A vehicle drive system output torque monitoring method, system and vehicle

Abstract

The application discloses a vehicle driving system output torque monitoring method and system and a vehicle. The method comprises the following steps: acquiring running parameter information of a driving motor and vehicle CAN communication information; acquiring motor torque information according to the running parameter information of the driving motor and the vehicle CAN communication information; acquiring a preset torque difference threshold value and a preset safety time threshold value; judging whether the motor torque information and the preset torque difference threshold value satisfy a torque fault judgment condition; if not, continuously acquiring the running parameter information of the driving motor and the vehicle CAN communication information; if yes, acquiring fault time information and judging whether the fault time information is greater than the preset safety time threshold value; if not, continuously acquiring the running parameter information of the driving motor and the vehicle CAN communication information; if yes, controlling the driving motor to enter a safety state. On the basis of ensuring a high safety level of motor torque function, the functional safety requirement of sensors in the system is reduced, and the development difficulty and cost are reduced.

Description

Technical Field

[0001] This invention relates to the field of vehicle drive technology, and in particular to a method, system, and vehicle for monitoring the output torque of a vehicle drive system. Background Technology

[0002] The vehicle drive system is the core system of a vehicle, providing the power source. The vehicle drive system mainly includes the drive motor and the motor controller. By setting the output torque control strategy, the vehicle drive system provides precise output torque, which is crucial to ensuring the safe operation of the vehicle.

[0003] Existing safety system architectures for motor torque control typically employ a three-layer monitoring architecture. The first layer operates the torque control function, the second layer monitors the output torque in real time, and the third layer monitors the underlying hardware and software of the system in real time. The second-layer torque monitoring layer calculates the actual torque using input signals independent of the first layer. Therefore, the input signals for the second layer also require a high level of safety, which places higher functional safety requirements on other controllers and sensors, increasing technical difficulty and development costs. Summary of the Invention

[0004] This invention provides a method, system, and vehicle for monitoring the output torque of a vehicle drive system. While ensuring a high level of safety for the motor torque function, it reduces the functional safety requirements of the sensors in the system, thereby reducing development difficulty and cost.

[0005] According to one aspect of the present invention, a method for monitoring the output torque of a vehicle drive system is provided, characterized in that it includes:

[0006] Obtain the operating parameters of the drive motor and the CAN communication information of the entire vehicle;

[0007] The motor torque information is obtained based on the operating parameters of the drive motor and the vehicle CAN communication information;

[0008] Obtain the preset torque difference threshold and the preset safety time threshold;

[0009] Determine whether the motor torque information and the preset torque difference threshold meet the torque fault determination conditions;

[0010] If not, continue to obtain the operating parameter information of the drive motor and the CAN communication information of the whole vehicle;

[0011] If so, obtain the fault time information and determine whether the fault time information is greater than the preset safe time threshold;

[0012] If not, continue to obtain the operating parameter information of the drive motor and the CAN communication information of the whole vehicle;

[0013] If so, the drive motor is controlled to enter a safe state.

[0014] Optionally, acquiring the operating parameter information of the drive motor and the vehicle CAN communication information includes:

[0015] It acquires the three-phase current information on the AC side of the drive motor, the bus voltage information on the DC side, the bus current information, the rotor position information and speed information of the motor, as well as the target torque information of the motor, the vehicle acceleration information, the vehicle speed information and the gradient information.

[0016] Optionally, obtaining motor torque information based on the operating parameters of the drive motor and the vehicle CAN communication information includes:

[0017] The actual torque information of the AC-side motor is determined based on the three-phase current information of the drive motor and the rotor position information of the motor.

[0018] The actual torque information of the DC motor is determined based on the DC side bus voltage information, the bus current information, and the speed information.

[0019] The actual torque information of the motor is determined based on the vehicle acceleration information, the vehicle speed information, and the slope information.

[0020] Optionally, determining the actual torque information of the AC-side motor based on the three-phase current information of the drive motor and the rotor position information of the motor includes:

[0021] Based on the three-phase current information of the AC side of the drive current and the rotor position information of the motor, current information under two-phase rotation coordinates is obtained;

[0022] The actual torque information of the AC side motor is determined based on the current information under the two-phase rotating coordinates.

[0023] Optionally, based on the first formula, the actual torque information of the AC-side motor is determined according to the current information under the two-phase rotating coordinates. The first formula is:

[0024]

[0025] Where T1 represents the actual torque information of the AC-side motor; P n Ψ is the number of magnetic pairs in the motor; f For permanent magnet flux linkage; i d i q These are the current components along the d-axis and q-axis in a two-phase rotating coordinate system, respectively; L d L q These are the inductance components on the d-axis and q-axis in a two-phase rotating coordinate system, respectively.

[0026] Optionally, based on the second formula, the actual torque information of the DC motor is determined according to the DC-side bus voltage information, the bus current information, and the speed information. The second formula is:

[0027]

[0028] Among them, T2 represents the actual torque information of the DC motor; U DC I is the DC-side bus voltage; DC η is the bus current; η is the motor efficiency; ω M This represents the motor speed.

[0029] Optionally, based on the third formula, the actual torque information of the motor is determined according to the vehicle acceleration information, the vehicle speed information, and the slope information. The third formula is:

[0030]

[0031] Where T3 represents the actual torque information of the motor; m represents the vehicle mass; a1 represents the vehicle acceleration; r represents the wheel radius; λ(v,i) represents the correction coefficient related to the vehicle speed v and the gradient i; and i o This refers to the speed ratio of the transmission system.

[0032] Optionally, determining whether the motor torque information and the preset torque difference threshold meet the torque fault determination conditions includes:

[0033] Determine whether the absolute value of the difference between the actual torque information of the AC motor and the target torque information of the motor is greater than the preset torque difference threshold, whether the absolute value of the difference between the actual torque information of the DC motor and the target torque information of the motor is greater than the preset torque difference threshold, or whether the absolute value of the difference between the actual torque information of the motor and the target torque information of the motor is greater than the preset torque difference threshold.

[0034] According to another aspect of the present invention, a vehicle drive system output torque monitoring system is provided, comprising the vehicle drive system output torque monitoring method described in any one of the above aspects, including:

[0035] The data acquisition module is used to acquire the operating parameter information of the drive motor and the CAN communication information of the whole vehicle;

[0036] The torque estimation module is used to obtain motor torque information based on the operating parameters of the drive motor and the vehicle CAN communication information.

[0037] The threshold acquisition module is used to acquire the preset torque difference threshold and the preset safety time threshold;

[0038] The fault determination module is used to determine whether the motor torque information and the preset torque difference threshold meet the torque fault determination conditions.

[0039] The motor fault handling module is used to: if the torque fault determination condition is not met, continue to acquire the operating parameter information of the drive motor and the vehicle CAN communication information; if the torque fault determination condition is met, acquire the fault time information and determine whether the fault time information is greater than the preset safe time threshold; if the fault time information is not greater than the preset safe time threshold, continue to acquire the operating parameter information of the drive motor and the vehicle CAN communication information; if the fault time information is greater than the preset safe time threshold, control the drive motor to enter a safe state.

[0040] According to another aspect of the present invention, a vehicle is provided, including the vehicle drive system output torque monitoring system described in any one of the foregoing aspects.

[0041] The technical solution of this invention provides a method for monitoring the output torque of a vehicle drive system, comprising: acquiring operating parameter information of the drive motor and vehicle CAN communication information; acquiring motor torque information based on the operating parameter information of the drive motor and vehicle CAN communication information; acquiring a preset torque difference threshold and a preset safety time threshold; determining whether the motor torque information and the preset torque difference threshold meet the torque fault determination condition; if not, continuing to acquire the operating parameter information of the drive motor and vehicle CAN communication information; if yes, acquiring fault time information and determining whether the fault time information is greater than the preset safety time threshold; if not, continuing to acquire the operating parameter information of the drive motor and vehicle CAN communication information; if yes, controlling the drive motor to enter a safe state. This method ensures a high safety level for the motor torque function while reducing the functional safety requirements of sensors in the system, thus reducing development difficulty and cost.

[0042] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This invention provides a schematic flowchart of a method for monitoring the output torque of a vehicle drive system.

[0045] Figure 2 A schematic diagram of the flow structure of another method for monitoring the output torque of a vehicle drive system provided in an embodiment of the present invention;

[0046] Figure 3 A schematic diagram of the flow structure of another method for monitoring the output torque of a vehicle drive system provided in an embodiment of the present invention;

[0047] Figure 4 A schematic diagram of the flow structure of another method for monitoring the output torque of a vehicle drive system provided in an embodiment of the present invention;

[0048] Figure 5 A schematic flowchart of another method for monitoring the output torque of a vehicle drive system provided in an embodiment of the present invention.

[0049] Figure 6 A schematic diagram of the structure of a vehicle drive system output torque monitoring system provided in an embodiment of the present invention;

[0050] Figure 7 This is a structural schematic diagram of a vehicle provided in an embodiment of the present invention. Detailed Implementation

[0051] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0052] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0053] Figure 1This invention provides a flowchart illustrating a method for monitoring the output torque of a vehicle drive system. This embodiment is applicable to motor torque monitoring and can be executed by a vehicle drive system output torque monitoring system, which can be implemented in hardware and / or software. Figure 1 As shown, the method includes:

[0054] S101 acquires the operating parameter information of the drive motor and the CAN communication information of the whole vehicle.

[0055] The vehicle drive system output torque monitoring system includes a signal input system, a motor control system, and a three-phase full-axle drive system. The signal input system can include a sensor unit and a CAN communication unit. The three-phase full-axle drive system can receive torque control signals to control the output torque of the drive motor, or receive shutdown control signals to select a shutdown path and safely stop the drive motor. The motor control system monitors the output torque of the vehicle's output system in real time by acquiring the drive motor's operating parameters from the sensor units in the signal input system and the vehicle's CAN communication information transmitted by the CAN communication unit.

[0056] S102 obtains motor torque information based on the operating parameters of the drive motor and the vehicle's CAN communication information.

[0057] The motor control system estimates the motor torque based on the obtained operating parameters of the drive motor and the vehicle's CAN communication information. This facilitates the comparison between the current motor torque and the preset torque information in the system, thereby ensuring the normal and safe operation of the drive motor.

[0058] S103, obtain the preset torque difference threshold and the preset safety time threshold.

[0059] Specifically, safety thresholds are pre-set in the motor control system based on functional safety objectives. These safety thresholds include a preset torque difference threshold and a preset safety time threshold. The specific values ​​can be selected according to actual design requirements to ensure that the vehicle drive motor operates normally or enters a safe state. The preset safety time threshold t... fusa Equal to the fault tolerance time interval FTTI, and the preset torque difference threshold T e_fusa Satisfy T e_fusa =m(Δa+a) offset ), where m is the vehicle mass, Δa is the unexpected acceleration measure, and a offset This represents the deviation in the acceleration estimate.

[0060] S104, determine whether the motor torque information and the preset torque difference threshold meet the torque fault judgment conditions; if yes, proceed to step S105; if no, proceed to step S101.

[0061] If the motor torque information does not meet the torque fault judgment condition according to the preset torque difference threshold, it is considered that the current vehicle drive motor is in normal working condition. Then, the operating parameter information of the drive motor and the vehicle CAN communication information are continuously obtained to obtain the actual torque of the drive motor in real time.

[0062] S105, obtain fault time information and determine whether the fault time information is greater than the preset safe time threshold; if yes, proceed to step S106; if no, proceed to step S101.

[0063] If the motor torque information and the preset torque difference threshold meet the torque fault judgment condition, it is considered that the current vehicle drive motor may be in an abnormal working state. Therefore, the fault time information is obtained and it is judged whether the fault time information is greater than the preset safe time threshold, so as to judge the state of the drive motor based on the fault occurrence duration.

[0064] If the fault time information is less than or equal to the preset safe time threshold, it is considered that the current vehicle drive motor has not failed, and the driving motor's operating parameter information and the vehicle's CAN communication information are continuously acquired to obtain the actual torque of the drive motor in real time.

[0065] S106 controls the drive motor to enter a safe state.

[0066] If the fault time exceeds the preset safe time threshold, the current vehicle drive motor is considered to have malfunctioned. It is necessary to control the motor torque to shut off and control the three-phase full-axle drive system to bring the vehicle drive motor into a safe state, so as to avoid the vehicle accelerating unexpectedly and causing an accident.

[0067] This invention acquires the operating parameters of the drive motor and the CAN communication information of the vehicle in real time, estimates the motor torque information, and sets a preset torque difference threshold and a preset safety time threshold. By comparing these, the real-time status of the motor is confirmed. This ensures the normal operation of the vehicle drive motor while maintaining a high safety level for the motor torque function, thus preventing unexpected acceleration of the vehicle.

[0068] Optional, Figure 2 This is a schematic flowchart of another method for monitoring the output torque of a vehicle drive system provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the method includes:

[0069] S201 acquires the three-phase current information on the AC side of the drive motor, the bus voltage information on the DC side, the bus current information, the rotor position information and speed information of the motor, as well as the target torque information of the motor, the vehicle acceleration information, the vehicle speed information and the gradient information.

[0070] The signal input system includes a sensor unit and a CAN communication unit. The sensor unit outputs the three-phase current information of the AC side of the drive motor, the DC side bus voltage information, the bus current information, and the motor rotor position information. The CAN communication unit transmits the vehicle's CAN communication information, which is sent by other sensors in the vehicle, including the motor target torque information, vehicle acceleration information, vehicle speed information, and slope information. This facilitates real-time monitoring of the output torque of the vehicle drive system.

[0071] S202 obtains motor torque information based on the three-phase current information on the AC side of the drive motor, the bus voltage information on the DC side, the bus current information, the motor rotor position information, the speed information, the vehicle CAN communication information, the motor target torque information, the vehicle acceleration information, the vehicle speed information, and the slope information.

[0072] Among them, the motor control performs three independent path calculations based on the three-phase current information of the drive motor AC side, the bus voltage information of the DC side, the bus current information, the motor rotor position information, the speed information, the vehicle CAN communication information, the motor target torque information, the vehicle acceleration information, the vehicle speed information, and the slope information, and obtains the motor torque information in real time.

[0073] S203, obtain the preset torque difference threshold and the preset safety time threshold.

[0074] S204, determine whether the motor torque information and the preset torque difference threshold meet the torque fault judgment conditions; if yes, proceed to step S205; if no, proceed to step S201.

[0075] S205, obtain fault time information and determine whether the fault time information is greater than the preset safe time threshold; if yes, proceed to step S206; if no, proceed to step S201.

[0076] S206 controls the drive motor to enter a safe state.

[0077] This invention provides real-time acquisition of the three-phase current information on the AC side of the drive motor, the bus voltage information on the DC side, the bus current information, the rotor position information and speed information of the motor, as well as the target torque information of the motor, the vehicle acceleration information, the vehicle speed information and the gradient information. It also estimates the motor torque information and sets preset torque difference thresholds and preset safety time thresholds. By comparing these, the real-time status of the motor is confirmed. This ensures the normal operation of the vehicle drive motor while maintaining a high safety level for the motor torque function, thus avoiding unexpected acceleration of the vehicle.

[0078] Optional, Figure 3 This is a schematic flowchart of another method for monitoring the output torque of a vehicle drive system provided in an embodiment of the present invention, as shown below. Figure 3As shown, the method includes:

[0079] S301 acquires the three-phase current information on the AC side of the drive motor, the bus voltage information on the DC side, the bus current information, the rotor position information and speed information of the motor, as well as the target torque information of the motor, the vehicle acceleration information, the vehicle speed information and the gradient information.

[0080] S302 determines the actual torque information of the AC side motor based on the three-phase current information of the AC side of the drive motor and the rotor position information of the motor.

[0081] The motor control system includes a torque estimation module. This module estimates the actual torque of the AC motor by acquiring the three-phase current information and rotor position information of the drive motor. This facilitates the subsequent use of the actual torque information of the AC motor to determine the state of the vehicle's drive motor.

[0082] S303 determines the actual torque information of the DC motor based on the DC side bus voltage information, bus current information, and speed information.

[0083] The torque estimation module, by acquiring DC-side bus voltage, bus current, and speed information, optionally uses the second formula. Where T2 represents the actual torque information of the DC motor; U DC I is the DC-side bus voltage. DC η is the bus current; η is the motor efficiency; ω M This refers to the motor speed. Based on the DC-side bus voltage, bus current, and speed information, the actual torque of the DC-side motor is estimated, facilitating subsequent judgment of the vehicle's drive motor status using this actual DC-side motor torque information.

[0084] S304 determines the actual torque information of the motor based on the vehicle's acceleration, speed, and gradient information.

[0085] The torque estimation module, based on the acquired vehicle acceleration, speed, and gradient information, uses a third formula... Where T3 represents the actual torque information of the motor; m represents the vehicle mass; a1 represents the vehicle acceleration; r represents the wheel radius; λ(v,i) represents the correction coefficient related to the vehicle speed v and the gradient i; and i o This refers to the transmission system speed ratio. Based on vehicle acceleration, speed, and gradient information, the actual torque of the motor is estimated to facilitate subsequent assessment of the vehicle's drive motor status.

[0086] S305, obtain the preset torque difference threshold and the preset safety time threshold.

[0087] S306, determine whether the actual torque information of the AC side motor, the actual torque information of the DC side motor, and the actual torque information of the motor meet the torque fault judgment conditions with the preset torque difference threshold; if yes, proceed to step S307; if no, proceed to step S301.

[0088] S307, Obtain fault time information and determine whether the fault time information is greater than the preset safe time threshold; if yes, proceed to step S308; if no, proceed to step S301.

[0089] S308 controls the drive motor to enter a safe state.

[0090] This invention employs a triple independent path to acquire the actual torque information of the vehicle's drive motor on the AC side, the actual torque information of the DC side, and the actual torque information of the drive motor, based on the obtained three-phase current information on the AC side of the drive motor, the bus voltage information on the DC side, the bus current information, the motor rotor position information, the speed information, the vehicle acceleration information, the vehicle speed information, and the slope information. Simultaneously, preset torque difference thresholds and preset safety time thresholds are set. By comparing these, the real-time status of the motor is confirmed. While ensuring a high safety level for the motor torque function, this ensures the normal operation of the vehicle's drive motor and avoids unexpected acceleration of the entire vehicle.

[0091] Optional, Figure 4 This is a schematic flowchart of another method for monitoring the output torque of a vehicle drive system provided in an embodiment of the present invention, as shown below. Figure 4 As shown, the method includes:

[0092] S401 acquires the three-phase current information on the AC side of the drive motor, the bus voltage information on the DC side, the bus current information, the rotor position information and speed information of the motor, as well as the target torque information of the motor, the vehicle acceleration information, the vehicle speed information and the gradient information.

[0093] S402 obtains current information in two-phase rotation coordinates based on the three-phase current information on the AC side of the drive current and the rotor position information of the motor.

[0094] S403 determines the actual torque information of the AC side motor based on the current information under the two-phase rotating coordinates.

[0095] Specifically, the three-phase AC current information of the drive motor and the rotor position are obtained, and then coordinate transformation is used to obtain the current information id and iq in two-phase rotational coordinates. Optionally, based on the first formula, Where T1 represents the actual torque information of the AC-side motor; P n Ψ is the number of magnetic pairs in the motor; f For permanent magnet flux linkage; i d i qThese are the current components along the d-axis and q-axis in a two-phase rotating coordinate system, respectively; L d L q These represent the inductance components on the d-axis and q-axis of the two-phase rotating coordinate system. The actual torque information of the AC-side motor is calculated based on the current information id and iq.

[0096] S404 determines the actual torque information of the DC motor based on the DC side bus voltage information, bus current information, and speed information.

[0097] S405 determines the actual torque information of the motor based on the vehicle's acceleration, speed, and gradient information.

[0098] S406, obtain the preset torque difference threshold and the preset safety time threshold.

[0099] S407, determine whether the actual torque information of the AC side motor, the actual torque information of the DC side motor, and the actual torque information of the motor meet the torque fault judgment conditions with the preset torque difference threshold; if yes, proceed to step S408; if no, proceed to step S401.

[0100] S408, Obtain fault time information and determine whether the fault time information is greater than the preset safe time threshold; if yes, proceed to step S409; if no, proceed to step S401.

[0101] S409 controls the drive motor to enter a safe state.

[0102] This invention obtains current information in two-phase rotation coordinates based on the three-phase current information of the AC side of the drive current and the rotor position information of the motor, thereby determining the actual torque information of the AC side motor. At the same time, it also obtains the actual torque information of the DC motor and the actual torque information of the motor. Simultaneously, it sets a preset torque difference threshold and a preset safety time threshold, and confirms the real-time status of the motor by comparison. While ensuring a high safety level of the motor torque function, it enables the normal operation of the vehicle drive motor and avoids unexpected acceleration of the whole vehicle.

[0103] Optional, Figure 5 This is a schematic flowchart of another method for monitoring the output torque of a vehicle drive system provided in an embodiment of the present invention, as shown below. Figure 5 As shown, the method includes:

[0104] S501 acquires the three-phase current information on the AC side of the drive motor, the bus voltage information on the DC side, the bus current information, the rotor position information and speed information of the motor, as well as the target torque information of the motor, the vehicle acceleration information, the vehicle speed information and the gradient information.

[0105] S502 obtains current information in two-phase rotation coordinates based on the three-phase current information on the AC side of the drive current and the rotor position information of the motor.

[0106] S503 determines the actual torque information of the AC side motor based on the current information under the two-phase rotating coordinate system.

[0107] S504 determines the actual torque information of the DC motor based on the DC side bus voltage information, bus current information, and speed information.

[0108] S505 determines the actual torque information of the motor based on the vehicle's acceleration, speed, and gradient information.

[0109] S506, obtain the preset torque difference threshold and the preset safety time threshold.

[0110] S507, determine whether the absolute value of the difference between the actual torque information of the AC motor and the target torque information of the motor is greater than a preset torque difference threshold, whether the absolute value of the difference between the actual torque information of the DC motor and the target torque information of the motor is greater than a preset torque difference threshold, or whether the absolute value of the difference between the actual torque information of the motor and the target torque information of the motor is greater than a preset torque difference threshold; if yes, proceed to step S508; if no, proceed to step S501.

[0111] Among them, if the calculated actual torque information of the AC side motor, the actual torque information of the DC side motor, and the actual torque information of the motor are all compared with the target torque information of the motor, and if the absolute value of the difference between the actual torque information of the AC side motor and the target torque information of the motor is greater than a preset torque difference threshold, or if the absolute value of the difference between the actual torque information of the DC side motor and the target torque information of the motor is greater than a preset torque difference threshold, or if the absolute value of the difference between the actual torque information of the motor and the target torque information of the motor is greater than a preset torque difference threshold, then the torque fault judgment condition is considered to be met.

[0112] S508, obtain fault time information and determine whether the fault time information is greater than the preset safe time threshold; if yes, proceed to step S509; if no, proceed to step S501.

[0113] S509 controls the drive motor to enter a safe state.

[0114] This invention compares the actual torque information of the AC-side motor, the actual torque information of the DC-side motor, and the actual torque information of the motor with the target torque information of the motor and a preset torque difference threshold, respectively. At the same time, a preset torque difference threshold and a preset safety time threshold are set. The real-time status of the motor is confirmed by comparison. While ensuring a high safety level of the motor torque function, the normal operation of the vehicle drive motor is ensured, and the unexpected acceleration of the whole vehicle is avoided.

[0115] Figure 6This is a schematic diagram of the structure of a vehicle drive system output torque monitoring system provided in an embodiment of the present invention, as shown below. Figure 6 As shown, the vehicle drive system output torque monitoring system 200 utilizes the vehicle drive system output torque monitoring method described in any of the above embodiments.

[0116] The vehicle drive system output torque monitoring system includes a signal input system 10, a motor control system 11, and a three-phase full-bridge drive system 12. The motor control system 11 includes a data acquisition module 101, a torque estimation module 102, a threshold acquisition module 103, a fault diagnosis module 104, and a motor fault handling module 105. The signal input system 10 may include a sensor unit 13 and a CAN communication unit 14. The three-phase full-bridge drive system 12 can receive torque control signals to control the output torque of the drive motor, or receive shutdown control signals to select a shutdown path and safely stop the drive motor. The data acquisition module 101 is connected to the signal input system 10, and the motor control system 11 is connected to the three-phase full-bridge drive system 12. The motor control system 11 has a three-layer monitoring architecture: the first layer operates the torque control function, the second layer monitors the output torque in real time, and the third layer monitors the underlying hardware and software of the system in real time. Typically, the motor control system 11 performs real-time monitoring of the drive motor's output torque at the second layer.

[0117] The motor control system 11 of the vehicle drive system output torque monitoring system 200 includes:

[0118] The data acquisition module 101 is used to acquire the operating parameter information of the drive motor and the CAN communication information of the vehicle.

[0119] The torque estimation module 102 is used to obtain motor torque information based on the operating parameters of the drive motor and the vehicle CAN communication information.

[0120] The threshold acquisition module 103 is used to acquire the preset torque difference threshold and the preset safety time threshold.

[0121] The fault judgment module 104 is used to determine whether the motor torque information and the preset torque difference threshold meet the torque fault judgment conditions.

[0122] The motor fault handling module 105 is used to: if the torque fault determination condition is not met, obtain the operating parameter information of the drive motor and the vehicle CAN communication information; if the torque fault determination condition is met, obtain the fault time information and determine whether the fault time information is greater than the preset safe time threshold; if the fault time information is not greater than the preset safe time threshold, re-obtain the preset torque difference threshold and the preset safe time threshold; if the fault time information is greater than the preset safe time threshold, control the drive motor to enter a safe state.

[0123] Specifically, when the torque fault judgment condition is met and the fault time information is less than or equal to the preset safe time threshold, the motor fault handling module outputs a torque control signal to enable the drive motor to work normally; when the torque fault judgment condition is met and the fault time information is greater than the preset safe time threshold, the motor fault handling module outputs a control motor torque shutdown signal, which in turn enables the three-phase full-bridge drive system to receive the motor torque shutdown signal, thereby enabling the drive motor to stop safely.

[0124] This invention, through a vehicle drive system output torque monitoring system, includes a data acquisition module, a torque estimation module, a threshold acquisition module, a fault judgment module, and a motor fault handling module. This allows for monitoring of the actual motor torque through three independent paths. While ensuring a high level of safety for the motor torque function, it reduces the functional safety requirements of the sensors in the system, lowers the overall vehicle development cost, and improves system reliability.

[0125] Figure 7 This is a schematic diagram of the structure of a vehicle provided in an embodiment of the present invention, such as... Figure 7 As shown, vehicle 300 includes the vehicle drive system output torque monitoring system 200 as described in any of the above embodiments.

[0126] Among them, vehicle 300 can be a pure electric vehicle, used in application scenarios where the drive motor is safely shut down.

[0127] It should be noted that, since the vehicle 300 provided in this embodiment includes any of the vehicle drive system output torque monitoring systems 200 described in the embodiments of the present invention, it has the same or corresponding beneficial effects as the vehicle drive system output torque monitoring system 200, which will not be elaborated here.

[0128] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for monitoring the output torque of a vehicle drive system, characterized in that, include: Obtain the operating parameters of the drive motor and the CAN communication information of the entire vehicle; The motor torque information is obtained based on the operating parameter information of the drive motor and the vehicle CAN communication information, including: determining the actual motor torque information based on the vehicle acceleration information, vehicle speed information and slope information; Based on the third formula, the actual torque information of the motor is determined according to the vehicle acceleration information, the vehicle speed information, and the slope information. The third formula is: Where T3 represents the actual torque information of the motor; m represents the vehicle mass; a1 represents the vehicle acceleration; r represents the wheel radius; λ(v,i) represents the correction coefficient related to the vehicle speed v and the gradient i; and i o For the speed ratio of the transmission system; Obtain the preset torque difference threshold and the preset safety time threshold; Determining whether the motor torque information and the preset torque difference threshold meet the torque fault determination conditions includes three determination conditions; The first judgment condition includes: determining whether the absolute value of the difference between the actual torque information of the AC side motor and the target torque information of the motor is greater than a preset torque difference threshold; the second judgment condition includes: determining whether the absolute value of the difference between the actual torque information of the DC side motor and the target torque information of the motor is greater than a preset torque difference threshold; the third judgment condition includes: determining whether the absolute value of the difference between the actual torque information of the motor and the target torque information of the motor is greater than a preset torque difference threshold. If all three judgment conditions are negative, the process continues to obtain the operating parameter information of the drive motor and the CAN communication information of the whole vehicle. If at least one of the three judgment conditions is true, then obtain the fault time information and determine whether the fault time information is greater than the preset safe time threshold. If the fault time information is not greater than the preset safe time threshold, then continue to obtain the operating parameter information of the drive motor and the CAN communication information of the whole vehicle; If the fault time information is greater than the preset safe time threshold, then the drive motor is controlled to enter a safe state.

2. The method for monitoring the output torque of a vehicle drive system according to claim 1, characterized in that, The acquisition of the driving motor's operating parameter information and the vehicle's CAN communication information includes: It acquires the three-phase current information on the AC side of the drive motor, the bus voltage information on the DC side, the bus current information, the rotor position information and speed information of the motor, as well as the target torque information of the motor, the vehicle acceleration information, the vehicle speed information and the gradient information.

3. The method for monitoring the output torque of a vehicle drive system according to claim 2, characterized in that, The step of obtaining motor torque information based on the operating parameter information of the drive motor and the vehicle CAN communication information includes: The actual torque information of the AC-side motor is determined based on the three-phase current information of the drive motor and the rotor position information of the motor. The actual torque information of the DC motor is determined based on the DC side bus voltage information, the bus current information, and the speed information.

4. The method for monitoring the output torque of a vehicle drive system according to claim 3, characterized in that, The step of determining the actual torque information of the AC-side motor based on the three-phase current information of the AC side of the drive motor and the rotor position information of the motor includes: Based on the three-phase current information of the AC side of the drive motor and the rotor position information of the motor, the current information under the two-phase rotation coordinates is obtained; The actual torque information of the AC side motor is determined based on the current information under the two-phase rotating coordinates.

5. The method for monitoring the output torque of a vehicle drive system according to claim 4, characterized in that, Based on the first formula, the actual torque information of the AC-side motor is determined according to the current information under the two-phase rotating coordinates. The first formula is: ; Where T1 represents the actual torque information of the AC-side motor; P n Ψ is the number of magnetic pairs in the motor; f For permanent magnet flux linkage; i d i q These represent the current components along the d-axis and q-axis in a two-phase rotating coordinate system; L d L q These are the inductance components on the d-axis and q-axis in a two-phase rotating coordinate system, respectively.

6. The method for monitoring the output torque of a vehicle drive system according to claim 3, characterized in that, Based on the second formula, the actual torque information of the DC motor is determined according to the DC-side bus voltage information, the bus current information, and the speed information. The second formula is: Where T2 represents the actual torque information of the DC motor; U DC I is the DC-side bus voltage. DC η is the bus current; η is the motor efficiency; ω M This represents the motor speed.

7. A vehicle drive system output torque monitoring system, utilizing the vehicle drive system output torque monitoring method according to any one of claims 1-6, characterized in that, include: The data acquisition module is used to acquire the operating parameter information of the drive motor and the CAN communication information of the vehicle. The torque estimation module is used to obtain motor torque information based on the operating parameters of the drive motor and the vehicle CAN communication information, including: determining the actual motor torque information based on vehicle acceleration information, vehicle speed information, and slope information; and determining the actual motor torque information based on the vehicle acceleration information, vehicle speed information, and slope information using a third formula, wherein the third formula is: Where T3 represents the actual torque information of the motor; m represents the vehicle mass; a1 represents the vehicle acceleration; r represents the wheel radius; λ(v,i) represents the correction coefficient related to the vehicle speed v and the gradient i; and i o For the speed ratio of the transmission system; The threshold acquisition module is used to acquire the preset torque difference threshold and the preset safety time threshold. The fault judgment module is used to determine whether the motor torque information and the preset torque difference threshold meet the torque fault judgment conditions, including three judgment conditions: the first judgment condition includes: whether the absolute value of the difference between the actual torque information of the AC side motor and the target torque information of the motor is greater than the preset torque difference threshold; the second judgment condition includes: whether the absolute value of the difference between the actual torque information of the DC side motor and the target torque information of the motor is greater than the preset torque difference threshold; the third judgment condition includes: whether the absolute value of the difference between the actual torque information of the motor and the target torque information of the motor is greater than the preset torque difference threshold. The motor fault handling module is used to: if the torque fault determination condition is not met, continue to acquire the operating parameter information of the drive motor and the vehicle CAN communication information; if the torque fault determination condition is met, acquire the fault time information and determine whether the fault time information is greater than the preset safe time threshold; if the fault time information is not greater than the preset safe time threshold, continue to acquire the operating parameter information of the drive motor and the vehicle CAN communication information; if the fault time information is greater than the preset safe time threshold, control the drive motor to enter a safe state. The actual torque information of the motor is determined based on the vehicle acceleration information, the vehicle speed information, and the slope information; Based on the third formula, the actual torque information of the motor is determined according to the vehicle acceleration information, the vehicle speed information, and the slope information. The third formula is: Where T3 represents the actual torque information of the motor; m represents the vehicle mass; a1 represents the vehicle acceleration; r represents the wheel radius; λ(v,i) represents the correction coefficient related to the vehicle speed v and the gradient i; and i o This refers to the speed ratio of the transmission system.

8. A vehicle, characterized in that, The vehicle drive system output torque monitoring system includes any one of claims 7.

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