Motor torque monitoring method, device, equipment and medium

Abstract

The embodiment of the invention provides a motor torque monitoring method and device, equipment and a medium, and relates to the technical field of vehicles. The method comprises the following steps: in a first processing unit in a motor controller, obtaining a functional layer estimation torque through an electromagnetic torque algorithm based on a three-phase current signal; in a second processing unit in the motor controller, a safety layer estimation torque is obtained through a power torque algorithm based on the bus voltage signal and the bus current signal, and the first processing unit and the second processing unit are physically isolated; and determining the state of the torque based on the comparison of the estimated torque of the motor function layer and the estimated torque of the safety layer, and executing a corresponding system protection strategy based on the torque state. According to the method, the problem that the vehicle safety is affected due to the fact that torque monitoring is prone to misalignment when equipment abnormity or working condition abnormity occurs in motor torque monitoring in the related technology is effectively solved.

Description

Technical Field

[0001] This application relates to the field of vehicle technology, and in particular to a method, device, equipment and medium for monitoring motor torque. Background Technology

[0002] The motor controller is the core execution unit of the power system in new energy vehicles. Based on driver intentions or instructions from the autonomous driving system, it adjusts the output torque and speed of the drive motor in real time. The accuracy and controllability of torque output are directly related to the longitudinal dynamics safety of the entire vehicle: unexpected torque increases may lead to sudden acceleration and loss of control; unexpected torque decreases or disappearance may lead to energy recovery failure and insufficient braking force; and residual torque under zero torque conditions may cause the vehicle to creep and roll backward. Therefore, to ensure motor safety, the motor controller must have a built-in high-coverage torque monitoring mechanism to detect and handle random hardware failures and system malfunctions, ensuring safe motor operation.

[0003] In related technologies, the monitoring of motor torque mainly relies on three-phase current sensors to detect current values, and then the torque is estimated and monitored by a calculation unit. When an abnormality occurs in this process or the vehicle itself is in an abnormal operating condition, it is easy to cause inaccurate detection and failure to detect hidden dangers, which in turn leads to the safety risk of unexpected torque output and affects vehicle safety. Summary of the Invention

[0004] This application provides a method, device, equipment, and medium for monitoring motor torque, which addresses the problem in related technologies where inaccurate torque monitoring and impact on vehicle safety can easily occur when equipment or operating conditions malfunction during motor torque monitoring.

[0005] In a first aspect, this application provides a method for monitoring motor torque, applied to a motor controller, the motor controller including a first processing unit and a second processing unit, the method comprising the following steps:

[0006] In the first processing unit of the motor controller, the functional layer estimated torque is obtained based on the three-phase current signal through the electromagnetic torque algorithm. The functional layer estimated torque is used to characterize the output torque that the motor can achieve under the current operating conditions.

[0007] In the second processing unit of the motor controller, the safety layer estimated torque is obtained through a power torque algorithm based on the bus voltage signal and the bus current signal. The safety layer estimated torque is used to characterize the output torque corresponding to the current actual output state of the motor. The first processing unit and the second processing unit are physically isolated.

[0008] Based on the comparison between the torque estimated by the motor functional layer and the torque estimated by the safety layer, the torque state is determined, and the corresponding system protection strategy is executed based on the torque state.

[0009] In one embodiment of this disclosure, the first processing unit and the second processing unit are two independent cores in a multi-core microcontroller; the three-phase current signal is independently acquired by the first processing unit, and the bus voltage signal and the bus current signal are independently acquired by the second processing unit.

[0010] In one embodiment of this disclosure, the functional layer estimates the torque based on the following steps: sampling the three-phase current signals of the motor; if a fault is detected in any one phase current sensor, calculating the estimated current of the faulty phase based on the sampled values ​​of the remaining two phase currents to obtain the reconstructed three-phase estimated current; performing coordinate transformation on the three-phase current or the reconstructed three-phase estimated current to obtain the corresponding d-axis current component and q-axis current component; and determining the functional layer estimated torque based on the electromagnetic torque formula, the d-axis current component, the q-axis current component, and preset calibration parameters.

[0011] In one embodiment of this disclosure, the safety layer estimated torque is obtained based on the following steps: acquiring bus voltage signals and bus current signals, and calculating the total input power of the motor corresponding to the bus; calculating the net mechanical power of the motor based on the total input power and the total system loss, wherein the total system loss includes inverter loss, motor loss and wiring harness loss; obtaining the real-time speed of the motor, and determining the safety layer estimated torque based on the ratio of net mechanical power to real-time speed.

[0012] In one embodiment of this disclosure, the torque state is determined by comparing the torque estimated at the motor functional layer and the torque estimated at the safety layer, and a corresponding system protection strategy is determined based on the torque state. This includes: in response to receiving a vehicle arbitration torque command, establishing at least one differentiated monitoring scenario based on at least two of the vehicle arbitration torque command, the torque estimated at the functional layer, and the torque estimated at the safety layer; when the comparison result under any monitoring scenario meets the corresponding anomaly judgment condition, determining the torque state and generating corresponding torque fault information; and executing the corresponding system protection strategy based on the preset risk level of the torque fault information.

[0013] In one embodiment of this disclosure, the monitoring scenarios and corresponding anomaly determination conditions include at least two of the following: a zero torque request scenario, where the corresponding anomaly determination condition includes the safety layer's estimated torque exceeding a first positive threshold; a torque direction monitoring scenario, where the corresponding anomaly determination condition includes the direction of the safety layer's estimated torque being opposite to the direction of the vehicle arbitration torque command and the difference exceeding a second threshold; a request deviation monitoring scenario, where the corresponding anomaly determination condition includes the difference between the safety layer's estimated torque and the vehicle arbitration torque command exceeding a third threshold; a dual estimation deviation monitoring scenario, where the corresponding anomaly determination condition includes the absolute value of the difference between the safety layer's estimated torque and the functional layer's estimated torque exceeding a fourth threshold; a torque deficiency monitoring scenario, where the corresponding anomaly determination condition includes the difference between the absolute value of the vehicle arbitration torque command and the absolute value of the safety layer's estimated torque exceeding a fifth threshold; and a capability deviation monitoring scenario, where the corresponding anomaly determination condition includes the difference between the functional layer's estimated torque and the safety layer's estimated torque corrected based on a preset derating factor exceeding a sixth threshold.

[0014] In one embodiment of this disclosure, based on a preset risk level of torque fault information, a corresponding system protection strategy is executed, including: if the preset risk level of torque fault information is minor, executing the response action corresponding to the fault code in the torque fault information, and / or reporting the diagnostic information corresponding to the torque fault information; if the preset risk level of torque fault information is severe, executing the corresponding hardware-level protection action; wherein, the hardware-level protection action includes: executing power transistor shutdown protection when the vehicle speed is lower than the vehicle speed threshold; or, executing three-phase winding short-circuit protection when the vehicle speed is higher than or equal to the vehicle speed threshold.

[0015] Secondly, embodiments of this disclosure provide a motor torque monitoring device applied to a motor controller, the motor controller including a first processing unit and a second processing unit, the motor torque monitoring device including:

[0016] The first acquisition module is used in the first processing unit of the motor controller to obtain the functional layer estimated torque based on the three-phase current signal through the electromagnetic torque algorithm. The functional layer estimated torque is used to characterize the output torque that the motor can achieve under the current operating conditions.

[0017] The second acquisition module is used in the second processing unit of the motor controller to obtain the safety layer estimated torque based on the bus voltage signal and the bus current signal through a power torque algorithm. The safety layer estimated torque is used to characterize the output torque corresponding to the current actual output state of the motor. The first processing unit and the second processing unit are physically isolated.

[0018] The processing module is used to determine the torque status by comparing the torque estimated by the motor functional layer and the torque estimated by the safety layer, and to execute the corresponding system protection strategy based on the torque status.

[0019] Optionally, the acquisition module specifically includes a first processing unit and a second processing unit, which are two independent cores in a multi-core microcontroller; the three-phase current signal is independently acquired by the first processing unit, and the bus voltage signal and the bus current signal are independently acquired by the second processing unit.

[0020] Optionally, the acquisition module is specifically used to sample the three-phase current signal of the motor; if a fault is detected in any one phase current sensor, the estimated current of the faulty phase is calculated based on the sampled values ​​of the remaining two phase currents to obtain the reconstructed three-phase estimated current; coordinate transformation is performed on the three-phase current or the reconstructed three-phase estimated current to obtain the corresponding d-axis current component and q-axis current component; based on the electromagnetic torque formula, the d-axis current component, the q-axis current component, and the preset calibration parameters, the estimated torque of the functional layer is determined.

[0021] Optionally, the acquisition module is specifically used to: collect bus voltage signals and bus current signals, and calculate the total input power of the motor corresponding to the bus; calculate the net mechanical power of the motor based on the total input power and the total system loss, the total system loss including inverter loss, motor loss and wiring harness loss; acquire the real-time speed of the motor, and determine the safety layer estimated torque based on the ratio of net mechanical power to real-time speed.

[0022] Optionally, the processing module is specifically configured to, in response to receiving a vehicle arbitration torque command, establish at least one differentiated monitoring scenario based on at least two of the vehicle arbitration torque command, the functional layer estimated torque, and the safety layer estimated torque; when the comparison result under any monitoring scenario meets the corresponding anomaly judgment condition, determine the torque status and generate corresponding torque fault information; and execute the corresponding system protection strategy based on the preset risk level of the torque fault information.

[0023] Optionally, the processing module specifically includes monitoring scenarios and corresponding anomaly judgment conditions, including at least two of the following: zero torque request scenario, with the corresponding anomaly judgment condition including the safety layer estimated torque exceeding a first positive threshold; torque direction monitoring scenario, with the corresponding anomaly judgment condition including the direction of the safety layer estimated torque being opposite to the direction of the vehicle arbitration torque command and the difference exceeding a second threshold; request deviation monitoring scenario, with the corresponding anomaly judgment condition including the difference between the safety layer estimated torque and the vehicle arbitration torque command exceeding a third threshold; dual estimation deviation monitoring scenario, with the corresponding anomaly judgment condition including the absolute value of the difference between the safety layer estimated torque and the functional layer estimated torque exceeding a fourth threshold; torque too low monitoring scenario, with the corresponding anomaly judgment condition including the difference between the absolute value of the vehicle arbitration torque command and the absolute value of the safety layer estimated torque exceeding a fifth threshold; and capability deviation monitoring scenario, with the corresponding anomaly judgment condition including the difference between the functional layer estimated torque and the safety layer estimated torque corrected based on a preset derating factor exceeding a sixth threshold.

[0024] Optionally, the processing module is specifically used to: if the preset risk level of the torque fault information is minor, execute the corresponding response action of the fault code in the torque fault information, and / or report the diagnostic information corresponding to the torque fault information; if the preset risk level of the torque fault information is severe, execute the corresponding hardware-level protection action; wherein, the hardware-level protection action includes: executing power transistor shutdown protection when the vehicle speed is lower than the vehicle speed threshold; or, executing three-phase winding short-circuit protection when the vehicle speed is higher than or equal to the vehicle speed threshold.

[0025] Thirdly, embodiments of this application provide a control device, including: a memory and a processor;

[0026] The memory stores the instructions that the computer executes;

[0027] The processor executes computer execution instructions stored in memory, causing the processor to perform a motor torque monitoring method as described in the first aspect of this disclosure.

[0028] Fourthly, embodiments of this disclosure also provide a computer-readable storage medium storing computer-executable instructions, which, when executed by a processor, are used to implement the motor torque monitoring method as described in the first aspect of this disclosure.

[0029] Fifthly, embodiments of this disclosure also provide a computer program product comprising computer execution instructions, which, when executed by a processor, are used to implement the motor torque monitoring method as described in the first aspect of this disclosure.

[0030] The motor torque monitoring method, apparatus, device, and medium provided in this disclosure, by setting up physically isolated first and second processing units in the motor controller, calculates the estimated torque at the functional layer based on the three-phase current signal using an electromagnetic torque algorithm, and calculates the estimated torque at the safety layer based on the bus voltage and current signal using a power torque algorithm. Finally, the torque state is determined by comparing the two torques, and the corresponding system protection strategy is executed. Thus, through the physical isolation of processing units and the dual torque determination mechanism at the logical layer, a monitoring architecture with dual redundancy in hardware and algorithms is constructed. This fundamentally solves the problem of monitoring failure caused by the failure of a single processing unit or a single path estimation deviation. Even if a processing unit fails or a sensor malfunctions, the system can still determine the torque state based on the estimation result output by the other physically isolated unit, effectively preventing safety hazards caused by unexpected torque output and significantly improving the reliability and functional safety level of motor torque monitoring. Attached Figure Description

[0031] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0032] Figure 1 This diagram illustrates an application scenario of the motor torque monitoring method, apparatus, equipment, and medium provided in the embodiments of this disclosure.

[0033] Figure 2 A flowchart of a motor torque monitoring method provided in one embodiment of this disclosure;

[0034] Figure 3 A flowchart of a motor torque monitoring method provided in yet another embodiment of this disclosure;

[0035] Figure 4 A schematic diagram of the structure of a motor torque monitoring device provided in yet another embodiment of this disclosure;

[0036] Figure 5 This is a schematic diagram of the structure of a control device provided in yet another embodiment of this disclosure.

[0037] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation

[0038] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0039] Motor torque monitoring is a core component in ensuring the power safety of new energy vehicles, directly impacting the longitudinal dynamics control of the vehicle under all operating conditions, including acceleration, braking, and coasting. Under functional safety standards, the monitoring system must possess extremely high failure coverage, accurately identifying torque anomalies and guiding the vehicle to a safe state even in the event of random hardware failures such as sensor drift, processing unit malfunction, or communication interruption. However, the inherent electromagnetic interference environment, multi-sensor coupling characteristics, and real-time requirements of motor control systems present significant challenges to building a highly reliable monitoring mechanism—any single monitoring path can fail due to a common cause failure.

[0040] While some motor monitoring solutions attempt to achieve redundancy through dual algorithms or multiple sensors, true physical isolation and logical heterogeneity are generally not achieved. Single-chip multi-algorithm operation still carries the risk of common-mode failure, and simple master-slave dual-core monitoring often deploys security layer algorithms and functional layer algorithms on the same computing resource, making it difficult to avoid scenarios where the entire processing unit fails. Furthermore, conventional torque comparison logic only focuses on the deviation between the estimated and target values, lacking coverage for complex operating conditions such as partial sensor failure and abnormal torque direction. This results in blind spots in the monitoring system under specific fault modes, failing to meet the diagnostic coverage requirements of high-level functional safety.

[0041] The motor torque monitoring method, device, equipment, and medium provided in this application perform torque estimation separately in physically isolated processing units, obtain multiple estimation results from heterogeneous data sources, and then determine the functional layer estimated torque and safety layer estimated torque representing different safety attributes. Finally, the comparison result of the two torques is used as the basis for state determination and protection triggering. Thus, physical redundancy at the hardware level solves the bottleneck of single-point failure, heterogeneous avoidance algorithm common factor deviation at the dual-torque logic level, and cross-validation of multi-source information achieves accurate identification of abnormal operating conditions, fundamentally overcoming the technical obstacles of traditional monitoring paths being single and failure coverage insufficient.

[0042] Figure 1 The following is a schematic diagram illustrating the application scenarios of the motor torque monitoring method, device, equipment, and medium provided in this application: Figure 1 As shown, during vehicle operation, the on-board controller 100 automatically collects motor operating parameters 110, determines the motor torque status, and outputs the corresponding control strategy 120 to control the vehicle motor.

[0043] It should be noted that, Figure 1 The scenario shown includes an on-board controller, motor operating parameters, and control strategies, which are only illustrated by one or a specific number of examples. However, this disclosure is not limited to this. In other words, the number of on-board controllers, motor operating parameters, and control strategies can be arbitrary.

[0044] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will now be described with reference to the accompanying drawings.

[0045] Figure 2 This is a flowchart illustrating the motor torque monitoring method provided in the embodiments of this application. The following is a summary of the process. Figure 2 The main process of the motor torque monitoring method is explained below:

[0046] S201. In the first processing unit of the motor controller, the estimated torque of the functional layer is obtained based on the three-phase current signal through the electromagnetic torque algorithm.

[0047] Among them, the estimated torque at the functional layer is used to characterize the output torque that the motor can achieve under the current operating conditions.

[0048] Specifically, the execution entity of the motor torque monitoring method in this embodiment is a motor controller capable of acquiring and analyzing vehicle motor torque and vehicle control commands, a system configured in the motor controller, or an on-board system capable of controlling the state of the motor controller. For ease of explanation, it will be referred to as the system below.

[0049] In this scheme, the motor controller will be equipped with at least two physically isolated processing units, that is, the motor controller includes at least a first processing unit and a second processing unit, thus serving as a key architecture based on the fundamental principle of avoiding single points of failure in functional safety design.

[0050] The physical isolation here refers to the fact that these processing units are independent of each other at the hardware level, with their own independent power management modules, clock sources, reset circuits and bus interfaces, and will not cause fault propagation due to sharing the same physical resources.

[0051] In practical engineering implementation, independent cores in multi-core microcontrollers can be used. These cores have independent arithmetic units, cache spaces, and register groups inside the chip, and can execute different instruction streams in parallel. Alternatively, multiple single-core microcontrollers can be used to cooperate through inter-chip communication to achieve more thorough physical isolation.

[0052] When performing torque estimation, each processing unit performs independent calculations based on the motor operating parameters. Acquiring these motor operating parameters is crucial for ensuring the independence of the estimation results; each processing unit should have its own independent sensor signal acquisition channel.

[0053] This independent design of the signal acquisition path can avoid common-mode failure caused by sharing sampling circuits. Even if a sampling circuit fails, other processing units can still obtain accurate parameter information.

[0054] Specifically, the first processing unit in the motor controller is specifically responsible for calculating the estimated torque of the functional layer based on the three-phase current signal using an electromagnetic torque algorithm. This means that the output torque that the motor can achieve under the current operating conditions is the torque value that the motor can theoretically output under the current operating conditions.

[0055] Acquiring three-phase current signals is the foundation for implementing the electromagnetic torque algorithm.

[0056] The first processing unit can be connected to current sensors installed on the three-phase output lines of the motor via a dedicated analog-to-digital converter interface. These sensors typically use the Hall effect or magnetoresistive effect to convert current signals into voltage signals.

[0057] The design of the sampling circuit needs to consider anti-aliasing filtering and level matching to ensure the accuracy and real-time performance of the sampled values. In a typical motor control system, the sampling frequency is set to 10kHz to 20kHz, synchronized with the pulse width modulation carrier frequency. The sampling time is generally selected at the midpoint or trough of the pulse width modulation period to minimize the impact of switching noise on the sampled values.

[0058] The system can store sampled values ​​into memory via direct memory access without the need for central processing unit intervention, thus ensuring the timeliness of the sampled data.

[0059] The core of the electromagnetic torque algorithm lies in converting the three-phase current into a value that can reflect the output torque of the motor.

[0060] The first processing unit first performs coordinate transformation on the acquired three-phase current, converting the three-phase AC quantities in the stationary coordinate system into DC components on the d-axis and q-axis that rotate synchronously with the rotor. This transformation process requires real-time acquisition of rotor position information, typically by acquiring rotor angles through a rotary transformer or magnetic encoder, and then converting them into digital angle values ​​through a decoding circuit.

[0061] After obtaining the d-axis and q-axis current components, the system calculates the estimated torque of the functional layer based on the electromagnetic torque formula. The general form of the electromagnetic torque formula includes parameters such as permanent magnet flux linkage, d-axis inductance, and q-axis inductance. These parameters are not constant values, but vary with the magnitude of the current and temperature.

[0062] In some embodiments, to solve the above problems, the system can adopt a lookup method based on a calibration database: during the motor bench test phase, the actual output torque under different working conditions is measured by a high-precision torque sensor, and a mapping relationship table between the d-axis current, q-axis current and actual torque is established.

[0063] When the vehicle is in operation, the system uses an interpolation algorithm to quickly query the corresponding functional layer to estimate the torque based on the currently calculated d-axis and q-axis current values, which ensures both calculation accuracy and real-time requirements.

[0064] S202. In the second processing unit of the motor controller, the safety layer estimated torque is obtained based on the bus voltage signal and the bus current signal through the power torque algorithm.

[0065] Among them, the safety layer estimated torque is used to characterize the output torque corresponding to the current actual output state of the motor, and the first processing unit and the second processing unit are physically isolated.

[0066] Specifically, the motor controller is equipped with a second processing unit, which is specifically responsible for calculating the safety layer estimated torque based on the bus voltage signal and the bus current signal using a power torque algorithm. This is the output torque corresponding to the current actual output state of the motor, or the actual output torque.

[0067] The second processing unit is physically isolated from the first processing unit at the hardware level, thus preventing fault propagation due to sharing the same physical resources. This design conforms to the basic principle of avoiding single points of failure in functional safety standards. Even if the first processing unit completely stops working due to software malfunction or hardware failure, the second processing unit can still independently complete the torque estimation task.

[0068] The acquisition of bus voltage and bus current signals is completed independently by the second processing unit.

[0069] Bus voltage sensors typically use a resistor divider with an isolation amplifier to convert high-voltage DC signals into low-voltage signals, which are then fed into an analog-to-digital converter. Bus current sensors often employ a closed-loop compensated sensor based on the Hall effect, capable of simultaneously measuring bidirectional current and meeting the negative current detection requirements under energy recovery conditions.

[0070] The two acquisition paths are completely independent of the acquisition path of the first processing unit in terms of power supply, reference voltage, and signal conditioning circuit. Even if one acquisition path fails due to short circuit or open circuit, the other path can still work normally.

[0071] After the system synchronously acquires voltage and current signals, it calculates the instantaneous total input power through a multiplier or digital signal processing. The calculation formula is the product of the instantaneous voltage value and the instantaneous current value.

[0072] In some embodiments, taking into account the potential ripple in bus voltage and current, an average value can be calculated within a sampling window to obtain a stable power value.

[0073] The core of the power-torque algorithm lies in calculating mechanical power through electrical power, and then obtaining the torque value.

[0074] Specifically, the system first calculates the net mechanical power based on the total input power and the total system losses. The estimation of the total system losses involves multiple energy conversion stages: inverter losses mainly include conduction losses and switching losses of power semiconductor devices; conduction losses are proportional to the square of the current, while switching losses are related to the switching frequency and bus voltage; motor losses include copper losses, iron losses, mechanical friction losses, and stray losses, with copper losses proportional to the square of the current and iron losses related to speed and magnetic flux; wiring harness losses are mainly Joule heat losses caused by cable resistance.

[0075] The system can establish a loss estimation model and calculate various loss values ​​in real time based on the current operating conditions, or establish a loss condition mapping table in advance through efficiency bench testing, and quickly obtain the total loss by looking up the table during runtime.

[0076] After obtaining the net mechanical power, the system needs to acquire the real-time speed of the motor to calculate the safety layer estimated torque. Speed ​​information can be processed based on signals from the rotor position sensor; common methods include decoding the sine and cosine signals output from the resolver, or measuring the frequency of the pulse signals output from the magnetic encoder.

[0077] The system can count the number of pulses output by the position sensor within a fixed time window, or measure the time interval between two adjacent pulses, and calculate the real-time rotational speed value.

[0078] Ultimately, the safety layer estimates the torque by dividing the net mechanical power by the rotational speed. When the rotational speed is close to zero, special handling is required, such as using the torque value from the previous cycle or directly outputting zero torque to avoid division-to-zero errors.

[0079] Thus, the second processing unit independently completes the entire process from signal acquisition to torque calculation, and the generated torque value is used as the safety layer's estimated torque for subsequent comparison and monitoring with the functional layer's estimated torque.

[0080] S203. Based on the comparison between the torque estimated by the motor functional layer and the torque estimated by the safety layer, determine the torque status, and execute the corresponding system protection strategy based on the torque status.

[0081] Specifically, the logic design for comparison needs to consider a variety of possible abnormal modes, including torque value deviation, direction error, response lag, and other situations.

[0082] In practical implementation, the system can establish a real-time comparison mechanism to calculate the difference or ratio of the two torques in each control cycle and compare it with a preset threshold. The threshold setting needs to balance sensitivity and anti-interference capabilities to avoid false alarms caused by minor fluctuations under normal operating conditions.

[0083] Torque status determination should differentiate between different fault levels. For minor, transient deviations, a recoverable warning state can be set, recording fault information without immediate protective action; for persistent, significant deviations, or deviations showing a rapidly increasing trend, a serious fault state should be determined, requiring triggering system protection response.

[0084] The judgment logic can also incorporate a time dimension, for example, requiring the deviation to exceed a threshold and persist for a certain period of time before it is confirmed as a fault, in order to filter out transient interference.

[0085] Accordingly, the execution of the system protection strategy needs to be differentiated based on the severity of the fault and the current operating status of the vehicle. For torque anomalies determined to be minor, the system can respond by recording fault codes or reporting diagnostic information.

[0086] Fault codes can be stored in non-volatile memory for after-sales diagnostic equipment to read; diagnostic information can be sent in real time to the vehicle controller or instrument panel via the vehicle network to remind the driver to check the vehicle. This response method ensures safety while preventing vehicle breakdowns caused by minor faults.

[0087] For torque anomalies deemed severe, the system needs to execute hardware-level protection actions to quickly cut off the path of unexpected torque output. The specific choice of protection action must consider the critical factor of vehicle speed: at low speeds, the vehicle's kinetic energy is relatively low, so a power transistor shutdown protection method can be used to immediately stop the energy supply to the motor; at high speeds, the vehicle's kinetic energy is relatively high, and shutting down the power transistor may lead to energy recovery failure and insufficient braking force. Therefore, a short-circuit protection method of the three-phase windings is more suitable, using the motor's own back electromotive force to generate a braking effect, allowing the vehicle to decelerate smoothly. The switching point between the two protection methods can be calibrated based on the vehicle's dynamic characteristics; for example, 30 kilometers per hour can be used as the vehicle speed threshold.

[0088] In some embodiments, the execution of the system protection strategy also needs to consider a fault recovery mechanism. After a protection action is triggered, the system can enter a safe state and continuously monitor the status of the fault source. If the fault source disappears on its own (e.g., a false trigger caused by transient electromagnetic interference), the system can attempt to exit the safe state and resume normal operation after certain conditions are met. This improves system availability and avoids the vehicle being in a power-limited state for extended periods due to intermittent faults.

[0089] The motor torque monitoring method provided in this application embodiment sets up a physically isolated first processing unit and a second processing unit in the motor controller. The first processing unit calculates the estimated torque at the functional layer based on the three-phase current signal using an electromagnetic torque algorithm, while the second processing unit calculates the estimated torque at the safety layer based on the bus voltage and current signal using a power torque algorithm. Finally, the torque state is determined by comparing the two torques, and the corresponding system protection strategy is executed. Thus, through the physical isolation of processing units and the dual torque determination mechanism at the logical layer, a monitoring architecture with dual redundancy in hardware and algorithms is constructed. This fundamentally solves the problem of monitoring failure caused by the failure of a single processing unit or the estimation deviation of a single path. Even if a processing unit fails or a certain type of sensor malfunctions, the system can still complete the torque state determination based on the estimation result output by the other physically isolated unit, effectively eliminating the safety hazards caused by unexpected torque output and significantly improving the reliability and functional safety level of motor torque monitoring.

[0090] Figure 3 Another embodiment of the motor torque monitoring method provided in this disclosure, in Figure 2 Based on the illustrated embodiment, the following is combined with Figure 3 The implementation process of the motor torque monitoring method is explained in detail, which includes the following steps:

[0091] S301. In the first processing unit of the motor controller, the estimated torque of the functional layer is obtained based on the three-phase current signal through the electromagnetic torque algorithm.

[0092] Among them, the estimated torque at the functional layer is used to characterize the output torque that the motor can achieve under the current operating conditions.

[0093] Specifically, this embodiment mainly provides further explanation of the calculation process for estimating torque and the judgment of torque state.

[0094] Furthermore, the first processing unit and the second processing unit are two independent cores in a multi-core microcontroller; the three-phase current signal is independently acquired by the first processing unit, and the bus voltage signal and the bus current signal are independently acquired by the second processing unit.

[0095] Specifically, at least two physically isolated processing units should be set up in the motor controller, and the specific implementation method can adopt a heterogeneous multi-core microcontroller architecture.

[0096] Taking a common automotive functional safety solution as an example, a multi-core processor that meets ASIL D requirements can be selected, where two independent cores undertake different computing tasks. The first and second processing units have their own independent interrupt controllers, timers, and memory protection units, ensuring that if one core experiences a software crash or hardware failure, it will not affect the normal operation of the other core, thus meeting the requirements for avoiding common-cause failures in relevant standards.

[0097] In some embodiments, the functional layer estimates the torque through the following steps:

[0098] Step A1: Sample the three-phase current signal of the motor.

[0099] Specifically, the sampling of the three-phase current signal of the motor needs to meet the real-time requirements of the control cycle.

[0100] In typical motor control systems, the sampling frequency is usually set to 10 kHz to 20 kHz, synchronized with the pulse width modulation carrier frequency. The sampling time is generally chosen at the midpoint or trough of the pulse width modulation period to minimize the impact of switching noise on the sampled values.

[0101] The system stores the sampled values ​​into memory via direct memory access, without the need for central processing unit intervention, thus ensuring the timeliness of the sampled data.

[0102] Step A2: If a fault is detected in any one phase current sensor, calculate the estimated current of the faulty phase based on the sampled values ​​of the remaining two phase currents to obtain the reconstructed estimated three-phase current.

[0103] Specifically, common fault modes of current sensors include signal loss, signal saturation, and signal offset. The system monitors the output status of each sensor in real time through a built-in fault diagnosis module, such as checking whether the sampled value exceeds a reasonable range, remains unchanged for a long time, or shows a step jump.

[0104] When a fault is detected in a phase sensor, the system activates a fault-tolerant algorithm: according to Kirchhoff's current law, the sum of the instantaneous values ​​of the three-phase currents is zero, so the fault phase current can be calculated using the sampled values ​​of the remaining two phase currents.

[0105] In practice, if the U-phase sensor fails, the system calculates the estimated value of the U-phase current using the sampled values ​​of the V-phase and W-phase. The calculation formula is the negative sum of the V-phase and W-phase currents.

[0106] This reconstruction method requires little computation and has high real-time performance, enabling it to quickly recover complete information about the three-phase current after sensor failure.

[0107] Step A3: Perform coordinate transformation on the three-phase current or the reconstructed estimated three-phase current to obtain the corresponding d-axis current component and q-axis current component.

[0108] Specifically, the coordinate transformation here is to convert the current in the three-phase stationary coordinate system to the two-phase rotating coordinate system, so as to facilitate the control strategy based on rotor magnetic field orientation.

[0109] First, a Clark transformation is performed to convert the three-phase currents into α-axis and β-axis current components in a two-phase stationary coordinate system. The transformation matrix is ​​based on either the principle of constant three-phase amplitude or the principle of constant power. This scheme adopts the principle of constant amplitude to ensure the intuitiveness of subsequent calculations.

[0110] Subsequently, a Park transformation is performed. Based on the real-time acquired rotor position angle, the α-axis and β-axis current components are rotated to the d-axis and q-axis coordinate systems synchronized with the rotor magnetic field to obtain the direct-axis current i. d (i.e., d-axis current component) and quadrature-axis current i q (i.e., the q-axis current component).

[0111] The rotor position angle is acquired in real time by a rotary transformer or magnetic encoder and converted into a digital angle value by a decoding circuit.

[0112] Step A4: Based on the electromagnetic torque formula, d-axis current component, q-axis current component, and preset calibration parameters, determine the estimated torque of the functional layer.

[0113] Specifically, the calculation of the estimated torque can be based on the electromagnetic torque formula. To facilitate the calculation, a parameter database needs to be established in advance through bench calibration.

[0114] The general form of the electromagnetic torque formula includes parameters such as permanent magnet flux linkage, d-axis and q-axis inductance. These parameters are not constant values ​​in actual operation, but vary with the magnitude of the current and the temperature.

[0115] Therefore, full-condition calibration is required during the motor bench testing phase: record the corresponding i values ​​at different speeds and torque output points. d i q The value is obtained by simultaneously measuring the actual output torque using a high-precision torque sensor, and establishing i. d i q Mapping table between torque and actual torque.

[0116] In actual vehicle operation, the system calculates i based on the current value. d and i q The value is obtained quickly by interpolating the corresponding functional layer torque through table lookup.

[0117] Databases can be stored in non-volatile memory in the form of multidimensional tables, supporting linear and bilinear interpolation algorithms to ensure the smoothness and accuracy of query results.

[0118] In some embodiments, the system also needs to consider torque compensation and dynamic response characteristic calibration during the determination of the estimated torque at the functional layer. Since the electromagnetic torque formula calculates the theoretical torque under ideal conditions, actual operation can lead to output deviations due to factors such as temperature changes and magnetic circuit saturation. Therefore, the system corrects the theoretically calculated value by loading torque compensation curves under different operating conditions during bench testing. Simultaneously, to meet the requirements of dynamic torque response, the calibration process also requires adjusting the response bandwidth of the current loop and the feedforward compensation parameters to ensure that the estimated torque at the functional layer accurately reflects the transient output characteristics of the motor, providing a precise reference value for subsequent torque monitoring.

[0119] S302. In the second processing unit of the motor controller, the safety layer estimated torque is obtained based on the bus voltage signal and the bus current signal through the power torque algorithm.

[0120] Among them, the safety layer estimated torque is used to characterize the output torque corresponding to the current actual output state of the motor, and the first processing unit and the second processing unit are physically isolated.

[0121] Specifically, the system can independently complete signal acquisition and determine the torque estimation of the safety layer through the second processing unit.

[0122] In some embodiments, the safety layer estimates the torque by means of the following steps:

[0123] Step B1: Collect the bus voltage signal and bus current signal, and calculate the total input power of the motor corresponding to the bus.

[0124] Specifically, bus voltage sensors typically use a resistor divider combined with an isolation amplifier to convert high-voltage DC signals into low-voltage signals which are then fed into an analog-to-digital converter.

[0125] Bus current sensors mostly adopt closed-loop compensation type sensors based on Hall effect, which can simultaneously measure bidirectional current and meet the negative current detection requirements under energy recovery conditions.

[0126] After the system synchronously acquires voltage and current signals, it calculates the instantaneous total input power through a multiplier or digital signal processing. The calculation formula is the product of the instantaneous voltage value and the instantaneous current value.

[0127] In some embodiments, taking into account the potential ripple in bus voltage and current, an average value can be calculated within a sampling window to obtain a stable power value.

[0128] Step B2: Calculate the net mechanical power of the motor based on the total input power and the total system loss.

[0129] The total system loss includes inverter loss, motor loss, and wiring harness loss.

[0130] Specifically, inverter losses mainly include the conduction losses and switching losses of power semiconductor devices. The conduction losses are proportional to the square of the current, while the switching losses are related to the switching frequency and the bus voltage.

[0131] Motor losses include copper losses, iron losses, mechanical friction losses, and stray losses. Copper losses are proportional to the square of the current, while iron losses are related to the rotational speed and magnetic flux. Wire harness losses are mainly Joule heat losses caused by cable resistance.

[0132] The system can establish a loss estimation model to calculate various loss values ​​in real time based on the current operating conditions (current, speed, bus voltage, temperature, etc.), or it can pre-establish a loss-operating condition mapping table through efficiency bench testing, and quickly obtain the total loss by looking up the table during operation. By subtracting the total system loss from the total input power, the net mechanical power, that is, the actual mechanical power output on the motor shaft, is obtained.

[0133] Step B3: Obtain the real-time speed of the motor and determine the safety layer estimated torque based on the ratio of net mechanical power to real-time speed.

[0134] Specifically, the motor speed can be obtained by processing the signal from the rotor position sensor.

[0135] Common methods include decoding the sine and cosine signals output by the rotary transformer, or measuring the frequency of the pulse signals output by the magnetic encoder.

[0136] The system can count the number of pulses output by the position sensor within a fixed time window, or measure the time interval between two adjacent pulses, and calculate the real-time rotational speed. The unit of rotational speed is usually radians per second or revolutions per minute, and needs to be standardized according to the unit used for subsequent torque calculations.

[0137] Ultimately, the safety layer estimates the torque by dividing the net mechanical power by the rotational speed. When the rotational speed is close to zero, special handling is required, such as using the torque value from the previous cycle or directly outputting zero torque to avoid division-to-zero errors.

[0138] In some embodiments, in a typical dual-processing unit configuration as in this embodiment and the foregoing embodiments, the result calculated by the first processing unit based on the electromagnetic torque algorithm is directly used as the torque estimated by the functional layer, and the result calculated by the second processing unit based on the power torque algorithm is directly used as the torque estimated by the safety layer.

[0139] However, besides the above situations, there are also scenarios where the motor controller contains three or more processing units. In this case, the system can employ a more complex determination mechanism to obtain the estimated torque at the functional layer and the estimated torque at the safety layer. For example, the three processing units may use different torque estimation methods, and the system can determine the final functional layer and safety layer torques through a voting mechanism or a weighted average. The voting mechanism could be a two-out-of-three logic, where the two closest values ​​among the three results are taken as valid values; the weighted average would allocate weights based on the historical accuracy performance of each processing unit, with units having higher accuracy receiving greater weights.

[0140] In some embodiments, the system may also incorporate health status monitoring information, and if a clock failure or memory error is detected in a processing unit, the results of that unit will be automatically excluded when determining torque.

[0141] In some embodiments, determining the torque estimated by the functional layer and the torque estimated by the safety layer also requires consideration of timeliness matching. Since the calculation cycles of the two processing units may differ, the system needs to align the estimation results under the same time reference. For example, the calculation result of the faster processing unit can be averaged or sampling, using the slower calculation cycle as the reference, to ensure that the two torque values ​​used for comparison correspond to the same physical time. The time synchronization mechanism can be implemented through hardware timer interrupts, triggering both processing units to simultaneously latch the calculation results in each synchronization cycle.

[0142] S303. In response to receiving the vehicle arbitration torque command, establish at least one differentiated monitoring scenario based on at least two of the vehicle arbitration torque command, the functional layer estimated torque, and the safety layer estimated torque.

[0143] Specifically, upon receiving the vehicle arbitration torque command, the system begins to establish differentiated monitoring scenarios.

[0144] The vehicle arbitration torque command is a target torque value that the vehicle controller sends to the motor controller after comprehensively calculating based on multi-source information such as driver pedal signals, autonomous driving system requests, and vehicle status. This command is transmitted in real time via the controller area network or the vehicle Ethernet and includes information on the magnitude and direction of the torque.

[0145] After receiving the instruction, the system combines the torque estimated by the functional layer and the torque estimated by the safety layer to build multiple independent monitoring channels, each designed for a specific abnormal mode.

[0146] In some embodiments, the system also needs to perform a self-test process for the motor controller before establishing differentiated monitoring scenarios.

[0147] The self-test includes the processing unit's built-in self-test, memory verification, clock frequency monitoring, analog-to-digital conversion channel verification, and sensor signal validity check.

[0148] After the self-test is completed, the system confirms that there are no faults in the torque calculation-related sensors, and that the vehicle controller has requested the motor controller to enter torque mode. Only then does the subsequent multi-scenario monitoring logic begin. The self-test process ensures that the monitoring system is built on healthy hardware, avoiding false alarms or missed alarms caused by hardware failures.

[0149] Furthermore, the monitoring scenarios and corresponding anomaly detection conditions include at least two of the following:

[0150] Scenario 1: Zero torque request scenario. The corresponding anomaly detection conditions include the safety layer estimating torque exceeding the first positive threshold.

[0151] Specifically, when the vehicle arbitration torque command is zero, the system enters the zero torque request monitoring scenario. This scenario corresponds to the operating conditions where the vehicle is idling, coasting, or the driver has no intention to accelerate or brake.

[0152] Under this operating condition, the motor should output zero torque; any non-zero torque may cause the vehicle to creep or roll backward unexpectedly. The monitoring logic determines whether the torque estimated by the safety layer exceeds the first positive threshold. The threshold setting needs to take into account sensor noise and system error, and can usually be set to one to two percent of the rated torque.

[0153] If the torque estimated by the safety layer exceeds the threshold and persists for a certain period of time, the system determines it as a zero torque anomaly.

[0154] In some embodiments, when determining anomalies in zero-torque request scenarios, the system not only monitors whether the torque estimated by the safety layer exceeds a first positive threshold, but also considers vehicle speed conditions for auxiliary judgment. For example, when the vehicle speed is below a certain value, such as five kilometers per hour, even if the torque estimated by the safety layer slightly exceeds the threshold, it may be a normal phenomenon caused by vehicle creep or road slope, and the judgment conditions can be appropriately relaxed in this case.

[0155] The system can dynamically adjust the threshold value based on vehicle speed, with a higher threshold at lower speeds to avoid misjudgments under low-speed conditions. This dynamic threshold adjustment mechanism further improves the adaptability and accuracy of the monitoring system.

[0156] Scenario 2: Torque direction monitoring scenario. The corresponding anomaly judgment conditions include the direction of the torque estimated by the safety layer being opposite to the direction of the torque command of the whole vehicle arbitration and the difference exceeding the second threshold.

[0157] Specifically, the torque direction monitoring scenario is used to detect faults where the torque direction is inconsistent with the command direction.

[0158] When the vehicle arbitration torque command is positive (driving condition), the system monitors whether the torque estimated by the safety layer is less than a negative second threshold; when the command is negative (energy recovery condition), it monitors whether the torque estimated by the safety layer is greater than a positive second threshold. The setting of the second threshold needs to take into account the dead zone near zero to avoid misjudgment due to small fluctuations.

[0159] This scenario can effectively cover serious faults such as reversed torque direction, for example, when a drive command is interpreted as a braking command due to a software logic error.

[0160] Scenario 3: Request deviation monitoring scenario. The corresponding anomaly judgment conditions include the difference between the torque estimated by the safety layer and the torque command of the whole vehicle arbitration exceeding the third threshold.

[0161] Specifically, in the scenario of requesting deviation monitoring, the torque estimated by the safety layer will be directly compared with the torque command of the whole vehicle arbitration.

[0162] Under driving conditions, the monitoring safety layer estimates whether the difference between the calculated torque and the commanded torque exceeds a third threshold; under braking conditions, it monitors whether the difference is less than a negative third threshold. The setting of the third threshold needs to comprehensively consider the dynamic response characteristics of the system, allowing for a certain tracking error during transient processes, but requiring the steady-state error to be controlled within a small range.

[0163] This scenario can detect faults where the torque output deviates from the target value over a long period of time.

[0164] Scenario 4: Dual estimation deviation monitoring scenario. The corresponding anomaly judgment conditions include the absolute value of the difference between the torque estimated by the safety layer and the torque estimated by the functional layer exceeding the fourth threshold.

[0165] Specifically, the dual estimation deviation monitoring scenario compares whether the absolute value of the difference between the torque estimated by the functional layer and the torque estimated by the safety layer exceeds the fourth threshold.

[0166] This scenario does not rely on vehicle commands but instead utilizes the outputs of two heterogeneous algorithms for cross-validation. Setting the fourth threshold requires analyzing the inherent deviation range of the two algorithms under normal operating conditions, which can be obtained through bench testing statistics. If the difference exceeds the threshold, it indicates that at least one of the two algorithms is malfunctioning, and the system triggers a fault log.

[0167] Scenario 5, Monitoring scenario for insufficient torque, the corresponding anomaly judgment conditions include the difference between the absolute value of the vehicle arbitration torque command and the absolute value of the torque estimated by the safety layer exceeding the fifth threshold.

[0168] Specifically, the low torque monitoring scenario is used to detect faults where the output torque is significantly less than the commanded torque.

[0169] The system compares the absolute value of the vehicle arbitration torque command with the absolute value of the torque estimated by the safety layer, and calculates whether the difference between the two exceeds the fifth threshold. This scenario is suitable for detecting insufficient output faults caused by drive circuit failures or motor demagnetization.

[0170] The fifth threshold is usually set as a certain percentage of the commanded torque, such as 20 percent, allowing for a certain dynamic deviation but requiring the steady-state output to be close to the commanded value.

[0171] Scenario 6, Capability Deviation Monitoring Scenario, the corresponding anomaly judgment condition is that the difference between the estimated torque of the functional layer and the estimated torque of the safety layer after correction based on the preset derating factor exceeds the sixth threshold.

[0172] Specifically, the capacity deviation monitoring scenario introduces the concepts of derating factor and current maximum capacity torque of the motor.

[0173] The derating factor here is a correction factor calculated based on the motor temperature, bus voltage, controller temperature, and other conditions, reflecting the maximum torque output capability of the motor under the current operating conditions.

[0174] The system multiplies the torque estimated by the safety layer by the derating factor and then by the current maximum torque capacity of the motor to obtain the corrected upper limit of the expected torque, which is then compared with the torque estimated by the functional layer.

[0175] If the estimated torque by the functional layer exceeds the upper limit and the sixth threshold, it indicates that the estimated result by the functional layer exceeds the actual capability range of the motor in the current state, which may be due to sensor drift or algorithm error leading to artificially high output.

[0176] In some embodiments, the calculation of the derating factor needs to consider multiple limiting factors. The motor controller comprehensively calculates the maximum allowable output capacity based on parameters such as the junction temperature of the power module, the temperature of the motor windings, the degree of bus voltage drop, and the operating time. The derating factor is typically between zero and one, and decreases accordingly when any limiting factor approaches the protection threshold.

[0177] The system multiplies the estimated torque from the safety layer by the derating factor, and then multiplies it by the current maximum torque capacity of the motor to obtain the theoretical upper limit value under the current state. If the estimated torque from the functional layer significantly exceeds this upper limit, it indicates that the calculation result of the functional layer may be artificially high, and fault handling needs to be triggered.

[0178] S304. When the comparison result in any monitoring scenario meets the corresponding anomaly judgment condition, determine the torque status and generate the corresponding torque fault information.

[0179] Specifically, when the comparison results in any monitoring scenario meet the corresponding anomaly judgment conditions, the system needs to accurately determine the torque status and generate the corresponding torque fault information.

[0180] Determining the torque state is not a simple binary judgment, but requires integrating the outputs of multiple monitoring channels. For example, alarms for both requested deviation scenarios and dual-estimated deviation scenarios may occur simultaneously. The system can use logical combinations to determine the severity of the fault and its possible causes.

[0181] The generation of fault information needs to include sufficiently rich diagnostic content. Each fault information can include data items such as fault code, fault level, fault time, fault scenario type, and abnormal difference magnitude. The fault code is encoded according to a predefined diagnostic protocol, such as using a five-byte format, which includes the system to which the fault belongs, the specific fault type, and the fault subtype.

[0182] Fault severity levels are categorized into minor, severe, and other levels to differentiate subsequent protection strategies. Fault time records are kept for the duration from anomaly detection to fault confirmation, allowing the diagnostic system to analyze the transient characteristics of the fault.

[0183] In some embodiments, the system can also temporarily store and perform preliminary analysis of fault information. Fault information is first stored in a fault buffer of random access memory; if the buffer is full, the oldest historical record is overwritten.

[0184] Meanwhile, the system can activate a fault confirmation timer, requiring an abnormal state to persist for a certain period before a fault is finally confirmed, thus avoiding false alarms caused by transient interference. The confirmation time can be set differently according to the fault type. For serious safety-related faults, the confirmation time can be set shorter, while for minor faults, it can be appropriately extended to filter out noise.

[0185] S305. Based on the preset risk level of torque fault information, execute the corresponding system protection strategy.

[0186] Specifically, different system protection strategies can be adopted depending on the preset risk level.

[0187] Furthermore, implementing system protection policies specifically includes the following situations:

[0188] Scenario 1: If the preset risk level of the torque fault information is minor, execute the response action corresponding to the fault code in the torque fault information, and / or report the diagnostic information corresponding to the torque fault information.

[0189] Specifically, for torque fault information that is preset to be of a minor level, the system adopts a non-intrusive response strategy.

[0190] Executing the response action corresponding to the fault code mainly refers to writing the fault code into the fault storage area of ​​the non-volatile memory for subsequent reading by the diagnostic instrument.

[0191] The memory can be an electrically erasable programmable read-only memory or a specific partition of flash memory, with power-loss retention capability. Fault codes are typically stored using a first-in, first-out (FIFO) or cyclic overwrite method to ensure that the most recent fault information is recorded.

[0192] Diagnostic information is reported and sent to other control units in real time via the vehicle network. The system can encapsulate fault codes and vehicle status parameters at the time of the fault (such as vehicle speed, torque, temperature, etc.) into diagnostic messages, which are then broadcast or directed to the vehicle controller and instrument panel via the controller area network. Upon receiving the diagnostic information, the vehicle controller can reduce the access privileges of certain functions or illuminate the fault indicator light to remind the driver to perform a vehicle inspection.

[0193] Thus, while ensuring safety, the vehicle's basic driving functions are maintained to the greatest extent possible.

[0194] Scenario 2: If the preset risk level of the torque fault information is severe, the corresponding hardware-level protection action will be executed. The hardware-level protection actions include: when the vehicle speed is lower than the vehicle speed threshold, power transistor shutdown protection will be executed; or when the vehicle speed is higher than or equal to the vehicle speed threshold, three-phase winding short-circuit protection will be executed.

[0195] Specifically, for torque fault information that is preset to a severe level, the system needs to execute hardware-level protection actions to immediately cut off the unexpected torque output.

[0196] The specific selection of protective actions is differentiated based on vehicle speed to meet the safety requirements at different speeds.

[0197] When the vehicle speed is lower than the vehicle speed threshold, the power transistor is shut down for protection.

[0198] Turning off the power transistors means ceasing the transmission of pulse-width modulated drive signals to the six power switching transistors of the inverter, thus putting all transistors in the off state. At this time, the motor is completely disconnected from the bus, and no drive torque or braking torque is generated. The vehicle coasts to a stop due to inertia.

[0199] This protection method is suitable for low-speed conditions because the vehicle's kinetic energy is relatively low, the sliding distance is short, and there is no risk of secondary collision. The shutdown action can be achieved by directly clearing the pulse width modulation duty cycle through a hardware comparator or software, with a response time typically in the microsecond range.

[0200] When the vehicle speed is higher than or equal to the vehicle speed threshold, the three-phase winding short-circuit protection is activated.

[0201] Shorting the three-phase windings means controlling the inverter to short-circuit the three-phase output terminals of the motor together. Specifically, this can be achieved by simultaneously turning on the three switches of the upper bridge arm or the three switches of the lower bridge arm.

[0202] After short-circuiting, a short-circuit current will be generated in the windings when the motor rotor rotates, forming a braking torque and causing the vehicle to decelerate smoothly.

[0203] Therefore, it is suitable for high-speed operating conditions because short-circuit braking can provide a controllable deceleration effect, avoiding the risk of instability caused by sudden power cut-off. Short-circuit protection can also be achieved through rapid software configuration of the switching transistor state, with a response time controlled in the microsecond range.

[0204] The calibration of the vehicle speed threshold here needs to take into account the vehicle dynamics characteristics, braking system capabilities, and functional safety objectives.

[0205] In typical passenger vehicle applications, the speed limit can be set to 30 kilometers per hour. Below this value, a shutdown protection is applied, and above this value, a short-circuit protection is applied. The system acquires vehicle speed information in real time through wheel speed sensors or motor speed sensors, quickly determines the current vehicle speed, and selects the corresponding protection method before triggering protection action.

[0206] After the protection action is executed, the system continuously monitors the fault status. If the fault disappears and the safety conditions are met, normal operation can be restored by restarting or resetting.

[0207] In some embodiments, after generating torque fault information, the system can also initiate different fault recovery attempts based on the fault type and severity.

[0208] For minor faults, the system can attempt to reinitialize the relevant sensors or restart the algorithm module to see if the fault disappears. For serious faults, the system can perform a more thorough reset operation, including clearing the fault memory, reloading configuration parameters, and executing a complete self-test process. After confirming that the source of the fault has been eliminated, it can attempt to exit the safe state and restore torque output.

[0209] Therefore, fault recovery mechanisms can improve system availability and reduce unnecessary maintenance.

[0210] In some embodiments, for recovery after performing power transistor shutdown protection or three-phase winding short-circuit protection, the system needs to continuously monitor the fault source status and vehicle status.

[0211] If the fault source disappears and the vehicle has come to a safe stop, the system can reinitialize the controller via a hard or soft reset and enter standby mode to await new commands. During the reset process, the system must ensure that the power transistors are in a safe off state to avoid brief conduction that could lead to unexpected output. After a successful reset, the system will perform a self-test procedure again, and only respond to new torque requests after confirming that there are no faults.

[0212] The motor torque monitoring method provided in this disclosure further refines the dual-core independent acquisition and heterogeneous algorithm implementation based on physically isolated dual processing units. At the functional layer estimation level, a two-phase reconstruction fault-tolerant mechanism is introduced to address single-phase sensor failures, ensuring continued system operation even after partial sensor failure. At the safety layer estimation level, a highly reliable torque reference is provided based on bus power calculation and deduction of system losses. It also provides multi-scenario monitoring coverage for six abnormal modes: zero torque, directional deviation, request deviation, dual estimation deviation, insufficient torque, and capacity deviation, achieving refined cross-verification. A graded protection strategy differentiates responses based on fault risk levels; minor faults are only recorded and reported to maintain basic vehicle operation, while severe faults intelligently select between power transistor shutdown or three-phase short-circuiting protection based on vehicle speed. This effectively solves the problems of insufficient redundancy, incomplete fault coverage, and simplistic protection strategies in existing monitoring schemes, achieving a comprehensive improvement in monitoring reliability, system robustness, and user experience.

[0213] Figure 4 This is a schematic diagram of the structure of a motor torque monitoring device provided in one embodiment of this disclosure. Figure 4 As shown, the motor torque monitoring device 400 includes:

[0214] The first acquisition module 410 is used in the first processing unit of the motor controller to obtain the functional layer estimated torque based on the three-phase current signal through the electromagnetic torque algorithm. The functional layer estimated torque is used to characterize the output torque that the motor can achieve under the current operating conditions.

[0215] The second acquisition module 420 is used in the second processing unit of the motor controller to obtain the safety layer estimated torque based on the bus voltage signal and the bus current signal through a power torque algorithm. The safety layer estimated torque is used to characterize the output torque corresponding to the current actual output state of the motor. The first processing unit and the second processing unit are physically isolated.

[0216] The processing module 430 is used to determine the torque status by comparing the torque estimated by the motor functional layer and the torque estimated by the safety layer, and to execute the corresponding system protection strategy based on the torque status.

[0217] Optionally, the acquisition module 410 specifically includes a first processing unit and a second processing unit, which are two independent cores in a multi-core microcontroller; the three-phase current signal is independently acquired by the first processing unit, and the bus voltage signal and the bus current signal are independently acquired by the second processing unit.

[0218] Optionally, the acquisition module 410 is specifically used to sample the three-phase current signal of the motor; if a fault is detected in any one phase current sensor, the estimated current of the faulty phase is calculated based on the sampled values ​​of the remaining two phase currents to obtain the reconstructed three-phase estimated current; coordinate transformation is performed on the three-phase current or the reconstructed three-phase estimated current to obtain the corresponding d-axis current component and q-axis current component; based on the electromagnetic torque formula, the d-axis current component, the q-axis current component, and the preset calibration parameters, the estimated torque of the functional layer is determined.

[0219] Optionally, the acquisition module 410 is specifically used to: acquire the bus voltage signal and the bus current signal, and calculate the total input power of the motor corresponding to the bus; calculate the net mechanical power of the motor based on the total input power and the total system loss, the total system loss including inverter loss, motor loss and wiring harness loss; acquire the real-time speed of the motor, and determine the safety layer estimated torque based on the ratio of net mechanical power to real-time speed.

[0220] Optionally, the processing module 430 is specifically configured to, in response to receiving a vehicle arbitration torque command, establish at least one differentiated monitoring scenario based on at least two of the vehicle arbitration torque command, the functional layer estimated torque, and the safety layer estimated torque; when the comparison result under any monitoring scenario meets the corresponding anomaly judgment condition, determine the torque state and generate corresponding torque fault information; and execute the corresponding system protection strategy based on the preset risk level of the torque fault information.

[0221] Optionally, the processing module 430 specifically includes monitoring scenarios and corresponding anomaly judgment conditions, including at least two of the following: zero torque request scenario, with the corresponding anomaly judgment condition including the safety layer estimated torque exceeding a first positive threshold; torque direction monitoring scenario, with the corresponding anomaly judgment condition including the direction of the safety layer estimated torque being opposite to the direction of the vehicle arbitration torque command and the difference exceeding a second threshold; request deviation monitoring scenario, with the corresponding anomaly judgment condition including the difference between the safety layer estimated torque and the vehicle arbitration torque command exceeding a third threshold; dual estimation deviation monitoring scenario, with the corresponding anomaly judgment condition including the absolute value of the difference between the safety layer estimated torque and the functional layer estimated torque exceeding a fourth threshold; torque too low monitoring scenario, with the corresponding anomaly judgment condition including the difference between the absolute value of the vehicle arbitration torque command and the absolute value of the safety layer estimated torque exceeding a fifth threshold; and capability deviation monitoring scenario, with the corresponding anomaly judgment condition including the difference between the functional layer estimated torque and the safety layer estimated torque corrected based on a preset derating factor exceeding a sixth threshold.

[0222] Optionally, the processing module 430 is specifically used to: if the preset risk level of the torque fault information is minor, execute the corresponding response action of the fault code in the torque fault information, and / or report the diagnostic information corresponding to the torque fault information; if the preset risk level of the torque fault information is severe, execute the corresponding hardware-level protection action; wherein, the hardware-level protection action includes: executing power transistor shutdown protection when the vehicle speed is lower than the vehicle speed threshold; or, executing three-phase winding short-circuit protection when the vehicle speed is higher than or equal to the vehicle speed threshold.

[0223] In this embodiment, the motor torque monitoring device, through the combination of various modules, solves the problem in related technologies where inaccurate torque monitoring and vehicle safety are easily affected when equipment or operating conditions malfunction during motor torque monitoring.

[0224] Figure 5 This is a schematic diagram of the structure of a control device provided in one embodiment of the present disclosure, as shown below. Figure 5 As shown, the control device 500 includes a memory 510 and a processor 520.

[0225] The memory 510 stores a computer program that can be executed by at least one processor 520. This computer program is executed by at least one processor 520 to enable the control device to implement the motor torque monitoring method provided in any of the above embodiments.

[0226] The memory 510 and the processor 520 can be connected via a bus 530.

[0227] The relevant explanations can be understood by referring to the corresponding descriptions and effects in the method embodiments, and will not be repeated here.

[0228] One embodiment of this disclosure provides a computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the motor torque monitoring method provided in any of the above embodiments.

[0229] The computer-readable storage medium may be ROM, random access memory (RAM), CD-ROM, magnetic tape, floppy disk, and optical data storage device, etc.

[0230] One embodiment of this disclosure provides a computer program product comprising computer-executable instructions that, when executed by a processor, are used to implement the motor torque monitoring method provided in any of the above embodiments.

[0231] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), or random access memory (RAM), etc.

[0232] In the above embodiments, the descriptions of each embodiment have their own emphasis. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments. The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification.

[0233] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0234] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this application is limited only by the appended claims.

Claims

1. A method for monitoring motor torque, characterized in that, Applied to a motor controller, the motor controller including a first processing unit and a second processing unit, the method includes the following steps: In the first processing unit of the motor controller, the estimated torque of the functional layer is obtained based on the three-phase current signal through the electromagnetic torque algorithm. The estimated torque of the functional layer is used to characterize the output torque that the motor can achieve under the current operating conditions. In the second processing unit of the motor controller, the safety layer estimated torque is obtained based on the bus voltage signal and the bus current signal through a power torque algorithm. The safety layer estimated torque is used to characterize the output torque corresponding to the current actual output state of the motor. The first processing unit and the second processing unit are physically isolated. Based on the comparison between the torque estimated by the motor functional layer and the torque estimated by the safety layer, the torque state is determined, and the corresponding system protection strategy is executed based on the torque state.

2. The method according to claim 1, characterized in that, The first processing unit and the second processing unit are two independent cores in a multi-core microcontroller; The three-phase current signal is independently acquired by the first processing unit, and the bus voltage signal and bus current signal are independently acquired by the second processing unit.

3. The method according to claim 2, characterized in that, The estimated torque in the functional layer is obtained based on the following steps: The three-phase current signal of the motor is sampled; If a fault is detected in any one phase current sensor, the estimated current of the faulty phase is calculated based on the sampled values ​​of the currents of the remaining two phases, and the reconstructed estimated three-phase current is obtained. Perform coordinate transformation on the three-phase current or the reconstructed three-phase estimated current to obtain the corresponding d-axis current component and q-axis current component; Based on the electromagnetic torque formula, the d-axis current component, the q-axis current component, and the preset calibration parameters, the estimated torque of the functional layer is determined.

4. The method according to claim 3, characterized in that, The safety layer estimates the torque based on the following steps: Collect bus voltage and bus current signals, and calculate the total input power of the motors corresponding to the bus. Based on the total input power and total system losses, the net mechanical power of the motor is calculated. The total system losses include inverter losses, motor losses, and wiring harness losses. The real-time speed of the motor is obtained, and the estimated torque of the safety layer is determined based on the ratio of the net mechanical power to the real-time speed.

5. The method according to any one of claims 1 to 4, characterized in that, The comparison between the torque estimated at the motor functional layer and the torque estimated at the safety layer determines the torque state, and based on the torque state, the corresponding system protection strategy is determined, including: In response to receiving a vehicle arbitration torque command, at least one differentiated monitoring scenario is established based on at least two of the vehicle arbitration torque command, the functional layer estimated torque, and the safety layer estimated torque; When the comparison result in any monitoring scenario meets the corresponding anomaly judgment condition, the state of the torque is determined and the corresponding torque fault information is generated. Based on the preset risk level of the torque fault information, the corresponding system protection strategy is executed.

6. The method according to claim 5, characterized in that, The monitoring scenarios and corresponding anomaly detection conditions include at least two of the following: In a zero-torque request scenario, the corresponding anomaly detection condition includes the safety layer estimating torque exceeding a first positive threshold. In the torque direction monitoring scenario, the corresponding anomaly judgment conditions include the direction of the torque estimated by the safety layer being opposite to the direction of the vehicle arbitration torque command and the difference exceeding the second threshold. In the scenario of requesting deviation monitoring, the corresponding anomaly judgment conditions include the difference between the torque estimated by the safety layer and the torque command of the whole vehicle exceeding the third threshold. In the dual estimation deviation monitoring scenario, the corresponding anomaly judgment condition includes the absolute value of the difference between the estimated torque of the safety layer and the estimated torque of the functional layer exceeding the fourth threshold. In the scenario of insufficient torque monitoring, the corresponding abnormal judgment conditions include the difference between the absolute value of the vehicle arbitration torque command and the absolute value of the torque estimated by the safety layer exceeding the fifth threshold. In the capability deviation monitoring scenario, the corresponding anomaly judgment condition includes the difference between the estimated torque of the functional layer and the estimated torque of the safety layer after correction based on the preset derating factor exceeding the sixth threshold.

7. The method according to claim 5, characterized in that, The system protection strategy executed based on the preset risk level of the torque fault information includes: If the preset risk level of the torque fault information is minor, execute the response action corresponding to the fault code in the torque fault information, and / or report the diagnostic information corresponding to the torque fault information. If the preset risk level of the torque fault information is severe, the corresponding hardware-level protection action is executed; wherein, the hardware-level protection action includes: when the vehicle speed is lower than the vehicle speed threshold, executing power transistor shutdown protection; or, when the vehicle speed is higher than or equal to the vehicle speed threshold, executing three-phase winding short-circuit protection.

8. A motor torque monitoring device, characterized in that, Applied to a motor controller, the motor controller includes a first processing unit and a second processing unit, including: The first acquisition module is used in the first processing unit of the motor controller to obtain the functional layer estimated torque based on the three-phase current signal through the electromagnetic torque algorithm, wherein the functional layer estimated torque is used to characterize the output torque that the motor can achieve under the current operating condition. The second acquisition module is used in the second processing unit of the motor controller to obtain the safety layer estimated torque based on the bus voltage signal and the bus current signal through a power torque algorithm. The safety layer estimated torque is used to characterize the output torque corresponding to the current actual output state of the motor. The first processing unit and the second processing unit are physically isolated. The processing module is used to determine the torque state based on the comparison between the torque estimated by the motor functional layer and the torque estimated by the safety layer, and to execute the corresponding system protection strategy based on the torque state.

9. A control device, characterized in that, include: Memory, processor; The memory stores computer-executed instructions; The processor executes computer execution instructions stored in the memory, causing the processor to perform the method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer-executable instructions, which, when executed by a processor, are used to implement the method as described in any one of claims 1 to 7.

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