A steer-by-wire control method, device, apparatus and storage medium

Abstract

The application discloses a kind of drive-by-wire steering control method, device, equipment and storage medium, it is related to the technical field of vehicle;A kind of drive-by-wire steering control method includes: obtaining the rotor position and winding current of motor;According to the rotor position of the motor, the winding current and compensation model, determine the inherent thrust pulse of motor;Compensation instruction of target thrust is generated, and the compensation instruction of target thrust is superimposed to the basic thrust instruction of the motor, to offset the inherent thrust pulsation of the motor.Steering field controller according to the rotor position of motor, winding current, through mapping model real-time calculation under current operating condition thrust pulsation value, generate and the pulsation value size equal, opposite compensation thrust instruction, superimposed to the basic target thrust instruction of motor, from the root, offset the inherent thrust pulsation of motor, realize the smooth output of steering torque, avoid steering wheel shaking and steering fluctuation.

Description

Technical Field

[0001] This invention belongs to the technical field of vehicles, and specifically relates to a steer-by-wire control method, device, equipment, and storage medium. Background Technology

[0002] With the rapid development of vehicle electrification and intelligence, steer-by-wire systems have become one of the core key configurations of intelligent new energy vehicles due to their advantages such as eliminating the rigid mechanical connection between the steering wheel and the steering wheels, fast response speed, flexible vehicle layout, and deep adaptation to the needs of high-level autonomous driving control.

[0003] Currently, in the global automotive industry, over 99% of the steer-by-wire systems that have achieved mass production still use rack and pinion mechanical transmission as their core architecture. This type of solution is essentially a steer-by-wire modification of the traditional electric power steering system by adding redundant motors, clutches, and angle sensors, while still retaining the core mechanical structures such as the steering column and rack and pinion transmission pair.

[0004] These mainstream solutions have inherent flaws that cannot be avoided: First, the meshing transmission of gears and racks has a natural clearance, and mechanical wear after long-term use will further amplify the transmission clearance, resulting in decreased steering control precision and lag in response, which cannot meet the millisecond-level precise control requirements of high-level autonomous driving; Second, the mechanical structure of the gear and rack transmission pair occupies a large space, resulting in poor flexibility in the layout of the front compartment of the vehicle, making it difficult to adapt to the design trend of integrated and skateboard-like chassis of new energy vehicles; Third, wear and fatigue failure of mechanical transmission pairs will bring long-term failure risks, poor performance consistency throughout the entire life cycle, and high maintenance costs. Summary of the Invention

[0005] The purpose of this invention is to provide a steer-by-wire control method that fundamentally counteracts the inherent thrust pulsation of the motor, achieving smooth output of steering torque and avoiding steering wheel vibration and steering fluctuation.

[0006] The present invention also provides a steer-by-wire control device.

[0007] The present invention also provides an electronic device.

[0008] The present invention also provides a non-transitory computer-readable storage medium.

[0009] The technical solution adopted to solve the above-mentioned technical problems is as follows: A first aspect of the present invention provides a steer-by-wire control method, wherein the reluctance linear motor includes a stator and a rotor; the teeth of the stator and the teeth of the rotor both adopt a double salient pole structure; the stator is sleeved around the periphery of the rotor; and a winding is wound around the outside of the stator; the method includes: Obtain the rotor position and winding current of the motor; The inherent thrust pulse of the motor is determined based on the rotor position of the motor, the winding current, and the compensation model. A compensation command for the target thrust is generated and superimposed on the basic thrust command of the motor to counteract the inherent thrust pulsation of the motor; the target thrust and the inherent thrust pulsation are equal in magnitude and opposite in direction.

[0010] According to the steer-by-wire control method of the present invention, the following formula is added to the compensation model; ; Where x is the current position of the motor mover, i is the winding current, λ is the thrust pulsation period, and An(i) and φn(i) are the amplitude and phase of the nth harmonic, respectively.

[0011] The compensation model also includes: Obtain the winding temperature; The amplitude and phase of the harmonics are adjusted in real time according to the winding temperature.

[0012] According to an embodiment of the steer-by-wire control method of the present invention, the method further includes: Obtain vehicle driving information, which includes at least one of vehicle speed information and road condition information; Based on the vehicle's driving information, steering parameters are determined; the steering parameters include at least one of the following: maximum thrust of the motor, steering gear ratio, maximum number of steering turns, and steering torque.

[0013] According to an embodiment of the steer-by-wire control method of the present invention, the method further includes: Obtain the mileage of the vehicle; If the vehicle's mileage exceeds the rated mileage, the thrust compensation coefficient and clearance compensation amount will be automatically adjusted.

[0014] A second aspect of the present invention provides a steer-by-wire control device, comprising an acquisition module and a control module, wherein the acquisition module is used to acquire the rotor position and winding current of a motor; The control module is used to determine the inherent thrust pulse of the motor based on the rotor position of the motor, the winding current, and the compensation model. The control module is also used to generate a compensation command for the target thrust and to superimpose the compensation command for the target thrust into the basic thrust command of the motor to counteract the inherent thrust pulsation of the motor; the target thrust and the inherent thrust pulsation are equal in magnitude and opposite in direction.

[0015] According to an embodiment of the steer-by-wire control device of the present invention, the acquisition module is further configured to acquire vehicle driving information, the driving information including at least one of vehicle speed information and road condition information; The control module is also used to determine steering parameters based on the vehicle's driving information; the steering parameters include at least one of the following: maximum thrust of the motor, steering gear ratio, maximum number of steering turns, and steering torque.

[0016] According to an embodiment of the steer-by-wire control device of the present invention, the acquisition module is further configured to acquire the mileage of the vehicle; The control module is also used to automatically correct the thrust compensation coefficient and clearance compensation amount if the vehicle's mileage exceeds the rated mileage.

[0017] A third aspect of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor, when executing the program, implements the steer-by-wire control method as described in any embodiment of the first aspect.

[0018] A fourth aspect of the present invention provides a non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, when the computer program is executed by a processor, it implements the steer-by-wire control method as described in any embodiment of the first aspect.

[0019] The present invention has at least the following beneficial effects: To address the inherent periodic thrust pulsation of reluctance linear motors, a harmonic feedforward compensation model based on the motor rotor position and winding current is constructed. The steering domain controller calculates the thrust pulsation value under the current operating condition in real time using a mapping model based on the motor's rotor position and winding current. It then generates a compensating thrust command equal in magnitude but opposite in direction to this pulsation value, which is superimposed on the motor's base target thrust command. This fundamentally cancels out the inherent thrust pulsation of the motor, achieving smooth steering torque output and preventing steering wheel vibration and steering fluctuations. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is a schematic flowchart of the steer-by-wire control method provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the steer-by-wire control device provided in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the electronic device provided in the embodiment of the present invention.

[0021] The following labels are shown in the attached diagram: 101. Control module; 201. Processor; 202. Communication interface; 203. Memory; 204. Communication bus. Detailed Implementation

[0022] This section will describe in detail specific embodiments of the present invention. Preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and overall technical solution of the present invention, but they should not be construed as limiting the scope of protection of the present invention.

[0023] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0024] In the description of this invention, the use of terms such as "a number" means one or more, with "more than" meaning two or more. Terms like "greater than," "less than," and "exceeding" are understood to exclude the stated number, while terms like "above," "below," and "within" are understood to include the stated number. The use of terms like "first," "second," and "third" is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, the number of indicated technical features, or the sequential relationship between indicated technical features.

[0025] In the description of this invention, unless otherwise explicitly defined, terms such as "setting," "installing," and "connecting" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0026] To address the inherent limitations of rack and pinion steer-by-wire systems, the industry currently has only a very limited number of academic research and prototype verification-level linear motor-driven steer-by-wire solutions. Almost all of these solutions use permanent magnet linear motors as the actuators. While eliminating the rack and pinion transmission pair, unresolved industry pain points remain: First, permanent magnet linear motors rely on rare-earth permanent magnets, which inherently carry the risk of demagnetization due to high temperatures and impacts. They also have poor resistance to extreme high and low temperatures and impacts, failing to meet the requirements for full-condition automotive operation. Second, the high cost of rare-earth permanent magnet raw materials significantly increases the mass production cost of steer-by-wire systems, making it difficult to popularize in economy vehicles. Third, existing solutions utilize control algorithms developed specifically for the characteristics of permanent magnet linear motors, which are completely unsuitable for the nonlinear and thrust pulsation characteristics of switched reluctance linear motors. Directly applying these algorithms can lead to fatal problems such as large steering torque fluctuations, steering wheel vibration, and inaccurate angle tracking.

[0027] Switched reluctance linear motors possess core advantages such as no permanent magnets, no risk of demagnetization, low raw material costs, simple structure, resistance to extreme high and low temperature environments, and strong impact resistance, making them the optimal alternative to permanent magnet linear motors and traditional rack and pinion steering solutions. However, current technology completely lacks dedicated control methods for switched reluctance linear motors specifically for automotive steer-by-wire scenarios, resulting in three major technological gaps: First, there is no dedicated thrust pulsation suppression scheme developed for the low-frequency, short-stroke, and high-precision operating characteristics of steering scenarios, failing to address the steering smoothness issues caused by inherent motor pulsation; second, there is no adaptive control scheme adapted to all driving conditions in automobiles, unable to balance low-speed agility, high-speed stability, and safety under extreme conditions; third, there is no performance degradation compensation scheme covering the entire vehicle lifecycle, failing to guarantee consistent steering performance after long-term use, thus hindering mass production and vehicle adoption.

[0028] Based on the aforementioned industry status and technological gaps, there is an urgent need to develop an adaptive control method specifically for switch reluctance linear motor steer-by-wire systems with gearless rack and pinion structures. This method would address the inherent defects of existing mainstream rack and pinion solutions and a very small number of permanent magnet linear motor solutions, thereby promoting the mass production and application of switch reluctance linear motors in the automotive steer-by-wire field.

[0029] Reference Figure 1 The following are several embodiments of a steer-by-wire control method, apparatus, device, and storage medium of the present invention.

[0030] like Figure 1 As shown, a steer-by-wire control method provided in the first aspect of the present invention includes: The first aspect of this invention provides a steer-by-wire control method applied to a reluctance linear motor, the reluctance linear motor including a stator and a rotor; the teeth of both the stator and the rotor adopt a double salient pole structure; the stator is sleeved around the periphery of the rotor; a winding is wound around the outside of the stator; the method includes: Step S100: Obtain the rotor position and winding current of the motor; Step S200: Determine the inherent thrust pulse of the motor based on the rotor position of the motor, the winding current, and the compensation model; Step S300: Generate a compensation command for the target thrust and superimpose the compensation command for the target thrust onto the basic thrust command of the motor to counteract the inherent thrust pulsation of the motor; the target thrust and the inherent thrust pulsation are equal in magnitude and opposite in direction.

[0031] To address the inherent periodic thrust pulsation of reluctance linear motors, a harmonic feedforward compensation model based on the motor rotor position and winding current is constructed. The steering domain controller calculates the thrust pulsation value under the current operating condition in real time using a mapping model based on the motor's rotor position and winding current. It then generates a compensating thrust command equal in magnitude but opposite in direction to this pulsation value, which is superimposed on the motor's base target thrust command. This fundamentally cancels out the inherent thrust pulsation of the motor, achieving smooth steering torque output and preventing steering wheel vibration and steering fluctuations.

[0032] This invention, adapted to a gearless rack and pinion switched reluctance linear motor, completely eliminates problems such as transmission backlash, long-term wear, and response lag caused by gear meshing, improving steering response speed by over 40%. It also significantly simplifies the chassis structure, aligning with the integrated design trend of skateboard chassis in new energy vehicles. This invention fills a technological gap in the industry, effectively suppressing inherent thrust pulsation in the motor and effectively suppressing steering torque fluctuations and steering wheel vibration.

[0033] In some embodiments, the following formula is added to the compensation model; ; Where x is the current position of the motor mover, i is the winding current, λ is the thrust pulsation period, and An(i) and φn(i) are the amplitude and phase of the nth harmonic, respectively.

[0034] During the pre-calibration stage of the compensation model, the thrust pulsation spectrum characteristics of the switched reluctance linear motor in the full stroke and full current range can be obtained through the motor test bench. By using Fourier series expansion, a multi-dimensional mapping relationship between thrust pulsation and motor mover position, winding current, and winding temperature can be established to obtain the inherent thrust pulse of the motor, which is beneficial for generating the corresponding target thrust compensation command.

[0035] In some embodiments, the compensation model further includes: Obtain the winding temperature; The amplitude and phase of the harmonics are adjusted in real time according to the winding temperature.

[0036] In the pre-calibration stage of the compensation model, the thrust pulsation spectrum characteristics of the switched reluctance linear motor in the full stroke, full current, and full operating temperature range are obtained through a motor test bench. By using Fourier series expansion, a multi-dimensional mapping relationship between thrust pulsation and motor mover position, winding current, and winding temperature is established in order to obtain the inherent thrust pulse of the motor, which is beneficial for generating the corresponding target thrust compensation command.

[0037] This invention, for the first time, addresses the low-frequency, short-stroke operating characteristics of automotive steering scenarios by constructing a multi-dimensional harmonic feedforward compensation model based on mover position, current, and temperature. This model can suppress the thrust fluctuation of switched reluctance linear motors from the conventional 15%-20% to within 5%, completely solving the core problems of steering torque fluctuation and steering wheel vibration, and making the mass production and application of switched reluctance linear motors in automotive steering scenarios possible.

[0038] In one embodiment, a switched reluctance linear motor with symmetrical arrangement of dual front wheels is used, featuring 7 stator salient poles, 5 mover salient poles, a 1.0mm air gap between the stator and mover, a rated thrust of 2500N, and an operating temperature range of 40℃~125℃. The steering domain controller uses an automotive-grade 32-bit MCU chip with a main control cycle of 1ms and a feedforward compensation calculation cycle of 200μs. The sensor configuration includes a steering wheel angle sensor, a front wheel angle sensor, and a tie rod force sensor. The steering wheel angle sensor has a measurement accuracy of 0.08° and a response time of 8ms; the front wheel angle sensor has a measurement accuracy of 0.05° and a response time of 5ms; motor current, temperature, and position sensors; and a tie rod force sensor.

[0039] The motor test bench was used for model pre-calibration. First, the thrust pulsation characteristics of the switched reluctance linear motor were acquired over the entire stroke, current, and temperature range using the test bench. Fourier series decomposition was used to establish a parameter mapping table for the harmonic feedforward compensation model, and the temperature correction coefficient was calibrated to ensure compensation accuracy across the entire temperature range. Second, model pre-training was performed. 1000 hours of operational data from the vehicle's full lifecycle durability test were collected to complete the supervised training and verification of the Long Short-Term Memory (LSTM) network performance degradation prediction model. After verification, the system health estimation error was less than 5%. Third, real-vehicle operation control was implemented. After the vehicle was powered on, the steering domain controller collected signals such as steering wheel angle, steering torque, motor three-phase current, winding temperature, mover position, front wheel angle, vehicle speed, yaw rate, and road adhesion coefficient in real time at a 1ms cycle. Extended Kalman filtering was used to denoise the signals, and simultaneously, the motor's thrust characteristics, system damping, and transmission clearance under the current operating conditions were identified online to establish a real-time dynamic model. Finally, thrust pulsation feedforward compensation is performed. The steering domain controller calculates the current thrust pulsation value in real time using a harmonic feedforward compensation model based on the current motor mover position, winding current, and winding temperature. It then generates a reverse compensation thrust command, which is superimposed on the motor's target thrust command to counteract the inherent thrust pulsation of the motor. In the actual vehicle test of this embodiment, the motor thrust fluctuation decreased from 18% before compensation to 4.2%, the steering torque showed no significant fluctuation, the steering wheel exhibited no perceptible vibration, and the steering smoothness fully met the standards for mass-produced passenger vehicles.

[0040] In some embodiments, the method further includes: Obtain vehicle driving information, which includes at least one of vehicle speed information and road condition information; It can capture images of the road surface using onboard cameras and identify road condition information (e.g., dry asphalt, wet cement, icy, and gravel roads) using existing algorithms. Road resistance can be estimated by combining the tie rod force sensor and front wheel steering angle deviation. By incorporating vehicle speed and thrust pulsation compensation, the output torque of the torque feedback motor is dynamically adjusted to filter high-frequency pulsations while retaining a realistic road feel. The road feel is light at low speeds and stable at high speeds, with no noticeable vibration or distortion. The steering feel is superior to traditional rack-and-pinion steer-by-wire systems in the same class. The tie rod is the vehicle's steering tie rod, and the tie rod force sensor can be a strain gauge or similar sensor.

[0041] Based on the vehicle's driving information, steering parameters are determined; the steering parameters include at least one of the following: maximum thrust of the motor, steering gear ratio, maximum number of steering turns, and steering torque.

[0042] This invention achieves dynamic optimization of steering performance under different vehicle speeds and road conditions by accurately classifying road conditions and driving states and inferring parameter matching. At low speeds, it enables flexible steering and light steering effort, which can significantly reduce the turning radius. At high speeds, it enables stable steering and no floating feeling, which can effectively suppress steering wheel deviation caused by road disturbances. Under low-adhesion road conditions, it can effectively suppress tire sideslip and improve steering safety, fully adapting to the driving needs of vehicles in all scenarios.

[0043] When the vehicle speed is less than or equal to 30 km / h, the maximum thrust of the motor is increased, the steering ratio is reduced, and the steering response speed is improved. When the vehicle speed is greater than or equal to 60 km / h, the motor thrust response bandwidth is reduced, the steering ratio and steering damping are increased, and sudden changes in steering angle are suppressed. Based on the road condition information, the low-adhesion road surface condition is determined to be a road surface adhesion coefficient of less than 0.4. The maximum thrust of the motor and the steering angular velocity are limited, and the weight of the steering angle tracking control is optimized.

[0044] The coordinated control of the switched reluctance linear motor incorporates the Ackerman correction algorithm, which dynamically adjusts the travel difference between the left and right motors according to the steering angle, so that the steering trajectory conforms to the Ackerman steering principle and reduces tire wear.

[0045] For example, when the vehicle speed is 10 km / h, it is determined that the vehicle is in a low-speed parking condition. The motor's target thrust is automatically increased to 3000 N, the steering ratio is reduced from 16:1 to 10:1, the steering response speed is improved, the number of steering turns is reduced from 2.8 turns to 1.8 turns, and the steering torque is controlled at 3 N. Within a range of m, it achieves flexible steering with a small radius, reducing the minimum steering radius by 0.8m compared to traditional rack and pinion systems. When the vehicle speed is 100km / h, it is determined that the vehicle is in high-speed cruising condition and automatically increases the steering ratio to 20:1, reduces the motor thrust response bandwidth by 30%, and increases steering damping to suppress steering wheel deviation caused by road disturbances, thus improving high-speed driving stability. Compared to traditional rack and pinion systems, its high-speed anti-interference capability is improved by 50%. When the road condition is icy or snowy with a road adhesion coefficient of 0.3, it automatically limits the maximum steering angular velocity to 30° / s and the maximum motor output thrust to 1500N, optimizes the steering angle tracking control weight, prevents tire sideslip, and improves steering safety. During steering, the prediction model is updated in real time, aiming to minimize steering angle tracking error and torque fluctuation, and uses rolling optimization to solve for the optimal control quantity. The steering angle tracking error is less than 0.1°. At the same time, the Ackerman correction algorithm dynamically adjusts the travel difference between the left and right motors to reduce tire wear.

[0046] This invention provides real-time correction of control parameters, enabling steering performance deviations to be kept within 3% throughout the vehicle's entire lifecycle. It addresses the industry pain point of traditional rack and pinion systems, which suffer from decreased steering precision and deteriorated feel due to component wear and performance degradation after long-term use. This significantly reduces the vehicle's lifecycle maintenance costs and aligns with advanced intelligent driving requirements. The invention employs a compensation model for predictive control, which can correct mismatches between the model and the actual system in real time, achieving a steering angle tracking error of less than 0.1°.

[0047] In some embodiments, for advanced intelligent driving modes, the target weights can be automatically adjusted and optimized to control the lateral tracking deviation of autonomous driving within ±5cm, fully meeting the lateral control requirements of L3 and above advanced intelligent driving. This invention can be implemented based on existing automotive-grade steering domain controllers, without additional hardware costs. The adapted switched reluctance linear motor has no rare-earth permanent magnets, reducing raw material costs by more than 35% compared to permanent magnet linear motors and by more than 20% compared to traditional rack and pinion steer-by-wire systems. It also meets automotive functional safety specifications, possessing extremely high mass production application and economic value. When the L3 advanced intelligent driving mode is activated, the system automatically switches to dedicated autonomous driving control parameters, adjusting the optimization target weights of the adaptive model predictive control algorithm, increasing the weight of path tracking accuracy to 60%, prioritizing the lateral tracking accuracy of autonomous driving. In real-vehicle testing, the lateral tracking deviation on straight roads is controlled within ±3cm, and the lateral tracking deviation on curves is controlled within ±5cm, fully meeting the control requirements of advanced intelligent driving. The system acquires navigation and environmental perception information about the road ahead through the onboard intelligent driving domain controller, anticipates changes in road surface adhesion and curves, and pre-adjusts the steering system's control parameters to achieve proactive pre-control. This significantly improves steering smoothness and reduces vehicle posture fluctuations during steering. When the system detects a minor fault, such as a partial short circuit in the windings of a single motor or a decrease in output thrust, it automatically adjusts the thrust distribution ratio between the left and right motors. The healthy motor compensates for the thrust loss on the faulty side, while the central tie rod ensures steering synchronization. This achieves shock-free fault-tolerant control, maintaining path tracking accuracy, and simultaneously issues a fault warning to the driver to ensure driving safety.

[0048] In some embodiments, the method further includes: Obtain the mileage of the vehicle; If the vehicle's mileage exceeds the rated mileage, the thrust compensation coefficient and clearance compensation amount will be automatically adjusted.

[0049] For example, after a vehicle has traveled 100,000 kilometers, if the motor thrust coefficient is detected to have decreased by 8% and the transmission mechanism clearance has increased by 0.07 mm, the system health is estimated to be 82% using an LSTM model. The thrust compensation coefficient and clearance compensation amount are automatically corrected to ensure that the steering accuracy is consistent with the new vehicle condition and the performance deviation is less than 2.5%. When the system health is below 70%, a maintenance warning is issued to the driver through the onboard instrument panel.

[0050] Figure 2 This is a schematic diagram of the structure of a steer-by-wire control device provided in an embodiment of the present invention; as shown. Figure 2 As shown, a steer-by-wire control device provided in a second aspect embodiment of the present invention includes an acquisition module 101, which is used to acquire the rotor position and winding current of a motor. The control module 102 is used to determine the inherent thrust pulse of the motor based on the rotor position of the motor, the winding current and the compensation model; The control module 102 is also used to generate a compensation command for the target thrust and to superimpose the compensation command for the target thrust onto the basic thrust command of the motor to counteract the inherent thrust pulsation of the motor; the target thrust and the inherent thrust pulsation are equal in magnitude and opposite in direction.

[0051] In some embodiments, the acquisition module 101 is further configured to acquire vehicle driving information, the driving information including at least one of vehicle speed information and road condition information; The control module 102 is also used to determine steering parameters based on the vehicle's driving information; the steering parameters include at least one of the following: maximum thrust of the motor, steering transmission ratio, maximum number of steering turns, and steering torque.

[0052] In some embodiments, the acquisition module 101 is further configured to acquire the mileage of the vehicle; The control module 102 is also used to automatically correct the thrust compensation coefficient and clearance compensation amount if the vehicle's mileage exceeds the rated mileage.

[0053] This invention relates to a steer-by-wire device based on a switched reluctance linear motor with a gearless rack and pinion transmission structure. The device includes a steering wheel angle detection module, a steering domain controller, a symmetrically arranged switched reluctance linear motor drive module for both front wheels, a tie rod, and a torque feedback motor. The steer-by-wire method includes: first, the steering domain controller collects three types of signals in real time at a fixed control cycle. The first type of signal is the driver input signal, including steering wheel angle, steering angular velocity, and steering torque; the second type of signal is the system execution signal, including the three-phase current and winding temperature of the switched reluctance linear motor. The first type of signal is the drive stroke, output thrust, actual front wheel steering angle, and tie rod force. The second type of signal is the vehicle status signal, including vehicle speed, yaw rate, center of gravity sideslip angle, road adhesion coefficient, and vehicle load. The center of gravity sideslip angle is the angle between the vehicle's heading and its actual driving direction. The steering domain controller uses an extended Kalman filter algorithm to denoise all collected signals and simultaneously identifies the thrust characteristics, system damping, and transmission clearance of the switched reluctance linear motor under the current operating conditions, establishing a real-time dynamic model of the system. Secondly, it addresses the doubly salient pole design of the switched reluctance linear motor. The inherent periodic thrust pulsation caused by the structure is addressed by constructing a harmonic feedforward compensation model based on the rotor position and winding current of the motor. The thrust pulsation spectrum characteristics across the entire stroke and current range of the motor are obtained through pre-calibration on a motor test bench, establishing a mapping relationship between thrust pulsation and rotor position and winding current. The steering domain controller calculates the current thrust pulsation value in real time based on the current rotor position and winding current, generates a compensating thrust command equal in magnitude but opposite in direction to this pulsation value, and superimposes the compensating thrust command onto the motor's basic target thrust command to counteract the inherent thrust pulsation of the motor. This achieves smooth output of steering torque. Furthermore, based on the current vehicle speed, road adhesion coefficient, and steering angle, the steering domain controller divides the vehicle's driving conditions into four categories: low-speed parking, urban road, high-speed cruising, and low-adhesion road surface. It adjusts the control parameters of the steering system, including the upper limit of motor thrust, steering transmission ratio, thrust response bandwidth, and steering damping, with the optimization objectives of minimizing steering angle tracking error and steering torque fluctuation. At the same time, it sets actuator physical constraints and vehicle stability constraints, and performs rolling optimization to solve for the optimal target thrust and stroke command of the motor in each control cycle.

[0054] Figure 3 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 3As shown, the electronic device may include: a processor 201, a communication interface 202, a memory 203, and a communication bus 204. The processor 201, communication interface 202, and memory 203 communicate with each other via the communication bus 204. The processor 201 can call logical instructions from the memory 203 to execute a drive-by-wire steering control method. This method includes: Obtain the rotor position and winding current of the motor; The inherent thrust pulse of the motor is determined based on the rotor position of the motor, the winding current, and the compensation model. A compensation command for the target thrust is generated and superimposed on the basic thrust command of the motor to counteract the inherent thrust pulsation of the motor; the target thrust and the inherent thrust pulsation are equal in magnitude and opposite in direction.

[0055] Furthermore, the logical instructions in the aforementioned memory 203 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes: a USB flash drive, a portable hard drive, and a read-only memory (ROM). Various media that can store program code, such as only memory, random access memory (RAM), magnetic disks or optical disks.

[0056] On the other hand, this application also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, is implemented to perform the steer-by-wire control methods provided by the above methods, the method comprising: Obtain the rotor position and winding current of the motor; The inherent thrust pulse of the motor is determined based on the rotor position of the motor, the winding current, and the compensation model. A compensation command for the target thrust is generated and superimposed on the basic thrust command of the motor to counteract the inherent thrust pulsation of the motor; the target thrust and the inherent thrust pulsation are equal in magnitude and opposite in direction.

[0057] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0058] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A steer-by-wire control method, characterized by, This invention relates to a reluctance linear motor, which includes a stator and a rotor; both the teeth of the stator and the teeth of the rotor adopt a double salient pole structure; the stator is sleeved around the rotor. The stator is externally wound with windings; the method includes: Obtain the rotor position and winding current of the motor; The inherent thrust pulse of the motor is determined based on the rotor position of the motor, the winding current, and the compensation model. A compensation command for the target thrust is generated and superimposed on the basic thrust command of the motor to counteract the inherent thrust pulsation of the motor; the target thrust and the inherent thrust pulsation are equal in magnitude and opposite in direction.

2. The steer-by-wire control method according to claim 1, characterized by, Add the following formula to the compensation model; ； Where x is the current position of the motor mover, i is the winding current, λ is the thrust pulsation period, and An(i) and φn(i) are the amplitude and phase of the nth harmonic, respectively.

3. The steer-by-wire control method according to claim 2, characterized by, The compensation model also includes: Obtain the winding temperature; The amplitude and phase of the harmonics are adjusted in real time according to the winding temperature.

4. The steer-by-wire control method according to claim 1, characterized by, The method further includes: Obtain vehicle driving information, which includes at least one of vehicle speed information and road condition information; Based on the vehicle's driving information, steering parameters are determined; the steering parameters include at least one of the following: maximum thrust of the motor, steering gear ratio, maximum number of steering turns, and steering torque.

5. The steer-by-wire control method according to claim 1, characterized by, The method further includes: Obtain the mileage of the vehicle; If the vehicle's mileage exceeds the rated mileage, the thrust compensation coefficient and clearance compensation amount will be automatically adjusted.

6. A steer-by-wire control device, characterized in that, It includes an acquisition module and a control module, wherein the acquisition module is used to acquire the rotor position and winding current of the motor; The control module is used to determine the inherent thrust pulse of the motor based on the rotor position of the motor, the winding current, and the compensation model. The control module is also used to generate a compensation command for the target thrust and to superimpose the compensation command for the target thrust into the basic thrust command of the motor to counteract the inherent thrust pulsation of the motor; the target thrust and the inherent thrust pulsation are equal in magnitude and opposite in direction.

7. The steer-by-wire control device according to claim 6, characterized in that, The acquisition module is also used to acquire vehicle driving information, which includes at least one of vehicle speed information and road condition information; The control module is also used to determine steering parameters based on the vehicle's driving information; the steering parameters include at least one of the following: maximum thrust of the motor, steering ratio, maximum number of steering turns, and steering torque.

8. The steer-by-wire control device according to claim 6, characterized in that, The acquisition module is also used to acquire the mileage of the vehicle; The control module is also used to automatically correct the thrust compensation coefficient and clearance compensation amount if the vehicle's mileage exceeds the rated mileage.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steer-by-wire control method as described in any one of claims 1 to 5.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steer-by-wire control method as described in any one of claims 1 to 5.

Images