WO2022095842A1

WO2022095842A1 - Output torque monitoring system and method for vehicle drive system, and vehicle

Info

Publication number: WO2022095842A1
Application number: PCT/CN2021/128099
Authority: WO
Inventors: 段立华; 赵慧超; 李帅
Original assignee: 中国第一汽车股份有限公司
Priority date: 2020-11-05
Filing date: 2021-11-02
Publication date: 2022-05-12
Also published as: CN112297877B; CN112297877A

Abstract

An output torque monitoring system and method for a vehicle drive system, and a vehicle. The output torque monitoring system (100) for the vehicle drive system comprises: a sampling module (10), which is configured to acquire voltage parameters and current parameters of a drive motor; a torque control module (210) of a main control chip (20) is configured to output a torque control signal according to a whole vehicle torque request value; a torque monitoring module (220) of the main control chip (20) is configured to calculate a rotary speed estimated value and a torque estimated value according to the voltage parameters and the current parameters, and sends a torque fault signal when the difference between the whole vehicle torque request value and the torque estimated value exceeds a preset threshold range; a switch-off control module (30) which is configured to output a switch-off control signal according to the torque fault signal and the rotary speed estimated value; and a three-phase full-bridge drive circuit (40) which is configured to control the motor to output the torque according to the torque control signal, or to select a switch-off route according to the switch-off control signal so as to control the motor to stop safely.

Description

Vehicle drive system output torque monitoring system, method and vehicle

This application claims the priority of the Chinese patent application with application number 202011223767.2 filed with the China Patent Office on November 05, 2020, the entire contents of which are incorporated herein by reference.

technical field

The present application relates to the technical field of vehicle drive control, for example, to a vehicle drive system output torque monitoring system, method and vehicle.

Background technique

The vehicle drive system is the core system of the vehicle and provides the power source for the vehicle. The vehicle drive system mainly includes the drive motor and the motor controller. By setting the output torque control strategy, the vehicle drive system is controlled to provide accurate output torque, which is essential for ensuring the safe operation of the vehicle. important.

The traditional output torque control strategy is to calculate the difference between the input power of the drive system and the power consumption of the drive system based on the method of energy conservation, and use the above difference as the actual output torque of the drive motor, and according to the actual output torque and The difference of the target torque compensates the output torque of the drive motor. The problem is that the power consumption of the drive system needs to consider the influence of the electrical load, which leads to a complicated calculation algorithm. In addition, the target torque in the control strategy is usually set to drive The rated torque of the motor. During the actual operation of the vehicle, changes in vehicle conditions and road conditions will lead to changes in the required torque of the vehicle. Torque control is performed according to the rated torque of the drive motor, which is likely to cause a large difference between the actual output torque and the required torque of the vehicle. problems, affecting the safety of vehicle operation and poor driving experience.

SUMMARY OF THE INVENTION

The application provides an output torque monitoring system of a vehicle drive system, which can quickly and effectively obtain the actual output torque of the drive system and the torque required by the entire vehicle, and solves the problems of complex and poor accuracy of the output torque control strategy and algorithm of the vehicle drive system.

The application provides an output torque monitoring system for a vehicle drive system, the vehicle drive system includes a drive motor, and the monitoring system includes: a sampling module, a main control chip, a shutdown control module, and a three-phase full-bridge drive circuit. The main control chip includes a torque control module and a torque monitoring module; the sampling module is configured to obtain operating parameters of the drive motor and send the operating parameters to the torque monitoring module, wherein the operating parameters include voltage parameters and current parameters The torque control module is configured to obtain the torque request value of the entire vehicle, and output a torque control signal to the three-phase full-axle drive circuit according to the torque request value of the entire vehicle; the torque monitoring module is configured to obtain the torque request value of the entire vehicle torque request value, the voltage parameter and the current parameter, and calculate the speed estimate value and the torque estimate value according to the voltage parameter and the current parameter, and calculate the torque request value and the torque estimate value between the vehicle torque request value and the torque estimate value. When the difference between the two exceeds a preset threshold range, send a torque fault signal and the estimated rotational speed to the shut-off control module; the shut-off control module is configured to output the torque fault signal and the estimated rotational speed value A turn-off control signal is sent to the three-phase full-bridge drive circuit; the three-phase full-bridge drive circuit is configured to control the output torque of the drive motor according to the torque control signal, or select turn-off according to the turn-off control signal path to control the drive motor to stop safely.

In one embodiment, the vehicle drive system output torque monitoring system further includes: a main control chip monitoring module, the main control chip monitoring module is electrically connected to the main control chip and the shutdown control module, and the main control chip is electrically connected to the main control chip and the shutdown control module. The chip monitoring module is configured to perform fault detection on the main control chip, and send a failure signal of the main control chip to the shutdown control module; the shutdown control module is also configured to output a shutdown signal according to the failure signal of the main control chip. off control signal.

In one embodiment, the shutdown control module includes a fault classification unit and a shutdown path selection unit, and the shutdown path selection unit is electrically connected to the control terminal of the three-phase full-bridge drive circuit; the fault classification unit is provided with In order to determine the fault level according to the received fault signal, and send the fault level to the shutdown path selection unit; the shutdown path selection unit is configured to output when judging that the fault level is the first fault level The first turn-off control signal controls the conduction of the lower bridge arm of the three-phase full-bridge drive circuit; and when it is judged that the fault level is the second fault level, and the estimated rotational speed value is less than the preset rotational speed threshold, output The second turn-off control signal controls the upper bridge arm and the lower bridge arm of the three-phase full-bridge drive circuit to turn off.

In one embodiment, the shutdown control module further includes a bridge arm fault diagnosis unit, and the bridge arm fault diagnosis unit is configured to perform fault detection on the lower bridge arm and send a bridge arm fault signal to the shutdown a path selection unit; the shutdown path selection unit is further configured to output a third shutdown control signal to control the three-phase full bridge when it is judged that the fault level is the first fault level and a bridge arm fault signal is received The upper bridge arm of the drive circuit is turned on.

In one embodiment, the three-phase full-bridge drive circuit includes an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT) drive chip, a power supply module and an IGBT module, and the IGBT module includes a three-phase upper-arm IGBT circuit and A three-phase lower arm IGBT circuit, the three-phase upper arm IGBT circuit is electrically connected with the three-phase lower arm IGBT circuit in a one-to-one correspondence; the IGBT driver chip includes a three-phase upper arm drive circuit and a three-phase lower arm A bridge arm drive circuit, the three-phase upper bridge arm drive circuit is electrically connected with the three-phase upper bridge arm IGBT circuit in a one-to-one correspondence, and the three-phase lower bridge arm drive circuit is one with the three-phase lower bridge arm IGBT circuit. A corresponding electrical connection, the upper bridge arm drive circuit is configured to drive the upper bridge arm IGBT to turn on or off, the lower bridge arm drive circuit is configured to drive the lower bridge arm IGBT to turn on or off; the power supply module includes A power supply circuit and a backup power supply circuit, the power supply circuit is configured to supply power to the three-phase upper arm drive circuit and the three-phase lower arm drive circuit, and the backup power supply circuit is configured to supply power to the three-phase lower arm Power supply for the drive circuit.

In one embodiment, the sampling module includes a voltage sampling circuit, a current sampling circuit and a rotational speed sensor, the voltage sampling circuit is configured to collect the three-phase voltage signal of the driving motor as a voltage parameter, and the current sampling circuit is configured to collect The three-phase current signal of the driving motor is used as a current parameter, and the rotational speed sensor is configured to collect the rotational speed of the driving motor as a rotational speed estimation value.

In one embodiment, the torque monitoring module includes a coordinate transformation unit and a calculation unit, and the coordinate transformation unit is configured to perform coordinate transformation on the voltage parameter to obtain the voltage component in a two-phase static coordinate system; the calculation unit is configured to Calculate the estimated torque value based on the voltage component in the two-phase stationary coordinate system, and calculate the estimated torque value based on the voltage parameter, the current parameter, and the estimated rotational speed.

In one embodiment, the calculating unit calculates the estimated torque value according to the following formula:

Among them, T _e represents the estimated torque value, η represents the driving efficiency of the vehicle drive system, n represents the estimated rotational speed of the motor, U represents the phase voltage of the driving motor, and I represents the phase current of the driving motor.

The present application also provides a method for monitoring output torque of a vehicle drive system, where the vehicle drive system includes a drive motor, including:

obtaining operating parameters of the drive motor, where the operating parameters include voltage parameters and current parameters;

obtaining a torque request value of the entire vehicle, and generating a torque control signal according to the torque request value of the entire vehicle;

Calculate a rotational speed estimate and a torque estimate according to the voltage parameter and the current parameter, and determine whether the difference between the vehicle torque request value and the torque estimate exceeds a preset threshold range;

If the difference between the vehicle torque request value and the torque estimate value exceeds a preset threshold range, generating a torque fault signal;

generating a shutdown control signal based on the torque fault signal and the speed estimate;

The output torque of the driving motor is controlled according to the torque control signal, or a shutdown path is selected according to the shutdown control signal to control the driving motor to stop safely.

The present application also provides a vehicle, including the above-mentioned system for monitoring the output torque of the vehicle drive system.

Description of drawings

1 is a schematic structural diagram of a vehicle drive system output torque monitoring system provided in Embodiment 1 of the present application;

2 is a schematic structural diagram of another vehicle drive system output torque monitoring system provided in Embodiment 1 of the present application;

3 is a flowchart of a method for monitoring output torque of a vehicle drive system provided in Embodiment 2 of the present application;

FIG. 4 is a schematic structural diagram of a vehicle according to Embodiment 3 of the present application.

Detailed ways

The present application will be described below with reference to the accompanying drawings and embodiments. The specific embodiments described herein are merely used to explain the present application. For the convenience of description, only the parts related to the present application are shown in the drawings.

Example 1

1 is a schematic structural diagram of an output torque monitoring system for a vehicle drive system provided in Embodiment 1 of the present application. This embodiment is applicable to an application scenario in which a drive motor is safely shut down through multiple mutually redundant shutdown paths. In this embodiment, the driving system includes a driving motor, and the driving motor may be a three-phase AC motor.

Referring to FIG. 1 , the vehicle drive system output torque monitoring system 100 includes: a sampling module 10 , a main control chip 20 , a shutdown control module 30 and a three-phase full-bridge drive circuit 40 , and the main control chip 20 includes a torque control module 210 and the torque monitoring module 220; the sampling module 10 is configured to obtain the operating parameters of the drive motor, the operating parameters include voltage parameters and current parameters; the torque control module 210 is configured to obtain the torque request value of the entire vehicle, and output torque control according to the torque request value of the entire vehicle signal; the torque monitoring module 220 is configured to obtain the torque request value, voltage parameter and current parameter of the whole vehicle, and calculate the speed estimation value and torque estimation value of the drive motor according to the voltage parameter and current parameter, and calculate the torque request value and torque estimation value of the whole vehicle. When the difference between the values exceeds the preset threshold range, a torque fault signal is sent to the shutdown control module 30; the shutdown control module 30 is set to output a shutdown control signal according to the torque fault signal and the estimated speed value; three-phase full-bridge drive The circuit 40 is configured to control the output torque of the driving motor according to the torque control signal, or select a shutdown path according to the shutdown control signal, and control the driving motor to stop safely.

The voltage parameter can be the phase voltage on the AC side of the drive motor, and the current parameter can be the phase current on the AC side of the drive motor. The three-phase full-bridge drive circuit 40 includes a three-phase upper arm and a three-phase lower arm, and the three-phase bridge arm and the drive The three-phase windings of the motor are electrically connected in one-to-one correspondence, and by controlling the on or off of the upper bridge arm and the corresponding lower bridge arm in the three-phase bridge arms, the drive motor is controlled to run or stop.

In this embodiment, the torque control module 210 can be connected to the vehicle controller, and the vehicle controller is configured to collect the torque request values of multiple modules of the vehicle in real time, and calculate the maximum torque request value among the torque request values of the multiple modules. As the vehicle torque request value, a torque request command is generated, and the torque control module 210 outputs a first pulse width modulation (Pulse Width Modulation, PWM) control signal according to the torque request command, and the first PWM control signal is used to control the three-phase full-bridge drive circuit The corresponding bridge arm in 40 is turned on to supply power to the drive motor, so that the output torque of the drive motor reaches the torque request value of the entire vehicle.

In this embodiment, the multiple mutually redundant shutdown paths include a three-phase bridge arm active short-circuit path and a three-phase bridge arm active disconnection and shutdown path. If the three-phase full-bridge driving circuit 40 is controlled to enter the active short-circuit mode of the three-phase bridge arms, the three-phase bridge arms of the three-phase full-bridge driving circuit 40 are not conductive, and the DC side and the AC side of the driving motor no longer form a loop, and the driving The motor generates reverse-phase braking torque to realize safe stop of the drive motor.

The torque monitoring module 220 receives the torque request value of the whole vehicle sent by the vehicle controller, and receives the voltage parameters and current parameters sent by the adopting module 10, calculates the torque estimation value through the preset torque calculation formula, and calculates the torque request value and the torque of the whole vehicle. The difference between the estimated values, if the difference does not exceed the preset threshold range, the shutdown control module 30 does not work, and the three-phase full-bridge drive circuit 40 receives the control signal output by the torque control module 210 to control the output of the drive motor. The torque equal to the torque request value of the whole vehicle; if the difference exceeds the preset threshold range, the torque monitoring module 220 sends a torque fault signal to the shutdown control module 30, and the shutdown control module 30 simultaneously obtains the current estimated value of the rotational speed to determine the current Whether the drive motor is in a low-speed operation state, if the current drive motor is in a low-speed operation state, the shutdown control module 30 controls the three-phase bridge arm of the three-phase full-bridge drive circuit 40 to actively open the circuit, and controls the drive motor to stop safely; In the low-speed running state, the shutdown control module 30 controls the three-phase bridge arm of the three-phase full-bridge drive circuit 40 to actively short-circuit, and controls the drive motor to stop safely.

Therefore, the output torque monitoring system of the vehicle drive system provided by the embodiment of the present application is provided with a sampling module, a torque control module, a torque monitoring module, a shutdown control module and a three-phase full-bridge drive circuit, and the voltage parameters of the drive motor are collected through the sampling module. and current parameters, obtain the torque request value of the whole vehicle through the torque control module, and output the torque control signal according to the torque request value of the whole vehicle, calculate the speed estimation value and torque estimation value of the drive motor through the torque monitoring module, and according to the vehicle torque request value The difference between the torque estimate value and the torque control signal is used to judge whether the output torque corresponding to the torque control signal is safe. It can quickly and effectively obtain the actual output torque of the drive system and the torque required by the vehicle, and control the safe operation or shutdown of the drive motor through multiple redundant shutdown paths. The output torque control strategy algorithm of the vehicle drive system is complex and the accuracy is poor, which is beneficial to improve the output torque safety of the drive system and improve the system reliability.

Optionally, continuing to refer to FIG. 1 , the vehicle drive system output torque monitoring system 100 further includes: a main control chip monitoring module 50 . The main control chip monitoring module 50 is electrically connected to the main control chip 20 and the shutdown control module 30 . The control chip monitoring module 50 is configured to perform fault detection on the main control chip 20 and send the main control chip failure signal to the shutdown control module 30; the shutdown control module 30 is also configured to output a shutdown control signal according to the main control chip failure signal .

In the present embodiment, the main control chip monitoring module 50 may be integrated with the main control chip 20 or independently provided, which is not limited.

Exemplarily, the main control chip monitoring module 50 may be configured to monitor the voltage, current, temperature and other chip operating parameters of the main control chip 20 in real time, and determine whether the chip operating parameters exceed the normal range. The control chip monitoring module 50 determines that the main control chip 20 is faulty, and sends the main control chip fault signal to the shutdown control module 30. If the shutdown control module 30 receives any one of the main control chip fault signal and the torque fault signal, Then, the shutdown control signal is output according to the fault level, and the three-phase full-bridge driving circuit 40 is controlled to act according to the selected shutdown path, and the driving motor is controlled to stop safely.

Optionally, the shutdown control module 30 includes a fault classification unit and a shutdown path selection unit, and the shutdown path selection unit is electrically connected to the control terminal of the three-phase full-bridge drive circuit 40; the fault classification unit is set to be based on the received fault signal. The fault level is determined, and the fault level is sent to the shutdown path selection unit; the shutdown path selection unit is set to output a first shutdown control signal when it is judged that the fault level is the first fault level to control the three-phase full-bridge drive circuit 40 The lower bridge arm is turned on; and when it is judged that the fault level is the second fault level, and the estimated rotational speed value is less than the preset rotational speed threshold, a second turn-off control signal is output to control the upper bridge arm of the three-phase full-bridge drive circuit 40 and The lower bridge arm is turned off.

Optionally, the shutdown control module 30 further includes a bridge arm fault diagnosis unit, and the bridge arm fault diagnosis unit is configured to perform fault detection on the lower bridge arm, and send the bridge arm fault signal to the shutdown path selection unit; The unit is further configured to output a third turn-off control signal to control the upper bridge arm of the three-phase full-bridge drive circuit 40 to be turned on when it is judged that the fault level is the first fault level and the bridge arm fault signal is received.

In this embodiment, the shutdown control module 30 can select any one of the three shutdown paths according to the fault signal and the estimated value of the rotational speed. First, the shutdown control module 30 can control the three-phase on-phase on the three-phase full-bridge drive circuit 40 . All bridge arms are turned off and all three-phase lower bridge arms are turned on, and the three-phase full-bridge drive circuit 40 is controlled to enter the three-phase bridge arm active short-circuit mode; secondly, the shutdown control module 30 can control the three-phase full-bridge drive circuit 40. All three-phase upper arms are turned on, and all three-phase lower arms are turned off, and the three-phase full-bridge drive circuit 40 is controlled to enter the three-phase bridge arm active short-circuit mode; thirdly, the shutdown control module 30 can control the three-phase full-bridge drive The three-phase upper bridge arm and the lower bridge arm of the circuit 40 are all turned off, and the three-phase full-bridge driving circuit 40 is controlled to enter the three-phase bridge arm active disconnection mode.

In this embodiment, the shutdown path is selected according to the fault level of the fault signal. For example, the fault level includes a first fault level with a high priority and a second fault level with a lower priority. For example, the first fault level may be The difference between the vehicle torque request value and the torque estimate value is greater than or equal to 5N.m, or the main control chip is faulty; the second fault level can be that the difference between the vehicle torque request value and the torque estimate value is less than 5N .m.

If the fault level is the first fault level, the shutdown control module 30 detects whether there is a fault in the lower bridge arm. If there is no fault in the lower bridge arm, a first shutdown control signal is generated to give priority to control all the upper bridge arms to be turned off and the third The lower bridge arms of the phases are all turned on, so that the three-phase full bridge drive circuit 40 enters the active short-circuit mode of the three-phase bridge arms, which is beneficial to cut off the connection between the motor winding and the power supply terminal; if there is a fault in the lower bridge arm, a third turn-off control signal is generated , control all the upper bridge arms to be turned on and the three-phase lower bridge arms to be turned off, so that the three-phase full-bridge drive circuit 40 enters the three-phase bridge arm active short-circuit mode, which is conducive to the use of reverse-phase braking torque to drive the motor to stop safely.

If the fault level is the second fault level, the shutdown control module 30 judges whether the rotational speed value corresponding to the estimated rotational speed value is smaller than the preset rotational speed threshold, and if the rotational speed value corresponding to the estimated rotational speed value is smaller than the preset rotational speed threshold, the upper bridge arm and the The three-phase lower bridge arms are all turned off, so that the three-phase full-bridge drive circuit 40 enters the three-phase bridge arm active disconnection mode, which is beneficial to avoid the excessive phase current caused by the three-phase active short circuit and damage the components, and at the same time avoid the reverse-phase braking torque. The resulting excessive braking torque produces a sense of frustration, which is conducive to improving the driving experience; if the speed value corresponding to the estimated speed value is greater than or equal to the preset speed threshold, the three-phase bridge arm active short-circuit mode is selected according to the above method to realize the safety of the drive motor. downtime.

FIG. 2 is a schematic structural diagram of another vehicle drive system output torque monitoring system provided in Embodiment 1 of the present application.

Optionally, as shown in FIG. 2 , the three-phase full-bridge drive circuit 40 includes an IGBT drive chip 410 , a power supply module 420 and an IGBT module 430 , and the IGBT module 430 includes a three-phase upper bridge arm IGBT circuit 431 and a three-phase lower bridge arm IGBT. In the circuit 432, the three-phase upper bridge arm IGBT circuit 431 is electrically connected to the three-phase lower bridge arm IGBT circuit 432 in one-to-one correspondence; the power supply module 420 includes a power supply circuit 421 and a backup power supply circuit 422, and the IGBT driver chip 410 includes a three-phase upper bridge arm driver The circuit 411 and the three-phase lower arm drive circuit 412, the three-phase upper arm drive circuit 411 is electrically connected with the three-phase upper arm IGBT circuit 431 in one-to-one correspondence, and the three-phase lower arm drive circuit 412 is electrically connected with the three-phase lower arm IGBT The circuits 432 are electrically connected in one-to-one correspondence, the upper arm drive circuit 411 is set to drive the upper arm IGBT on or off, the lower arm drive circuit 412 is set to drive the lower arm IGBT on or off, and the power supply circuit 421 is set to In order to supply power to the three-phase upper arm drive circuit 411 and the three-phase lower arm drive circuit 412 , the backup power supply circuit 422 is configured to supply power to the three-phase lower arm drive circuit 412 .

In this embodiment, the power supply circuit 421 is used to supply power to the three-phase upper arm drive circuit 411 and the three-phase lower arm drive circuit 412 at the same time, and the power supply of the three-phase full-bridge drive circuit 40 can be detected in real time through the main control chip monitoring module 50 voltage, to determine whether the power supply module fails, if the power supply module fails, the main control chip monitoring module 50 outputs a switching signal to control the backup power supply circuit 422 to supply power to the three-phase lower arm drive circuit 412 to ensure that in the event of a failure, priority The safety shutdown of the drive motor is realized by short-circuiting the lower three bridge arms, which is beneficial to improve the reliability of the system.

Optionally, the sampling module 10 includes a voltage sampling circuit and a current sampling circuit, the voltage sampling circuit is set to collect the three-phase voltage signal of the driving motor as a voltage parameter, and the current sampling circuit is set to collect the three-phase current signal of the driving motor as the current parameter.

In this embodiment, the three-phase voltage transformer can be set to collect the three-phase voltage signal of the drive motor, and the three-phase current transformer can be set to collect the three-phase current signal of the drive motor, and the sampled value is sent to the main control chip 20.

Optionally, the torque monitoring module 220 includes a coordinate transformation unit and a calculation unit, and the coordinate transformation unit is set to perform coordinate transformation on the voltage parameter to obtain the voltage component under the two-phase static coordinate system; the calculation unit is set to be based on the two-phase static coordinate system. Calculates the estimated speed value based on the voltage component of , and calculates the estimated torque value based on the voltage parameter, the current parameter, and the estimated speed value.

The coordinate transformation unit obtains the phase voltages U _u , U _v and U _w of the driving motor, and transforms the phase voltages into the two-phase static αβ coordinate system through three-phase-two-phase coordinate transformation. The formula is as follows:

Among them, U _α and U _β represent the α-axis and β-axis voltage components of the phase voltage.

Through formula 1, the α-axis and β-axis voltage components U _α and U _β of the phase voltage in the two-phase static αβ coordinate system can be obtained. The calculation unit obtains the voltage components U _α and U _β , and substitutes them into the following formula to calculate the driving motor. RPM estimate for:

Among them, n represents the estimated value of the rotational speed of the driving motor, ω represents the electrical angular velocity of the motor, and p represents the number of pole pairs of the driving motor.

The calculation unit calculates the torque estimate according to the following formula three:

Among them, T _e represents the estimated torque value, η represents the driving efficiency of the drive system, n represents the estimated value of the rotational speed of the motor, U represents the phase voltage of the driving motor, and I represents the phase current of the driving motor.

In this embodiment, torque estimation is performed by using the AC side torque estimation model, which is beneficial to improve the torque calculation accuracy, improve the efficiency of torque monitoring and control, and improve the driving experience.

Embodiment 2

Embodiments of the present application also provide a method for monitoring output torque of a vehicle drive system. 3 is a flowchart of a method for monitoring output torque of a vehicle drive system provided in Embodiment 2 of the present application. In this embodiment, the drive system includes a drive motor, and the torque monitoring method in this embodiment is implemented by using the hardware structure in the above embodiment , has the same technical effect as the above-mentioned embodiment.

Referring to FIG. 3 , the method for monitoring the output torque of the vehicle drive system includes the following steps:

Step S1: Obtain the operating parameters of the driving motor, where the operating parameters include voltage parameters and current parameters.

Step S2: Obtain the torque request value of the entire vehicle, and output a torque control signal according to the torque request value of the entire vehicle.

Step S3: Calculate the estimated speed and torque of the driving motor according to the voltage parameter and the current parameter.

Step S4: Determine whether the difference between the vehicle torque request value and the torque estimate value exceeds a preset threshold range.

If the difference between the vehicle torque request value and the torque estimate value exceeds the preset threshold range, step S5 is executed; if the difference between the vehicle torque request value and the torque estimate value does not exceed the preset threshold value range, execute step S5 S8.

Step S5: Send a torque fault signal.

Step S6: output a shutdown control signal according to the torque fault signal and the speed estimation value.

Step S7: Select a shutdown path according to the shutdown control signal, and control the drive motor to stop safely.

Step S8: control the output torque of the drive motor according to the torque control signal.

In this embodiment, the drive motor can be controlled to run or stop safely by controlling the bridge arm of the three-phase full-bridge drive circuit to be turned on or off.

In this embodiment, the main control chip can be used to calculate the torque estimation value.

Optionally, the method for monitoring the output torque of the vehicle drive system includes the following steps: performing fault detection on the main control chip to obtain a fault signal of the main control chip; and outputting a shutdown control signal according to the fault signal of the main control chip.

Optionally, the method for monitoring the output torque of the vehicle drive system includes the following steps: determining a fault level according to the received fault signal; if it is judged that the fault level is the first fault level, outputting a first shutdown control signal to control the three-phase full-bridge The lower arms of the drive circuit are all turned on; if it is judged that the fault level is the second fault level and the estimated speed is less than the preset speed threshold, the second shutdown control signal is output to control the upper arm of the three-phase full-bridge drive circuit and the lower bridge arm is turned off.

Optionally, the method for monitoring the output torque of the vehicle drive system includes the following steps: performing fault detection on the lower bridge arm to obtain a bridge arm fault signal; if it is judged that the fault level is the first fault level, when receiving the bridge arm fault signal, output the first fault signal. The three turn-off control signals control all the upper arms of the three-phase full-bridge drive circuit to be turned on.

Optionally, the three-phase voltage signal of the drive motor can be collected as the voltage parameter through the voltage sampling circuit, the three-phase current signal of the drive motor can be collected as the current parameter through the current sampling circuit, and the rotational speed of the drive motor can be collected through the rotational speed sensor as the rotational speed estimation value.

Optionally, the method for monitoring the output torque of the vehicle drive system includes the following steps: performing coordinate transformation on a voltage parameter to obtain a voltage component in a two-phase static coordinate system; value, and calculate the torque estimate based on the voltage parameter, current parameter and speed estimate.

Obtain the phase voltages U _u , U _v and U _w of the driving motor, and transform the phase voltages into the two-phase static αβ coordinate system through three-phase-two-phase coordinate transformation. The formula is as follows:

By formula 1, the α-axis and β-axis voltage components U _α and U _β of the phase voltage in the two-phase static αβ coordinate system can be obtained, and they are substituted into the following formula to calculate the estimated value of the rotational speed of the driving motor:

Calculate the torque estimate according to Equation 3 below:

In the embodiment of the present application, torque estimation is performed by using the AC side torque estimation model, which is beneficial to improve the accuracy of torque calculation, improve the efficiency of torque monitoring and control, and improve the driving experience.

Therefore, the method for monitoring the output torque of the vehicle drive system provided by the embodiments of the present application acquires the torque request value of the vehicle through the torque control module by collecting the voltage parameters and current parameters of the drive motor, and outputs the torque control signal according to the torque request value of the vehicle. , calculate the speed estimation value and torque estimation value of the drive motor through the torque monitoring module, and judge whether the output torque corresponding to the torque control signal is safe according to the difference between the vehicle torque request value and the torque estimation value. If the difference between the value and the estimated torque value is greater than the preset threshold range, the shutdown control module will select the shutdown path to control the safe shutdown of the drive motor, which can quickly and effectively obtain the actual output torque of the drive system and the torque required by the vehicle. , and control the safe operation or shutdown of the drive motor through multiple mutually redundant shutdown paths, which solves the problem of complex output torque control strategy algorithm and poor accuracy of the vehicle drive system, which is beneficial to improve the output torque safety of the drive system. , improve system reliability.

Embodiment 3

The third embodiment of the present application provides a vehicle. FIG. 4 is a schematic structural diagram of a vehicle according to Embodiment 3 of the present application. The embodiment of the present application is suitable for an application scenario in which the drive motor is safely shut down through multiple shutdown paths.

As shown in FIG. 4 , the vehicle 200 includes the above-mentioned vehicle drive system output torque monitoring system 100 .

In this embodiment, the vehicle 200 may be a pure electric vehicle.

To sum up, the vehicle provided by the embodiment of the present application is provided with a vehicle drive system output torque monitoring system. The system is provided with a sampling module, a torque control module, a torque monitoring module, a shutdown control module and a three-phase full-bridge drive circuit. The voltage parameters and current parameters of the drive motor are obtained through the torque control module to obtain the torque request value of the whole vehicle, and the torque control signal is output according to the torque request value of the whole vehicle. The difference between the vehicle torque request value and the torque estimate value is used to judge whether the output torque corresponding to the torque control signal is safe. The shutdown control module selects the shutdown path to control the safe shutdown of the drive motor, which can quickly and effectively obtain the actual output torque of the drive system and the required torque of the vehicle, and control the safe operation of the drive motor through multiple redundant shutdown paths. Or shutdown, which solves the problems of complex and poor accuracy of the output torque control strategy and algorithm of the vehicle drive system, which is beneficial to improve the output torque safety of the drive system and improve the system reliability.

Claims

A vehicle drive system output torque monitoring system, the vehicle drive system includes a drive motor, the monitoring system includes: a sampling module, a main control chip, a shutdown control module and a three-phase full-bridge drive circuit, the main control chip includes Torque control module and torque monitoring module;

The sampling module is configured to acquire operating parameters of the driving motor and send the operating parameters to the torque monitoring module, wherein the operating parameters include voltage parameters and current parameters;

The torque control module is configured to obtain a torque request value of the entire vehicle, and output a torque control signal to the three-phase full-bridge drive circuit according to the torque request value of the entire vehicle;

The torque monitoring module is configured to obtain the torque request value of the entire vehicle, the voltage parameter and the current parameter, and calculate the speed estimation value and the torque estimation value according to the voltage parameter and the current parameter, and in the When the difference between the vehicle torque request value and the torque estimate value exceeds a preset threshold range, send a torque fault signal and the speed estimate value to the shutdown control module;

The shutdown control module is configured to output a shutdown control signal to the three-phase full-bridge drive circuit according to the torque fault signal and the estimated speed value;

The three-phase full-bridge driving circuit is configured to control the output torque of the driving motor according to the torque control signal, or select a shutdown path according to the shutdown control signal to control the driving motor to stop safely.
The output torque monitoring system of the vehicle drive system according to claim 1, further comprising: a main control chip monitoring module, the main control chip monitoring module is electrically connected to the main control chip and the shutdown control module, the main control chip monitoring module is electrically connected to the main control chip and the shutdown control module The control chip monitoring module is configured to perform fault detection on the main control chip, and send a fault signal of the main control chip to the shutdown control module;

The shutdown control module is further configured to output a shutdown control signal according to the failure signal of the main control chip.
The output torque monitoring system of the vehicle drive system according to claim 1 or 2, wherein the shutdown control module comprises a fault classification unit and a shutdown path selection unit, the shutdown path selection unit and the three-phase full bridge The control terminal of the driving circuit is electrically connected;

The fault classification unit is configured to determine a fault level according to the received fault signal, and send the fault level to the shutdown path selection unit;

The turn-off path selection unit is configured to output a first turn-off control signal when it is judged that the fault level is the first fault level, and control all the lower arms of the three-phase full-bridge drive circuit to be turned on; and When it is judged that the fault level is the second fault level, and the estimated rotational speed is less than the preset rotational speed threshold, a second shutdown control signal is output to control the upper and lower arms of the three-phase full-bridge drive circuit. The bridge arm is turned off.
The output torque monitoring system of the vehicle drive system according to claim 3, wherein the shutdown control module further comprises an axle arm fault diagnosis unit, and the axle arm fault diagnosis unit is configured to perform fault detection on the lower axle arm, and send the bridge arm fault signal to the shutdown path selection unit;

The turn-off path selection unit is further configured to output a third turn-off control signal to control the three-phase full bridge when it is judged that the fault level is the first fault level and a bridge arm fault signal is received The upper arms of the drive circuit are all turned on.
The output torque monitoring system of a vehicle drive system according to claim 1 or 2, wherein the three-phase full-bridge drive circuit comprises an insulated gate bipolar transistor IGBT drive chip, a power supply module and an IGBT module, and the IGBT module comprises three A phase upper bridge arm IGBT circuit and a three-phase lower bridge arm IGBT circuit, the three-phase upper bridge arm IGBT circuit and the three-phase lower bridge arm IGBT circuit are electrically connected in one-to-one correspondence;

The IGBT driver chip includes a three-phase upper arm drive circuit and a three-phase lower arm drive circuit, the three-phase upper arm drive circuit and the three-phase upper arm IGBT circuit are electrically connected in one-to-one correspondence, and the three The phase lower arm drive circuit is electrically connected to the three-phase lower arm IGBT circuit in one-to-one correspondence, and the upper arm drive circuit is configured to drive the upper arm IGBT to turn on or off, and the lower arm drives The circuit is configured to drive the lower bridge arm IGBT to be turned on or off;

The power supply module includes a power supply circuit and a backup power supply circuit, the power supply circuit is configured to supply power to the three-phase upper arm drive circuit and the three-phase lower arm drive circuit, and the backup power supply circuit is configured to supply power to the three-phase upper arm drive circuit and the three-phase lower arm drive circuit. The three-phase lower arm drive circuit is powered.
The output torque monitoring system for a vehicle drive system according to any one of claims 1-5, wherein the sampling module includes a voltage sampling circuit and a current sampling circuit, and the voltage sampling circuit is configured to collect three-phase signals of the drive motor. The voltage signal is used as the voltage parameter, and the current sampling circuit is configured to collect the three-phase current signal of the driving motor as the current parameter.
The output torque monitoring system of a vehicle drive system according to claim 6, wherein the torque monitoring module includes a coordinate transformation unit and a calculation unit, and the coordinate transformation unit is configured to perform coordinate transformation on the voltage parameter to obtain a two-phase static state The voltage component in the coordinate system; the calculation unit is configured to calculate the estimated value of the rotational speed according to the voltage component in the two-phase stationary coordinate system, and calculate the estimated value of the rotational speed according to the voltage parameter, the current parameter and the estimated rotational speed value Torque estimate.
The vehicle drive system output torque monitoring system according to claim 7, wherein the calculation unit calculates the torque estimation value according to the following formula:

Wherein, Te represents the estimated torque value, η represents the driving efficiency of the vehicle drive system, n represents the estimated rotational speed value, U represents the phase voltage of the drive motor, and I represents the phase current of the drive motor.
A method for monitoring output torque of a vehicle drive system, the vehicle drive system comprising a drive motor, including:

Acquiring operating parameters of the drive motor, wherein the operating parameters include voltage parameters and current parameters;

obtaining a torque request value of the entire vehicle, and generating a torque control signal according to the torque request value of the entire vehicle;

Calculate a rotational speed estimate and a torque estimate according to the voltage parameter and the current parameter, and determine whether the difference between the vehicle torque request value and the torque estimate exceeds a preset threshold range;

generating a torque fault signal in response to a difference between the vehicle torque request value and the torque estimate value exceeding a preset threshold range;

generating a shutdown control signal based on the torque fault signal and the speed estimate;

The output torque of the driving motor is controlled according to the torque control signal, or a shutdown path is selected according to the shutdown control signal to control the driving motor to stop safely.
A vehicle, comprising: the vehicle drive system output torque monitoring system of any one of claims 1-8.