Vehicle steering control method and related device

Abstract

Provided are a vehicle steering control method and a related device. The method comprises: acquiring a rotating speed signal of a motor (107) in a steering system of a vehicle and a vehicle speed signal of the vehicle (S201); on the basis of the rotating speed signal and the vehicle speed signal, generating a target vibration suppression torque signal, the target vibration suppression torque signal being used for adjusting an assist torque of the steering system (S202); on the basis of the target vibration suppression torque signal and a first torque signal, synthesizing a second torque signal, the first torque signal being determined on the basis of a torque signal from a target sensor (103), and the target sensor (103) being used for detecting a steering wheel torque signal of the vehicle (S203); and on the basis of the second torque signal, controlling the motor (107) to implement power-assisted steering (S204). The resonance caused by the steering system can be effectively reduced.

Description

Vehicle steering control method and related device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on September 1, 2023, with application number 202311138697.4, and priority to the Chinese patent application entitled “Vehicle Steering Control Method and Related Devices”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of vehicle technology, and in particular to a vehicle steering control method and related devices. Background Art

[0003] In a vehicle, due to factors such as the interior structure and layout, the interior and body will experience resonance points within a certain frequency range. In a vehicle's steering system, imperfect motor control, such as zero-current sampling deviation and delay, and motor position sensor (MPS) signal bias, can lead to order vibration in the motor. When order vibration occurs, the steering system becomes an excitation source, causing resonance between the steering system and the vehicle.

[0004] The above resonance is more serious when the vehicle is traveling at a low speed or when the vehicle is stationary. For example, when the vehicle is creeping on a road with a low friction coefficient (such as a tiled water-sprinkled road, a slippery epoxy floor road, an indoor underground parking lot or an icy and snowy road, etc.), or when the vehicle enters a maintenance state and is lifted off the ground by a lift, the resonance is more serious. Once the resonance of the vehicle body is aroused, in addition to the violent fluctuations in the steering wheel torque, severe vibrations may also occur in the doors and the floor, causing a serious reduction in driving comfort and posing a safety hazard. For this reason, how to reduce this resonance is a technical problem that people in this field urgently need to solve.

[0005] Summary of the Invention

[0006] The present application provides a vehicle steering control method and related devices, which can effectively reduce the resonance caused by the steering system, improve the user's driving experience and reduce potential safety hazards.

[0007] In a first aspect, the present application provides a vehicle steering control method, the method comprising:

[0008] Obtaining a rotation speed signal of a motor in a steering system of the aforementioned vehicle and a vehicle speed signal of the aforementioned vehicle;

[0009] generating a target vibration suppression torque signal based on the aforementioned rotational speed signal and the aforementioned vehicle speed signal; the aforementioned target vibration suppression torque signal is used to adjust the assist torque of the aforementioned steering system;

[0010] synthesizing a second torque signal based on the target vibration suppression torque signal and a first torque signal, wherein the first torque signal is determined based on a torque signal from a target sensor; the target sensor is used to detect a steering wheel torque signal of the vehicle;

[0011] The motor is controlled based on the second torque signal to achieve power steering.

[0012] In a specific implementation, motor speed fluctuations can be reflected by the steering system, leading to forced resonance. Therefore, in the aforementioned implementation, a target vibration suppression torque signal is generated using the steering system's motor speed signal and the vehicle speed signal. This target vibration suppression torque signal can be combined with the feel-related torque signal (the aforementioned first torque signal) to create a new torque signal (the aforementioned second torque signal) to adjust the steering system's torque. Since the resonant main frequency of the entire vehicle including the steering system is not only affected by the overall structure and layout, the overall dynamic response can also be improved through electrical signals. For example, adding speed-related feedback torque to the steering controller is equivalent to adding damping to the system. This solution extracts motor speed vibrations, effectively generating a signal equivalent to the motor's angular acceleration (the differential of the motor speed), thereby changing the equivalent moment of inertia of the entire system. In other words, this solution adjusts the resonant main frequency of the entire vehicle including the steering system. Therefore, vibrations caused by the motor will not cause resonance in the entire vehicle, achieving a vibration isolation effect. At this point, the motor speed is relatively stable due to vibration isolation. Furthermore, since the motor speed is determined by the steering wheel speed input, changing the torque does not change the motor speed and thus does not affect the stability of the first current. Therefore, using the adjusted second torque signal to control the motor for power steering eliminates resonance, thereby reducing steering system resonance, improving the user's driving experience, and mitigating potential safety hazards.

[0013] In one possible implementation, generating the target vibration suppression torque signal based on the rotational speed signal and the vehicle speed signal includes:

[0014] acquiring a first vibration suppression torque signal based on the rotational speed signal, wherein a frequency of the first vibration suppression torque signal includes a resonance frequency of the vehicle;

[0015] obtaining a target gain coefficient based on the vehicle speed signal; the target gain coefficient is used to adjust the amplitude of the first vibration suppression torque signal;

[0016] The target vibration-suppression torque signal is calculated based on the first vibration-suppression torque signal and the target gain coefficient.

[0017] In the above scheme, the target vibration-suppression torque signal is obtained by extracting the component at the resonant primary frequency from the speed signal and determining its gain coefficient based on the vehicle speed signal. In this implementation, the target vibration-suppression torque signal has a frequency at the resonant primary frequency, thereby suppressing the resonant primary frequency signal in the first torque signal and effectively reducing vibration.

[0018] In one possible implementation, the step of obtaining the first vibration suppression torque signal based on the speed signal includes:

[0019] Extracting a second vibration suppression torque signal from the aforementioned speed signal; the aforementioned second vibration suppression torque signal includes a signal of the aforementioned speed signal having a frequency of the aforementioned resonance frequency;

[0020] The phase of the second vibration suppression torque signal is adjusted to obtain the first vibration suppression torque signal; the phases of the first vibration suppression torque signal and the second vibration suppression torque signal are the same or different.

[0021] In the above scheme, the component with the resonant main frequency in the speed signal is first extracted, and then the phase adjustment is performed to reduce the phase difference with the above-mentioned first torque signal, thereby better suppressing the signal of the resonant main frequency in the first torque signal, thereby effectively reducing vibration.

[0022] In a possible implementation, adjusting the phase of the second vibration suppression torque signal includes: performing lead compensation on the phase of the second vibration suppression torque signal.

[0023] In the above solution, phase advance compensation is performed to eliminate phase delay, thereby reducing the phase difference with the above first torque signal, thereby better suppressing the resonant main frequency signal in the first torque signal, and effectively reducing vibration.

[0024] In one possible implementation, extracting the second vibration suppression torque signal from the speed signal includes:

[0025] The second vibration suppression torque signal is extracted from the rotational speed signal by a resonant oscillator; the amplitude gain of the resonant oscillator at the resonant frequency is 0 dB.

[0026] In the above solution, a resonant oscillator having an amplitude gain of 0 dB at the above resonance frequency is used, so that the second vibration suppression torque signal can be extracted from the vehicle speed signal without distortion.

[0027] In one possible implementation, extracting the second vibration suppression torque signal from the speed signal includes:

[0028] extracting a third vibration suppression torque signal from the aforementioned speed signal through a high-pass filter; wherein the cutoff frequency of the aforementioned high-pass filter is less than the aforementioned resonance frequency;

[0029] extracting a fourth vibration suppression torque signal from the third vibration suppression torque signal through a low-pass filter; wherein the cutoff frequency of the low-pass filter is greater than the resonance frequency; and the frequency of the fourth vibration suppression torque signal includes the resonance frequency;

[0030] The amplitude of the fourth vibration suppression torque signal is adjusted by the amplitude adjustment module to obtain the second vibration suppression torque signal; the amplitude gain of the second vibration suppression torque signal at the resonance frequency is 0 dB.

[0031] In the above solution, a high-pass filter, a low-pass filter, and an amplitude adjustment module are combined, and the amplitude adjustment module is designed to adjust the amplitude gain of the fourth vibration suppression torque signal to 0 dB at the resonant frequency to obtain the second vibration suppression torque signal. In this way, the second vibration suppression torque signal can be extracted from the vehicle speed signal without distortion.

[0032] In a possible implementation, the acquiring of the target gain coefficient based on the vehicle speed signal includes: searching for the target gain coefficient in a negative gain relationship table based on the vehicle speed signal; and the gain coefficient in the negative gain relationship table is less than zero.

[0033] In the above scheme, acceleration feedback is constructed through the negative gain coefficient, which improves the system's rotational inertia and then changes the frequency response of the entire vehicle system, thereby changing the vehicle's resonant frequency to suppress resonance.

[0034] In a possible implementation, the gain coefficient in the aforementioned negative gain relationship table increases as the vehicle speed increases.

[0035] In the above solution, as the vehicle speed increases, indicating that the vehicle has entered a normal driving state, the steering wheel rotation will not be too violent, and the resonance caused will also be weakened. By increasing the negative gain coefficient, excessive torque suppression can be avoided, thereby reducing the impact on the user's steering wheel feel.

[0036] In a possible implementation, the method of obtaining the target gain coefficient based on the vehicle speed signal further includes:

[0037] searching a negative gain coefficient in a negative gain relationship table based on the vehicle speed signal; wherein the gain coefficient in the negative gain relationship table is less than zero;

[0038] Searching for a positive gain coefficient in a positive gain relationship table based on the vehicle speed signal; wherein the gain coefficient in the positive gain relationship table is greater than zero;

[0039] The target gain coefficient is calculated based on the negative gain coefficient and the positive gain coefficient.

[0040] In the above scheme, the target gain coefficient is calculated based on the negative and positive gain coefficients, employing a design approach that combines both positive and negative gains. This approach allows for adjustable dynamic characteristics at varying vehicle speeds. Furthermore, the feedback generated by the negative gain and the compensation provided by the positive gain enable universal vibration suppression in various control scenarios, including closed-loop and open-loop control.

[0041] In a possible implementation, the gain coefficient in the aforementioned negative gain relationship table increases with the increase of vehicle speed, and the gain coefficient in the aforementioned positive gain relationship table decreases with the increase of vehicle speed.

[0042] In the above scheme, as the vehicle speed increases, indicating that the vehicle has entered a normal driving state, the steering wheel rotation will not be too violent, and the resonance caused will also be weakened. By increasing the negative gain coefficient and decreasing the positive gain coefficient, excessive torque suppression can be avoided, thereby reducing the impact on the user's steering wheel feel.

[0043] In a possible implementation, the target sensor is further used to detect a steering wheel angle signal of the vehicle;

[0044] The first torque signal is determined based on a torque signal from a target sensor, including:

[0045] The first torque signal includes a signal obtained by one or more of the following processes based on the torque signal from the target sensor, the vehicle speed signal and the steering wheel angle signal: basic power assist control processing, high frequency gain processing, phase compensation and damping control processing.

[0046] In the above solution, after the above processing, the user's feeling of using the steering wheel can be optimized and the user experience can be improved.

[0047] In a second aspect, the present application provides a motor controller, which is applied to a steering system of a vehicle. The motor controller includes:

[0048] an acquisition unit, configured to acquire a rotation speed signal of a motor in a steering system of the aforementioned vehicle and a vehicle speed signal of the aforementioned vehicle;

[0049] a resonance suppression processing unit, configured to generate a target vibration suppression torque signal based on the rotational speed signal and the vehicle speed signal; the target vibration suppression torque signal being used to adjust the assist torque of the steering system;

[0050] a synthesis unit configured to synthesize a second torque signal based on the target vibration suppression torque signal and a first torque signal, wherein the first torque signal is determined based on a torque signal from a target sensor; the target sensor is configured to detect a steering wheel torque signal of the vehicle;

[0051] A control unit is used to control the motor to achieve power steering based on the second torque signal.

[0052] In one possible implementation, the resonance suppression processing unit is specifically configured to:

[0053] acquiring a first vibration suppression torque signal based on the rotational speed signal, wherein a frequency of the first vibration suppression torque signal includes a resonance frequency of the vehicle;

[0054] obtaining a target gain coefficient based on the vehicle speed signal; the target gain coefficient is used to adjust the amplitude of the first vibration suppression torque signal;

[0055] The target vibration-suppression torque signal is calculated based on the first vibration-suppression torque signal and the target gain coefficient.

[0056] In one possible implementation, the resonance suppression processing unit is specifically configured to:

[0057] Extracting a second vibration suppression torque signal from the aforementioned speed signal; the aforementioned second vibration suppression torque signal includes a signal of the aforementioned speed signal having a frequency of the aforementioned resonance frequency;

[0058] The phase of the second vibration suppression torque signal is adjusted to obtain the first vibration suppression torque signal; the phases of the first vibration suppression torque signal and the second vibration suppression torque signal are the same or different.

[0059] In a possible implementation, the resonance suppression processing unit is specifically configured to perform lead compensation on the phase of the second vibration suppression torque signal.

[0060] In a possible implementation, the resonance suppression processing unit is specifically configured to extract the second vibration suppression torque signal from the speed signal via a resonant oscillator; the amplitude gain of the resonant oscillator at the resonant frequency is 0 dB.

[0061] In one possible implementation, the resonance suppression processing unit is specifically configured to:

[0062] extracting a third vibration suppression torque signal from the aforementioned speed signal through a high-pass filter; wherein the cutoff frequency of the aforementioned high-pass filter is less than the aforementioned resonance frequency;

[0063] extracting a fourth vibration suppression torque signal from the third vibration suppression torque signal through a low-pass filter; wherein the cutoff frequency of the low-pass filter is greater than the resonance frequency; and the frequency of the fourth vibration suppression torque signal includes the resonance frequency;

[0064] The amplitude of the fourth vibration suppression torque signal is adjusted by the amplitude adjustment module to obtain the second vibration suppression torque signal; the amplitude gain of the second vibration suppression torque signal at the resonance frequency is 0 dB.

[0065] In a possible implementation, the resonance suppression processing unit is specifically configured to: search for the target gain coefficient in a negative gain relationship table based on the vehicle speed signal; and the gain coefficient in the negative gain relationship table is less than zero.

[0066] In a possible implementation, the gain coefficient in the aforementioned negative gain relationship table increases as the vehicle speed increases.

[0067] In one possible implementation, the resonance suppression processing unit is specifically configured to:

[0068] searching a negative gain coefficient in a negative gain relationship table based on the vehicle speed signal; wherein the gain coefficient in the negative gain relationship table is less than zero;

[0069] Searching for a positive gain coefficient in a positive gain relationship table based on the vehicle speed signal; wherein the gain coefficient in the positive gain relationship table is greater than zero;

[0070] The target gain coefficient is calculated based on the negative gain coefficient and the positive gain coefficient.

[0071] In a possible implementation, the gain coefficient in the aforementioned negative gain relationship table increases with the increase of vehicle speed, and the gain coefficient in the aforementioned positive gain relationship table decreases with the increase of vehicle speed.

[0072] In a possible implementation, the target sensor is further used to detect a steering wheel angle signal of the vehicle;

[0073] The first torque signal is determined based on a torque signal from a target sensor, including:

[0074] The first torque signal includes a signal obtained by one or more of the following processes based on the torque signal from the target sensor, the vehicle speed signal and the steering wheel angle signal: basic power assist control processing, high frequency gain processing, phase compensation and damping control processing.

[0075] In a third aspect, the present application provides a motor controller, which is applied to a steering system of a vehicle. The motor controller includes a processor, a communication interface and a memory, wherein the communication interface is used to realize the reception and transmission of data, the memory is used to store computer programs or computer instructions, and the processor is used to execute the computer programs or computer instructions stored in the memory, so that the motor controller performs the method as described in any one of the first aspect and its possible implementation methods.

[0076] In a fourth aspect, the present application provides a steering system, which includes a motor controller as described in any one of the second aspect and its possible implementation methods; or, the steering system includes a motor controller as described in the third aspect.

[0077] In a fifth aspect, the present application provides a vehicle comprising the steering system as described in the fourth aspect above.

[0078] In a sixth aspect, the present application provides a chip, which is applied to a vehicle steering system, wherein the chip includes a processor, a communication interface and a memory, wherein the communication interface is used to realize the reception and transmission of data, the memory is used to store computer programs or computer instructions, and the processor is used to execute the computer programs or computer instructions stored in the memory, so that the chip executes the method as described in any one of the first aspect and its possible implementation methods.

[0079] In a seventh aspect, the present application provides a computer-readable storage medium, which stores a computer program or computer instructions, and the aforementioned computer program or computer instructions are executed by a processor to implement a method as described in any one of the above-mentioned first aspect and its possible implementation methods.

[0080] In an eighth aspect, the present application provides a computer program product. When the computer program product is executed by a processor, the method as described in any one of the above-mentioned first aspect and its possible implementation methods will be implemented.

[0081] The solutions provided in the second to eighth aspects are used to implement or cooperate with the corresponding methods provided in the first aspect, and therefore can achieve the same or corresponding beneficial effects as the corresponding methods in the first aspect, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0082] FIG1 is a schematic structural diagram of a steering system provided in an embodiment of the present application;

[0083] FIG2 is a schematic diagram of a method flow chart provided in an embodiment of the present application;

[0084] 3 and 4 are schematic diagrams of the structure of the motor controller provided in the embodiments of the present application;

[0085] FIG5 is a schematic structural diagram of a resonance suppression processing unit provided in an embodiment of the present application;

[0086] FIG6 is a schematic diagram of a frequency response characteristic curve provided in an embodiment of the present application;

[0087] FIG7 is a schematic diagram of the structure of a signal extraction module provided in an embodiment of the present application;

[0088] FIG8 is a schematic diagram of a curve showing the relationship between vehicle speed and gain coefficient provided in an embodiment of the present application;

[0089] FIG9 is a schematic structural diagram of a gain adjustment module provided in an embodiment of the present application;

[0090] FIG10 is a schematic diagram of a curve showing the relationship between vehicle speed and gain coefficient provided in an embodiment of the present application;

[0091] FIG11 is a schematic diagram of the resonance reduction effect provided by an embodiment of the present application;

[0092] FIG12 is a schematic diagram of a virtual structure of a motor controller provided in an embodiment of the present application;

[0093] FIG13 is a schematic diagram of the physical structure of the motor controller provided in an embodiment of the present application. DETAILED DESCRIPTION

[0094] In the embodiment of the present application, "multiple" refers to two or more. In the embodiment of the present application, "and / or" is used to describe the association relationship of associated objects, indicating three relationships that can exist independently. For example, A and / or B can be expressed as follows: A exists alone, B exists alone, or A and B exist at the same time. The description methods such as "at least one of a1, a2, ... and an" used in the embodiment of the present application include the situation where any one of a1, a2, ... and an exists alone, and also include any combination of any multiple of a1, a2, ... and an, each of which can exist alone; for example, the description method of "at least one of a, b and c" includes the situation where a is alone, b is alone, c is alone, a and b combination, a and c combination, b and c combination, or abc combination.

[0095] In the various embodiments of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between the various embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0096] In practice, the steering system becomes an excitation source due to the motor's order vibration, causing resonance between the steering system and the vehicle. Once this resonance is aroused, not only can the steering wheel torque fluctuate dramatically, but severe vibrations can also occur in the doors and floor, severely reducing driving comfort and posing a safety hazard.

[0097] To address the aforementioned resonance issue, one possible implementation involves using a feel-related functional module to attenuate vibration. This approach primarily reduces the steering system's bandwidth, resulting in a significantly delayed dynamic response. However, this approach reduces the system's power assist response, leaving the entire system feeling very sluggish, affecting the steering feel and making it difficult for users to accept. More importantly, this approach can only partially attenuate vibrations, reducing their amplitude or duration. However, perceptible vibrations persist, significantly degrading the driving experience or posing safety risks.

[0098] For example, the feel-related functional module may be a processing module for optimizing the steering wheel feel. The feel-related functional module may include, for example, part or all of the following modules: a basic power assist module, a high-frequency gain module, a phase compensation module (also known as a stability compensation module), and a damping control module.

[0099] Exemplarily, the basic power assist module can decompose the torque from the steering wheel (which can be detected by a target sensor) into two components: a high-frequency component and a low-frequency component. Exemplarily, the target sensor can be, for example, a torque angle sensor that can simultaneously detect the torque signal and the steering wheel angle signal. Alternatively, the target sensor can be, for example, a combination of a torque sensor and an angle sensor. The torque sensor can detect the steering wheel torque signal, and the angle sensor can detect the steering wheel angle signal.

[0100] The high-frequency part is mainly compensated for by the high-frequency hand force through the high-frequency gain module. This module can be regarded as a differential link to improve the dynamic response of the system, and can also be used to adjust the phase and amplitude gain of the system. The basic power assist can be calculated by the low-frequency part of the steering wheel torque or the full amount of the steering wheel torque. It is a key module for achieving flexible steering. The phase compensation module can realize the lead-lag correction of the torque signal to obtain a larger phase margin. The damping control enhances the stability of the system by introducing the steering wheel speed signal (which can be obtained by detection of the target sensor).

[0101] For example, the existing solutions mentioned above, when addressing the resonance issue, suffer from some or all of the following drawbacks: increased damping, reduced high-frequency hand force compensation, reduced basic power assist, reduced amplitude response of stability compensation at low frequencies, and reduced bandwidth of motor current closed-loop control. This impacts the steering feel of the system, making it difficult for users to accept.

[0102] In a specific implementation, the aforementioned feel-related functional modules are not limited to the functional modules listed here. For example, they may also include a return control module, an inertia compensation module, or a friction compensation module. The relevant functional modules are specifically configured according to actual application requirements, and the embodiments of the present application do not impose any restrictions on this.

[0103] Another existing solution to the resonance problem is to generate a compensation current based on the motor angular velocity signal and a target reference current (a current generated based on the steering torque signal and the vehicle speed signal). This compensation current is then added to the target reference current to obtain a compensated current, which is then used to control the motor. However, this solution has the following drawbacks.

[0104] First, the compensation current is superimposed on the reference current. This makes this solution ineffective in suppressing vibration when applied to steering systems where the reference current is determined by the steering torque signal, vehicle speed signal, and motor speed signal. For ease of understanding, let's take the electric power steering (EPS) system (EPS) as an example. This is because modern EPS systems, whether using surface-mounted magnetic or embedded rotor solutions, use the motor speed signal, in addition to the steering torque and vehicle speed signals, as a fundamental input for motor field-weakening control, in the calculation of the reference current. Consequently, fluctuations in the motor speed signal inevitably lead to fluctuations in the reference current. Simultaneously, the steering wheel hand force signal detected by the target sensor also fluctuates. Although these two fluctuations are caused by forced resonance, there is a phase difference between the motor speed signal and the steering torque signal. Consequently, the reference current calculated using these two signals as inputs inevitably has a phase difference with both the motor speed signal and the steering torque signal. Since the motor speed signal is the motor angular velocity signal, the calculated reference current also has a phase difference with the motor angular velocity signal. The above-mentioned compensation current is generated based on the motor angular velocity signal, so there must be a phase difference between the reference current and the compensation current, and the phase difference is uncontrollable. In this case, if the reference current and the compensation current are superimposed, the signal component that causes resonance cannot be effectively eliminated due to the existence of the phase difference, and may even be enhanced. Therefore, controlling the motor based on the compensated current obtained after the superposition cannot effectively eliminate the resonance and may even enhance the resonance. In addition, when this solution generates the compensation current, it is necessary to consider the vibration amplitude, which may not necessarily lead to thorough compensation.

[0105] Secondly, the above solution is less effective in embedded systems (which consist of hardware and software and are capable of independent operation). According to the embedded calculation process, the motor angular velocity signal used to calculate the compensation current is generated after the previous cycle's vibration and steering. The compensation component extracted during the previous cycle's vibration is then applied to the current cycle, inevitably resulting in a phase delay and incomplete compensation.

[0106] Based on the above analysis, existing resonance elimination solutions may not fully compensate and may even enhance resonance. Therefore, the present embodiment provides a vehicle steering control method and related device. These methods can effectively reduce the resonance caused by the steering system, enhance the user's driving experience, and reduce potential safety hazards. The following is an illustrative description of the solution in the present embodiment.

[0107] First, the steering system applicable to the embodiment of the present application is introduced as an example. The main function of the steering system is to change or maintain the direction of a vehicle that is moving or reversing. In the case of wheeled vehicles, the method for achieving vehicle steering is that the driver uses the steering mechanism to deflect the wheels (steering wheels) on the vehicle's steering axle (such as the front axle) by a certain angle relative to the longitudinal axis of the vehicle. When the vehicle is traveling in a straight line, the steering wheel is often also affected by the lateral interference force of the road surface, automatically deflecting to change the direction of travel. The driver can also use the steering mechanism to deflect the steering wheel in the opposite direction, thereby restoring the vehicle to its original direction of travel. This mechanism for changing or restoring the vehicle's direction of travel is called a vehicle steering system (steering system for short).

[0108] Steering systems include, for example, hydraulic power steering (HPS), electro hydraulic power steering (EHPS), electric power steering (EPS), and steering by wire (SBW). The following describes the structure of a steering system using EPS as an example, with reference to Figure 1.

[0109] Figure 1 shows the structure of the EPS. It can be seen that the EPS includes components such as a steering wheel 101, a steering shaft 102, a target sensor 103, a motor controller 104, a speed reduction mechanism 105, a clutch 106, a motor 107, a steering gear 108, a steering tie rod 109, and wheels 110.

[0110] Illustratively, the steering wheel 101 is mechanically connected to the steering shaft 102. The steering shaft 102 may, for example, include multiple sections for ease of installation. A target sensor 103 and a reduction mechanism 105 are mounted on the steering shaft 102. The target sensor 103 is electrically connected to the motor controller 104. The reduction mechanism 105 is electrically connected to a clutch 106. The clutch 106 is electrically connected to the motor controller 104 and the motor 107. The motor 107 is electrically connected to the motor controller 104. The steering shaft 102 is also mechanically connected to a steering gear 108. The steering gear 108 is mechanically connected to the wheels 110 via a steering tie rod 109. The following is an exemplary description of the operating principle of EPS.

[0111] For example, the driver can rotate the steering wheel 101. The rotational motion of the steering wheel 101 is transmitted to the steering gear 108 via the steering shaft 102. The steering gear 108 pulls the steering rod 109, causing the wheels 110 to rotate by a specified angle. Furthermore, the motor 107 can further assist the movement of the steering rod 109 based on control commands from the motor controller 104. For example, the target sensor 103 can detect the rotational torque and angle of the steering wheel 101, convert the detected rotational torque into a torque signal, and the angle into an angle signal, which are then transmitted to the motor controller 104. The motor controller 104 can generate motor control commands based on the torque signal, vehicle speed signal, and motor speed signal. These commands are then transmitted to the motor 107. Based on these commands, the motor 107 transmits assist torque to the steering gear 108 to control the intensity of the steering assist. The clutch 106 ensures that the electric power steering operates within a predetermined range. When the vehicle speed or current exceeds a specified maximum value, or when a steering system failure occurs, the clutch 106 automatically cuts off the motor power, resuming manual steering control. The speed reduction mechanism 105 is used to increase the torque transmitted from the motor to the steering gear 108 .

[0112] Exemplarily, the vehicle speed signal input to the motor controller 104 may be, for example, from a vehicle speed sensor or from the controller area network (CAN) of the vehicle. The motor speed signal input to the motor controller 104 may be, for example, from a motor position sensor (MPS) or other sensor that can detect the motor speed. Alternatively, the motor speed signal may be, for example, a signal obtained by indirectly calculating a signal from a sensor such as the MPS. Exemplarily, the indirect solution may be to differentiate the motor mechanical angle collected by the MPS, or to extract the speed information using a Kalman filter. The vehicle speed signal and motor speed signal described later are similar and will not be described in detail.

[0113] It will be understood that the above description of the steering system is merely an example and does not constitute a limitation to the embodiments of the present application.

[0114] For example, the vehicle steering control method provided in the embodiment of the present application can be implemented by the motor controller in the above-mentioned steering system. For example, referring to FIG. 2 , the vehicle steering control method provided in the embodiment of the present application can include but is not limited to the following steps:

[0115] S201: Acquire a rotation speed signal of a motor in a steering system of the vehicle and a vehicle speed signal of the vehicle.

[0116] S202 : Generate a target vibration suppression torque signal based on the rotational speed signal and the vehicle speed signal; the target vibration suppression torque signal is used to adjust the power assist torque of the steering system.

[0117] S203 . Synthesize a second torque signal based on the target vibration suppression torque signal and a first torque signal, where the first torque signal is determined based on a torque signal from a target sensor; the target sensor is used to detect a steering wheel torque signal of the vehicle.

[0118] S204 : Control the motor to implement power steering based on the second torque signal.

[0119] For ease of understanding, the implementation process of the above method is exemplarily described below with reference to the structural diagram of the motor controller 200 shown in Figure 3. For example, the motor controller 200 can be the motor controller 104 in the EPS shown in Figure 1, or can be a motor controller in other types of steering systems.

[0120] As shown in Figure 3, the motor controller 200 may include a resonance suppression processing unit 210, a hand-feel related function module 220, a torque superposition unit 230, a current calculation unit 240, a subtraction unit 250, and a motor drive unit 260. The functions of each module are exemplarily described below.

[0121] For example, the resonance suppression processing unit 210 may receive a motor speed signal and a vehicle speed signal as inputs. Based on these signals, the unit calculates a target vibration suppression torque signal. This target vibration suppression torque signal can be used to adjust the torque of the steering system. The resonance suppression processing unit 210 may then output the calculated target vibration suppression torque signal to the torque superposition unit 230.

[0122] In addition, the above-mentioned feel-related functional module 220 can take the target sensor signal and the vehicle speed signal as input. The target sensor signal includes a torque signal from the target sensor. Optionally, the target sensor signal also includes a steering wheel angle signal from the target sensor. Based on the target sensor signal and the vehicle speed signal, the feel-related functional module 220 can calculate the feel-related power-assist torque signal (which can be referred to as the first torque signal). Based on the previous introduction, it can be seen that the feel-related functional module 220 can include multiple functional modules. The first torque signal may include the torque signals output by the multiple functional modules. For ease of understanding, please refer to Figure 4 for example.

[0123] As can be seen in Figure 4, the feel-related functional module 220 can include a basic assist module 2201, a high-frequency gain module 2202, a phase compensation module 2203, and a damping control module 2204. For the specific functional description of these modules, please refer to the above introduction and will not be repeated here. It can be seen that after the above-mentioned target sensor signal and vehicle speed signal are input into the feel-related functional module 220, the signal processed by the basic assist module 2201 and the high-frequency gain module 2202 can output a torque signal (referred to as torque signal A for short) after being processed by the phase compensation module 2203. In addition, after being processed by the damping control module 2204, a torque signal (referred to as torque signal B for short) can be output. Then, the above-mentioned first torque signal includes the torque signal A and the torque signal B.

[0124] It is understood that the structure of the feel-related functional module 220 shown in FIG4 is merely an example and does not constitute a limitation on the embodiments of the present application. In a specific implementation, the feel-related functional module 220 may include more or fewer functional modules, depending on the actual application needs, and the embodiments of the present application do not impose any limitation on this.

[0125] After the feel-related functional module 220 calculates the first torque signal, it may output the first torque signal to the torque superposition unit 230 .

[0126] After the torque superposition unit 230 obtains the target vibration suppression torque signal and the first torque signal, it can synthesize a target torque signal (which can be referred to as the second torque signal) based on the target vibration suppression torque signal and the first torque signal. For example, the target vibration suppression torque signal and the first torque signal can be directly superimposed to obtain the second torque signal. Or, for example, the target vibration suppression torque signal and the first torque signal can be preprocessed separately (for example, filtering to reduce noise, etc.). Then, the two preprocessed signals are superimposed to obtain the second torque signal. It can be understood that this is only an example and does not constitute a limitation to the embodiments of the present application.

[0127] After the torque superposition unit 230 synthesizes the second torque signal, it can output the second torque signal to the current calculation unit 240. The current calculation unit 240 calculates the first current based on the second torque signal and the input vehicle speed signal and the motor speed signal. Alternatively, the current calculation unit 240 calculates the first current based on the second torque signal and the input vehicle speed signal, that is, the motor speed signal does not participate in the calculation of the first current. Alternatively, the current calculation unit 240 calculates the first current based on the second torque signal, the input vehicle speed signal, and parameters such as the steering wheel steering angle. It will be understood that this is only an example and does not constitute a limitation to the embodiments of the present application.

[0128] The first current is output to subtraction unit 250 and subtracted from the feedback current to obtain a second current. This feedback current is the current output by motor drive unit 260 for controlling the motor. This second current is input to motor drive unit 260. Based on this second current, motor drive unit 260 can output a three-phase control voltage and current to motor 270 to control motor 270 and implement power steering.

[0129] As previously discussed, motor speed fluctuations can be triggered by the steering system, generating forced resonance. Therefore, in the aforementioned implementation, a target vibration suppression torque signal is generated using the steering system's motor speed signal and the vehicle speed signal. This target vibration suppression torque signal can be combined with the feel-related torque signal (the aforementioned first torque signal) to create a new torque signal (the aforementioned second torque signal) to adjust the steering system's torque. Since the resonant main frequency of the entire vehicle, including the steering system, is not only affected by its overall structure and layout, electrical signals can also be used to improve the overall dynamic response. For example, adding speed-related feedback torque to the steering controller is equivalent to adding damping to the system. This solution extracts motor speed vibrations, effectively generating a signal equivalent to the motor's angular acceleration (the differential of the motor speed). This modifies the equivalent moment of inertia of the entire system. In other words, this solution adjusts the resonant main frequency of the entire vehicle, including the steering system. Consequently, vibrations caused by the motor will not cause resonance in the entire vehicle, achieving a vibration isolation effect. At this point, the motor speed is relatively stable due to vibration isolation. Furthermore, since the motor speed is determined by the steering wheel speed input, changing the torque does not change the motor speed and thus does not affect the stability of the first current. Therefore, using the adjusted second torque signal to control the motor for power steering eliminates resonance, thereby reducing steering system resonance, improving the user's driving experience, and mitigating potential safety hazards.

[0130] In one possible implementation, the resonance suppression processing unit 210 may calculate the target vibration suppression torque signal based on the motor speed signal and the vehicle speed signal, including the following steps: obtaining a first vibration suppression torque signal based on the motor speed signal, obtaining a target gain coefficient based on the vehicle speed signal, and then generating the target vibration suppression torque signal based on the first vibration suppression torque signal and the target gain coefficient.

[0131] The target gain coefficient can be used to adjust the amplitude of the first vibration suppression torque signal. The frequency of the first vibration suppression torque signal includes the resonant frequency of the vehicle including the steering system. Exemplarily, the first vibration suppression torque signal has the same frequency as the target speed signal and may have a different or the same phase as the target speed signal. The signal frequency is typically the resonant frequency of the vehicle including the steering system. Exemplarily, the resonant frequency is pre-tested. That is, without using this solution to induce resonance, the steering wheel torque signal is collected, the frequency domain characteristics of the signal are analyzed, and the frequency at which energy is concentrated is found to be the resonant frequency. The resonant frequency can be, for example, between 5 Hz and 50 Hz. In particular, if the vehicle is a new energy vehicle, the resonant frequency can be, for example, between 20 Hz and 35 Hz. It should be understood that the resonant frequency values ​​described here are merely examples and do not constitute limitations on the embodiments of the present application. In specific implementations, the resonant frequency can also have other values, which are not limited by the embodiments of the present application.

[0132] To facilitate understanding of the above implementation, please refer to Figure 5 for example. Figure 5 illustrates a schematic structural diagram of the resonance suppression processing unit 210. As can be seen, the resonance suppression processing unit 210 may include a signal extraction module 2101, a phase adjustment module 2102, a gain adjustment module 2103, and a multiplication module 2104. The following describes the functions of each module.

[0133] Exemplarily, the signal extraction module 2101 takes a motor speed signal as input and extracts a characteristic signal from the motor speed signal. This characteristic signal can then be input into the phase adjustment module 2102. The phase adjustment module 2102 performs phase compensation on the characteristic signal and outputs a first vibration suppression torque signal after phase compensation. The gain adjustment module 2103 takes a vehicle speed signal as input and can obtain the target gain coefficient based on the vehicle speed signal. The first vibration suppression torque signal and the target gain coefficient are input into the multiplication module 2104 and multiplied to obtain the target vibration suppression torque signal.

[0134] The following is an exemplary description of the implementation process of the signal extraction module 2101 extracting characteristic signals.

[0135] The frequency of the characteristic signal includes the resonant frequency. For example, the characteristic signal may include a signal within a preset frequency range. The preset frequency range includes the resonant frequency. That is, the signal extraction module 2101 is used to extract the signal within the preset frequency range from the motor speed signal and filter out the signal outside the preset frequency range. For example, the signal outside the preset frequency range may be rapidly attenuated.

[0136] For example, assuming that the resonant frequency is f0, the preset frequency range may be, for example, f0-f1 to f0+f2. The values ​​of f1 and f2 are set according to actual application requirements and are not limited in this embodiment of the present application.

[0137] For example, to extract the characteristic signal without distortion, the amplitude and phase of the extracted characteristic signal are ensured to remain unchanged as much as possible. In one possible implementation, the characteristic signal can be extracted using a resonant oscillator. Specifically, the signal extraction module 2101 can be the resonant oscillator. To extract the signal without distortion, the amplitude gain of the resonant oscillator at the resonant frequency is 0 dB. For example, a frequency response characteristic diagram of the resonant oscillator can be shown in FIG6 . FIG6 shows that the amplitude-frequency response curve has a value of 0 dB at the resonant frequency, and the phase-frequency response curve has a value of 0 degrees at the resonant frequency. That is, after the motor speed signal is input into the resonant oscillator, the signal within the motor speed signal with a frequency corresponding to the resonant main frequency can be output without distortion. FIG6 also shows that the amplitude-frequency response curve has a value close to 0 dB within the preset frequency range, and the phase-frequency response curve has a value close to 0 degrees within the preset frequency range. Therefore, signals within the motor speed signal with frequencies within the preset frequency range can be output effectively. All other signals are rapidly attenuated and filtered out. The signal output from the resonant oscillator is the aforementioned characteristic signal (for the convenience of subsequent description, the characteristic signal is referred to as a second vibration suppression torque signal).

[0138] For example, the resonant oscillator may be a second-order resonant oscillator, a third-order resonant oscillator, a fourth-order resonant oscillator, etc. The embodiment of the present application does not limit the order of the resonant oscillator, which can be selected according to actual application requirements.

[0139] In order to extract the above-mentioned characteristic signal without distortion, in another possible implementation, as exemplified in Figure 7, the above-mentioned signal extraction module 2101 may include a high-pass filter 21011, a low-pass filter 21012 and an amplitude adjustment module 21013. The cut-off frequency of the high-pass filter 21011 is less than the above-mentioned resonance frequency. Exemplarily, the cut-off frequency of the high-pass filter 21011 may be, for example, the above-mentioned f0-f1. The cut-off frequency of the low-pass filter is greater than the resonance frequency. Exemplarily, the cut-off frequency of the low-pass filter 21012 may be, for example, the above-mentioned f0+f2. The amplitude adjustment module 21013 is used to adjust the amplitude of the signal so that the amplitude gain of the output characteristic signal at the resonance frequency is 0dB.

[0140] For example, in signal extraction module 2101 shown in FIG. 7 , the motor speed signal is first input to high-pass filter 21011. High-pass filter 21011 filters the motor speed signal and outputs a third vibration-suppression torque signal. For example, the cutoff frequency of high-pass filter 21011 is f0-f1. After filtering by high-pass filter 21011, signals in the motor speed signal with frequencies less than the cutoff frequency f0-f1 are removed. The output third vibration-suppression torque signal includes signals in the motor signal with frequencies greater than the cutoff frequency f0-f1.

[0141] The third vibration suppression torque signal is input to low-pass filter 21012. Low-pass filter 21012 filters the third vibration suppression torque signal and outputs a fourth vibration suppression torque signal. For example, if the cutoff frequency of low-pass filter 21012 is f0+f2, then, after filtering by low-pass filter 21012, signals in the third vibration suppression torque signal with frequencies greater than the cutoff frequency f0+f2 are filtered out. The output fourth vibration suppression torque signal includes signals whose frequencies are less than the cutoff frequency f0+f2 of the third vibration suppression torque signal. That is, the fourth vibration suppression torque signal includes signals with frequencies between f0-f1 and f0+f2. In other words, the fourth vibration suppression torque signal includes signals within the aforementioned preset frequency range. Of course, the frequency of the fourth vibration suppression torque signal also includes the aforementioned resonant frequency.

[0142] The fourth vibration-suppression torque signal output by low-pass filter 21012 is input to amplitude adjustment module 21013. Amplitude adjustment module 21013 adjusts the amplitude of the fourth vibration-suppression torque signal so that the amplitude gain of the output signal (referred to as the fifth vibration-suppression torque signal) at the resonant frequency is 0 dB. This fifth vibration-suppression torque signal is the characteristic signal output by signal extraction module 2101.

[0143] The following is an exemplary description of the implementation process of the phase adjustment module 2102 adjusting the phase of the characteristic signal.

[0144] Exemplarily, based on the above description, after the characteristic signal undergoes phase compensation by the phase adjustment module 2102, a phase-compensated first vibration suppression torque signal is output. Phase adjustment module 2102 is a phase-advance compensation module, configured to reduce the phase difference between the target vibration suppression torque signal output by the resonance suppression processing unit 210 and the first torque signal. Specifically, as previously described, the target vibration suppression torque signal is calculated based on the first vibration suppression torque signal and the target gain coefficient. The target gain coefficient adjusts the amplitude of the first vibration suppression torque signal and does not change its phase. Therefore, when the phase adjustment module 2102 compensates the characteristic signal to obtain the compensated first vibration suppression torque signal, it effectively performs phase compensation on the target vibration suppression torque signal. This ensures that the phase difference between the first vibration suppression torque signal and the target vibration suppression torque signal, and the first torque signal, is less than a preset value. Optionally, the phase difference can even be zero. This eliminates the phase difference between the target vibration suppression torque signal and the first torque signal. Exemplarily, the phase adjustment module 2102 is configured to reduce a phase difference between the target vibration suppression torque signal and the first torque signal at a resonance frequency.

[0145] In one possible implementation, in order to decouple the signal amplitude and reduce the impact of phase adjustment on the amplitude, the phase adjustment module 2102 can be a unity gain phase adjustment module. In this implementation, the transfer function of the phase adjustment module 2102 in the continuous domain can be expressed as:

[0146] Among them, f0 is the main resonance frequency mentioned above. is the maximum phase compensation angle at the resonant main frequency, The specific value of can be set according to actual application requirements, and the embodiments of the present application do not limit this.

[0147] The transfer function of the phase adjustment module 2102 can be transformed into a discrete domain (i.e., z-domain) by a bilinear transformation or zero-mapping. For example, a bilinear transformation is used as an example. The discrete domain expression of the transfer function after bilinear transformation is as follows:

[0148] Among them, T s is the calculation period of the phase adjustment module 2102.

[0149] It is understood that the above implementation of the phase adjustment module 2102 is only an example and does not constitute a limitation on the embodiments of the present application. In a specific implementation, the above phase adjustment module 2102 may not be a unity gain phase adjustment module and can be specifically set according to actual application requirements.

[0150] For example, the phases of the first vibration-suppression torque signal and the characteristic signal may be the same or different. Specifically, although the first vibration-suppression torque signal is the signal output after the characteristic signal has been phase-compensated by the phase adjustment module 2102, in one possible implementation, the compensated phase may be 0 degrees. In this case, the first vibration-suppression torque signal and the characteristic signal have the same phase. In another possible implementation, the compensated phase is not 0 degrees. In this case, the first vibration-suppression torque signal and the characteristic signal have different phases.

[0151] In the above implementation, the signal extraction module 2101 is first used to extract the component with the resonant main frequency in the motor speed signal, and then phase advance compensation is performed to reduce the phase difference with the above-mentioned first torque signal, thereby better suppressing the signal of the resonant main frequency in the first torque signal, thereby effectively reducing vibration.

[0152] The following is an exemplary description of the implementation process of the gain adjustment module 2103 obtaining the target gain coefficient based on the vehicle speed signal.

[0153] In one possible implementation, the target gain coefficient is a negative gain coefficient. The gain adjustment module 2103 can search for the target gain coefficient in a negative gain relationship table based on the vehicle speed signal. The negative gain relationship table pre-stores the correspondence between vehicle speed and gain coefficient. The vehicle speed signal also has a correspondence with the specific vehicle speed. Therefore, the target gain coefficient can be searched in the negative gain relationship table based on the vehicle speed signal. The gain coefficients in the negative gain relationship table are less than zero.

[0154] In one possible implementation, the gain coefficient in the above-mentioned negative gain relationship table increases with the increase of vehicle speed. For ease of understanding, please refer to Figure 8. Figure 8 exemplarily shows a schematic diagram of the relationship curve between vehicle speed and gain coefficient in the negative gain relationship table. It can be seen in Figure 8 that the gain coefficient is less than zero, and the gain coefficient increases with the increase of vehicle speed. For example, there may be some situations in the negative gain relationship table where the gain coefficient decreases as the vehicle speed increases, but this does not affect the trend in the negative gain relationship table that the gain coefficient increases with the increase of vehicle speed. In addition, the curve shown in Figure 8 represents this trend and does not constitute a limitation to the embodiments of the present application.

[0155] In this implementation, the negative gain coefficient constructs acceleration feedback, improves the system's moment of inertia, and then changes the frequency response of the entire vehicle system, thereby changing the vehicle's resonant frequency to suppress resonance.

[0156] In another possible implementation, the target gain coefficient is a gain coefficient obtained by combining a negative gain coefficient and a positive gain coefficient. For example, FIG9 shows a schematic diagram of the structure of the gain adjustment module 2103. As shown in FIG9, the gain adjustment module 2103 may include a negative gain adjustment module 21031, a positive gain adjustment module 21032, and an accumulation module 21033. In a specific implementation, the vehicle speed signal may be input into the negative gain adjustment module 21031 and the positive gain adjustment module 21032, respectively.

[0157] The negative gain adjustment module 21031 can find the negative gain coefficient in the negative gain relationship table based on the vehicle speed signal. For specific implementation, please refer to the above description of the target gain coefficient being a negative gain coefficient, which will not be repeated here.

[0158] Positive gain adjustment module 21032 can search the positive gain relationship table for the positive gain coefficient based on the vehicle speed signal. The positive gain relationship table pre-stores the correspondence between vehicle speed and gain coefficient. The vehicle speed signal also has a correspondence with the specific vehicle speed. Therefore, the target gain coefficient can be searched in the positive gain relationship table based on the vehicle speed signal. The gain coefficients in the positive gain relationship table are greater than zero.

[0159] In one possible implementation, in the above-mentioned positive gain relationship table, the gain coefficient decreases as the vehicle speed increases. For ease of understanding, please refer to Figure 10. Figure 10 exemplarily shows a schematic diagram of the relationship curve between the vehicle speed and the gain coefficient in the positive gain relationship table. It can be seen in Figure 10 that the gain coefficient is greater than zero, and the gain coefficient decreases as the vehicle speed increases. For example, in the positive gain relationship table, there may be some situations where the vehicle speed increases and the gain coefficient increases instead, but this does not affect the trend in the positive gain relationship table that the gain coefficient decreases as the vehicle speed increases. In addition, the curve shown in Figure 10 represents this trend and does not constitute a limitation to the embodiments of the present application.

[0160] After obtaining the negative gain coefficient, the negative gain adjustment module 21031 outputs the negative gain coefficient to the accumulation module 21033. After obtaining the positive gain coefficient, the positive gain adjustment module 21032 outputs the positive gain coefficient to the accumulation module 21033. The accumulation module 21033 adds the negative gain coefficient and the positive gain coefficient or performs weighted addition to obtain the target gain coefficient.

[0161] In this implementation, a positive gain and negative gain design scheme is adopted. On the one hand, it takes into account the adjustable dynamic characteristics under different vehicle speeds. On the other hand, the feedback formed by the negative gain and the compensation formed by the positive gain can universally suppress vibrations in different control scenarios such as closed-loop and open-loop.

[0162] In summary, in the above embodiment, the target vibration suppression torque signal is obtained by extracting the component with the resonant main frequency from the motor speed signal and then determining the gain coefficient of the component through the vehicle speed signal. In this implementation, the frequency of the target vibration suppression torque signal is the resonant main frequency, thereby suppressing the signal with the resonant main frequency in the above-mentioned first torque signal, thereby effectively reducing the vibration. In addition, the embodiment of the present application does not require the identification of the vibration scene, and the vibration characteristic signal can be adaptively collected through the above-mentioned signal extraction module 2101. Reduce the limitations of the solution implementation and expand the application scenarios.

[0163] In order to more intuitively understand the effect of eliminating resonance after adopting the embodiment of the present application, you can refer to Figure 11 for example. For example, the solution of the embodiment of the present application is applied to the redundant EPS for actual vehicle verification. The redundant EPS adopts a surface-mounted magnetic rotor, and the weak magnetic control method adopts a solution that introduces the motor speed for control. During the actual vehicle verification process, the steering wheel vibration can be intuitively represented by the steering wheel torque signal collected by the steering wheel target sensor. For example, the collected torque signal is shown in Figure 11. It can be seen that before the solution of the embodiment of the present application is adopted, the collected torque signal fluctuates greatly, indicating that a severe resonance occurs. After adopting the solution of the embodiment of the present application, that is, after introducing the target vibration suppression torque, the fluctuation of the collected torque signal is greatly reduced. In addition, the shaking of the driver's hand force tested is eliminated; at the same time, the subjective vehicle body resonance stops.

[0164] It is understood that the structure of the control unit described above is merely illustrative and does not constitute a limitation on the embodiments of the present application. In a specific implementation, the control unit may further include more or fewer functional modules. As long as the steering control method provided in the embodiments of the present application can be implemented to reduce resonance, it should not be considered beyond the scope of the present application.

[0165] Each module in the above-mentioned control unit can be implemented by software, hardware, firmware or any combination of the three, and the embodiments of the present application do not limit this. The specific implementation of a certain function depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application. In addition, the division of the above-mentioned various functional modules is schematic and is only a logical function division. There may be other division methods in actual implementation, and the embodiments of the present application do not limit this.

[0166] In the case of dividing each functional module according to each function, an embodiment of the present application also provides a motor controller for implementing any of the above methods. For example, a motor controller is provided that includes a unit (or means) for implementing each step in any of the above methods. For example, please refer to Figure 12, which is a structural diagram of a motor controller 1200 provided in an embodiment of the present application. The motor controller 1200 is applied to the steering system of a vehicle. The motor controller 1200 can be a motor controller described in any embodiment for implementing the steering control method of the above-mentioned vehicle. The motor controller 1200 may include an acquisition unit 1201, a resonance suppression processing unit 1202, a synthesis unit 1203 and a control unit 1204. Among them:

[0167] The acquisition unit 1201 is configured to acquire a rotation speed signal of a motor in the steering system of the aforementioned vehicle and a vehicle speed signal of the aforementioned vehicle. For example, the acquisition unit 1201 may be a module in the motor controller 1200 that receives the rotation speed signal and the vehicle speed signal.

[0168] Resonance suppression processing unit 1202 is configured to generate a target vibration suppression torque signal based on the aforementioned rotational speed signal and the aforementioned vehicle speed signal. The target vibration suppression torque signal is used to adjust the assist torque of the aforementioned steering system. For example, resonance suppression processing unit 1202 may be resonance suppression processing unit 210 described in the aforementioned method embodiment.

[0169] Synthesis unit 1203 is configured to synthesize a second torque signal based on the target vibration suppression torque signal and the first torque signal, where the first torque signal is determined based on a torque signal from a target sensor; the target sensor is configured to detect a steering wheel torque signal of the vehicle. Synthesis unit 1203 may, for example, be torque superposition unit 230 described in the aforementioned method embodiment.

[0170] The control unit 1204 is configured to control the motor to implement power steering based on the second torque signal. For example, the control unit 1204 may include the current calculation unit 240, the subtraction unit 250, and the motor drive unit 260 described in the above method embodiment.

[0171] In one possible implementation, the resonance suppression processing unit 1202 is specifically configured to:

[0172] acquiring a first vibration suppression torque signal based on the rotational speed signal, wherein a frequency of the first vibration suppression torque signal includes a resonance frequency of the vehicle;

[0173] obtaining a target gain coefficient based on the vehicle speed signal; the target gain coefficient is used to adjust the amplitude of the first vibration suppression torque signal;

[0174] The target vibration-suppression torque signal is calculated based on the first vibration-suppression torque signal and the target gain coefficient.

[0175] In one possible implementation, the resonance suppression processing unit 1202 is specifically configured to:

[0176] Extracting a second vibration suppression torque signal from the aforementioned speed signal; the aforementioned second vibration suppression torque signal includes a signal of the aforementioned speed signal having a frequency of the aforementioned resonance frequency;

[0177] The phase of the second vibration suppression torque signal is adjusted to obtain the first vibration suppression torque signal; the phases of the first vibration suppression torque signal and the second vibration suppression torque signal are the same or different.

[0178] In a possible implementation, the resonance suppression processing unit 1202 is specifically configured to perform lead compensation on the phase of the second vibration suppression torque signal.

[0179] In a possible implementation, the resonance suppression processing unit 1202 is specifically configured to: extract the second vibration suppression torque signal from the speed signal via a resonant oscillator; and the amplitude gain of the resonant oscillator at the resonant frequency is 0 dB.

[0180] In one possible implementation, the resonance suppression processing unit 1202 is specifically configured to:

[0181] extracting a third vibration suppression torque signal from the aforementioned speed signal through a high-pass filter; wherein the cutoff frequency of the aforementioned high-pass filter is less than the aforementioned resonance frequency;

[0182] extracting a fourth vibration suppression torque signal from the third vibration suppression torque signal through a low-pass filter; wherein the cutoff frequency of the low-pass filter is greater than the resonance frequency; and the frequency of the fourth vibration suppression torque signal includes the resonance frequency;

[0183] The amplitude of the fourth vibration suppression torque signal is adjusted by the amplitude adjustment module to obtain the second vibration suppression torque signal; the amplitude gain of the second vibration suppression torque signal at the resonance frequency is 0 dB.

[0184] In a possible implementation, the resonance suppression processing unit 1202 is specifically configured to: search for the target gain coefficient in a negative gain relationship table based on the vehicle speed signal; and the gain coefficient in the negative gain relationship table is less than zero.

[0185] In a possible implementation, the gain coefficient in the aforementioned negative gain relationship table increases as the vehicle speed increases.

[0186] In one possible implementation, the resonance suppression processing unit 1202 is specifically configured to:

[0187] searching a negative gain coefficient in a negative gain relationship table based on the vehicle speed signal; wherein the gain coefficient in the negative gain relationship table is less than zero;

[0188] Searching for a positive gain coefficient in a positive gain relationship table based on the vehicle speed signal; wherein the gain coefficient in the positive gain relationship table is greater than zero;

[0189] The target gain coefficient is calculated based on the negative gain coefficient and the positive gain coefficient.

[0190] In a possible implementation, the gain coefficient in the aforementioned negative gain relationship table increases with the increase of vehicle speed, and the gain coefficient in the aforementioned positive gain relationship table decreases with the increase of vehicle speed.

[0191] In a possible implementation, the target sensor is further used to detect a steering wheel angle signal of the vehicle;

[0192] The first torque signal is determined based on a torque signal from a target sensor, including:

[0193] The first torque signal includes a signal obtained by one or more of the following processes based on the torque signal from the target sensor, the vehicle speed signal and the steering wheel angle signal: basic power assist control processing, high frequency gain processing, phase compensation and damping control processing.

[0194] The specific operations and beneficial effects of each unit in the motor controller 1200 shown in FIG12 can be found in the corresponding descriptions in FIG2 to FIG9 and their possible embodiments, and will not be repeated here.

[0195] For example, see Figure 13, which is a schematic diagram of the structure of a possible physical entity of the motor controller provided in this application. The motor controller 1300 shown in Figure 13 can be a motor controller for implementing any embodiment of the vehicle steering control method described above. The motor controller 1300 includes: a processor 1301, a memory 1302, and a communication interface 1303. The processor 1301, the communication interface 1303, and the memory 1302 can be interconnected or connected to each other via a bus 1304.

[0196] Exemplarily, the memory 1302 is used to store computer programs and data of the motor controller 1300. The memory 1302 may include, but is not limited to, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or portable read-only memory (CD-ROM).

[0197] The software or program codes required for all or part of the functions of the motor controller in the above method embodiment may be stored in the memory 1302 .

[0198] In one possible implementation, if the software or program code required for some functions is stored in the memory 1302, the processor 1301, in addition to calling the program code in the memory 1302 to implement some functions, can also cooperate with other components (such as the communication interface 1303) to jointly complete other functions described in the method embodiment (such as the function of receiving or sending data).

[0199] There may be multiple communication interfaces 1303 for supporting the motor controller 1300 to communicate, such as receiving or sending data.

[0200] Exemplarily, the processor 1301 may be a circuit with data processing capabilities. In one implementation, the processor may include a circuit with instruction reading and execution capabilities. For example, it includes an electronic control unit (ECU), a microcontroller unit (MCU), or a digital signal processor (DSP), etc. In another implementation, the processor can implement certain functions through the logical relationship of a hardware circuit, and the logical relationship of the hardware circuit is fixed or reconfigurable. For example, the processor is a hardware circuit implemented by an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), such as a field programmable gate array (FPGA). In a reconfigurable hardware circuit, the process of the processor loading a configuration file and implementing the hardware circuit configuration can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units. Alternatively, the processor 1301 may be a combination of at least two of these processor forms, etc.

[0201] The processor 1301 can be used to read the program stored in the memory 1302 and execute the operations performed by the motor controller in FIG. 2 and its possible embodiments.

[0202] The specific operations and beneficial effects of each unit in the motor controller 1300 shown in Figure 13 can be found in the corresponding descriptions in Figures 2 to 9 and their possible embodiments, and will not be repeated here.

[0203] An embodiment of the present application also provides a vehicle, which includes a steering system including the above-mentioned motor controller.

[0204] An embodiment of the present application also provides a chip, which is applied to a vehicle steering system. The chip includes a processor, a communication interface, and a memory, wherein the communication interface is used to realize the reception and transmission of data, the memory is used to store computer programs or computer instructions, and the processor is used to execute the computer programs or computer instructions stored in the memory, so that the chip executes any method as described in Figures 2 to 9 above and their possible implementation methods.

[0205] An embodiment of the present application also provides a computer-readable storage medium, which stores a computer program or computer instructions, and the computer program or computer instructions are executed by a processor to implement a method as described in any one of Figures 2 to 9 and their possible implementation methods.

[0206] An embodiment of the present application further provides a computer program product. When the computer program product is executed by a processor, the method described in any one of Figures 2 to 9 and their possible implementations will be implemented.

[0207] In summary, the solution of the embodiments of the present application can effectively reduce the resonance caused by the steering system, improve the user's driving experience and reduce potential safety hazards.

[0208] In this application, the terms "first," "second," and the like are used to distinguish between identical or similar items having substantially the same function or effect. It should be understood that "first," "second," and "nth" do not have a logical or temporal dependency, nor do they limit the quantity or order of execution. It should also be understood that although the following description uses the terms "first," "second," and the like to describe various elements, these elements should not be limited by these terms. These terms are simply used to distinguish one element from another.

[0209] It should also be understood that in the various embodiments of the present application, the size of the serial number of each process does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0210] It will also be understood that the term “comprise” (also known as “includes,” “including,” “comprises,” and / or “comprising”) when used in this specification specifies the presence of stated features, integers, steps, operations, elements, and / or components, but does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0211] It should also be understood that references throughout this specification to "one embodiment," "an embodiment," or "one possible implementation" mean that specific features, structures, or characteristics associated with that embodiment or implementation are included in at least one embodiment of the present application. Therefore, the appearance of "in one embodiment," "in an embodiment," or "one possible implementation" throughout this specification does not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0212] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A vehicle steering control method, characterized in that: The method comprises: Acquiring a rotation speed signal of a motor in a steering system of the vehicle and a vehicle speed signal of the vehicle; generating a target vibration suppression torque signal based on the rotation speed signal and the vehicle speed signal; the target vibration suppression torque signal is used to adjust the power assist torque of the steering system; synthesizing a second torque signal based on the target vibration suppression torque signal and a first torque signal, wherein the first torque signal is determined based on a torque signal from a target sensor; the target sensor is used to detect a steering wheel torque signal of the vehicle; The motor is controlled based on the second torque signal to achieve power steering.

2. The method according to claim 1, characterized in that: The generating a target vibration suppression torque signal based on the rotation speed signal and the vehicle speed signal comprises: acquiring a first vibration suppression torque signal based on the rotation speed signal, wherein a frequency of the first vibration suppression torque signal includes a resonance frequency of the vehicle; acquiring a target gain coefficient based on the vehicle speed signal; the target gain coefficient is used to adjust the amplitude of the first vibration suppression torque signal; The target vibration suppression torque signal is calculated based on the first vibration suppression torque signal and the target gain coefficient.

3. The method according to claim 2, characterized in that The obtaining of a first vibration suppression torque signal based on the rotation speed signal comprises: Extracting a second vibration suppression torque signal from the speed signal; the second vibration suppression torque signal includes a signal in the speed signal having a frequency of the resonance frequency; The phase of the second vibration suppression torque signal is adjusted to obtain the first vibration suppression torque signal; the phases of the first vibration suppression torque signal and the second vibration suppression torque signal are the same or different.

4. The method according to claim 3, characterized in that The adjusting the phase of the second vibration suppression torque signal comprises: The phase of the second vibration suppression torque signal is advanced and compensated.

5. The method according to claim 3 or 4, characterized in that: The step of extracting the second vibration suppression torque signal from the rotation speed signal comprises: The second vibration suppression torque signal is extracted from the rotation speed signal by a resonant oscillator; the amplitude gain of the resonant oscillator at the resonant frequency is 0 dB.

6. The method according to claim 3 or 4, characterized in that: The step of extracting the second vibration suppression torque signal from the rotation speed signal comprises: extracting a third vibration suppression torque signal from the speed signal through a high-pass filter; the cut-off frequency of the high-pass filter is less than the resonance frequency; extracting a fourth vibration suppression torque signal from the third vibration suppression torque signal through a low-pass filter; the cut-off frequency of the low-pass filter is greater than the resonance frequency; and the frequency of the fourth vibration suppression torque signal includes the resonance frequency; The amplitude of the fourth vibration suppression torque signal is adjusted by an amplitude adjustment module to obtain the second vibration suppression torque signal; the amplitude gain of the second vibration suppression torque signal at the resonance frequency is 0 dB.

7. The method according to any one of claims 2 to 6, characterized in that: The step of obtaining a target gain coefficient based on the vehicle speed signal includes: The target gain coefficient is searched in a negative gain relationship table based on the vehicle speed signal; the gain coefficient in the negative gain relationship table is less than zero.

8. The method according to claim 7, characterized in that The gain coefficient in the negative gain relationship table increases as the vehicle speed increases.

9. The method according to any one of claims 2 to 6, characterized in that: The step of obtaining a target gain coefficient based on the vehicle speed signal further includes: Searching for a negative gain coefficient in a negative gain relationship table based on the vehicle speed signal; the gain coefficient in the negative gain relationship table is less than zero; Searching for a positive gain coefficient in a positive gain relationship table based on the vehicle speed signal; the gain coefficient in the positive gain relationship table being greater than zero; The target gain coefficient is calculated based on the negative gain coefficient and the positive gain coefficient.

10. The method according to claim 9, characterized in that The gain coefficient in the negative gain relationship table increases as the vehicle speed increases, and the gain coefficient in the positive gain relationship table decreases as the vehicle speed increases.

11. The method according to any one of claims 1 to 10, characterized in that: The target sensor is also used to detect a steering wheel angle signal of the vehicle; The first torque signal is determined based on a torque signal from a target sensor, comprising: The first torque signal includes a signal obtained by one or more of the following processes based on the torque signal from the target sensor, the vehicle speed signal and the steering wheel angle signal: basic power assist control processing, high frequency gain processing, phase compensation and damping control processing.

12. A motor controller, characterized in that: The motor controller is applied to a steering system of a vehicle, and the motor controller comprises: An acquisition unit, used for acquiring a rotation speed signal of a motor in a steering system of the vehicle and a vehicle speed signal of the vehicle; a resonance suppression processing unit, configured to generate a target vibration suppression torque signal based on the rotation speed signal and the vehicle speed signal; the target vibration suppression torque signal is used to adjust the power assist torque of the steering system; a synthesis unit, configured to synthesize a second torque signal based on the target vibration suppression torque signal and a first torque signal, wherein the first torque signal is determined based on a torque signal from a target sensor; the target sensor is configured to detect a steering wheel torque signal of the vehicle; A control unit is used to control the motor to achieve power steering based on the second torque signal.

13. The motor controller according to claim 12, characterized in that: The resonance suppression processing unit is specifically used for: acquiring a first vibration suppression torque signal based on the rotation speed signal, wherein a frequency of the first vibration suppression torque signal includes a resonance frequency of the vehicle; acquiring a target gain coefficient based on the vehicle speed signal; the target gain coefficient is used to adjust the amplitude of the first vibration suppression torque signal; The target vibration-suppression torque signal is generated based on the first vibration-suppression torque signal and the target gain coefficient.

14. The motor controller according to claim 13, characterized in that: The resonance suppression processing unit is specifically used for: Extracting a second vibration suppression torque signal from the speed signal; the second vibration suppression torque signal includes a signal in the speed signal having a frequency of the resonance frequency; The phase of the second vibration suppression torque signal is adjusted to obtain the first vibration suppression torque signal; the phases of the first vibration suppression torque signal and the second vibration suppression torque signal are the same or different.

15. The motor controller according to claim 14, characterized in that: The resonance suppression processing unit is specifically used for: The phase of the second vibration suppression torque signal is advanced and compensated.

16. The motor controller according to claim 14 or 15, characterized in that: The resonance suppression processing unit is specifically used for: The second vibration suppression torque signal is extracted from the rotation speed signal by a resonant oscillator; the amplitude gain of the resonant oscillator at the resonant frequency is 0 dB.

17. The motor controller according to claim 14 or 15, characterized in that: The resonance suppression processing unit is specifically used for: extracting a third vibration suppression torque signal from the speed signal through a high-pass filter; the cut-off frequency of the high-pass filter is less than the resonance frequency; extracting a fourth vibration suppression torque signal from the third vibration suppression torque signal through a low-pass filter; the cut-off frequency of the low-pass filter is greater than the resonance frequency; and the frequency of the fourth vibration suppression torque signal includes the resonance frequency; The amplitude of the fourth vibration suppression torque signal is adjusted by an amplitude adjustment module to obtain the second vibration suppression torque signal; the amplitude gain of the second vibration suppression torque signal at the resonance frequency is 0 dB.

18. The motor controller according to any one of claims 13 to 17, characterized in that: The resonance suppression processing unit is specifically used for: The target gain coefficient is searched in a negative gain relationship table based on the vehicle speed signal; the gain coefficient in the negative gain relationship table is less than zero.

19. The motor controller according to claim 18, characterized in that: The gain coefficient in the negative gain relationship table increases as the vehicle speed increases.

20. The motor controller according to any one of claims 13 to 17, characterized in that: The resonance suppression processing unit is specifically used for: Searching for a negative gain coefficient in a negative gain relationship table based on the vehicle speed signal; the gain coefficient in the negative gain relationship table is less than zero; Searching for a positive gain coefficient in a positive gain relationship table based on the vehicle speed signal; The gain coefficient in the positive gain relationship table is greater than zero; The target gain coefficient is calculated based on the negative gain coefficient and the positive gain coefficient.

21. The motor controller according to claim 20, characterized in that: The gain coefficient in the negative gain relationship table increases as the vehicle speed increases, and the gain coefficient in the positive gain relationship table decreases as the vehicle speed increases.

22. The motor controller according to any one of claims 12 to 21, characterized in that: The target sensor is also used to detect a steering wheel angle signal of the vehicle; The first torque signal is determined based on a torque signal from a target sensor, comprising: The first torque signal includes a signal obtained by one or more of the following processes based on the torque signal from the target sensor, the vehicle speed signal and the steering wheel angle signal: basic power assist control processing, high frequency gain processing, phase compensation and damping control processing.

23. A motor controller, characterized in that: The motor controller is applied to the steering system of a vehicle, and the motor controller includes a processor, a communication interface and a memory, wherein the communication interface is used to realize the reception and transmission of data, the memory is used to store computer programs or computer instructions, and the processor is used to execute the computer programs or computer instructions stored in the memory, so that the motor controller executes the method described in any one of claims 1-11.

24. A steering system, characterized in that: The steering system comprises a motor controller as claimed in any one of claims 12 to 22; or, The steering system includes the motor controller of claim 23.

25. A vehicle, characterized in that: Comprising a steering system as claimed in claim 24.

26. A chip, characterized in that: The chip is applied to a steering system of a vehicle, and the chip includes a processor, a communication interface and a memory, wherein the communication interface is used to realize the reception and transmission of data, the memory is used to store computer programs or computer instructions, and the processor is used to execute the computer programs or computer instructions stored in the memory, so that the chip executes the method described in any one of claims 1-11.

27. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program or computer instructions, and the computer program or computer instructions are executed by a processor to implement the method according to any one of claims 1 to 11.

28. A computer program product, characterized in that When the computer program product is executed by a processor, the method described in any one of claims 1 to 11 will be implemented.

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