A motor control method, device and related equipment

Abstract

The application provides a motor control method and device and related equipment. For a vehicle including a steer-by-wire system, time domain wheel speed information of multiple steering wheels of the vehicle can be acquired first. The time domain wheel speed information refers to the change of the speed of the steering wheels with time. Through Fourier transform on the time domain wheel speed information, frequency domain wheel speed information of each steering wheel is obtained. The frequency domain wheel speed information represents the frequency and amplitude of each sub-wave in the time domain wheel speed information. Through analysis on the frequency domain wheel speed information of the multiple steering wheels, a power spectral density function of each steering wheel is obtained. Based on the power spectral density function, the average power of the wheel speed signal of each frequency band is analyzed, so as to determine the driving condition of the vehicle, determine the corresponding feedback torque based on the driving condition of the vehicle, and control the feedback motor according to the feedback torque, so as to realize the road feeling feedback to the driver. In this way, the feedback torque of the vehicle can be better simulated, the road surface condition can be better simulated, and the driving experience of the driver can be improved.

Description

Technical Field

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

[0002] The steering system, used to change the direction of a vehicle, is an important component of the vehicle. Compared to traditional mechanical power steering, the upper and lower steering subsystems of a steer-by-wire system are independent. The upper and lower steering subsystems are connected via electrical signals. The driver's operations on the upper steering system (e.g., the steering wheel) are input as electrical signals to the lower steering subsystem, whose motor controls the vehicle's steering based on these signals.

[0003] Because there is no mechanical connection between the upper and lower steering subsystems in a steer-by-wire system, feedback information from the lower steering subsystem cannot be directly transmitted to the driver through the upper steering subsystem. Therefore, in some implementations, road surface information can be estimated based on rack force to determine the feedback torque, and this feedback torque can then be used to simulate road feel.

[0004] However, the calculation of rack force often has a large error, resulting in poor road feel simulation. Summary of the Invention

[0005] In view of this, this application provides a motor control method, apparatus and related equipment, which are designed to accurately simulate road feel.

[0006] In a first aspect, this application provides a motor control method for controlling the feedback motor of the upper steering subsystem in a vehicle's steer-by-wire system, the method comprising:

[0007] Obtain the time-domain wheel speed information of multiple steering wheels of the vehicle;

[0008] Perform a Fourier transform on the time-domain wheel speed information to determine the frequency-domain wheel speed information of each steering wheel;

[0009] Based on the frequency domain wheel speed information, determine the power spectral density function of each steering wheel;

[0010] Based on the power spectral density function, the driving conditions of the vehicle are determined, and the feedback torque corresponding to the driving conditions is determined.

[0011] The feedback motor is controlled based on the feedback torque.

[0012] In some possible implementations, determining the vehicle's driving condition based on the power spectral density function and determining the feedback torque corresponding to the driving condition includes:

[0013] The average power of the steering wheel within the preset frequency band is determined based on the power spectral density function.

[0014] In response to the average power being higher than a first threshold, it is determined that the vehicle's driving condition includes a bumpy road condition.

[0015] The feedback torque is determined based on the bumpy road surface conditions and the preset frequency range, and the vibration frequency of the feedback torque matches the preset frequency range.

[0016] In some possible implementations, the plurality of steering wheels includes a first steering wheel and a second steering wheel, the first steering wheel and the second steering wheel being located on different sides of the vehicle;

[0017] The step of determining the vehicle's driving condition based on the power spectral density function, and determining the feedback torque corresponding to the driving condition, includes:

[0018] Based on the power spectral density function of the first steering wheel and the power spectral density function of the second steering wheel, it is determined whether there is a target frequency band such that the absolute value of the difference between the average power of the first steering wheel in the target frequency band and the average power of the second steering wheel in the target frequency band is greater than a second threshold.

[0019] If the target frequency band exists, the vehicle's driving conditions are determined to include unilateral bump conditions;

[0020] The feedback torque is determined based on the unilateral bumpy condition, and the direction of the feedback torque is determined by the direction of the steering wheel with the greater average power in the target frequency band among the first and second steering wheels.

[0021] In some possible implementations, the method further includes, before determining the bumpy road surface condition:

[0022] Obtain the operating condition information of the steering motor of the lower steering subsystem in the steer-by-wire system, wherein the operating condition information includes any one or more of the steering angle, steering speed and torque of the steering motor;

[0023] Perform a Fourier transform on the operating condition information to determine the frequency domain operating condition information and power spectral density function of the steering motor;

[0024] The power spectral density function of the steering motor is determined to match the power spectral density function of the plurality of steering wheels.

[0025] In some possible implementations, determining the feedback torque corresponding to the driving condition includes:

[0026] The feedback torque is determined based on the torque amplitude coefficient and the driving conditions.

[0027] The method further includes:

[0028] In response to the coefficient adjustment command, the torque amplitude coefficient is adjusted.

[0029] Secondly, this application provides a motor control device for controlling the feedback motor of the upper steering subsystem in a vehicle's steer-by-wire system, the device comprising:

[0030] The acquisition unit is used to acquire the time-domain wheel speed information of multiple steering wheels of the vehicle;

[0031] The Fourier transform unit is used to perform Fourier transform on the time-domain wheel speed information to determine the frequency-domain wheel speed information of each steering wheel;

[0032] A power spectrum determination unit is used to determine the power spectral density function of each steering wheel based on the frequency domain wheel speed information.

[0033] The torque determination unit is used to determine the driving conditions of the vehicle based on the power spectral density function, and to determine the feedback torque corresponding to the driving conditions.

[0034] A control unit for controlling the feedback motor based on the feedback torque.

[0035] In some possible implementations, the torque determination unit is specifically used to determine the average power of the steering wheel within a preset frequency band based on the power spectral density function; in response to the average power being higher than a first threshold, determine that the vehicle's driving conditions include bumpy road conditions; and determine the feedback torque based on the bumpy road conditions and the preset frequency range, wherein the vibration frequency of the feedback torque matches the preset frequency range.

[0036] In some possible implementations, the plurality of steering wheels includes a first steering wheel and a second steering wheel, the first steering wheel and the second steering wheel being located on different sides of the vehicle; the torque determination unit is specifically used to determine whether a target frequency band exists based on the power spectral density function of the first steering wheel and the power spectral density function of the second steering wheel, such that the absolute value of the difference between the average power of the first steering wheel and the average power of the second steering wheel in the target frequency band is greater than a second threshold; if the target frequency band exists, the vehicle's driving condition is determined to include a unilateral bumpy driving condition; the feedback torque is determined based on the unilateral bumpy driving condition, the direction of the feedback torque being determined by the direction of the steering wheel with the greater average power in the target frequency band among the first and second steering wheels.

[0037] In some possible implementations, the acquisition unit is further configured to acquire the operating condition information of the steering motor of the lower steering subsystem in the steer-by-wire system, the operating condition information including any one or more of the steering angle, steering speed, and torque of the steering motor; the torque determination unit is specifically configured to perform a Fourier transform on the operating condition information to determine the frequency domain operating condition information and power spectral density function of the steering motor; and to determine that the power spectral density function of the steering motor matches the power spectral density functions of the plurality of steering wheels.

[0038] In some possible implementations, the torque determining unit is specifically used to determine the feedback torque based on the torque amplitude coefficient and the driving conditions; the device further includes a coefficient adjusting unit, which is used to adjust the torque amplitude coefficient in response to a coefficient adjusting command.

[0039] Thirdly, this application provides a control device, the device including a memory and a controller, the memory for storing instructions or code, and the controller for instructing the instructions or code stored in the memory to implement the method as described in any of the first aspects above.

[0040] Fourthly, this application provides a steer-by-wire system, the steer-by-wire system including an upper steering subsystem and a lower steering subsystem, the upper steering subsystem including a feedback motor, and the steer-by-wire system further including a controller, the controller being used to implement the method as described in any of the first aspects above.

[0041] Fifthly, this application provides a vehicle including a steer-by-wire system and a controller, the steer-by-wire system including an upper steering subsystem and a lower steering subsystem, the upper steering subsystem including a feedback motor, and the controller being configured to implement the method as described in any of the preceding first aspects.

[0042] In a sixth aspect, this application provides a computer storage medium storing code, wherein when the code is executed, a device executing the code implements the method described in any of the first aspects or the method described in the second aspect.

[0043] In a seventh aspect, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to perform the method described in any one of the first aspects or the method described in the second aspect.

[0044] This application provides a motor control method, apparatus, and related equipment. For vehicles including a steer-by-wire system, the time-domain wheel speed information of multiple steering wheels can be obtained first. Time-domain wheel speed information refers to the change in steering wheel rotation speed over time. By performing a Fourier transform on the time-domain wheel speed information, the frequency-domain wheel speed information of each steering wheel can be obtained. The frequency-domain wheel speed information represents the frequency and amplitude of each wavelet in the time-domain wheel speed information. By analyzing the frequency-domain wheel speed information of multiple steering wheels, the power spectral density function of each steering wheel can be obtained. Based on the power spectral density function, the average power of the wheel speed signal in each frequency band can be analyzed, thereby determining the vehicle's driving conditions. Based on the vehicle's driving conditions, the corresponding feedback torque is determined, and the feedback motor is controlled according to the feedback torque to achieve road feel feedback to the driver. It is evident that the feedback torque used for road feel feedback is calculated based on the time-domain wheel speed information of the steering wheels, rather than based on rack force. Compared to rack force, the steering wheel rotation speed is more accurate; therefore, the feedback torque calculated based on the steering wheel rotation speed is closer to the actual situation. This allows for a better simulation of vehicle feedback torque and road conditions, thus enhancing the driver's driving experience. Attached Figure Description

[0045] To more clearly illustrate the technical solutions in this embodiment or the prior art, the drawings used in the description of the embodiment or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0046] Figure 1 A schematic diagram of a steer-by-wire system provided in an embodiment of this application;

[0047] Figure 2 A schematic flowchart of a motor control method provided in an embodiment of this application;

[0048] Figure 3 Another schematic flowchart of the motor control method provided in the embodiments of this application;

[0049] Figure 4 This is a schematic diagram of a motor control device provided in an embodiment of this application. Detailed Implementation

[0050] The steer-by-wire system consists of two parts: an upper steering subsystem and a lower steering subsystem. There is no mechanical connection between the upper and lower steering subsystems; instead, steering is achieved through electrical signals.

[0051] Specifically, such as Figure 1 As shown. In Figure 1The illustrated steer-by-wire system includes an upper steering subsystem and a lower steering subsystem. The upper steering subsystem includes a steering wheel, a motor, and a reduction gear. The lower steering subsystem includes a motor and a reduction gear. To decelerate the vehicle, the driver can rotate the steering wheel. The upper steering system can acquire the steering wheel's rotation angle and send a control signal to the motor in the lower steering subsystem based on this angle. The motor in the lower steering subsystem operates according to the control signal, controlling the wheel rotation via the reduction gear. The wheels controlled by the lower steering subsystem can be referred to as steering wheels.

[0052] To improve the driver's experience, a corresponding feedback torque can be determined when the motor in the lower steering subsystem pushes the wheel, and then applied to the steering wheel via the motor in the upper steering subsystem. This allows the driver to feel the resistance through the steering wheel, thus understanding the forces acting on the vehicle during steering and achieving a road feel simulation effect. In this way, the feedback torque can simulate the effect of a mechanical connection between the upper and lower steering subsystems even without an actual mechanical connection between them.

[0053] However, traditional feedback torque is calculated based on the rack force of the lower steering subsystem. Since rack force cannot be measured directly by sensors, it is obtained through data from other sensors. Therefore, feedback torque calculated based on rack force is inaccurate, resulting in poor road feel simulation. In particular, for conditions such as bumpy roads, feedback torque calculated based on rack force cannot achieve the desired road feel simulation.

[0054] In view of this, embodiments of this application provide a motor control method. This method can accurately calculate the feedback torque based on the rotational speed signal of the vehicle's steering wheels, thereby improving road feel simulation.

[0055] The motor control method provided in this application embodiment will be described below from the perspective of the motor control device. The motor control device can be a submodule of a steer-by-wire system, such as a submodule of an upper steering system or a lower steering system. Alternatively, the motor control device can be a submodule of a vehicle control system. The motor control device can be implemented in software or in hardware.

[0056] Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0057] See Figure 2 , Figure 2 A flowchart of a motor control method provided in this application embodiment includes:

[0058] S201: Obtain time-domain wheel speed information of multiple steering wheels of the vehicle.

[0059] To simulate road feel, the time-domain wheel speed information of multiple steering wheels of the vehicle can first be obtained. Here, the steering wheels refer to the steering wheels controlled by the lower steering system in a steer-by-wire system, and may include, for example, the left and right front wheels of the vehicle.

[0060] The time-domain wheel speed information of a steering wheel refers to the variation of its rotational speed over time. Based on this information, the rotational speed of the steering wheel at any given moment can be determined. Specifically, a wheel speed sensor can be installed on each steering wheel. By using the wheel speed sensor, the wheel speed at any given moment can be determined. Recording the correlation between the wheel speed and time yields the time-domain wheel speed information of the steering wheel.

[0061] Since time-domain wheel speed information represents the relationship between wheel speed and time, it can be considered a time-domain signal. This time-domain signal can be expressed as s = f(t), where t represents time, f(t) represents the mapping relationship between time and steering wheel speed, and s represents the steering wheel speed at time t. Because the steering wheel speed at any given time is known, the time-domain signal corresponding to the time-domain wheel speed information is a continuous time-domain signal.

[0062] S202: Perform a Fourier transform on the time-domain wheel speed information to determine the frequency-domain wheel speed information for each steering wheel.

[0063] After obtaining the time-domain wheel speed information of multiple steering wheels, a Fourier transform can be performed on the time-domain wheel speed information to obtain the frequency-domain wheel speed information of each steering wheel. The frequency-domain wheel speed information indicates the frequency wavelets into which the wheel speed can be decomposed, and the magnitude of each frequency wavelet. Optionally, during vehicle operation, the time-domain wheel speed information can be collected in real time, and a Fourier transform can be performed on the time-domain wheel speed information accordingly.

[0064] As mentioned earlier, the time-domain wheel speed information of the steering wheel can be regarded as a continuous time-domain signal. Therefore, by using Fourier transform, the time-domain signal can be converted into a frequency signal to obtain the frequency-domain wheel speed information corresponding to the time-domain wheel speed information.

[0065] Optionally, if the time-domain wheel speed information of a certain steering wheel can be expressed as s = f(t), then the frequency-domain wheel speed information of that steering wheel can be expressed as:

[0066] S=F(ω)=∫f(t)e -jωt dt

[0067] Where ω is the frequency of the wavelet, T is the current time, and S represents the intensity of the wavelet with frequency ω in the time-domain signal s = f(t).

[0068] By using Fourier transform, the fluctuation of the steering wheel's rotational speed over time can be decomposed into multiple frequency wavelets, and the intensity of each frequency wavelet can be displayed. If the intensity of a certain frequency wavelet is large, it indicates that the frequency wavelet has a greater impact on the steering wheel's rotational speed, and the steering wheel's rotational speed will be frequently disturbed by that frequency.

[0069] S203: Determine the power spectral density function of each steering wheel based on the frequency domain wheel speed information.

[0070] After obtaining the wheel speed information in the frequency domain, the power spectral density function of each steering wheel can be determined based on the wheel speed frequency information. The power spectral density (PSD) function represents the power distribution of a signal in the frequency domain. The independent variable of the power spectral density function is the frequency band, representing the average power of the signal belonging to that frequency band. According to the power spectral density function, the average power of any frequency band in the frequency domain wheel speed information can be determined.

[0071] S204: Determine the vehicle's driving conditions based on the power spectral density function, and determine the corresponding feedback torque for each driving condition.

[0072] After obtaining the power spectral density function of each steering wheel, the vehicle's driving conditions can be determined based on the power spectral density function.

[0073] Based on the power spectral density function of the steering wheel, the average power of the steering wheel speed signal within any frequency band can be calculated. If the average power of the steering wheel speed is high within a certain frequency band, it indicates that the steering wheel speed fluctuates significantly within that band during vehicle operation. Since the steering wheel speed is mainly affected by road conditions, the fluctuation in this frequency band can be considered to be caused by road conditions. Thus, by analyzing the power spectral density function, the frequency band of the steering wheel speed fluctuation can be determined, and the driving conditions can be determined based on this frequency.

[0074] Specifically, the frequency band of steering wheel speed fluctuation can be calibrated in advance through experiments to determine the frequency band of steering wheel speed fluctuation corresponding to various road conditions. During actual vehicle operation, the corresponding frequency band and road conditions can be determined based on the power spectral density function.

[0075] For example, experiments show that on bumpy roads, the steering wheel speed often fluctuates between 5 Hz and 20 Hz. Therefore, bumpy road conditions can be considered to correspond to the 5 Hz-20 Hz frequency band. This frequency band can be referred to as the preset frequency band. Accordingly, after obtaining the power spectral density function of the steering wheel, the average power of the preset frequency band can be calculated based on the power spectral density function. If the average power of the preset frequency band is higher than a pre-set first threshold, it can be considered that the steering wheel speed fluctuates more strongly within the preset frequency band. Therefore, it can be determined that the vehicle's driving conditions include bumpy road conditions.

[0076] In real-world applications, a vehicle's steering wheels may be located on different sides of the vehicle. The road conditions corresponding to these different steering wheels may also differ. Therefore, when analyzing a vehicle's driving conditions, the analysis can be performed on a per-steering-wheel basis, and a comprehensive judgment can be made considering all the different steering wheels.

[0077] Using the example given above, if power spectral density function analysis reveals that the average power of the steering wheel on the left side of the vehicle in the preset frequency band is higher than the first threshold, while the average power of the steering wheel on the right side of the vehicle in the preset frequency band is lower than the first threshold, and the difference between the two is significant, then it can be assumed that the road on the left side of the vehicle is more bumpy, while the road on the right side is smoother, and it can be determined that the vehicle is in a unilateral bumpy condition.

[0078] Alternatively, if multiple steering wheels include a first steering wheel and a second steering wheel, the existence of a target frequency band can be determined based on the power spectral density functions of the first and second steering wheels, such that the absolute value of the difference between the average power of the first steering wheel and the average power of the second steering wheel in the target frequency band is greater than a second threshold. If it is greater, it indicates that the wheel speed of the first steering wheel fluctuates significantly within the target frequency band while the wheel speed of the second steering wheel does not exhibit corresponding fluctuations, or vice versa. Therefore, it can be determined that the road conditions on the road surface traveled by the first steering wheel differ from those on the road surface traveled by the second steering wheel. Consequently, it can be determined that the vehicle's driving conditions include unilateral bumpy driving conditions.

[0079] After determining the vehicle's driving conditions, the feedback torque can be determined based on these conditions. Specifically, the direction and frequency of the feedback torque can be determined according to the vehicle's driving conditions. For example, if the vehicle's driving conditions include bumpy road conditions, a vibration torque with a frequency matching a preset frequency range can be generated as the feedback torque. As another example, if the vehicle's driving conditions include unilateral bumpy conditions, the direction of the feedback torque can be determined based on the steering wheel with higher average power.

[0080] The magnitude of the feedback torque can be preset or adjusted according to actual conditions. Specifically, the driver or passenger can trigger a coefficient adjustment command. Based on the coefficient adjustment command, the torque amplitude coefficient can be adjusted. The magnitude of the feedback torque can be obtained from the torque amplitude coefficient. Optionally, the driver or passenger can trigger the coefficient adjustment command via vehicle buttons, a dial, or an in-vehicle screen.

[0081] S205: Feedback motor based on feedback torque control.

[0082] Once the feedback torque is determined, the feedback motor can be controlled based on this torque. The feedback motor applies torque to control devices such as the steering wheel, allowing the driver to better feel the road conditions.

[0083] This application provides a motor control method. For vehicles including a steer-by-wire system, the time-domain wheel speed information of multiple steering wheels can be obtained first. Time-domain wheel speed information refers to the change in steering wheel rotation speed over time. By performing a Fourier transform on the time-domain wheel speed information, the frequency-domain wheel speed information of each steering wheel can be obtained. The frequency-domain wheel speed information represents the frequency and amplitude of each wavelet in the time-domain wheel speed information. By analyzing the frequency-domain wheel speed information of multiple steering wheels, the power spectral density function of each steering wheel can be obtained. Based on the power spectral density function, the average power of the wheel speed signal in each frequency band can be analyzed, thereby determining the vehicle's driving conditions. Based on the vehicle's driving conditions, the corresponding feedback torque is determined, and the feedback motor is controlled according to the feedback torque to achieve road feel feedback to the driver. It is evident that the feedback torque used for road feel feedback is calculated based on the time-domain wheel speed information of the steering wheels, rather than based on rack force. Compared to rack force, the steering wheel rotation speed is more accurate; therefore, the feedback torque calculated based on the steering wheel rotation speed is closer to the actual situation. This allows for a better simulation of vehicle feedback torque and road conditions, thus enhancing the driver's driving experience.

[0084] In the implementation method described above, the vehicle's driving condition can be determined based on the power spectral density function of the steering wheels. This power spectral density function is obtained from the time-domain wheel speed information monitored by sensors. However, in practical applications, sensor monitoring may be inaccurate, and relying solely on time-domain wheel speed information for judgment may introduce errors.

[0085] Therefore, in some possible implementations, information related to the steering motor can be incorporated to determine the vehicle's driving conditions. The following section will combine... Figure 3 A detailed introduction will be provided.

[0086] See Figure 3 , Figure 3 Another method flowchart of the motor control method provided in the embodiments of this application includes:

[0087] S301: Obtain time-domain wheel speed information of multiple steering wheels of the vehicle.

[0088] S302: Determine the power spectral density function of each steering wheel based on the time-domain wheel speed information.

[0089] For a description of steps S301 and S302, please refer to the above text; they will not be repeated here.

[0090] S303: Obtain the operating condition information of the steering motor of the lower steering subsystem.

[0091] To reduce errors, Figure 3 In the implementation shown, the operating condition information of the steering motor in the lower steering subsystem can also be incorporated to determine the feedback torque. The steering motor in the lower steering subsystem drives the steering wheels for steering. Therefore, the road surface on which the vehicle travels affects the steering wheels, and consequently, the steering motor. Thus, by acquiring and analyzing the operating condition information of the steering motor, the road surface conditions on which the vehicle is traveling can be determined.

[0092] The operating information of the steering motor can include any one or more of the following: steering motor angle information, speed information, and torque information. This operating information can be acquired through corresponding sensors.

[0093] Similar to the time-domain speed information of the steering wheels mentioned above, the operating condition information of the steering motor is time-related information. For example, the operating condition information of the steering motor may include one or more of the time-domain angle signal, time-domain speed signal, and time-domain torque signal of the steering motor.

[0094] S304: Determine the frequency domain operating conditions and power spectral density function of the steering motor.

[0095] After obtaining the operating condition information of the steering motor, the power spectral density function of that information can be determined. Specifically, a Fourier transform can be performed on the steering motor's operating condition information to convert the time-domain signal into a frequency-domain signal, thus obtaining the frequency-domain operating condition information of the steering motor. Based on this frequency-domain operating condition information, the power spectral density function of the steering motor can then be determined.

[0096] For an introduction to frequency domain operating conditions and power spectral density functions, please refer to the above text, which will not be repeated here.

[0097] S305: Based on the power spectral density function of the steering wheel and the power spectral density function of the operating condition information, determine the vehicle's driving conditions and the corresponding feedback torque.

[0098] Through steps S301 and S302, the power spectral density function of the steering wheel can be obtained. Through steps S303 and S304, the power spectral density function of the steering motor can be obtained. Then, the vehicle's driving conditions can be determined by combining the power spectral density functions of the steering wheel and the steering motor.

[0099] Optionally, it can be determined whether the power spectral density function of the steering wheel and the power spectral density function of the steering motor match. If the power spectral density function of the steering wheel and the power spectral density function of the steering motor match, it indicates that the time-domain speed information of the steering wheel is relatively accurate, and the vehicle's driving conditions can be determined according to the time-domain speed information of the steering wheel.

[0100] Alternatively, the vehicle's driving conditions can be determined separately based on the power spectral density function of the steering wheel and the power spectral density function of the steering motor. It can then be determined whether the driving conditions obtained based on the power spectral density function of the steering wheel and the driving conditions obtained based on the power spectral density function of the steering motor match. If they match, the driving conditions can be determined as those of the target vehicle.

[0101] Alternatively, the driving conditions can be determined first based on the power spectral density function of the steering wheel, and then the driving conditions obtained can be verified based on the power spectral density function of the steering motor. If they are correct, the driving conditions of the vehicle can be determined as those obtained based on the power spectral density function of the steering wheel.

[0102] After obtaining the driving conditions, the feedback torque can be determined based on those conditions. For details on how to determine the driving conditions and the feedback torque, please refer to the previous text; they will not be repeated here.

[0103] S306: Controls the feedback motor based on the feedback torque.

[0104] After obtaining the feedback torque, the feedback motor can be controlled based on the feedback torque to provide torque feedback to the driver.

[0105] exist Figure 3 In the implementation shown, the vehicle's driving conditions are determined not only by the power spectral density function of the steering wheels but also by the power spectral density function of the steering motor. Thus, even if the sensor used to collect the time-domain rotational speed information of the steering wheels or the sensor used to collect the driving conditions information of the steering motor has errors, the vehicle's driving conditions can be accurately determined by combining the power spectral density functions of the steering wheels and the steering motor, thus avoiding errors.

[0106] The above are some specific implementations of the motor control method provided in the embodiments of this application. Based on this, this application also provides a corresponding motor control device. The motor control device provided in the embodiments of this application will be described below from the perspective of functional modularity.

[0107] See Figure 4 , Figure 4 This is a schematic diagram of a motor control device provided in an embodiment of this application. Specifically, Figure 4 The motor control device 400 shown includes:

[0108] Acquisition unit 410 is used to acquire time-domain wheel speed information of multiple steering wheels of the vehicle;

[0109] Fourier transform unit 420 is used to perform Fourier transform on the time-domain wheel speed information to determine the frequency-domain wheel speed information of each steering wheel;

[0110] The power spectrum determination unit 430 is used to determine the power spectral density function of each steering wheel based on the frequency domain wheel speed information.

[0111] The torque determination unit 440 is used to determine the driving conditions of the vehicle based on the power spectral density function, and to determine the feedback torque corresponding to the driving conditions.

[0112] Control unit 450 is used to control the feedback motor based on the feedback torque.

[0113] In some possible implementations, the torque determination unit 440 is specifically used to determine the average power of the steering wheel within a preset frequency band based on the power spectral density function; in response to the average power being higher than a first threshold, determine that the vehicle's driving conditions include bumpy road conditions; determine the feedback torque based on the bumpy road conditions and the preset frequency range, wherein the vibration frequency of the feedback torque matches the preset frequency range.

[0114] In some possible implementations, the plurality of steering wheels includes a first steering wheel and a second steering wheel, the first steering wheel and the second steering wheel being located on different sides of the vehicle; the torque determination unit 440 is specifically used to determine whether a target frequency band exists based on the power spectral density function of the first steering wheel and the power spectral density function of the second steering wheel, such that the absolute value of the difference between the average power of the first steering wheel and the average power of the second steering wheel in the target frequency band is greater than a second threshold; if the target frequency band exists, the driving condition of the vehicle is determined to include a unilateral bumpy condition; the feedback torque is determined based on the unilateral bumpy condition, the direction of the feedback torque being determined by the direction of the steering wheel with the greater average power in the target frequency band among the first and second steering wheels.

[0115] In some possible implementations, the acquisition unit 410 is further configured to acquire the operating condition information of the steering motor of the lower steering subsystem in the steer-by-wire system, the operating condition information including any one or more of the steering angle, steering speed, and torque of the steering motor; the torque determination unit 440 is specifically configured to perform a Fourier transform on the operating condition information to determine the frequency domain operating condition information and power spectral density function of the steering motor; and to determine that the power spectral density function of the steering motor matches the power spectral density function of the plurality of steering wheels.

[0116] In some possible implementations, the torque determination unit 440 is specifically used to determine the feedback torque based on the torque amplitude coefficient and the driving conditions; the device further includes a coefficient adjustment unit, which is used to adjust the torque amplitude coefficient in response to a coefficient adjustment command.

[0117] This application also provides corresponding control devices, steer-by-wire systems, vehicles, computer storage media, and computer program products to implement the technical solutions provided in this application.

[0118] The device includes a memory and a processor. The memory stores instructions or code, and the processor executes the instructions or code stored in the memory to enable the device to perform the motor control method described in any embodiment of this application.

[0119] The steer-by-wire system includes an upper steering subsystem and a lower steering subsystem. The upper steering subsystem includes a feedback motor. The steer-by-wire system also includes a controller, which is used to implement the method described in any embodiment of this application.

[0120] The vehicle includes a steer-by-wire system and a controller. The steer-by-wire system includes an upper steering subsystem and a lower steering subsystem. The upper steering subsystem includes a feedback motor. The controller is used to implement the method described in any embodiment of this application.

[0121] The computer storage medium stores code, and when the code is run, the device running the code implements the motor control method described in any embodiment of this application.

[0122] The computer program product contains instructions. When run on a computer, it causes the computer to perform the motor control method described in any embodiment of this application.

[0123] In the embodiments of this application, the terms "first" and "second" (if they exist) are used only as name identifiers and do not represent the order of first and second.

[0124] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that all or part of the steps in the methods of the above embodiments can be implemented by means of software plus a general-purpose hardware platform. Based on this understanding, the technical solution of this application can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as a read-only memory (ROM) / RAM, magnetic disk, optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, a server, or a network communication device such as a router) to execute the methods described in various embodiments or some parts of the embodiments of this application.

[0125] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, the apparatus embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0126] The above description is merely an exemplary implementation of this application and is not intended to limit the scope of protection of this application.

Claims

1. A motor control method, characterized in that, The method is used to control the feedback motor of the upper steering subsystem in a vehicle's steer-by-wire system, and the method includes: Obtain the time-domain wheel speed information of multiple steering wheels of the vehicle; Perform a Fourier transform on the time-domain wheel speed information to determine the frequency-domain wheel speed information of each steering wheel; Based on the frequency domain wheel speed information, determine the power spectral density function of each steering wheel; Based on the power spectral density function, the driving conditions of the vehicle are determined, and the feedback torque corresponding to the driving conditions is determined. The feedback motor is controlled based on the feedback torque.

2. The method according to claim 1, characterized in that, The step of determining the vehicle's driving condition based on the power spectral density function, and determining the feedback torque corresponding to the driving condition, includes: The average power of the steering wheel within the preset frequency band is determined based on the power spectral density function. In response to the average power being higher than a first threshold, it is determined that the vehicle's driving condition includes a bumpy road condition. The feedback torque is determined based on the bumpy road surface conditions and the preset frequency range, and the vibration frequency of the feedback torque matches the preset frequency range.

3. The method according to claim 1, characterized in that, The plurality of steering wheels includes a first steering wheel and a second steering wheel, the first steering wheel and the second steering wheel being located on different sides of the vehicle; The step of determining the vehicle's driving condition based on the power spectral density function, and determining the feedback torque corresponding to the driving condition, includes: Based on the power spectral density function of the first steering wheel and the power spectral density function of the second steering wheel, it is determined whether there is a target frequency band such that the absolute value of the difference between the average power of the first steering wheel in the target frequency band and the average power of the second steering wheel in the target frequency band is greater than a second threshold. If the target frequency band exists, the vehicle's driving conditions are determined to include unilateral bump conditions. The feedback torque is determined based on the unilateral bumpy condition, and the direction of the feedback torque is determined by the direction of the steering wheel with the greater average power in the target frequency band among the first and second steering wheels.

4. The method according to any one of claims 1-3, characterized in that, Before determining the bumpy road surface condition, the method further includes: Obtain the operating condition information of the steering motor of the lower steering subsystem in the steer-by-wire system. The operating condition information includes any one or more of the steering angle, steering speed and torque of the steering motor. Perform a Fourier transform on the operating condition information to determine the frequency domain operating condition information and power spectral density function of the steering motor; The power spectral density function of the steering motor is determined to match the power spectral density function of the plurality of steering wheels.

5. The method according to any one of claims 1-4, characterized in that, The determination of the feedback torque corresponding to the driving condition includes: The feedback torque is determined based on the torque amplitude coefficient and the driving conditions. The method further includes: In response to the coefficient adjustment command, the torque amplitude coefficient is adjusted.

6. A motor control device, characterized in that, The device is used to control the feedback motor of the upper steering subsystem in the steer-by-wire system of a vehicle, and the device includes: The acquisition unit is used to acquire the time-domain wheel speed information of multiple steering wheels of the vehicle; The Fourier transform unit is used to perform Fourier transform on the time-domain wheel speed information to determine the frequency-domain wheel speed information of each steering wheel; A power spectrum determination unit is used to determine the power spectral density function of each steering wheel based on the frequency domain wheel speed information. The torque determination unit is used to determine the driving conditions of the vehicle based on the power spectral density function, and to determine the feedback torque corresponding to the driving conditions. A control unit for controlling the feedback motor based on the feedback torque.

7. A control device, characterized in that, The device includes a memory and a controller, the memory being used to store instructions or code, and the controller being used to instruct the instructions or code stored in the memory to implement the method of any one of claims 1-5.

8. A steer-by-wire system, characterized in that, The steer-by-wire system includes an upper steering subsystem and a lower steering subsystem. The upper steering subsystem includes a feedback motor. The steer-by-wire system also includes a controller, which is used to implement the method of any one of claims 1-5.

9. A vehicle, characterized in that, The vehicle includes a steer-by-wire system and a controller. The steer-by-wire system includes an upper steering subsystem and a lower steering subsystem. The upper steering subsystem includes a feedback motor. The controller is used to implement the method of any one of claims 1-5.

10. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is run by a processor, the processor performs the method according to any one of claims 1-5.

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