abnormal torque request protection module is used to execute the abnormal torque request protection mechanism; The slippage protection module is used to execute the slippage protection mechanism. The torque response anomaly protection module is used to execute the torque response anomaly protection mechanism.

[0015] The technical effects of this invention are as follows: 1. This invention establishes a strict torque protection monitoring mechanism, from judging torque output conditions to judging abnormal and sudden changes in VCU torque commands, judging slippage conditions, and emergency response measures for abnormal torque in MCU, etc., to prevent accidents such as vehicle runaway and loss of control caused by abnormal torque output at the source, thereby improving torque safety. 2. This invention sets a torque request priority to prioritize safe operating conditions such as braking and parking, avoiding conflicts between power and safety commands; 3. This invention sets clear judgment thresholds and timing logic for invalid torque and abnormal torque, so as to achieve accurate identification of abnormal requests and flexible torque limiting, and avoid power shock; 4. This invention is adapted to extreme working conditions such as slippage and abnormal MCU response, and adopts a combination of protection strategies including fast response, braking deceleration, and high voltage cut-off to comprehensively improve vehicle driving safety. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the torque response multi-condition access protection mechanism provided in an embodiment of the present invention; Figure 2 A schematic diagram of the invalid torque request protection mechanism provided in this embodiment of the invention; Figure 3 A schematic diagram of the abnormal torque request protection mechanism provided in an embodiment of the present invention. Detailed Implementation

[0017] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. This is to help those skilled in the art to have a more complete, accurate, and in-depth understanding of the inventive concept and technical solutions of the present invention, and to facilitate its implementation. It should be noted that the terms "first," "second," etc., used in this application are only for the convenience of describing the technical solutions and to distinguish components; the corresponding component configurations may be the same or different, and are not intended to limit the scope of this application. To make the technical solutions of the present invention clearer, the present invention will be explained and illustrated through the following embodiments.

[0018] To address the issues of insufficient safety in torque control and inadequate protection mechanisms for abnormal operating conditions in existing technologies for new energy vehicles, this invention provides a torque protection method and system for new energy vehicles. Through multiple torque protection mechanisms, including a multi-condition access protection mechanism for torque response, a priority protection mechanism for torque requests, an invalid torque request protection mechanism, an abnormal torque request protection mechanism, a slippage protection mechanism, and an abnormal torque response protection mechanism, the system achieves full-process safety protection for the torque output of new energy vehicles, thereby improving vehicle driving safety and reliability.

[0019] Foreword: The new energy vehicle described in this embodiment of the invention includes components such as a vehicle control unit (VCU), a motor controller (MCU), a battery management system (BMS), an ABS / ESC system, a gear position sensor, wheel speed sensors, a brake pedal sensor, and a handbrake / electronic parking switch. The vehicle control unit communicates with the motor controller, battery management system, ABS / ESC system, and other components via a CAN bus to obtain real-time vehicle status information and issue control commands. After receiving a torque request from the vehicle controller, the motor controller controls the drive motor to output the corresponding torque.

[0020] Specifically, this invention provides a torque protection method for new energy vehicles, comprising: establishing a torque protection mechanism to control the safe output of torque during the process of the vehicle controller issuing a torque request (VCU_TorqueCommand) and the motor controller responding to the torque request. The torque protection mechanism includes one or more of the following: a torque response multi-condition access protection mechanism, a torque request priority protection mechanism, an invalid torque request protection mechanism, an abnormal torque request protection mechanism, a slippage condition protection mechanism, and a torque response anomaly protection mechanism. The vehicle controller and the motor controller work collaboratively, each undertaking different protection responsibilities. The vehicle controller is mainly responsible for protection during the torque request generation stage, including torque request priority protection; the motor controller is mainly responsible for protection during the torque response execution stage, including torque response multi-condition access protection, invalid torque request protection, abnormal torque request protection, slippage condition protection, and torque response anomaly protection. This layered and division-of-labor protection architecture ensures complete coverage of the protection mechanism while avoiding excessive centralization of protection logic, thus improving the reliability and maintainability of the system.

[0021] The protection mechanisms used in this embodiment will be explained in detail below.

[0022] In existing technologies, the access conditions for motor controllers to respond to torque requests from vehicle controllers are often designed to be too simple, typically relying on a single condition. This single-condition approach is prone to misjudgment and poses safety hazards. Therefore, this embodiment establishes a multi-condition access protection mechanism for torque response, such as… Figure 1 As shown, this includes setting the following three linkage conditions: (1) The vehicle is in the READY state; (2) The vehicle is in D or R gear; (3) The vehicle controller enables the motor controller; Only when all three conditions are met simultaneously is the motor controller allowed to respond to torque requests from the vehicle controller and execute torque output operations. If any one of the three conditions is not met, the motor controller will prohibit torque output, enabling the vehicle controller to detect the fault in a timely manner and take further measures (such as alarms, speed limits, or requesting the driver to stop). This rapid isolation mechanism prevents the fault from escalating and protects critical components such as the motor, battery, and transmission system.

[0023] The READY state is a sign that the high-voltage system of a new energy vehicle is ready. The vehicle being in the READY state only indicates that the high-voltage system is powered on and all controllers have completed initialization, but it does not explicitly state whether the vehicle controller has officially authorized the motor controller to output torque. In certain fault scenarios (such as a vehicle controller software crash or a communication timeout followed by a erroneous recovery), the vehicle may still be in the READY state, but the vehicle controller has not correctly enabled the motor controller. If the motor controller responds to a historically residual or externally injected torque request, it will cause the vehicle to move unexpectedly. Therefore, this embodiment sets condition (1): the vehicle controller periodically broadcasts the READY state via the CAN bus, and the motor controller receives and parses this state signal in real time. If the motor controller does not receive a valid READY state signal within a preset time (e.g., 500ms), or if the received signal indicates that the vehicle is not in the READY state, then condition (1) is not met.

[0024] The gear position signal is collected by the gear position sensor and sent to the vehicle controller. The vehicle controller broadcasts the gear position status to the motor controller via the CAN bus. After receiving the gear position signal, the motor controller determines its validity (such as whether the signal is within the valid range, whether there is an abnormal transition, etc.) and confirms that the gear is in D (drive) or R (reverse). If the gear is in N (neutral) or P (park), the judgment condition (2) is not met, and the motor controller prohibits the output of drive torque. In addition, if the gear position signal is abnormal (such as multiple gear position signals are detected at the same time, the signal exceeds the physical range, the signal change rate is abnormal, etc.), the motor controller also determines that the condition (2) is not met and records the fault code.

[0025] In a distributed electronic and electrical architecture, the vehicle controller, as the initiator of torque control, has its enable state as crucial for authorizing torque output. In existing technologies, some solutions do not treat the vehicle controller's enable signal as an independent admission condition, but rather embed it within other conditions (such as the READY state containing the meaning of enable). This design blurs the control boundaries and is detrimental to fault diagnosis and responsibility allocation. When an unexpected torque output fault occurs, it is difficult to quickly determine whether the vehicle controller mis-enables or the motor controller mis-responds. Therefore, this embodiment specifically sets condition (3) regarding whether the vehicle controller enables the motor controller. This determination depends on the enable signal sent by the vehicle controller to the motor controller. Typically, an enable signal of 1 (i.e., active high) indicates that the motor controller is allowed to start working; an enable signal of 0 (i.e., active low) indicates that the motor controller is not allowed to start working. This enable signal can be an independent CAN signal or a specific position included in the torque request message.

[0026] The torque response multi-condition access protection mechanism designed in this invention forms multiple safety barriers by setting three linked conditions: READY state, gear position state, and vehicle controller enable state. Even if one condition is mistakenly met due to a fault or interference, the other conditions can still effectively prevent unexpected torque output. For example, if a gear position sensor malfunctions and mistakenly detects a D gear signal, the motor controller will not output torque because the vehicle is not in the READY state or the vehicle controller is not enabling the motor controller, thus preventing unexpected vehicle movement. The three conditions are based on different signal sources and judgment logics: the READY state is based on the high-voltage system and controller self-test results, the gear position state is based on the gear position sensor, and the enable state is based on the active authorization of the vehicle controller. This multi-source heterogeneous access condition design makes the system more robust to faults or interference from a single signal source. Even if one signal source is subject to electromagnetic interference or hardware failure, the other signal sources can still maintain correct access judgment.

[0027] In torque control of new energy vehicles, the vehicle controller needs to comprehensively consider multiple input signals to generate the final torque request. However, existing technologies lack proper processing and arbitration of these input signals, leading to conflicts between power and safety commands. For example, when braking and accelerator pedal signals coexist, some solutions may calculate the torque request based solely on the accelerator pedal opening, ignoring the safety priority of the braking signal, resulting in braking and driving conflicts. Therefore, this embodiment of the invention establishes a torque request priority protection mechanism, including: the vehicle controller determining whether to send a torque request to the motor controller based on preset priority logic.

[0028] The priority logic preset in this embodiment includes the following priority order from high to low: braking signal > handbrake or electronic parking signal > normal torque request. (1) When a braking signal is detected, the vehicle controller does not issue any torque request; (2) In the absence of a braking signal, if the mechanical handbrake is detected to be engaged, the vehicle controller will not issue a torque request; (3) In the absence of a braking signal, if the vehicle is detected to be in electronic parking mode, the vehicle controller will not issue a torque request; (4) The vehicle controller is only allowed to send a torque request to the motor controller when there is no braking signal and the mechanical handbrake is released or the electronic parking mode is disengaged.

[0029] Braking signals are collected by brake pedal sensors and transmitted to the vehicle controller via hardwire or CAN bus, with the highest priority. Once a valid braking signal is detected, the vehicle controller immediately sets the torque request to 0 and ceases sending any positive torque requests to the motor controller. Furthermore, in addition to disabling positive torque requests, the vehicle controller can also calculate the regenerative braking torque (negative torque) based on the brake pedal opening and vehicle speed, and send this calculation to the motor controller to achieve energy recovery and assisted braking.

[0030] The handbrake signal is collected by the handbrake switch, while the electronic parking brake signal is transmitted by the Electronic Parking Brake (EPB) control unit via the CAN bus. The handbrake and electronic parking brake signals have secondary priority. The handbrake switch is typically a two-position switch (engaged / disengaged). When the mechanical handbrake is detected as engaged, the vehicle controller does not issue any torque request regardless of the accelerator pedal opening. The vehicle controller only allows the resumption of normal torque request transmission when the mechanical handbrake is detected as disengaged. The electronic parking brake system sends a parking status signal to the vehicle controller via the CAN bus. When the vehicle is detected as being in electronic parking brake mode (EPB activated), the vehicle controller does not issue any torque request. The vehicle controller only allows the resumption of normal torque request transmission after the electronic parking brake is released. For vehicles equipped with both a mechanical handbrake and electronic parking brake, the vehicle controller treats both as signals of equal priority; when either is active, torque request transmission is prohibited.

[0031] A standard torque request is a drive torque request calculated by the vehicle controller based on parameters such as the driver's accelerator pedal opening, vehicle speed, battery status, and motor status, using a preset torque MAP or algorithm. Standard torque requests have the lowest priority; the vehicle controller is only allowed to send a standard torque request to the motor controller when there is no braking signal and the mechanical handbrake is released or the electronic parking brake is disengaged.

[0032] The torque request priority protection mechanism of this invention sets the braking signal as the highest priority, ensuring that the vehicle controller immediately stops issuing any positive drive torque requests when the driver intends to brake. This fundamentally avoids the conflict between the braking system and the drive system, which not only shortens the braking distance and improves braking safety but also reduces the thermal load on the braking system and extends the service life of braking components. Furthermore, by setting the handbrake or electronic parking brake signal as the second highest priority, this embodiment ensures that the motor will not output drive torque to the locked transmission system when the vehicle is parked. This avoids mechanical damage to transmission system components (such as half-shafts, differentials, reducer gears, bearings, etc.) due to overload, and also protects the motor and power devices from the impact of high stall current. In summary, through a clear priority hierarchy design, this embodiment enables the vehicle controller to clearly arbitrate multiple torque request sources, avoiding control confusion caused by conflicts between multiple requests and improving driving safety. This systematic priority management makes the torque control logic clearer and more maintainable.

[0033] The torque request value issued by the vehicle controller should theoretically be within the peak torque capability range of the motor controller. However, in actual operation, invalid (excessively high) torque requests may occur due to various reasons. Existing technologies often treat this in a generalized way, failing to distinguish whether invalid requests are intermittent or continuous, thus hindering targeted measures and subsequent fault handling. Therefore, this invention provides an invalid torque request protection mechanism, such as... Figure 2 As shown, the process includes: After receiving the torque request from the vehicle controller, the motor controller parses out the torque request value and determines whether the torque request value is greater than the preset peak torque of the motor controller. If the requested torque value is greater than the preset peak torque of the motor controller, the duration T1 is timed. During the timed period, the motor controller maintains the current torque output and does not respond to the torque request of the vehicle controller to avoid vehicle impact caused by sudden change in torque output during the judgment process; otherwise, the motor controller responds to the torque request of the vehicle controller. Determine if the duration T1 is greater than the preset duration threshold T1max (e.g., 100ms); if it is, the current torque request from the vehicle controller is considered an invalid torque request, and the system enters a fault state and performs a torque limiting operation, that is, the target torque is limited to the preset torque limit value and the system no longer responds to torque requests issued by the vehicle controller; otherwise, the motor controller resumes normal response to torque requests from the vehicle controller. After entering a fault state and performing a torque limiting operation, it is determined whether the preset fault recovery conditions are met. If they are met, the fault state is exited and the current torque limiting operation is lifted. At this time, the motor controller is allowed to respond normally to the torque request of the vehicle controller. Otherwise, the current torque limiting operation is maintained.

[0034] The invalid torque request protection mechanism of this invention distinguishes between occasional communication interference and persistent systemic faults by setting a peak torque comparison and a duration threshold T1max. For occasional invalid requests (duration less than T1max), the system only performs temporary hold-up processing, without affecting normal driving; for persistent invalid requests (duration greater than T1max), the system determines it as a fault, executes an alarm and torque limiting, effectively preventing long-term overload of the motor and power devices. This hierarchical processing strategy ensures safety while minimizing interference with normal driving. Simultaneously, when the duration of an invalid torque request exceeds T1max, the motor controller can trigger an alarm via the CAN bus, enabling the vehicle controller and background diagnostic system to obtain fault information promptly, which facilitates rapid fault location. Furthermore, it strictly enforces torque limiting operations, restricting the motor output torque within a safe range, avoiding thermal and mechanical damage to the motor windings, power devices, and transmission system caused by long-term high-load operation. The torque limiting value must maintain the vehicle's basic driving capability, allowing the driver to drive the vehicle at low speed to a safe area or repair point after a fault occurs, avoiding secondary safety risks caused by the vehicle completely breaking down on the road.

[0035] The torque loading slope reflects the rate of change of torque request and is an important indicator for measuring the dynamic characteristics of torque request. During normal driving operations, the torque loading slope should change smoothly within a certain range. However, in existing technologies, the judgment of torque requests with abnormal torque loading slopes cannot distinguish whether the abnormal request is intermittent or continuous, thus preventing targeted measures from being taken and hindering subsequent fault handling. Therefore, this embodiment of the invention establishes the aforementioned abnormal torque request protection mechanism, such as... Figure 3 As shown, the process includes: After receiving the torque request from the vehicle controller, the motor controller parses the slope of the torque loading and determines whether the slope of the torque loading is greater than N times the maximum slope of the motor controller's torque loading, where N is a preset value and N≥1 (in this embodiment, N is 1.5). If the slope of the torque loading is greater than N times the maximum slope of the motor controller torque loading, then the duration T2 is obtained by timing. During the timing, the motor controller maintains the current torque output and does not respond to the torque request of the vehicle controller; otherwise, the motor controller responds to the torque request of the vehicle controller. Determine whether the duration T2 is greater than the preset duration threshold T2max (e.g., 100ms); if it is, the current torque request of the vehicle controller is regarded as an abnormal torque request, and a fault state is entered and torque limiting operation is performed; otherwise, the motor controller resumes normal response to the torque request of the vehicle controller. After entering a fault state and performing a torque limiting operation, it is determined whether the preset fault recovery conditions are met. If they are met, the fault state is exited and the current torque limiting operation is lifted. At this time, the motor controller is allowed to respond normally to the torque request of the vehicle controller. Otherwise, the current torque limiting operation is maintained.

[0036] The abnormal torque request protection mechanism in this embodiment monitors the torque loading slope in real time and compares it with the maximum capacity of the motor controller. This allows for timely identification of abnormal torque requests caused by software errors, communication interference, or sensor mutations. During the judgment process, the current output is maintained, avoiding the impact of sudden torque changes on motor current, transmission system mechanical stress, and vehicle acceleration, thus protecting the motor windings, power devices, and transmission components, while also improving ride comfort. Furthermore, considering the duration T2, for brief abnormal slopes (duration T2 less than T2max), the system only performs temporary hold-up processing, without affecting normal driving; for continuous abnormal slopes (duration T2 greater than T2max), the system determines it as a fault and executes torque limiting. This tiered processing minimizes interference with normal driving while ensuring safety, avoiding over-protection due to occasional communication interference or sensor noise. The invalid torque request protection mechanism targets abnormal torque request amplitude (too high), while the abnormal torque request protection mechanism targets abnormal torque request rate of change (too large slope). The combination of these two mechanisms provides comprehensive protection for both the static and dynamic characteristics of the torque request, covering a wider range of fault scenarios.

[0037] In both the invalid torque request protection mechanism and the abnormal torque request protection mechanism, the preset fault recovery conditions include: when the vehicle controller requests a torque value of 0 and this value remains at 0 for a preset period of time (e.g., 1 second), and the motor controller's torque output is already set to 0 (i.e., the actual output torque is 0, ensuring the vehicle has stopped or is in a powerless state), the current torque limiting operation is lifted, allowing the motor controller to respond normally to the vehicle controller's torque request; otherwise, the current torque limiting operation is maintained. In the above fault recovery conditions, requiring the vehicle controller to request a torque value of 0 and this value to remain at 0 indicates that the vehicle controller has recognized the fault and actively stopped the torque request, and the fault state has been cleared; requiring the motor controller's torque output to be set to 0 ensures the vehicle is in a safe state when the torque limit is lifted, preventing sudden acceleration of the vehicle due to the vehicle controller still sending a high torque request when the torque limit is lifted.

[0038] When driving on low-traction surfaces (such as icy, wet, or gravel roads), the drive wheels are prone to slippage. In this situation, the ABS or ESC system activates, adjusting braking force or requesting a reduction in drive torque to restore wheel traction and ensure vehicle stability. This requires the motor controller to respond quickly to the torque request to rapidly stabilize the vehicle. In other words, under slippage conditions, the safety requirement shifts from preventing motor overload to rapidly restoring vehicle stability, and the focus and strategy of protection should be adjusted accordingly. However, existing technologies lack torque adaptive control mechanisms based on operating conditions. Therefore, this embodiment establishes a slippage protection mechanism, including: When the wheel speed sensor detects a wheel slippage signal, the ABS or ESC system activates and issues a torque request: The vehicle controller directly forwards the torque request sent by the ABS or ESC to the motor controller. At this time, the motor controller disables the invalid torque request protection mechanism and the abnormal torque request protection mechanism to quickly respond to the torque request forwarded by the vehicle controller.

[0039] Specifically, wheel speed sensors monitor the rotational speed of each wheel in real time. When the rotational speed of a drive wheel is significantly higher than that of other wheels or exceeds the vehicle speed reference value, wheel slippage is detected. After detecting the slippage signal, the ABS or ESC system activates the anti-slip control logic and calculates the required torque adjustment (usually reducing drive torque or requesting negative torque to suppress slippage). This calculation is then packaged into a torque request and sent to the vehicle controller via the CAN bus. Upon receiving the torque request from the ABS / ESC, the vehicle controller does not perform complex arbitration calculations but directly forwards the torque request to the motor controller. This direct forwarding mechanism minimizes communication and processing latency, ensuring that the motor controller can quickly receive the torque request required for anti-slip control. During the direct forwarding process, the vehicle controller can identify the source of the torque request as ABS / ESC so that the motor controller can perform subsequent processing.

[0040] After receiving the ABS / ESC torque request forwarded by the vehicle controller, the motor controller can confirm that the request originates from the ABS / ESC system based on the request's source identifier. Subsequently, the motor controller disables the invalid torque request protection mechanism: because the torque value requested by ABS / ESC may be negative (used for anti-slip driving) or 0, its absolute value may exceed the motor controller's peak torque (e.g., a direct request from +200Nm to -100Nm results in a 300Nm change, which may trigger invalid torque request protection). Therefore, upon recognizing the ABS / ESC request, the motor controller temporarily disables the invalid torque request protection mechanism and no longer limits the magnitude of the requested value. Simultaneously, the abnormal torque request protection mechanism is disabled: because ABS / ESC requests need to reduce the torque from a high value to 0 or a negative value within a very short time (e.g., tens of milliseconds), its loading slope may far exceed the normal maximum slope threshold. Therefore, the motor controller temporarily disables the abnormal torque request protection mechanism and no longer limits the request slope. After disabling the two protection mechanisms mentioned above, the motor controller directly responds to the torque request from the ABS / ESC system, adjusting the motor output torque as quickly as possible to restore wheel traction and ensure vehicle stability. Once the ABS / ESC system determines that slippage has been eliminated and stops sending torque requests (or sends a command to restore normal control), the vehicle controller resumes its normal torque request generation logic, and the motor controller reactivates the invalid torque request protection mechanism and the abnormal torque request protection mechanism, restoring normal protection status.

[0041] The slippage protection mechanism in this embodiment directly forwards the request from the vehicle controller and dynamically disables it through the protection mechanism of the motor controller. This invention minimizes the transmission and processing delays of anti-slip control torque requests. The torque reduction request from ABS / ESC can be executed by the motor controller in the shortest possible time, quickly reducing the torque of the drive wheels, restoring wheel traction, effectively preventing the vehicle from skidding and losing control on low-traction surfaces, and significantly improving driving safety.

[0042] In existing technologies, for abnormal torque response, only the deviation between the actual torque and the requested torque is monitored, and a fault is triggered when the deviation exceeds a threshold. However, abnormal torque response is not only manifested as excessive deviation, but may also manifest as reverse torque output (e.g., requesting positive torque but outputting negative torque) or outputting torque on its own when not requested. Single deviation monitoring cannot cover these abnormal patterns, leading to some serious faults not being detected in time. Therefore, this embodiment sets up a torque response abnormality protection mechanism, specifically including: (1) Fault diagnosis: The following three fault conditions are set: A. The deviation of the actual output torque of the motor controller from the torque value requested by the vehicle controller is greater than the preset threshold and continues for a preset period of time (e.g., 50ms). B. The motor controller's response torque is opposite to the vehicle controller's requested torque, and this continues for a preset period of time (e.g., 50ms). C. When the vehicle controller does not request torque, the motor controller outputs torque uncontrollably for a preset period of time (e.g., 50ms). This indicates that the motor controller has lost its ability to respond to commands from the vehicle controller, which may be due to reasons such as control algorithm malfunction, abnormal PWM output, or short circuit in power devices.

[0043] (2) Fault triggering: When any of A, B, or C is satisfied, the vehicle controller enters a fault lockout state, triggers a fault alarm, and executes emergency avoidance measures. Correspondingly, the chassis braking and vehicle power supply should work together to execute emergency avoidance measures: the chassis control system applies emergency braking force to the drive wheels, reducing the wheel speed to 0 km / h; the battery management system executes high-voltage cutoff control, disconnecting the high-voltage DC power supply to the motor controller.

[0044] (3) Fault recovery: The current fault is not self-recoverable; it can only be restored after the vehicle is reconnected to high and low voltage power and the vehicle controller detects that the fault has been eliminated. This avoids false recovery caused by the disappearance of temporary fault conditions (such as zero deviation when the vehicle is stationary), ensuring that the fault has been fundamentally resolved.

[0045] The torque response anomaly protection mechanism in this embodiment covers the main manifestations of torque response anomalies by setting three fault conditions (excessive deviation, reverse output, and self-output). Excessive deviation monitoring targets progressive faults caused by decreased control accuracy or parameter drift; reverse output monitoring targets severe faults caused by control logic errors or phase sequence errors; and self-output monitoring targets the most serious faults caused by controller malfunction or hardware short circuits. These three fault conditions form a comprehensive diagnostic network for torque response anomalies.

[0046] This invention also provides a torque protection system for new energy vehicles, using the aforementioned torque protection method for new energy vehicles, the system comprising: The torque response multi-condition access protection module is used to execute the torque response multi-condition access protection mechanism; The torque request priority protection module is used to execute the torque request priority protection mechanism; The invalid torque request protection module is used to execute the invalid torque request protection mechanism; The abnormal torque request protection module is used to execute the abnormal torque request protection mechanism; The slippage protection module is used to execute the slippage protection mechanism. The torque response anomaly protection module is used to execute the torque response anomaly protection mechanism.

[0047] In summary, the embodiments of the present invention provide a torque protection method and system for new energy vehicles. By establishing a multi-condition access protection mechanism for torque response, a torque request priority protection mechanism, an invalid torque request protection mechanism, an abnormal torque request protection mechanism, a slippage condition protection mechanism, and an abnormal torque response protection mechanism, a comprehensive, multi-level, and condition-adaptive torque safety protection system is formed. This effectively solves the problem of imperfect torque control safety protection mechanisms in the prior art, significantly improves the driving safety and system reliability of new energy vehicles, and has good prospects for promotion and application.

[0048] 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; or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A torque protection method for new energy vehicles, characterized in that: The method includes: establishing a torque protection mechanism to control the safe output of torque during the process of the vehicle controller issuing a torque request and the motor controller responding to the torque request. The torque protection mechanism includes one or more of the following: a torque response multi-condition access protection mechanism, a torque request priority protection mechanism, an invalid torque request protection mechanism, an abnormal torque request protection mechanism, a slippage condition protection mechanism, and an abnormal torque response protection mechanism.

2. The new energy vehicle torque protection method according to claim 1, characterized in that: The torque response multi-condition access protection mechanism includes setting the following three linkage conditions: (1) The vehicle is in the READY state; (2) The vehicle is in D or R gear; (3) The vehicle controller enables the motor controller; The motor controller is only allowed to respond to the torque request issued by the vehicle controller and perform torque output operation when all three conditions are met; if any one of the three conditions is not met, the motor controller will prohibit the output of torque.

3. The new energy vehicle torque protection method according to claim 1, characterized in that: The torque request priority protection mechanism includes: the vehicle controller determines whether to send a torque request to the motor controller based on a preset priority logic.

4. The new energy vehicle torque protection method according to claim 3, characterized in that: The preset priority logic includes the following order from highest to lowest: braking signal > handbrake or electronic parking signal > normal torque request. (1) When a braking signal is detected, the vehicle controller does not issue any torque request; (2) In the absence of a braking signal, if the mechanical handbrake is detected to be engaged, the vehicle controller will not issue a torque request; (3) In the absence of a braking signal, if the vehicle is detected to be in electronic parking mode, the vehicle controller will not issue a torque request; (4) The vehicle controller is only allowed to send a torque request to the motor controller when there is no braking signal and the mechanical handbrake is released or the electronic parking mode is disengaged.

5. The new energy vehicle torque protection method according to claim 1, characterized in that: The invalid torque request protection mechanism includes: After receiving the torque request from the vehicle controller, the motor controller parses out the torque request value and determines whether the torque request value is greater than the preset peak torque of the motor controller. If the requested torque value is greater than the preset peak torque of the motor controller, the duration T1 is timed. During the timed period, the motor controller maintains the current torque output and does not respond to the torque request of the vehicle controller; otherwise, the motor controller responds to the torque request of the vehicle controller. Determine whether the duration T1 is greater than the preset duration threshold T1max; if it is, the current torque request of the vehicle controller is regarded as an invalid torque request, and the system enters a fault state and performs a torque limiting operation; otherwise, the motor controller resumes normal response to the torque request of the vehicle controller. After entering a fault state and performing a torque limiting operation, it is determined whether the preset fault recovery conditions are met. If they are met, the fault state is exited and the current torque limiting operation is lifted. At this time, the motor controller is allowed to respond normally to the torque request of the vehicle controller. Otherwise, the current torque limiting operation is maintained.

6. The new energy vehicle torque protection method according to claim 1, characterized in that: The abnormal torque request protection mechanism includes: After receiving the torque request from the vehicle controller, the motor controller parses the slope of the torque loading and determines whether the slope of the torque loading is greater than N times the maximum slope of the motor controller's torque loading, where N is a preset value and N≥1. If the slope of the torque loading is greater than N times the maximum slope of the motor controller torque loading, then the duration T2 is obtained by timing. During the timing, the motor controller maintains the current torque output and does not respond to the torque request of the vehicle controller; otherwise, the motor controller responds to the torque request of the vehicle controller. Determine whether the duration T2 is greater than the preset duration threshold T2max; if it is, treat the current torque request of the vehicle controller as an abnormal torque request, enter a fault state and perform torque limiting operation; otherwise, the motor controller resumes normal response to the torque request of the vehicle controller. After entering a fault state and performing a torque limiting operation, it is determined whether the preset fault recovery conditions are met. If they are met, the fault state is exited and the current torque limiting operation is lifted. At this time, the motor controller is allowed to respond normally to the torque request of the vehicle controller. Otherwise, the current torque limiting operation is maintained.

7. The new energy vehicle torque protection method according to claim 5 or 6, characterized in that: The preset fault recovery conditions include: when the vehicle controller requests the torque value to be restored to 0 and this remains so for a preset period of time, and the torque output of the motor controller has been set to 0, the current torque limiting operation is lifted, allowing the motor controller to respond normally to the torque request of the vehicle controller; otherwise, the current torque limiting operation is maintained.

8. A method for torque protection of new energy vehicles according to claim 1, characterized in that: The slippage protection mechanism includes: When the wheel speed sensor detects a wheel slippage signal, the ABS or ESC system activates and issues a torque request: The vehicle controller directly forwards the torque request sent by the ABS or ESC to the motor controller. At this time, the motor controller disables the invalid torque request protection mechanism and the abnormal torque request protection mechanism to quickly respond to the torque request forwarded by the vehicle controller.

9. A method for torque protection in a new energy vehicle according to claim 1, characterized in that: The torque response anomaly protection mechanism includes: (1) Fault diagnosis: A. The deviation of the actual output torque of the motor controller from the torque value requested by the vehicle controller is greater than a preset threshold and continues for a preset period of time. B. The motor controller's response torque is opposite to the vehicle controller's requested torque, and this continues for a preset period of time; C. When the vehicle controller does not request torque, the motor controller will output torque uncontrollably for a preset period of time. (2) Fault triggering: When any one of A, B, or C is detected to be satisfied, the vehicle controller enters a fault lock state, triggers a fault alarm, and executes emergency avoidance measures: (3) Fault recovery: The current fault is not self-recoverable. It can only be restored after the vehicle is powered back on with high and low voltage and the vehicle controller detects that the fault has been eliminated.

10. A torque protection system for a new energy vehicle, using a torque protection method for a new energy vehicle according to any one of claims 1-9, characterized in that: The system includes: The torque response multi-condition access protection module is used to execute the torque response multi-condition access protection mechanism; The torque request priority protection module is used to execute the torque request priority protection mechanism; The invalid torque request protection module is used to execute the invalid torque request protection mechanism; The abnormal torque request protection module is used to execute the abnormal torque request protection mechanism; The slippage protection module is used to execute the slippage protection mechanism. The torque response anomaly protection module is used to execute the torque response anomaly protection mechanism.

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