Steer-by-wire system and steering wheel angle determination method and device thereof

Abstract

The invention provides a steer-by-wire system and a steering wheel rotation angle determination method and device thereof, and the method comprises the steps: obtaining motor end sensor data, steering wheel torque and steering wheel sensor detection rotation angle at a correction moment after a vehicle is started; calculating a motor end steering wheel angle at the correction moment according to the motor end sensor data at the correction moment, and calculating a torsional rigidity influence angle at the correction moment according to the steering wheel torque at the correction moment; calculating a centering position correction angle according to the motor end steering wheel rotation angle, the torsional rigidity influence angle and the steering wheel sensor detection rotation angle at the correction moment; acquiring real-time motor end sensor data and steering wheel torque so as to respectively calculate a current real-time motor end steering wheel angle and a current real-time torsional rigidity influence angle; and the steering wheel angle is calculated according to the current real-time steering wheel angle of the motor end, the torsional rigidity influence angle and the centering position correction angle, so that the accuracy of the obtained steering wheel angle is higher.

Description

Technical Field

[0001] The present application relates to the field of vehicle engineering, and in particular to a steer-by-wire system and a method and device for determining a steering wheel angle thereof. Background Art

[0002] A vehicle's steer-by-wire system uses electronic signals to control steering. To achieve steering control in a steer-by-wire system, it's necessary to measure the steering wheel angle, also known as the steering wheel angle.

[0003] At present, most people directly use the angle detected by the steering wheel angle sensor as the steering wheel angle to determine the steering position of the steering wheel. Although this method is simple, it does not consider the impact of other factors on the trend of angle change. The accuracy is not high, resulting in a certain lag in rapid steering or frequent left and right switching conditions. Summary of the Invention

[0004] The present application provides a steer-by-wire system and a method and device for determining a steering wheel angle thereof, to solve the above-mentioned technical problems in the prior art.

[0005] According to a first aspect of the present application, a method for determining a steering wheel angle of a steer-by-wire system is provided, the method comprising:

[0006] After the vehicle is started, when a correction time is detected when a preset correction condition is met, the motor-end sensor data, the steering wheel torque, and the steering wheel sensor detection angle at the correction time are obtained;

[0007] Calculating the motor-end steering wheel angle at the correction moment based on the motor-end sensor data at the correction moment, and calculating the torsional stiffness influence angle at the correction moment based on the steering wheel torque at the correction moment;

[0008] Calculating a centering position correction angle based on a motor-end steering wheel angle at the correction moment, a torsional stiffness influence angle at the correction moment, and a steering wheel sensor detection angle at the correction moment;

[0009] Obtain real-time motor-end sensor data and steering wheel torque;

[0010] Calculating the current real-time motor-end steering wheel angle according to the real-time motor-end sensor data, and calculating the current real-time torsional stiffness influence angle according to the real-time steering wheel torque;

[0011] The current real-time steering wheel angle is calculated according to the current real-time motor-end steering wheel angle, the current real-time torsional stiffness influence angle and the centering position correction angle, so as to output a torque request signal according to the current real-time steering wheel angle.

[0012] In some embodiments, the motor-side sensor data includes a road-sensing motor encoder angle;

[0013] The calculating the motor-end steering wheel angle at the correction time according to the motor-end sensor data at the correction time includes:

[0014] Calculating the electrical rotation angle according to the road sensor motor encoder angle and the number of encoder teeth at the correction moment;

[0015] The motor-end steering wheel angle corresponding to the correction moment is calculated according to the electric angle, the set shaft angle multiplier and the speed ratio of the road-feeling reduction mechanism.

[0016] In some embodiments, calculating the motor-end steering wheel angle corresponding to the correction moment based on the electrical angle, the set axle angle multiplier, and the road-feeling deceleration mechanism speed ratio includes calculating according to the following formula:

[0017] Steering wheel angle at the motor end = electric angle ÷ shaft angle multiplier ÷ road feel reduction mechanism speed ratio.

[0018] In some embodiments, calculating the torsional stiffness influence angle at the correction moment based on the steering wheel torque at the correction moment includes calculating the torsional stiffness influence angle using the following formula:

[0019] T = k·θ;

[0020] Where k is the set stiffness, T is the steering wheel torque, and θ is the torsional stiffness influence angle.

[0021] In some embodiments, calculating the centering position correction angle based on the motor-end steering wheel angle at the correction moment, the torsional stiffness influence angle at the correction moment, and the steering wheel sensor detection angle at the correction moment includes using the following formula to calculate the centering position correction angle:

[0022] Centering position correction angle = steering wheel sensor detection angle at the time of correction – torsional stiffness influence angle at the time of correction – motor-end steering wheel angle at the time of correction.

[0023] In some embodiments, calculating the current real-time steering wheel angle based on the current real-time motor-end steering wheel angle, the current real-time torsional stiffness influence angle, and the centering position correction angle includes calculating the current real-time steering wheel angle using the following formula:

[0024] The current real-time steering wheel angle = the current real-time motor-end steering wheel angle + the centering position correction angle + the current real-time torsional stiffness influence angle.

[0025] In some embodiments, the preset correction conditions include:

[0026] The difference between the collected wheel angle and the collected steering wheel sensor detection angle is less than a preset value.

[0027] According to a second aspect of the present application, a device for determining a steering wheel angle of a steer-by-wire system is provided, the device comprising:

[0028] A first data acquisition module is configured to acquire motor-end sensor data, steering wheel torque, and steering wheel sensor detection angle at a correction moment when a preset correction condition is detected after the vehicle is started;

[0029] a first calculation module, configured to calculate the motor-end steering wheel angle at the correction moment based on the motor-end sensor data at the correction moment, and calculate the torsional stiffness influence angle at the correction moment based on the steering wheel torque at the correction moment;

[0030] a correction angle calculation module, configured to calculate a centering position correction angle based on a motor-end steering wheel angle at the correction moment, a torsional stiffness influence angle at the correction moment, and a steering wheel sensor detection angle at the correction moment;

[0031] The second data acquisition module is used to obtain real-time motor-end sensor data and steering wheel torque;

[0032] a second calculation module, configured to calculate a current real-time motor-end steering wheel angle according to the real-time motor-end sensor data, and calculate a current real-time torsional stiffness influence angle according to the real-time steering wheel torque;

[0033] A steering wheel angle determination module is used to calculate the current real-time steering wheel angle based on the current real-time motor-end steering wheel angle, the current real-time torsional stiffness influence angle and the centering position correction angle, so as to output a torque request signal based on the current real-time steering wheel angle.

[0034] According to a third aspect of the present application, a road feel controller is provided, comprising a processor and a memory storing computer program instructions; the processor implements the steps of the above-mentioned steering wheel angle determination method when executing the computer program instructions.

[0035] According to a fourth aspect of the present application, a steer-by-wire system is provided, comprising the above-mentioned road feel controller.

[0036] In some embodiments, the road sense controller includes a first road sense controller and a second road sense controller, and the steer-by-wire system further includes a first road sense motor drive, a second road sense motor drive, and a road sense motor;

[0037] The first road sense controller is connected to the second road sense controller, and the first road sense controller is connected to the first road sense motor driver, the second road sense controller is connected to the second road sense motor driver, and the first road sense motor driver and the second road sense motor driver are both connected to the road sense motor;

[0038] The first road sense controller and the second road sense controller transmit their calculated steering wheel angles to each other, and output torque request signals to the corresponding first road sense motor drive / second road sense motor drive according to the steering wheel angles;

[0039] The first road sensing motor driver and the second road sensing motor driver drive the road sensing motor to operate according to the torque request signal.

[0040] In some embodiments, the steer-by-wire system further includes a torque sensor, a rotation angle sensor, and an encoder angle sensor;

[0041] The torque sensor and the rotation angle sensor are arranged on the steering wheel assembly and connected to the first road feel controller and the second road feel controller. The torque sensor is used to collect steering wheel torque and send it to the first road feel controller and the second road feel controller. The rotation angle sensor is used to collect steering wheel angle detected by the steering wheel sensor and send it to the first road feel controller and the second road feel controller.

[0042] The encoder angle sensor is provided on the road sense motor and connected to the first road sense motor driver and the second road sense motor driver, and is used to collect the road sense motor encoder angle and send it to the first road sense motor driver and the second road sense motor driver.

[0043] In some embodiments, when the steering wheel angle calculated by the first road sense controller / the second road sense controller exceeds a preset range, if the obtained steering wheel sensor detected angle is within the preset range, the steering wheel sensor detected angle is used as the steering wheel angle;

[0044] If the steering wheel sensor detects that the turning angle exceeds the preset range, an alarm signal is output.

[0045] In summary, the steer-by-wire system and its steering wheel angle determination method, device, and road feel controller provided by this application have at least the following beneficial effects:

[0046] When the preset correction conditions are met, data is collected to calculate the centering position correction angle, and then real-time data is collected to calculate the current real-time motor-end steering wheel angle and torsional stiffness influence angle. The steering wheel angle is calculated by combining the centering position correction angle, the current real-time motor-end steering wheel angle and torsional stiffness influence angle. The calculated steering wheel angle is corrected by the centering position correction angle and is based on the motor-end steering wheel angle. The influence of the angle change trend caused by torsional stiffness is taken into account, and the steering wheel angle obtained is more accurate. Therefore, the torque request signal output according to the higher-precision steering wheel angle is more accurate in torque control, which can improve system response. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the specific implementation methods of the present application, the following will briefly introduce the drawings required for use in the specific implementation methods in conjunction with the accompanying drawings. Obviously, the drawings described below are some implementation methods of the present application. For those skilled in the art, other drawings or solutions can be obtained based on these drawings without any creative work.

[0048] Figure 1 This is a flow chart of a method for determining a steering wheel angle of a steer-by-wire system in one embodiment of the present application;

[0049] Figure 2 This is a logic diagram of calculating the steering wheel angle in a specific embodiment of the present application;

[0050] Figure 3 This is a structural diagram of a steering wheel angle determination device of a steer-by-wire system in one embodiment of the present application;

[0051] Figure 4 A structural diagram of a road sense controller provided in an embodiment of the present application;

[0052] Figure 5 This is a partial structural diagram of a steer-by-wire system in one embodiment of the present application. DETAILED DESCRIPTION

[0053] In order to make the above and other features and advantages of the present application more clear, the present application is further described below with reference to the accompanying drawings. It should be understood that the specific embodiments given herein are for the purpose of explaining to those skilled in the art and are only exemplary and not restrictive.

[0054] In the following description, many specific details are set forth to provide a thorough understanding of the present application. However, it will be apparent to those skilled in the art that it is not necessary to adopt the specific details to practice the present application. In other cases, well-known steps or operations are not described in detail to avoid obscuring the present application.

[0055] The steering wheel angle determination method of the steer-by-wire system provided in the embodiment of the present application can be performed by the steering wheel angle determination device of the steer-by-wire system provided in the embodiment of the present application, and the device can be configured in a road sense controller.

[0056] refer to Figure 1 The present application provides a method for determining a steering wheel angle of a steer-by-wire system, the method comprising the following steps:

[0057] S110: After the vehicle is started, when a correction time when a preset correction condition is detected to be satisfied, the motor-end sensor data, the steering wheel torque, and the steering wheel sensor detection angle at the correction time are obtained.

[0058] The preset correction condition is a condition for pre-setting the correction angle. In one embodiment, the preset correction condition includes: the difference between the collected wheel angle and the collected steering wheel sensor detection angle is less than a preset value. The wheel angle can be measured by the sensor of the wheel's actuator motor; the steering wheel sensor detection angle is an angle measured by an angle sensor provided in the steering wheel assembly. Specifically, after the vehicle is started, the wheel angle and the steering wheel sensor detection angle are collected. If the difference between the two is less than the preset value, the preset correction condition is met. It can be understood that the preset correction condition can also be set to other values ​​according to actual needs, for example, receiving a correction instruction input by the user.

[0059] The moment when the preset correction conditions are detected is used as the correction moment. The motor-end sensor data, steering wheel torque, and steering wheel sensor detected angle collected at the correction moment are obtained to obtain the motor-end sensor data, steering wheel torque, and steering wheel sensor detected angle at the correction moment. Specifically, the motor-end sensor data is data measured by a sensor located at the motor end and represents the motor operating parameters. For example, the motor-end sensor data may include the road sensor motor encoder angle. Specifically, the steering wheel torque may be collected by a torque sensor located in the steering wheel assembly.

[0060] S120: Calculating the motor-end steering wheel angle at the correction time based on the motor-end sensor data at the correction time, and calculating the torsional stiffness influence angle at the correction time based on the steering wheel torque at the correction time.

[0061] The motor-side steering wheel angle is calculated based on motor-side sensor data and reflects the steering angle. The torsional stiffness impact angle is the angle difference caused by torsional stiffness, indicating the impact of torsional stiffness on the steering wheel angle trend. Specifically, the torsional stiffness impact angle is calculated based on steering wheel torque and a given stiffness. Stiffness is the ability of the road sensor to resist torsional deformation and can be predetermined.

[0062] S130: Calculating a centering position correction angle based on the motor-end steering wheel angle at the correction time, the torsional stiffness influence angle at the correction time, and the steering wheel sensor detection angle at the correction time.

[0063] The centering position correction angle is used for subsequent angle correction calculations. Once the vehicle is started, the centering position correction angle remains unchanged until the road sense controller is powered off, at which point it is reset.

[0064] S140: Acquires real-time motor-end sensor data and steering wheel torque.

[0065] After obtaining the centering position correction angle, the current real-time motor-end sensor data and steering wheel torque are obtained for calculating the steering wheel angle.

[0066] S150: Calculate the current real-time motor-end steering wheel angle based on the real-time motor-end sensor data, and calculate the current real-time torsional stiffness influence angle based on the real-time steering wheel torque.

[0067] S160: Calculating the current real-time steering wheel angle according to the current real-time motor-end steering wheel angle, the current real-time torsional stiffness influence angle, and the centering position correction angle, so as to output a torque request signal according to the current real-time steering wheel angle.

[0068] For example, after the road sense controller obtains the steering wheel angle, it can output a torque request signal based on the steering wheel angle and send it to the road sense motor driver. The road sense motor driver receives the torque request signal from the road sense controller, converts it into a three-phase current, and drives the road sense motor to work.

[0069] The above-mentioned method for determining the steering wheel angle of the wire-controlled steer system collects data to calculate the centering position correction angle when the preset correction conditions are met, and then collects real-time data to calculate the current real-time motor-end steering wheel angle and the torsional stiffness influence angle. The steering wheel angle is calculated by combining the centering position correction angle, the current real-time motor-end steering wheel angle and the torsional stiffness influence angle. The calculated steering wheel angle is corrected by the centering position correction angle and is based on the motor-end steering wheel angle. The influence of the angle change trend caused by torsional stiffness is taken into account, and the steering wheel angle obtained is more accurate. Therefore, the torque request signal output according to the higher-precision steering wheel angle is more accurate for torque control, which can improve system response.

[0070] Furthermore, the above steering wheel angle determination method also includes: when the preset correction condition is not met, the real-time steering wheel sensor detection angle can be obtained as the current real-time steering wheel angle without correction.

[0071] In one embodiment, the motor-side sensor data includes a road-sensing motor encoder angle. Specifically, in step S120, calculating the motor-side steering wheel angle at the correction time based on the motor-side sensor data at the correction time includes: calculating the electrical angle based on the road-sensing motor encoder angle and the number of encoder teeth at the correction time; and calculating the motor-side steering wheel angle at the correction time based on the electrical angle, a set axle angle multiplier, and the road-sensing reduction mechanism speed ratio.

[0072] The road sense motor encoder angle can be measured by an angle sensor installed in the road sense motor. For example, the angle sensor measures the road sense motor encoder angle and sends it to the road sense motor driver, which then forwards it to the road sense controller. Alternatively, in other embodiments, the road sense motor driver can calculate the electrical angle based on the road sense motor encoder angle and the number of encoder teeth, and send the electrical angle to the road sense controller.

[0073] Among them, the number of encoder teeth refers to the number of teeth corresponding to one circle of the encoder. The number of encoder teeth, the shaft angle multiplier, and the speed ratio of the road-feeling deceleration mechanism are fixed parameters of the wire control system and can be given in advance. Specifically, the electric angle can be calculated according to: electric angle = road-feeling motor encoder angle ÷ number of encoder teeth. Among them, the road-feeling motor encoder angle uses the road-feeling motor encoder collected at the time of correction, and the electric angle at the time of correction can be calculated. Then, the steering wheel angle at the motor end is calculated based on the electric angle, the shaft angle multiplier, and the speed ratio of the road-feeling deceleration mechanism, and thus the angle reflecting the steering size of the steering wheel is calculated based on the relevant data at the motor end.

[0074] In one embodiment, the motor-end steering wheel angle corresponding to the correction time is calculated based on the electric angle, the set shaft angle multiplier, and the speed ratio of the road-feeling deceleration mechanism, including calculation according to the following formula:

[0075] Steering wheel angle at the motor end = electric angle ÷ shaft angle multiplier ÷ road feel reduction mechanism speed ratio.

[0076] Specifically, the electric angle based on the correction moment is divided by the shaft angle multiplier to obtain the road sense motor angle at the correction moment. The road sense motor angle at the correction moment is then divided by the road sense deceleration mechanism speed ratio to accurately calculate the motor-end steering wheel angle at the correction moment.

[0077] It can be understood that the calculation formula for calculating the current real-time motor-end steering wheel angle based on the real-time motor-end sensor data in step S150 is the same as the calculation formula for calculating the motor-end steering wheel angle at the correction time based on the motor-end sensor data at the correction time in step S120. The real-time motor-end sensor data can be used for calculation.

[0078] In one embodiment, in step S120, the torsional stiffness influence angle at the correction moment is calculated based on the steering wheel torque at the correction moment, including using the following formula (1) to calculate the torsional stiffness influence angle:

[0079] T = k·θ(1);

[0080] Where k is the set stiffness in N·m / rad (Newton-meter / radian), T is the steering wheel torque, and θ is the torsional stiffness influence angle. Specifically, based on formula (1), the steering wheel torque at the correction time is divided by the stiffness to obtain the torsional stiffness influence angle at the corresponding correction time.

[0081] Stiffness is an inherent parameter of a component, influenced by factors such as material, cross-sectional shape, and length. Once the component is selected, stiffness is determined. Stiffness reflects the road feel mechanism's ability to resist torsional deformation. A greater stiffness, k, results in a smaller torsional stiffness influence angle, θ (i.e., less deformation) when the same steering wheel torque, T, is applied. Conversely, a smaller k results in greater deformation under the same steering wheel torque.

[0082] It can be understood that the calculation formula for calculating the current real-time torsional stiffness influence angle based on the real-time steering wheel torque in step S150 is the same as the calculation formula for calculating the torsional stiffness influence angle at the correction moment based on the steering wheel torque at the correction moment in step S120, and the real-time steering wheel torque can be used for calculation.

[0083] In one embodiment, step S130 includes calculating the centering position correction angle using the following formula:

[0084] Centering position correction angle = steering wheel sensor detection angle at the time of correction – torsional stiffness influence angle at the time of correction – motor-end steering wheel angle at the time of correction.

[0085] When the vehicle starts, the wheels may be centered or misaligned. This correction angle is calculated by subtracting the torsional stiffness effect angle and the motor-side steering wheel angle at the time of correction from the steering wheel sensor's detected angle. This angle is then used in subsequent steering wheel angle calculations to correct for any deviations caused by misaligned wheels.

[0086] In one embodiment, step S160 includes calculating the current real-time steering wheel angle using the following formula:

[0087] The current real-time steering wheel angle = the current real-time motor-end steering wheel angle + the centering position correction angle + the current real-time torsional stiffness influence angle.

[0088] The steering wheel angle is calculated with high accuracy by combining the centering position correction angle, the current real-time motor-end steering wheel angle, and the torsional stiffness influence angle.

[0089] like Figure 2 As shown, taking the road sense controller as an example, the logic of the road sense controller calculating the steering wheel angle is as follows:

[0090] 1. Calculate the electric angle by dividing the road-sensing motor encoder angle by the number of encoder teeth; calculate the steering wheel angle at the motor end by dividing the electric angle by the shaft angle multiplier and the speed ratio of the road-sensing reduction mechanism.

[0091] 2. Divide the steering wheel torque at the time of correction by the stiffness to calculate the torsional stiffness influence angle;

[0092] 3. Calculate the centering position correction angle by taking the steering wheel sensor detection angle at the time of correction, the torsional stiffness influence angle at the time of correction, and the steering wheel angle at the motor end at the time of correction.

[0093] 4. The current real-time motor-end steering wheel angle + centering position correction angle + current real-time torsional stiffness influence angle are used to calculate the current real-time steering wheel angle.

[0094] After the road sense controller calculates the steering wheel angle, it sends it to another redundant road sense controller in the steer-by-wire system, and receives the steering wheel angle calculated and sent by the other road sense controller. The two road sense controllers exchange data with each other for data backup and judgment, output the steering wheel angle, and output the torque request signal based on the steering wheel angle.

[0095] The present application provides a device for determining the steering wheel angle of a steer-by-wire system. Figure 3 As shown, the device includes a first data acquisition module 310 , a first calculation module 320 , a correction angle calculation module 330 , a second data acquisition module 340 , a second calculation module 350 and a steering wheel angle determination module 360 ​​.

[0096] The first data acquisition module 310 is used to obtain the motor end sensor data, steering wheel torque and steering wheel sensor detection angle at the correction moment when it is detected that the preset correction conditions are met after the vehicle is started.

[0097] The first calculation module 320 is used to calculate the motor-end steering wheel angle at the correction time based on the motor-end sensor data at the correction time, and calculate the torsional stiffness influence angle at the correction time based on the steering wheel torque at the correction time.

[0098] The correction angle calculation module 330 is used to calculate the centering position correction angle based on the motor-end steering wheel angle at the correction time, the torsional stiffness influence angle at the correction time, and the steering wheel sensor detection angle at the correction time.

[0099] The second data acquisition module 340 is used to obtain real-time motor-end sensor data and steering wheel torque.

[0100] The second calculation module 350 is used to calculate the current real-time motor-end steering wheel angle according to the real-time motor-end sensor data, and calculate the current real-time torsional stiffness influence angle according to the real-time steering wheel torque.

[0101] The steering wheel angle determination module 360 ​​is used to calculate the current real-time steering wheel angle based on the current real-time motor end steering wheel angle, the current real-time torsional stiffness influence angle and the centering position correction angle, so as to output a torque request signal based on the current real-time steering wheel angle.

[0102] Furthermore, the steering wheel angle determination module 360 ​​is further configured to obtain the real-time steering wheel sensor detection angle as the current real-time steering wheel angle when the preset correction condition is not satisfied.

[0103] In one embodiment, the motor-end sensor data includes a road-feeling motor encoder angle; the first calculation module 320 is further used to calculate the electric angle based on the road-feeling motor encoder angle and the number of encoder teeth at the correction time; and calculate the motor-end steering wheel angle corresponding to the correction time based on the electric angle, the set shaft angle multiplier and the road-feeling deceleration mechanism speed ratio.

[0104] In one embodiment, the first calculation module 320 performs calculation according to the following formula:

[0105] Steering wheel angle at the motor end = electric angle ÷ shaft angle multiplier ÷ road feel reduction mechanism speed ratio.

[0106] In one embodiment, the first calculation module 320 is further configured to calculate the torsional stiffness influence angle using the following formula:

[0107] T = k·θ;

[0108] Where k is the set stiffness, T is the steering wheel torque, and θ is the torsional stiffness influence angle.

[0109] In one embodiment, the correction angle calculation module 330 calculates the centering position correction angle using the following formula:

[0110] Centering position correction angle = steering wheel sensor detection angle at the time of correction – torsional stiffness influence angle at the time of correction – motor-end steering wheel angle at the time of correction.

[0111] In one embodiment, the steering wheel angle determination module 360 ​​calculates the current real-time steering wheel angle using the following formula:

[0112] The current real-time steering wheel angle = the current real-time motor-end steering wheel angle + the centering position correction angle + the current real-time torsional stiffness influence angle.

[0113] It should be understood that the specific features, operations, and details described hereinabove with respect to the method of the present application may also be similarly applied to the apparatus and system of the present application, or vice versa. In addition, each step of the method of the present application described above may be performed by a corresponding component or unit of the apparatus or system of the present application.

[0114] It should be understood that the various modules / units of the apparatus of the present application may be implemented in whole or in part by software, hardware, firmware, or a combination thereof. Each module / unit may be embedded in the processor of the road sense controller in the form of hardware or firmware or independent of the processor, or may be stored in the memory of the road sense controller in the form of software for the processor to call to execute the operations of each module / unit. Each module / unit may be implemented as an independent component or module, or two or more modules / units may be implemented as a single component or module.

[0115] like Figure 4 As shown, the present application provides a road feel controller 400, which includes a processor 401 and a memory 402 storing computer program instructions. When the processor 401 executes the computer program instructions, each step of the above-mentioned method for determining the steering wheel angle is implemented.

[0116] In one embodiment, the road sense controller 400 may include a processor, a memory, a network interface, a communication interface, etc. connected via a system bus. The processor of the road sense controller 400 may be used to provide necessary computing, processing and / or control capabilities. The memory of the road sense controller 400 may include a non-volatile storage medium and an internal memory. The non-volatile storage medium may store an operating system, a computer program, etc. The internal memory may provide an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The network interface and the communication interface of the road sense controller 400 may be used to connect and communicate with external devices via a network. When the computer program is executed by the processor, the steps of the method of the present application are performed.

[0117] The present application provides a computer-readable storage medium having computer program instructions stored thereon. When the computer program instructions are executed by a processor, the above-mentioned method for determining a steering wheel angle is implemented.

[0118] Those skilled in the art will appreciate that the method steps of the present application can be performed by instructing relevant hardware or processors through a computer program, and the computer program can be stored in a non-transitory computer-readable storage medium, which causes the steps of the present application to be performed when the computer program is executed. Depending on the circumstances, any reference to memory, storage or other media herein may include non-volatile or volatile memory. Examples of non-volatile memory include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic tape, floppy disk, magneto-optical data storage device, optical data storage device, hard disk, solid-state disk, etc. Examples of volatile memory include random access memory (RAM), external cache memory, etc.

[0119] In addition, the present application also provides a steer-by-wire system, which includes the road feel controller in the above embodiment.

[0120] Further, refer to Figure 5 The road sense controller includes a first road sense controller (road sense controller 1) and a second road sense controller (road sense controller 2). The steer-by-wire system also includes a first road sense motor drive (road sense motor drive 1), a second road sense motor drive (road sense motor drive 2), and a road sense motor. The first road sense controller is connected to the second road sense controller, and the first road sense controller is connected to the first road sense motor drive, the second road sense controller is connected to the second road sense motor drive, and both the first road sense motor drive and the second road sense motor drive are connected to the road sense motor.

[0121] Specifically, the first road sense controller and the second road sense controller transmit their calculated steering wheel angles to each other, and output torque request signals to the corresponding first road sense motor driver / second road sense motor driver according to the steering wheel angle. The first road sense motor driver and the second road sense motor driver drive the road sense motor to operate according to the torque request signals. For example Figure 5 As shown, the torque request signal output by the road sense controller 1 to the road sense motor driver 1 is the torque command 1 , and the torque request signal output by the road sense controller 2 to the road sense motor driver 2 is the torque command 2 .

[0122] By adopting two redundant road sense controllers and two road sense motor drives, and using dual-channel independent control, the steering wheel angle is calculated and data is exchanged separately, which can be backed up and mutually verified, making the signal more effective and accurate.

[0123] Specifically, the first and second road-sensing motor drivers each obtain the road-sensing motor encoder angles and can also calculate the current electrical rotation angle based on the road-sensing motor encoder angles. These angles are then sent to the corresponding road-sensing controller via CAN communication. The driver also receives the torque request signal from the road-sensing controller, converts it into a three-phase current, and drives the road-sensing motor. Furthermore, in addition to sending the torque request signal to the road-sensing motor driver, the driver also sends the torque request signal to the actuator motor driver to drive the actuator motor.

[0124] Specifically, the road sensing motor uses a 6-phase motor, one road sensing motor drives and controls three of the phases, and adopts two independent control systems. Each control system can work completely independently to achieve functional backup.

[0125] In one embodiment, reference Figure 5 The above-mentioned steer-by-wire system also includes a torque sensor, a rotation angle sensor, and an encoder angle sensor (not shown). The torque sensor and the rotation angle sensor are arranged on the steering wheel assembly and connected to the first and second road sense controllers. The torque sensor is used to collect the steering wheel torque and send it to the first and second road sense controllers. The rotation angle sensor is used to collect the steering wheel sensor detected angle and send it to the first and second road sense controllers. For example, Figure 5 As shown, the torque sensor measures the steering wheel torque and sends torque signal 1 to road feel controller 1 and torque signal 2 to road feel controller 2; the angle sensor measures the steering wheel torque and detects the steering angle and sends angle signal 1 to road feel controller 1 and angle signal 2 to road feel controller 2.

[0126] The encoder angle sensor is arranged on the road sensing motor and connected to the first road sensing motor driver and the second road sensing motor driver, and is used to collect the road sensing motor encoder angle and send it to the first road sensing motor driver and the second road sensing motor driver.

[0127] By using a torque sensor and a rotation angle sensor to send detection signals to the two road sense controllers respectively, and using an encoder angle sensor to send detection signals to the two road sense motor drivers respectively, dual-channel collection of sensor signals is achieved, allowing the two control systems to collect signals independently.

[0128] Specifically, each sensor signal path consists of a power supply, a signal ground, and a signal line. Zero steering wheel torque is represented by T0. A signal value less than T0 indicates a left turn; a signal value greater than T0 indicates a right turn. The steering angle sensor uses CAN (Controller Area Network) communication to transmit the steering wheel sensor's detected steering angle to Road Sense Controllers 1 and 2. The sensor features a centering calibration function to ensure accurate centering angles and eliminate installation errors.

[0129] In one embodiment, when the steering wheel angle calculated by the first or second road sense controller exceeds a preset range, if the steering wheel sensor detected angle is within the preset range, the steering wheel angle detected by the steering wheel sensor is used as the steering wheel angle. If the steering wheel sensor detected angle exceeds the preset range, an alarm signal is output. This ensures that the final steering wheel angle used is within the normal preset range, improving the accuracy and effectiveness of torque control.

[0130] Taking the first road sense controller as an example, when the calculated steering wheel angle exceeds the preset range, if the steering wheel sensor detection angle collected by this route is within the preset range, the steering wheel sensor detection angle is used as the steering wheel angle of this route to output the torque request signal. When the calculated steering wheel angle and the steering wheel sensor detection angle collected by this route both exceed the preset range, an alarm signal is output to prompt. For the entire wire control system, when the steering wheel angle calculated by one road sense controller exceeds the preset range, and the steering wheel sensor detection angle collected by this route exceeds the preset range, the calculation result of this road sense controller is shielded, and a signal within the normal range is used for control, and an alarm prompt is issued. If the steering wheel angles of both road sense controllers exceed the normal range, and the steering wheel sensor detection angles collected by both routes exceed the preset range, the highest fault level is sent through an alarm signal, and the vehicle control prohibits the vehicle from driving.

[0131] The various technical features described above can be combined arbitrarily. Although not all possible combinations of these technical features are described, any combination of these technical features should be considered to be covered by this specification as long as such combination does not conflict.

[0132] 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 replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for determining a steering wheel angle of a steer-by-wire system, characterized in that: include: After the vehicle is started, when a correction time is detected when a preset correction condition is met, the motor-end sensor data, the steering wheel torque, and the steering wheel sensor detection angle at the correction time are obtained; Calculating the motor-end steering wheel angle at the correction moment based on the motor-end sensor data at the correction moment, and calculating the torsional stiffness influence angle at the correction moment based on the steering wheel torque at the correction moment; Calculating a centering position correction angle based on a motor-end steering wheel angle at the correction moment, a torsional stiffness influence angle at the correction moment, and a steering wheel sensor detection angle at the correction moment; Obtain real-time motor-end sensor data and steering wheel torque; Calculating the current real-time motor-end steering wheel angle according to the real-time motor-end sensor data, and calculating the current real-time torsional stiffness influence angle according to the real-time steering wheel torque; The current real-time steering wheel angle is calculated according to the current real-time motor-end steering wheel angle, the current real-time torsional stiffness influence angle and the centering position correction angle, so as to output a torque request signal according to the current real-time steering wheel angle.

2. The method according to claim 1, characterized in that The motor-end sensor data includes the road-sensing motor encoder angle; The calculating the motor-end steering wheel angle at the correction time according to the motor-end sensor data at the correction time includes: Calculating the electrical rotation angle according to the road sensor motor encoder angle and the number of encoder teeth at the correction moment; The motor-end steering wheel angle corresponding to the correction moment is calculated according to the electric angle, the set shaft angle multiplier and the speed ratio of the road-feeling reduction mechanism.

3. The method according to claim 2, characterized in that The calculating of the motor-end steering wheel angle corresponding to the correction moment according to the electric angle, the set shaft angle multiplier, and the road-sensing deceleration mechanism speed ratio includes calculating according to the following formula: Steering wheel angle at the motor end = electric angle ÷ shaft angle multiplier ÷ road feel reduction mechanism speed ratio.

4. The method according to claim 1, wherein Calculating the torsional stiffness influence angle at the correction moment based on the steering wheel torque at the correction moment includes calculating the torsional stiffness influence angle using the following formula: T = k·θ; Where k is the set stiffness, T is the steering wheel torque, and θ is the torsional stiffness influence angle.

5. The method according to claim 1, wherein Calculating the centering position correction angle according to the motor-end steering wheel angle at the correction moment, the torsional stiffness influence angle at the correction moment, and the steering wheel sensor detection angle at the correction moment includes using the following formula to calculate the centering position correction angle: Centering position correction angle = steering wheel sensor detection angle at the time of correction – torsional stiffness influence angle at the time of correction – motor-end steering wheel angle at the time of correction.

6. The method according to claim 1, characterized in that The calculating the current real-time steering wheel angle according to the current real-time motor-end steering wheel angle, the current real-time torsional stiffness influence angle, and the centering position correction angle includes calculating the current real-time steering wheel angle using the following formula: The current real-time steering wheel angle = the current real-time motor-end steering wheel angle + the centering position correction angle + the current real-time torsional stiffness influence angle.

7. The method according to claim 1, characterized in that The preset correction conditions include: The difference between the collected wheel angle and the collected steering wheel sensor detection angle is less than a preset value.

8. A device for determining the steering wheel angle of a steer-by-wire system, characterized in that: The device comprises: The first data acquisition module is configured to acquire the motor-end sensor data, the steering wheel torque, and the steering wheel sensor detection angle at a correction moment when a preset correction condition is detected after the vehicle is started; a first calculation module, configured to calculate the motor-end steering wheel angle at the correction moment based on the motor-end sensor data at the correction moment, and calculate the torsional stiffness influence angle at the correction moment based on the steering wheel torque at the correction moment; a correction angle calculation module, configured to calculate a centering position correction angle based on a motor-end steering wheel angle at the correction moment, a torsional stiffness influence angle at the correction moment, and a steering wheel sensor detection angle at the correction moment; The second data acquisition module is used to obtain real-time motor-end sensor data and steering wheel torque; a second calculation module, configured to calculate a current real-time motor-end steering wheel angle according to the real-time motor-end sensor data, and calculate a current real-time torsional stiffness influence angle according to the real-time steering wheel torque; A steering wheel angle determination module is used to calculate the current real-time steering wheel angle based on the current real-time motor-end steering wheel angle, the current real-time torsional stiffness influence angle and the centering position correction angle, so as to output a torque request signal based on the current real-time steering wheel angle.

9. A road sense controller, characterized in that: The method comprises a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A steer-by-wire system, characterized in that: include: The road sense controller according to claim 9.

11. The steer-by-wire system according to claim 10, wherein: The road sense controller includes a first road sense controller and a second road sense controller, and the steer-by-wire system also includes a first road sense motor drive, a second road sense motor drive and a road sense motor; The first road sense controller is connected to the second road sense controller, and the first road sense controller is connected to the first road sense motor driver, the second road sense controller is connected to the second road sense motor driver, and the first road sense motor driver and the second road sense motor driver are both connected to the road sense motor; The first road sense controller and the second road sense controller transmit their calculated steering wheel angles to each other, and output a torque request signal to the corresponding first road sense motor drive / second road sense motor drive according to the steering wheel angle; The first road sensing motor driver and the second road sensing motor driver drive the road sensing motor to operate according to the torque request signal.

12. The steer-by-wire system according to claim 10, wherein: It also includes torque sensors, rotation angle sensors and encoder angle sensors; The torque sensor and the rotation angle sensor are arranged on the steering wheel assembly and connected to the first road feel controller and the second road feel controller. The torque sensor is used to collect steering wheel torque and send it to the first road feel controller and the second road feel controller. The rotation angle sensor is used to collect steering wheel angle detected by the steering wheel sensor and send it to the first road feel controller and the second road feel controller. The encoder angle sensor is provided on the road sense motor and connected to the first road sense motor driver and the second road sense motor driver, and is used to collect the road sense motor encoder angle and send it to the first road sense motor driver and the second road sense motor driver.

13. The steer-by-wire system according to claim 10, wherein: When the steering wheel angle calculated by the first road sense controller / the second road sense controller exceeds a preset range, if the obtained steering wheel sensor detected angle is within the preset range, the steering wheel sensor detected angle is used as the steering wheel angle; If the steering wheel sensor detects that the turning angle exceeds the preset range, an alarm signal is output.

Images