CONTROLLER OF MOTOR CONTROL MODULE, MOTOR CONTROL METHOD, AND RELATED DEVICE

Abstract

A controller (1011, 3022) of a motor control module is provided. An input end of the controller is connected to a rotation velocity detection apparatus. A communication end of the controller is directly connected to a first communication bus (103, 303). An output end of the controller is connected to a control end of an inverter circuit (1012, 3012) in the motor control module. The controller controls, when the vehicle velocity and the rotation velocity signal of the motor meet a preset condition, the inverter circuit to adjust a current output to the motor. A motor control method, an electric drive system (101) including the controller, and a vehicle (10) including the electric drive system are further provided. Through use of the controller, slipping of a wheel can be quickly suppressed, so that slipping suppression quickly intervenes, and safety is good.

Description

TECHNICAL FIELD

This application relates to the field of new energy vehicle technologies, and in particular, to a controller of a motor control module, a motor control method, and a related device.

BACKGROUND

In a daily driving scenario, when a vehicle is switched from driving on a high-adhesion ground surface to driving on a low-adhesion road surface, for example, a wet road surface or a frozen road surface, a driving force of a wheel is greater than adhesion of the road surface, causing slipping of the wheel, and even causing an over-velocity fault of a motor, “tire burning” of the wheel, loss of steering of the vehicle, and the like. In this case, to guarantee driving safety, how to suppress the slipping of the wheel should be a focus of research.

SUMMARY

This application provides a controller of a motor control module, a motor control method, and a related device, to quickly determine whether a wheel corresponding to a motor slips. In addition, slipping can be quickly suppressed when the wheel slips, so that accuracy of determining whether the wheel slips is high, slipping suppression quickly intervenes, and safety is good.

According to a first aspect, an embodiment of this application provides a controller of a motor control module. An input end of the controller is connected to a rotation velocity detection apparatus, so that the controller may receive a rotation velocity signal of a motor from the rotation velocity detection apparatus. A communication end of the controller is directly connected to a first communication bus, so that the controller may directly obtain a vehicle velocity from the first communication bus. An output end of the controller is connected to a control end of an inverter circuit in the motor control module, so that the controller may output a control signal to the inverter circuit.

In this embodiment of this application, the controller may control, based on at least one of a torque demand signal, a throttle signal, and a brake signal that are received, a current output by the inverter circuit in the motor control module to the motor. Alternatively, the controller may receive the rotation velocity signal of the motor, directly obtain the vehicle velocity from the first communication bus, and determine, when the vehicle velocity and the rotation velocity signal of the motor meet a preset condition, that a wheel corresponding to the motor slips. In this case, the controller controls the inverter circuit to adjust a current output to the motor. Through implementation of this embodiment of this application, whether the wheel corresponding to the motor slips can be quickly determined, and accuracy of determining whether the wheel slips is high. In addition, slipping can be quickly suppressed when the wheel slips, so that slipping suppression quickly intervenes, and safety is good.

With reference to the first aspect, in a first possible implementation, the communication end of the controller is further connected to a torque calculation module through a second communication bus. Responding to that the vehicle velocity and the rotation velocity signal of the motor meet the preset condition, the controller indicates the torque calculation module to stop sending the torque demand signal; or responding to that the vehicle velocity and the rotation velocity signal of the motor meet the preset condition, the controller stops responding to the torque demand signal sent by the torque calculation module.

With reference to the first possible implementation of the first aspect, in a second possible implementation, the first communication bus is connected to the torque calculation module, so that the controller may obtain, from the first communication bus, the torque demand signal sent by the torque calculation module, and control, responding to the torque demand signal sent by the torque calculation module, the inverter circuit in the motor control module to adjust the current output to the motor. It may be learned that the controller may implement communication and control through the first communication bus, thereby further improving safety and reliability of vehicle control.

With reference to the first aspect or with reference to either of the foregoing possible implementations of the first aspect, in a third possible implementation, the input end of the controller is further connected to a throttle pedal, and the input end of the controller may directly receive a throttle signal generated by triggering of the throttle pedal. In this embodiment of this application, the controller may be directly connected to the throttle pedal, and control the inverter circuit based on the throttle signal, thereby further improving the safety and the reliability of vehicle control.

With reference to the first aspect, with reference to the first possible implementation of the first aspect, or with reference to the second possible implementation of the first aspect, in a fourth possible implementation, the input end of the controller is further connected to a brake pedal, and the input end of the controller may directly receive a brake signal generated by triggering of the brake pedal. In this embodiment of this application, the controller may be directly connected to the brake pedal, and control the inverter circuit based on the brake signal, thereby further improving the safety and the reliability of vehicle control.

According to a second aspect, an embodiment of this application provides a motor control method. The control method is applicable to a controller in a motor control module. An input end of the controller is connected to a rotation velocity detection apparatus. A communication end of the controller is connected to a first communication bus, so that the controller may directly obtain a vehicle velocity from the first communication bus. An output end of the controller is connected to a control end of an inverter circuit in the motor control module, so that the controller may output a control signal to the inverter circuit.

During specific implementation, the controller may control, based on at least one of a torque demand signal, a throttle signal, and a brake signal that are received, a current output by the inverter circuit in the motor control module to the motor. Alternatively, the controller may receive a rotation velocity signal of the motor, directly obtain the vehicle velocity from the first communication bus, and calculate, based on the rotation velocity signal of the motor and the vehicle velocity, an actual slip ratio of a wheel corresponding to the motor; and the controller controls, responding to that a difference between the actual slip ratio and a target slip ratio of the wheel corresponding to the motor is greater than a first preset threshold, the inverter circuit to adjust a current output to the motor.

With reference to the second aspect, in a first possible implementation, that the controller calculates, based on the rotation velocity signal of the motor and the vehicle velocity, an actual slip ratio of a wheel corresponding to the motor is specifically implemented as follows:

The controller calculates, based on the rotation velocity signal of the motor, a wheel rolling radius corresponding to the motor, and a transmission ratio of the motor to the wheel corresponding to the motor, a linear velocity of the wheel corresponding to the motor.

The controller determines, based on a ratio of the linear velocity of the wheel corresponding to the motor to the vehicle velocity, the actual slip ratio of the wheel corresponding to the motor.

With reference to the second aspect or with reference to the first possible implementation of the second aspect, in a second possible implementation, that the controller controls, responding to that a difference between the actual slip ratio and a target slip ratio of the wheel corresponding to the motor is greater than a first preset threshold, the inverter circuit to adjust a current output to the motor is specifically implemented as follows:

The controller controls, responding to that the difference between the actual slip ratio and the target slip ratio of the wheel corresponding to the motor is greater than the first preset threshold and responding to that a difference between a theoretical acceleration and an actual acceleration of the wheel corresponding to the motor is greater than a second preset threshold, the inverter circuit to adjust the current output to the motor.

With reference to the second possible implementation of the second aspect, in a third possible implementation, before the responding to that a difference between a theoretical acceleration and an actual acceleration of the wheel corresponding to the motor is greater than a second preset threshold, the controller obtains, through calculation based on an angular acceleration of the motor, the wheel rolling radius corresponding to the motor, and the transmission ratio of the motor to the wheel corresponding to the motor, the theoretical acceleration of the wheel corresponding to the motor; and

• • the controller obtains the actual acceleration of the wheel corresponding to the motor, and compares the theoretical acceleration and the actual acceleration of the wheel corresponding to the motor.

With reference to the second aspect or with reference to any one of the foregoing possible implementations of the second aspect, in a fourth possible implementation, the controlling the inverter circuit to adjust a current output to the motor is specifically implemented as follows:

• • obtaining, by the controller based on the target slip ratio, the vehicle velocity, and the wheel rolling radius corresponding to the motor, a target rotation velocity of the wheel corresponding to the motor; and
  • controlling, based on the target rotation velocity of the wheel corresponding to the motor, the inverter circuit to adjust the current output to the motor.

According to a third aspect, an embodiment of this application provides an electric drive system. The electric drive system includes a motor control module and a motor, and the motor control module includes an inverter circuit and the controller with reference to the first aspect or with reference to any one of the foregoing possible implementations of the first aspect.

According to a fourth aspect, an embodiment of this application provides a vehicle. The vehicle includes a power battery and the electric drive system described with reference to the third aspect, and the power battery is connected to an input end of an inverter circuit.

It should be understood that mutual reference may be made to implementations and beneficial effects of the foregoing aspects of this application.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram of a scenario of a vehicle according to an embodiment of this application;

FIG. 2 is a block diagram of a structure of an electric drive system according to an embodiment of this application;

FIG. 3 is a block diagram of a structure of a vehicle according to an embodiment of this application;

FIG. 4 is a diagram of an architecture of vehicle communication according to an embodiment of this application; and

FIG. 5 is a diagram of decomposition of a vehicle acceleration according to an embodiment of this application.

DESCRIPTION OF EMBODIMENTS

The following clearly and completely describes the technical solutions in embodiments of this application with reference to the accompanying drawings in embodiments of this application. It is clear that the described embodiments are a part rather than all of embodiments of this application. All other embodiments obtained by a person of ordinary skill in the art based on embodiments of this application without creative efforts shall fall within the protection scope of this application.

Implementations of the technical solutions of this application are further described below in detail with reference to the accompanying drawings.

FIG. 1 is a diagram of a scenario of a vehicle according to an embodiment of this application. As shown in FIG. 1, a vehicle 10 includes an electric drive system 101 and a power battery 102 connected to the electric drive system 101, and the power battery 102 provides a power supply to the electric drive system 101.

A structure of the electric drive system 101 may be shown in FIG. 2. The electric drive system 101 includes a controller 1011, an inverter circuit 1012, and a motor 1013.

A communication end of the controller 1011 is directly connected to a first communication bus 103, so that the controller 1011 may establish communication with another component in the vehicle 10 through the first communication bus 103. To be specific, the controller 1011 may directly obtain a signal from the first communication bus 103, for example, a vehicle velocity, a torque demand signal, a throttle signal, and a brake signal. The controller 1011 may alternatively upload a signal to the first communication bus 103, for example, an actual torque of the motor 1013 or a current of the inverter circuit 1012.

For example, the first communication bus 103 may be a controller area network (CAN) bus, and is specifically implemented as a chassis CAN bus of the vehicle 10.

The controller 1011 may be specifically implemented as a central processing unit (CPU), another general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or another programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, or the like.

An input end of the controller 1011 is connected to a rotation velocity detection apparatus, and the rotation velocity detection apparatus is disposed on a rotor of the motor 1013. In this case, the controller 1011 may receive a rotation velocity signal of the motor 1013 from the rotation velocity detection apparatus. For example, the rotation velocity detection apparatus may be a resolver or a rotation velocity sensor.

In an embodiment, the controller 1011 may determine, based on the rotation velocity signal of the motor 1013 and a vehicle velocity obtained from the first communication bus 103, whether a wheel corresponding to the motor 1013 slips. For example, the controller 1011 determines whether the rotation velocity signal of the motor 1013 and the vehicle velocity meet a preset condition. If the rotation velocity signal of the motor 1013 and the vehicle velocity meet the preset condition, the controller 1011 determines that the wheel corresponding to the motor 1013 slips. It may be understood that the wheel corresponding to the motor 1013 is a wheel driven by the motor 1013.

In addition, an output end of the controller 1011 is connected to a control end of the inverter circuit 1012, an input end of the inverter circuit 1012 is connected to the power battery 102, and an output end of the inverter circuit 1012 is connected to the motor 1013.

In an embodiment, the controller 1011 may control an output current of the inverter circuit 1012, to control a rotation velocity or a torque of the motor 1013. For example, when the wheel corresponding to the motor 1013 does not slip, the controller 1011 may control the output current of the inverter circuit 1012 based on at least one of a torque demand signal, a throttle signal, and a brake signal that are received, to control an output torque of the motor 1013. It may be understood that the throttle signal and the brake signal are generated by triggering of a throttle pedal or a brake pedal on which a driver steps. In this case, the controller 1011 receives the corresponding throttle signal or brake signal from the throttle pedal or the brake pedal. The torque demand signal is received by the controller 1011 from a torque calculation module, and the torque demand signal is obtained by the torque calculation module through calculation based on the throttle signal and the brake signal.

When the wheel corresponding to the motor 1013 slips, the controller 1011 may adjust the output current of the inverter circuit 1012 based on a target rotation velocity of the motor 1013, to control the rotation velocity of the motor 1013.

It should be noted that a port type in the controller 1011 may include but is not limited to an input end, an output end, and a communication end. The input end, the output end, or the communication end in this application may be specifically implemented as any one of a plurality of ports. Alternatively, one port may both have input, output, and communication functions. In this case, at least one of the input end, the output end, and the communication end in this application may be specifically implemented as a same port, or may be implemented as different ports. Alternatively, the communication port may be used as a simple input port or output port. In other words, connections between the communication end, the output end, and the input end in this embodiment of this application and other components are merely divided by function, and are not limited to specific ports in actual production and application.

For example, the inverter circuit 1012 may be a three-phase two-level inverter, a three-phase three-level inverter, or a three-phase multi-level inverter. To be specific, specific implementation of the inverter circuit 1012 is not limited in this embodiment of this application, provided that a direct current output by the power battery 102 can be converted into an alternating current that drives the motor 1013.

The following describes, with reference to the accompanying drawings by using examples, how the controller in this embodiment of this application specifically performs slipping determining on the wheel corresponding to the motor.

In an embodiment, FIG. 3 is a block diagram of a structure of a vehicle according to an embodiment of this application. As shown in FIG. 3, the vehicle may include a controller 3011, an inverter circuit 3012, a motor 3013, and a first communication bus 303. For example, in FIG. 3, an example in which the inverter circuit 3012 is specifically implemented as a three-phase two-level inverter is used.

It should be first explained that, in FIG. 3, an example in which the vehicle is specifically implemented as a two-wheel drive vehicle is used. In other words, there is no mechanical connection between an axle of a front wheel and an axle of a rear wheel. FIG. 3 shows a front-wheel drive vehicle. In other words, the motor 3013 is disposed over the front wheels. In specific practice, the motor may alternatively be disposed over the rear wheels (not shown in the figure), and the vehicle is a rear-wheel drive vehicle. Optionally, the vehicle may alternatively be specifically implemented as a four-wheel drive vehicle. In other words, there is a mechanical connection (not shown in the figure) between an axle of front wheels and an axle of rear wheels. In conclusion, a drive manner of the vehicle is not limited in this application.

In this embodiment of this application, an input end of the controller 3011 is connected to a rotation velocity detection apparatus (not shown in the figure), and the rotation velocity detection apparatus is disposed on a rotor of the motor 3013. For example, the rotation velocity detection apparatus is specifically implemented as a resolver. In this case, the controller 3011 receives a sine signal sin α and a cosine signal cos α of the resolver based on a preset time periodicity, where α is an angle by which the motor 3013 rotates. The preset time periodicity may be understood as a sampling periodicity of the controller 3011. In other words, the controller 3011 collects the sine signal sin α and the cosine signal cos α of the resolver in real time. The controller 3011 obtains the angle α through calculation based on a ratio of the sine signal sin α to the cosine signal cos α. The controller 3011 further obtains a rotation velocity n of the motor 3013 through calculation based on the angle α and time t used by the motor 3013 for rotating by the angle α. A formula may be expressed as follows:

$\begin{array}{cc}n=\frac{\alpha }{2\pi t}& \mathrm{Formula}1\end{array}$

The controller 3011 may directly obtain a vehicle velocity from the first communication bus 303, and calculate, based on the vehicle velocity and the rotation velocity of the motor 3013, an actual slip ratio of a wheel corresponding to the motor 3013.

During specific implementation, the controller 3011 may obtain, through calculation based on the rotation velocity of the motor 3013 and a transmission ratio of the motor 3013 to the wheel corresponding to the motor 3013, an angular velocity of the wheel corresponding to the motor 3013. A formula is expressed as follows:

$\begin{array}{cc}{w}_1=\frac{w}{i}=\frac{2\pi n}{i}& \mathrm{Formula}2\end{array}$

w₁ is the angular velocity of the wheel corresponding to the motor 3013, w is an angular velocity of the motor 3013, n is the rotation velocity of the motor 3013, and i is the transmission ratio of the motor 3013 to the wheel corresponding to the motor 3013.

The controller 3011 obtains, through calculation based on the angular velocity w₁ of the wheel corresponding to the motor 3013 and a wheel rolling radius R corresponding to the motor 3013, a linear velocity w₁R of the wheel corresponding to the motor 3013.

The controller 3011 may determine, based on a ratio of the linear velocity w₁R of the wheel corresponding to the motor 3013 to the vehicle velocity, the actual slip ratio of the wheel corresponding to the motor 3013. For example, when the linear velocity w₁R of the wheel corresponding to the motor 3013 is greater than the vehicle velocity V, the controller 3011 determines that the vehicle is in a driving state, and uses a ratio of a difference obtained by subtracting the vehicle velocity V from the linear velocity w₁R of the wheel corresponding to the motor 3013 to the linear velocity w₁R of the wheel corresponding to the motor 3013 as the actual slip ratio of the wheel corresponding to the motor 3013. When the linear velocity w₁R of the wheel corresponding to the motor 3013 is less than the vehicle velocity V, the controller 3011 determines that the vehicle is in a braking state, and uses a ratio of a difference obtained by subtracting the linear velocity w₁R of the wheel corresponding to the motor 3013 from the vehicle velocity V to the vehicle velocity V as the actual slip ratio of the wheel corresponding to the motor 3013. A formula may be expressed as follows:

$\begin{array}{cc}\lambda =\{\begin{array}{c}\frac{V-w_{1}R}{V},V>w_{1}R\\ \frac{w_{1}R-V}{w_{1}R},V<w_{1}R\end{array}& \mathrm{Formula}3\end{array}$

The controller 3011 determines, based on the actual slip ratio and a target slip ratio of the wheel corresponding to the motor 3013, whether the wheel corresponding to the motor 3013 slips.

It should be explained that the first communication bus 303 is a CAN bus, and the controller 3011 obtains the vehicle velocity from the first communication bus 303 at a preset communication periodicity according to a CAN communication protocol. For example, if a communication periodicity on the first communication bus 303 is 10 ms, the controller 3011 may obtain the vehicle velocity from the first communication bus every 10 ms. It may be understood that the communication periodicity and the sampling periodicity may be different. Generally, a sampling frequency is higher than a communication frequency. In other words, the sampling periodicity is less than the communication periodicity. It is assumed that the sampling periodicity is 2 ms. In this case, the controller 3011 may obtain a plurality of rotation velocity signals, for example, a plurality of sine signals sin a and a plurality of cosine signals cos a, of the motor through sampling in one communication periodicity. For example, the controller 3011 receives a rotation velocity signal of the motor and obtains a vehicle velocity at a moment T, and calculates, based on the rotation velocity signal of the motor and the vehicle velocity that are received at the moment T, an actual slip ratio of the wheel corresponding to the motor 3013. The controller 3011 continues to receive a new rotation velocity signal of the motor 2 ms after the moment T, but the vehicle velocity is not updated at this time. In this case, the controller 3011 may calculate, based on the rotation velocity that is of the motor and that is received 2 ms after the moment T and the vehicle velocity obtained at the moment T, an actual slip ratio of the wheel corresponding to the motor 3013. In conclusion, the controller 3011 may calculate, in one communication periodicity, for example, 10 ms, the actual slip ratio of the wheel corresponding to the motor 3013 for five times, so that the actual slip ratio of the wheel is calculated more accurately.

In an embodiment, when a difference between the actual slip ratio and the target slip ratio that are of the wheel corresponding to the motor 3013 is greater than a first preset threshold, the controller 3011 determines that the wheel corresponding to the motor 3013 slips.

In an embodiment, the controller 3011 may subtract the target slip ratio from the actual slip ratio of the wheel corresponding to the motor 3013, to obtain a difference Δλ=λ−λ_target between the actual slip ratio and the target slip ratio, where λ_target is the target slip ratio. In this case, when Δλ is greater than the first preset threshold, the controller 3011 determines that the wheel corresponding to the motor 3013 slips.

In this embodiment of this application, the controller may receive the rotation velocity signal of the motor, directly obtain the vehicle velocity from the first communication bus, and directly calculate the actual slip ratio of the wheel corresponding to the motor. Then the controller may determine, based on the actual slip ratio and the target slip ratio of the wheel corresponding to the motor, whether the wheel corresponding to the motor slips. Through implementation of this embodiment of this application, whether the wheel corresponding to the motor slips may be quickly determined, accuracy is high, and safety is good.

In an embodiment, the controller 3011 may control the actual slip ratio of the wheel corresponding to the motor 3013 to be the target slip ratio λ_target. That is, λ in Formula 3 is replaced with λ_target, and a target angular velocity w_{1_target} of the wheel corresponding to the motor 3013 may be obtained through calculation. A formula may be expressed as follows:

$\begin{array}{cc}{w}_{1\_\mathrm{target}}=\{\begin{array}{c}\frac{\left(1-{\lambda }_{\mathrm{target}}\right)V}{R},V>w_{1}R\\ \frac{V}{\left(1-{\lambda }_{\mathrm{target}}\right)R},V<w_{1}R\end{array}& \mathrm{Formula}4\end{array}$

The controller 3011 may obtain a target angular velocity of the motor 3013 based on the target angular velocity w_{1_target} of the wheel corresponding to the motor 3013 and the transmission ratio of the motor 3013 to the wheel corresponding to the motor 3013. A formula may be expressed as follows:

$\begin{array}{cc}{w}_{\mathrm{motor}\_\mathrm{target}}=w_{1\_\mathrm{target}}\times i& \mathrm{Formula}5\end{array}$

In this case, a target rotation velocity of the motor 3013 is n_{motor_target}=w_{motor_target}/2π.

The controller 3011 generates a rotation velocity control signal based on the target rotation velocity n_{motor_target} of the motor 3013, and specifically controls, based on the rotation velocity control signal, a current output by the inverter circuit 3012 to the motor 3013, so that the motor 3013 may rotate based on the target rotation velocity.

In this embodiment of this application, the controller may directly generate the rotation velocity control signal, and may directly control the rotation velocity of the motor without intervention of a torque calculation module, thereby reducing time for information transmission, shortening slipping control time, and achieving high control precision.

In an embodiment, the vehicle further includes a second communication bus 304 and a torque calculation module 305. A communication end of the controller 3011 is further connected to the second communication bus 304, and the second communication bus 304 is connected to the torque calculation module 305. For example, the second communication bus 304 may be specifically implemented as a power CAN bus of the vehicle.

During specific implementation, the vehicle velocity on the first communication bus 303 is uploaded by the torque calculation module 305. For example, the torque calculation module 305 specifically includes an anti-lock brake system 3053. In this case, the anti-lock brake system 3053 may calculate the vehicle velocity based on a wheel velocity sensed by a velocity sensor, where the velocity sensor is disposed on a wheel. Alternatively, the torque calculation module 305 specifically further includes an electronic stability program 3052. In this case, the electronic stability program 3052 may alternatively calculate the vehicle velocity based on a wheel velocity sensed by a velocity sensor. For a specific manner of calculating the vehicle velocity, refer to the conventional technology. Details are not described herein again.

The torque calculation module 305 further sends a torque demand signal to the controller 3011. For example, the torque calculation module 305 specifically further includes a vehicle control unit 3051. In this case, the vehicle control unit 3051 may deliver the torque demand signal through the second communication bus 304. Alternatively, when the second communication bus 304 is faulty, the vehicle control unit 3051 may alternatively upload the torque demand signal to the first communication bus 303, so that the controller 3011 may obtain the torque demand signal from the first communication bus 303, and control, based on the torque demand signal, the current output by the inverter circuit 3012 to the motor 3013. It may be learned that because the controller 3011 is directly connected to the first communication bus 303, the first communication bus 303 may be used as a backup of the second communication bus 304. When the first communication bus 303 is faulty, the controller 3011 may implement normal communication and control through the first communication bus 303, thereby further improving safety and reliability of vehicle control.

In this case, a diagram of an architecture of vehicle communication may be specifically shown in FIG. 4. The controller 3011, the vehicle control unit 3051, the electronic stability program 3052, and the anti-lock brake system 3053 are in a same gateway. For example, it may be understood that the controller 3011, the electronic stability program 3052, and the anti-lock brake system 3053 all communicate with the vehicle control unit 3051. The controller 3011 and the vehicle control unit 3051 are connected to both the first communication bus 303 and the second communication bus 304. The electronic stability program 3052 and the anti-lock brake system 3053 are connected to the first communication bus 303.

In an embodiment, when determining that the wheel corresponding to the motor 3013 slips, the controller 3011 indicates the torque calculation module 305 to stop sending the torque demand signal. In this case, it may be understood that the controller 3011 takes over control of the current output by the inverter circuit 3012 to the motor 3013, and the current is not controlled by the torque calculation module 305. Alternatively, when determining that the wheel corresponding to the motor 3013 slips, the controller 3011 stops responding to the torque demand signal sent by the torque calculation module 305. In this case, it may be understood that the torque demand signal sent by the torque calculation module 305 is invalid.

In an embodiment, the vehicle further includes a throttle pedal 302, and the throttle pedal 302 is connected to the input end of the controller 3011. In this case, the controller 3011 may receive a throttle signal. The throttle signal is generated by triggering of the throttle pedal 302, and is specifically determined by location information of the throttle pedal 302. The controller 3011 may calculate an input torque of a driver based on the throttle signal. For example, when the torque calculation module 305 is faulty, the controller 3011 may back up the throttle signal, and directly calculate the input torque of the driver, to directly control the current output by the inverter circuit 3012 to the motor 3013. It may be learned that, because the controller 3011 is directly connected to the throttle pedal 302, when the torque calculation module 305 is faulty, the controller 3011 may directly calculate the input torque of the driver, to control the inverter circuit 3012, thereby further improving safety and reliability of the vehicle.

In an embodiment, the vehicle further includes a brake pedal 306, and the brake pedal 306 is connected to the input end of the controller 3011. In this case, the controller 3011 may receive a brake signal. The brake signal is generated by triggering of the brake pedal 306, and is specifically determined by location information of the brake pedal 306. The controller 3011 may calculate an input torque of a driver based on the brake signal. For example, when the torque calculation module 305 is faulty, the controller 3011 may back up the brake signal, and directly calculate the input torque of the driver, to directly control the current output by the inverter circuit 3012 to the motor 3013. It may be learned that, because the controller 3011 is directly connected to the brake pedal 306, when the torque calculation module 305 is faulty, the controller 3011 may directly calculate the input torque of the driver, to control the inverter circuit 3012, thereby further improving safety and reliability of the vehicle.

In an embodiment, the controller 3011 may further determine, based on a theoretical acceleration and an actual acceleration of the motor 3013, whether the wheel corresponding to the motor 3013 slips.

During specific implementation, the controller 3011 may obtain, through calculation based on an angular acceleration of the motor 3013, the wheel rolling radius corresponding to the motor 3013, and the transmission ratio of the motor 3013 to the wheel corresponding to the motor 3013, a theoretical acceleration of the wheel corresponding to the motor 3013. A formula is expressed as follows:

$\begin{array}{cc}\mathrm{a\_motor}\mathrm{\_wheel}=a_{w\_\mathrm{motor}}\times R\times i& \mathrm{Formula}6\end{array}$

a_motor_wheel is the theoretical acceleration of the wheel corresponding to the motor 3013, a_{w_motor} is the angular acceleration of the motor 3013, R is the wheel rolling radius corresponding to the motor 3013, and i is the transmission ratio of the motor 3013 to the wheel corresponding to the motor 3013.

It may be understood that the angular acceleration a_{w_motor} of the motor 3013 may be obtained based on the rotation velocity signal of the motor 3013. For example, a rotation velocity variation Δn of the motor 3013 within time Δt may be obtained, and a_{w_motor}=2πΔ/Δt.

The controller 3011 obtains an actual acceleration of the wheel corresponding to the motor 3013. The actual acceleration of the wheel corresponding to the motor 3013 may be sensed by an acceleration sensor. The velocity sensor sends a sensed velocity signal of the wheel to the controller 3011, and the controller 3011 obtains, through calculation based on the velocity signal, an acceleration of the wheel corresponding to the motor 3013.

It should be explained that both the theoretical acceleration and the actual acceleration of the wheel corresponding to the motor 3013 have a direction. For example, a direction of the theoretical acceleration of the wheel corresponding to the motor 3013 is a first direction, and the first direction is perpendicular to an axle on which the motor 3013 is located. A direction of the actual acceleration of the wheel corresponding to the motor 3013 is a second direction, the second direction is a tangential direction of a traveling path of the vehicle, and the second direction is related to a rotation angle of a steering wheel of the vehicle.

The controller 3011 decomposes the theoretical acceleration of the wheel corresponding to the motor 3013 into a direction of the actual acceleration of the wheel corresponding to the motor 3013. That is, the controller 3011 decomposes the theoretical acceleration of the wheel corresponding to the motor 3013 into the second direction. In this case, FIG. 5 is a diagram of decomposition of a vehicle acceleration according to an embodiment of this application. As shown in FIG. 5, an acceleration obtained by decomposing the theoretical acceleration of the wheel corresponding to the motor 3013 into the second direction may be expressed by using a formula:

$\begin{array}{cc}\mathrm{a\_motor}\mathrm{\_wheel}\mathrm{\_y}=\mathrm{a\_motor}\mathrm{\_wheel}\times \sin \theta & \mathrm{Formula}7\end{array}$

a_motor_wheel_y is the acceleration obtained by decomposing the theoretical acceleration of the wheel corresponding to the motor 3013 into the second direction, a_motor_wheel is the theoretical acceleration of the wheel corresponding to the motor 3013, and θ is the rotation angle of the steering wheel.

The controller 3011 determines, when the acceleration a_motor_wheel_y obtained by decomposing the theoretical acceleration of the wheel corresponding to the motor 3013 into the second direction is greater than the actual acceleration of the wheel corresponding to the motor 3013 by a second preset threshold, that the wheel corresponding to the motor 3013 slips.

In an embodiment, the theoretical acceleration of the wheel corresponding to the motor 3013 may alternatively be obtained by the controller 3011 through calculation based on a torque carried in the torque demand signal.

In this embodiment of this application, whether the wheel corresponding to the motor slips is determined in an acceleration dimension, so that accuracy of determining whether the wheel slips can be improved.

It should be noted that the terms “first” and “second” are merely intended for a purpose of description, and shall not be understood as an indication or implication of relative importance. The foregoing descriptions are merely specific implementations of the present invention, but are not intended to limit the protection scope of the present invention. Any variation or replacement readily figured out by a person skilled in the art within the technical scope disclosed in the present invention shall fall within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A controller of a motor control module, wherein an input end of the controller is configured to receive a rotation velocity signal of a motor, a communication end of the controller is configured to obtain a vehicle velocity through a first communication bus, an output end of the controller is configured to output a control signal to control an inverter circuit in the motor control module, and the controller is configured to: control, based on at least one of a torque demand signal, a throttle signal, and a brake signal that are received, a current output by the inverter circuit to the motor; orcontrol, in response to the rotation velocity signal of the motor and the vehicle velocity meeting a preset condition, the inverter circuit to adjust a current output to the motor.

2. The controller according to claim 1, wherein the communication end of the controller is further configured to connect to a torque calculation module through a second communication bus, and the controller is further configured to: in response to the rotation velocity signal of the motor and the vehicle velocity meeting the preset condition, indicate the torque calculation module to stop sending the torque demand signal; or in response to the vehicle velocity and the rotation velocity signal of the motor meeting the preset condition, stop responding to the torque demand signal sent by the torque calculation module.

3. The controller according to claim 2, wherein the first communication bus is connected to the torque calculation module, and the controller is further configured to: obtain, from the first communication bus, the torque demand signal sent by the torque calculation module, and control, responding to the torque demand signal sent by the torque calculation module, the current output by the inverter circuit to the motor.

4. The controller according to claim 1, wherein the input end of the controller is connected to a throttle pedal, and configured to receive a throttle signal generated by triggering of the throttle pedal.

5. The controller according to claim 1, wherein the input end of the controller is connected to a brake pedal, and configured to receive a brake signal generated by triggering of the brake pedal.

6. A motor control method, wherein the control method is applicable to a controller in a motor control module comprising an input end, a communication end, and an output end, the method comprising: the input end of the controller receiving a rotation velocity signal of a motor;the communication end of the controller obtaining a vehicle velocity through a first communication bus;the output end of the controller outputing a control signal to control an inverter circuit in the motor control module; andthe control method further comprises: controlling, by the controller based on at least one of a torque demand signal, a throttle signal, and a brake signal that are received, a current output by the inverter circuit to the motor; orcalculating, by the controller based on the rotation velocity signal of the motor and the vehicle velocity, an actual slip ratio of a wheel corresponding to the motor; and controlling, by the controller in response to a difference between the actual slip ratio and a target slip ratio of the wheel corresponding to the motor being greater than a first preset threshold, the inverter circuit to adjust a current output to the motor.

7. The control method according to claim 6, wherein the control method comprises the calculating, by the controller based on the rotation velocity signal of the motor and the vehicle velocity, the actual slip ratio of the wheel corresponding to the motor, and said calculating further comprises: calculating a linear velocity of a wheel corresponding to the motor, by the controller based on the rotation velocity signal of the motor, the wheel rolling radius corresponding to the motor, and a transmission ratio of the motor to the wheel corresponding to the motor; anddetermining, by the controller based on a ratio of the linear velocity of the wheel corresponding to the motor to the vehicle velocity, the actual slip ratio of the wheel corresponding to the motor.

8. The control method according to claim 6, wherein the control method comprises the controlling, by the controller in response to the difference between the actual slip ratio and the target slip ratio of the wheel corresponding to the motor being greater than a first preset threshold, the inverter circuit to adjust the current output to the motor, and said controlling further comprises: controlling, by the controller in response to the difference between the actual slip ratio and the target slip ratio of the wheel corresponding to the motor being greater than the first preset threshold and in response to a difference between a theoretical acceleration and an actual acceleration of the wheel corresponding to the motor being greater than a second preset threshold, the inverter circuit to adjust the current output to the motor.

9. The control method according to claim 8, wherein before the controlling, in response to the difference between the theoretical acceleration and the actual acceleration of the wheel corresponding to the motor being greater than the second preset threshold, the inverter circuit to adjust the current output to the motor, the control method further comprises: obtaining, by the controller through calculation based on an angular acceleration of the motor, the wheel rolling radius corresponding to the motor, and the transmission ratio of the motor to the wheel corresponding to the motor, the theoretical acceleration of the wheel corresponding to the motor; andobtaining, by the controller, the actual acceleration of the wheel corresponding to the motor, and comparing the theoretical acceleration and the actual acceleration of the wheel corresponding to the motor.

10. The control method according to claim 6, wherein the control method comprises controlling the inverter circuit to adjust the current output to the motor, and said controlling further comprises: obtaining, by the controller based on the target slip ratio, the vehicle velocity, and the wheel rolling radius corresponding to the motor, a target rotation velocity of the wheel corresponding to the motor; andcontrolling, based on the target rotation velocity of the wheel corresponding to the motor, the inverter circuit to adjust the current output to the motor.

11. An electric drive system, wherein the electric drive system comprises a motor control module, a first communication bus, and a motor, and the motor control module comprises an inverter circuit and a controller; wherein an input end of the controller is configured to receive a rotation velocity signal of the motor, a communication end of the controller is configured to obtain a vehicle velocity through the first communication bus, an output end of the controller is configured to output a control signal to control the inverter circuit in the motor control module, and the controller is configured to:control, based on at least one of a torque demand signal, a throttle signal, and a brake signal that are received, a current output by the inverter circuit to the motor; orcontrol, in response to the rotation velocity signal of the motor and the vehicle velocity meeting a preset condition, the inverter circuit to adjust a current output to the motor.

12. The electric drive system according to claim 11, wherein the communication end of the controller is further connected to a torque calculation module through a second communication bus, and the controller is further configured to: in response to the rotation velocity signal of the motor and the vehicle velocity meeting the preset condition, indicate the torque calculation module to stop sending the torque demand signal; or in response to the vehicle velocity and the rotation velocity signal of the motor meeting the preset condition, stop responding to the torque demand signal sent by the torque calculation module.

13. The electric drive system according to claim 12, wherein the first communication bus is connected to the torque calculation module, and the controller is further configured to: obtain, from the first communication bus, the torque demand signal sent by the torque calculation module, and control, responding to the torque demand signal sent by the torque calculation module, the current output by the inverter circuit to the motor.

14. The electric drive system according to claim 11, wherein the input end of the controller is further connected to a throttle pedal, and configured to receive a throttle signal generated by triggering of the throttle pedal.

15. The electric drive system according to claim 11, wherein the input end of the controller is further connected to a brake pedal, and configured to receive a brake signal generated by triggering of the brake pedal.