Steer-by-wire hand feeling simulation system and method and steering control system

Abstract

The invention discloses a steer-by-wire hand feeling simulation system and method and a steering control system.The simulation system comprises a target hand force calculation module, a torque angle sensor, a motor torque calculation module and a hand force moment calculation module, the motor torque calculation module is used for calculating the torque of a steering wheel, and the hand force moment calculation module is used for calculating the torque of the steering wheel; the output end of the torque and angle sensor is connected to the hand torque calculation module, the torque and angle sensor is used for collecting torque signals and angle signals of a rotating steering wheel, and the output end of the torque and angle sensor is connected to the hand torque calculation module; and the hand torque calculation module judges whether the steering wheel torque is within the range of the torque angle sensor, and if yes, weighted calculation is carried out on the calculated steering wheel torque and the torque value collected by the torque angle sensor to obtain weighted real-time torque, and the weighted real-time torque is transmitted to the target hand torque calculation module. According to the scheme, the steer-by-wire redundant backup is added, and the steer-by-wire safety is improved.

Description

Technical Field

[0001] The present invention relates to the field of automobile steering systems, and in particular to a wire-controlled steering feel simulation system, method and steering control system. Background Art

[0002] As one of the key components of the automobile chassis, the steering system has entered a new stage of development with the advancement of automobile electrification and intelligence, and the steer-by-wire system (SBW) has gradually begun to be used.

[0003] The steer-by-wire system eliminates the mechanical connection between the steering wheel and the wheels. It is the core of the lateral motion control in the steer-by-wire chassis and the actuator for achieving high-level autonomous driving. The steer-by-wire system relies on electrical energy to achieve steering. During operation, sensors detect the driver's steering intention and vehicle driving status, and transmit the data to the electronic control unit in the form of electrical signals. After the electronic control unit calculates and processes, it sends electrical signals to the motor to complete the driving operation.

[0004] Due to the physical decoupling between the steering wheel and the wheels, the steer-by-wire system has higher requirements for safety and reliability. In the event of a single point failure, the steering system is required to still have a certain road feel feedback and steering capability. Redundant steer-by-wire technology helps to solve the driving risk caused by power failure during driving and ensure the safety of the vehicle and passengers.

[0005] The existing wire-controlled steering system mainly includes two parts: the feel simulation actuator and the steering actuator. The road feel simulator includes a steering wheel, a dual redundant torque angle sensor, a road feel motor, a first ECU and a second ECU. The steering actuator consists of a first motor unit, a second motor unit and a steering gear. When either the first motor module or the second motor module fails, the other can work normally.

[0006] The existing technology mainly has the following disadvantages:

[0007] ① Currently, ±10Nm sensors are commonly used in the steering industry, but the torque of the soft stop or locking function of the wire control steering needs to be 40Nm or more, which results in the inability to measure the actual steering wheel torque when a large steering wheel torque is required. If the torque sensor range is increased, the accuracy will be reduced and the cost will increase at low torque.

[0008] ② When the redundant circuits of the torque angle sensor fail, the driver loses effective control of the vehicle and the redundant design is insufficient. Summary of the invention

[0009] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a wire-controlled steering feel simulation system, method and steering control system, improve the wire-controlled steering feel simulator, add a hand torque calculation module and a steering wheel angle calculation module, use the motor torque and angle to calculate the steering wheel torque and angle, as a supplement and redundancy solution for the torque angle sensor, and realize quad redundancy of torque and angle signals on the basis of dual redundant torque sensors.

[0010] In order to achieve the above object, the technical solution adopted by the present invention is: a wire-controlled steering feel simulation system, the system includes a target hand force calculation module, a torque angle sensor, the system also includes a motor torque calculation module, a hand torque calculation module, the motor torque calculation module is used to calculate the steering wheel torque, and its output end is connected to the hand torque calculation module, the torque angle sensor is used to collect the steering wheel torque signal and the angle signal, and its output end is connected to the hand torque calculation module;

[0011] The hand force calculation module determines whether the steering wheel torque is within the range of the torque angle sensor. If so, the calculated steering wheel torque and the torque value collected by the torque angle sensor are weighted to obtain the weighted real-time torque and transmit it to the target hand force calculation module.

[0012] The system also includes a steering wheel angle calculation module and a motor angle conversion calculation module connected; the motor angle conversion calculation module calculates the calculated angle A2 based on the motor angle position, and the steering wheel angle signal A1 collected by the torque angle sensor is sent to the steering wheel angle calculation module;

[0013] The steering wheel angle calculation module determines whether the steering wheel angle is within the range of the torque angle sensor. If so, the angles A2 and A1 are weighted and sent to the target rack position calculation module to achieve vehicle control.

[0014] When the steering wheel torque exceeds the measuring range of the torque angle sensor, the steering wheel torque calculated by the motor torque calculation module is output to the target hand force calculation module.

[0015] When the hand force torque calculation module determines that the torque acquisition function of the torque angle sensor fails, the steering wheel torque calculated by the motor torque calculation module is output to the target hand force calculation module.

[0016] When the steering wheel angle exceeds the angle range of the torque angle sensor, the motor angle conversion calculation module calculates the calculated angle A2 based on the motor angle position and directly sends it to the target rack position calculation module.

[0017] When the steering wheel angle calculation module determines that the angle acquisition function of the torque angle sensor fails, the motor angle conversion calculation module directly sends the calculated angle A2 calculated based on the motor angle position to the target rack position calculation module.

[0018] A method for simulating the feel of a wire-controlled steering system comprises the following steps:

[0019] The torque value T1 of the steering wheel is collected by the torque angle sensor; the steering wheel torque value T2 is obtained by converting the motor torque calculation; the weights of the torque values ​​T1 and T2 are allocated according to the relationship between the torque value T1 and the torque range of the torque angle sensor, and then the hand torque value T3 is obtained by weighted calculation as the input value of the target hand force calculation module.

[0020] The method further includes collecting a steering wheel angle value A1 through a torque angle sensor, and converting it according to the motor rotation position to obtain a steering wheel angle A2 calculated based on the motor;

[0021] The weights of angles A1 and A2 are allocated according to the relationship between the rotation angle A1 and the angle range of the torque angle sensor, and then the angle value A3 is obtained through weighted calculation, and the angle value A3 is used as the input of the target rack position calculation module.

[0022] When performing weight allocation, if the signal of the torque angle sensor is lost or invalid, the weight of the signal collected by the torque angle sensor is set to 0.

[0023] A steer-by-wire control system, and a steer-by-wire feel simulation system.

[0024] The advantages of the present invention are: improving the wire-controlled steering feel simulator, adding a hand torque calculation module and a steering wheel angle calculation module, using the motor torque and angle to calculate the torque and angle of the steering wheel, as a supplement and redundancy solution for the torque angle sensor, and realizing quad redundancy of torque and angle signals on the basis of the dual redundant torque sensor. Without increasing the hardware cost, the hand force closed-loop control of the feel simulator beyond the sensor range is realized, the feel simulator hand control and vehicle control are realized after the torque angle fails, the redundant backup of the wire-controlled steering is increased, and the safety of the wire-controlled steering is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The following is a brief description of the contents expressed in the drawings of the present invention and the symbols in the drawings:

[0026] Figure 1 This is a structural block diagram of the wire-controlled steering system of the present invention;

[0027] Figure 2 This is a schematic diagram of the hand torque calculation module of the present invention;

[0028] Figure 3 This is a schematic diagram of the steering wheel angle calculation module of the present invention. DETAILED DESCRIPTION

[0029] The specific implementation of the present invention will be further explained in detail below by describing the optimal embodiment with reference to the accompanying drawings.

[0030] In the prior art, the hand feel simulator includes a target hand force calculation module and a target rack position calculation module. The target hand force calculation module is used to calculate the control torque required by the corresponding matching wire-controlled steering system ECU according to the torque of the steering wheel to achieve control of the steering torque; the target rack position calculation module is used to calculate the current position used to control the tire according to the turning angle, and provide control parameters for subsequent wire-controlled steering through the rack position. Since both modules can only be realized based on accurate turning angle and torque, this solution mainly controls the torque and turning angle input into these two modules to achieve accurate, reliable and redundant input of torque and turning angle into these two modules.

[0031] like Figure 1-3 As shown, the present solution provides a wire-controlled steering feel simulation system, the feel simulation system includes a target hand force calculation module, a torque angle sensor, a motor torque calculation module, and a hand moment calculation module;

[0032] The torque angle sensor is used to collect the torque value and angle data when the steering wheel is turned. For safety and reliability, it can adopt a dual redundant setting, using dual redundant torque angle sensors to reduce the risk of torque sensor failure. The output end of the torque angle sensor is connected to the hand torque calculation module.

[0033] The motor torque calculation module is used to calculate the steering wheel torque, and its output end is connected to the hand torque calculation module. Here, the motor torque calculation module can obtain the calculated steering wheel torque T2 based on the torque of the road sense motor through calculation and conversion, which is input into the hand torque calculation module.

[0034] The torque angle sensor is a two-in-one integrated sensor, which can collect the steering wheel torque signal T1 and the angle signal A1. Here, the output end corresponding to the collected steering wheel torque signal is connected to the hand torque calculation module, so as to realize the sending of the angle signal collected by the torque angle sensor to the hand torque calculation module.

[0035] The hand torque calculation module determines whether the steering wheel torque is within the range of the torque angle sensor. If so, the calculated steering wheel torque and the torque value collected by the torque angle sensor are weighted to obtain the weighted real-time torque and transmit it to the target hand force calculation module. The judgment on the range is to avoid the defect of inaccurate measurement of the torque angle sensor due to the range problem. In this solution, the torque T1 collected by the torque angle sensor is used to determine its relationship with the range. If it is within the range, the hand torque is weighted by torque T1 and torque T2 to obtain the corresponding torque T3 as the input torque value of the target hand force calculation module.

[0036] When performing weight distribution, it is determined whether the sensor range is exceeded based on the torque T2. If the steering wheel torque T2 value exceeds the maximum value of the torque angle sensor range, the steering wheel torque T2 calculated by the motor torque calculation module is directly output to the target hand force calculation module, and the target hand force calculation module calculates the target hand force based on the input torque value. Since the T1 value collected by the sensor after exceeding the range cannot be accurate, T2 is used to determine whether the range is exceeded and the torque T2 is directly used as the input of the target force calculation module after it is determined to exceed the range.

[0037] In a preferred embodiment, when the hand torque calculation module determines that the torque acquisition function of the torque angle sensor fails, the steering wheel torque T2 calculated by the motor torque calculation module is output to the target hand force calculation module. The failure of the sensor includes multiple ways such as the data output by the sensor is obviously abnormal, exceeds the range, is not within the normal range, and any of these ways can determine that the sensor is abnormal or the sensor acquisition function fails. After the sensor function fails, in order to achieve redundancy and safety and reliability, this solution uses torque T2 to directly send it to the target hand force calculation module.

[0038] In this embodiment, the system further includes a steering wheel angle calculation module and a motor angle conversion calculation module; the motor angle conversion calculation module calculates the calculated angle A2 based on the motor angle position, and the steering wheel angle signal A1 collected by the torque angle sensor is sent to the steering wheel angle calculation module;

[0039] The torque angle sensor is a two-in-one sensor that can collect the torque and angle of the steering wheel respectively. Its angle output end is connected to the steering wheel angle calculation module to input the collected steering wheel angle into the steering wheel angle calculation module. The motor angle conversion calculation module obtains the calculated steering wheel angle A2 through conversion and calculation based on the motor position collected by the motor position sensor. Since there is a corresponding relationship between the steering wheel and the motor, the angle data can also be calculated through the motor position conversion. This angle data also belongs to the steering wheel angle, but it is calculated through different angle conversions.

[0040] The steering wheel angle calculation module inputs angles A1 and A2 respectively. The steering wheel angle calculation module determines whether the steering wheel angle is within the range of the torque angle sensor. If so, the angles A2 and A1 are weighted and sent to the target rack position calculation module to achieve vehicle control. The steering wheel angle calculation module determines whether the steering wheel angle is within the range of the torque angle sensor. If so, the calculated steering wheel angle A2 and the angle value A1 collected by the torque angle sensor are weighted to obtain the weighted real-time angle A3 and transmit it to the target rack position calculation module. The judgment on the range is to avoid the defect of inaccurate measurement of the torque angle sensor due to the range problem. In this scheme, the relationship between the angle A1 collected by the torque angle sensor and the range is judged. If it is within the range, the corresponding angle A3 is obtained by weighted calculation through angles A1 and A2 as the input of the target rack position calculation module.

[0041] When the steering wheel angle exceeds the angle range of the torque angle sensor, the motor angle conversion calculation module calculates the calculated angle A2 based on the motor angle position and directly sends it to the target rack position calculation module. When the steering wheel angle calculation module determines that the angle acquisition function of the torque angle sensor fails, the motor angle conversion calculation module calculates the calculated angle A2 based on the motor angle position and directly sends it to the target rack position calculation module.

[0042] When performing weight distribution, the angle A2 is used to determine whether the sensor range is exceeded. If the value of the angle A2 exceeds the maximum value of the torque angle sensor range, the calculated angle A2 is directly output to the target rack position calculation module. Since the A1 value collected by the sensor after exceeding the range cannot be accurate, A2 is used to determine whether the range is exceeded, and after determining that the range is exceeded, the torque A2 is directly used as the input of the target rack position calculation module.

[0043] This embodiment also provides a method for simulating the feel of a wire-controlled steering system, comprising the following steps:

[0044] The torque value T1 of the steering wheel is collected by the torque angle sensor; the steering wheel torque value T2 is obtained by converting the motor torque calculation;

[0045] The weights of the torque values ​​T1 and T2 are allocated according to the relationship between the torque value T1 and the torque range of the torque angle sensor, and then the hand torque value T3 is obtained by weighted calculation as the input value of the target hand force calculation module.

[0046] The simulation method further includes: collecting a steering wheel angle value A1 through a torque angle sensor, and converting it according to a motor rotation position to obtain a steering wheel angle A2 calculated based on the motor;

[0047] The weights of angles A1 and A2 are allocated according to the relationship between the rotation angle A1 and the angle range of the torque angle sensor, and then the angle value A3 is obtained through weighted calculation, and the angle value A3 is used as the input of the target rack position calculation module.

[0048] When performing weight distribution, if the signal of the torque angle sensor is lost or invalid, the weight of the signal collected by the torque angle sensor is set to 0. When within the range, the weighted coefficients of the two can be pre-calibrated. The specific design is as follows:

[0049] The hand torque calculation module includes:

[0050] a) Motor torque T 机 Multiply it by the transmission ratio i1 from the steering wheel to the motor, and then divide it by the transmission efficiency g to get the hand torque T2.

[0051] T2=T 机 ×i1÷g

[0052] b) The weight coefficient module allocates the weights of T1 and T2 according to the size of the hand torque T1:

[0053] ①When T1 is greater than the torque sensor range T 量 When it is 90% (calibrable), the weight Q1 of T1 is 0, and the weight of T2 is 1.

[0054] ②When T1 is less than the torque sensor range T 量 When the value is 90% (calibrable), the weight of T1 is Q1 (0<Q1≤1), and the weight of T2 is 1-Q1. When Q1=1, the weight of T2 is 0.

[0055] ③When the T1 signal is lost or invalid, the weight of T1 is Q1=0 and the weight of T2 is 1.

[0056] c) Hand torque T3 = T1 × Q1 + T2 × (1 – Q1)

[0057] The hand torque T3 is used to be input into the target hand force calculation module, and T3 is calculated according to the above scheme to obtain the corresponding value.

[0058] The steering wheel angle calculation module includes:

[0059] a) After the steering system is assembled on the vehicle, the steering wheel is centered and the steering wheel zero position is initialized, and the motor angle A is memorized 0, This motor angle is used as the initial angle for steering wheel zero position calculation.

[0060] b) Motor angular position A 机 Subtract A 0, Divide by the steering wheel to motor transmission ratio i1 to get the steering wheel angle A2 calculated based on the motor

[0061] A2=(A 机 -A0) / i1

[0062] c) The weight coefficient module allocates the weights of A1 and A2 according to the size of the steering wheel angle A1:

[0063] ①When A1 is greater than the angle range A 量 90% (calibrable), the weight of A1 is Q A =0, the weight of A2 is 1.

[0064] ②When A1 is less than the angle range A 量 90% (calibrable), the weight of A1 is Q A (Adjustable, 0<Q A ≤1), the weight of A2 is 1-Q A When Q A When =1, the weight of A2 is 0.

[0065] ③When the A1 signal is lost or invalid, the weight Q of A1 A =0, the weight of A2 is 1.

[0066] d) Steering wheel angle A3 = A1 × Q A +A2×(1–Q A )

[0067] The steering wheel angle A3 is used to be input into the target rack position calculation module. The angle A3 is weighted according to the above calculation scheme to obtain the angle and is sent to the target rack position calculation module.

[0068] In one embodiment, the present solution further provides a steer-by-wire control system, which includes the steer-by-wire feel simulation system in the above-mentioned embodiment.

[0069] In this scheme, this scheme adopts:

[0070] (I) Use the motor torque to calculate the steering wheel torque. When the steering wheel torque is in mass production, it is consistent with the sensor.

[0071] The real-time hand torque is calculated by weighting the actual measured value of the device and output to the target hand force calculation module as the steering wheel hand force value.

[0072] (2) When the steering wheel torque exceeds the range, the steering wheel hand torque is calculated by the motor torque and output to the target hand force

[0073] Computing module.

[0074] (III) When the torque angle sensor fails, the hand force calculated by the motor torque is used as the steering wheel hand force value

[0075] Output to the target hand force calculation module.

[0076] (IV) When the torque angle sensor fails, the steering wheel angle is calculated by the motor position sensor and output

[0077] Provide the target rack position calculation module to realize the control of the vehicle.

[0078] By adopting the above scheme, closed-loop control of hand force of the feel simulator beyond the sensor range can be realized without increasing the cost. After the torque angle fails, the feel simulator hand control and vehicle control are realized, and the redundant backup of the wire control steering is increased to improve the safety of the wire control steering.

[0079] Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, they are all within the protection scope of the present invention.

Claims

1. A steering-by-wire feel simulation system, comprising a target hand force calculation module and a torque angle sensor, characterized in that: The system also includes a motor torque calculation module and a hand torque calculation module. The motor torque calculation module is used to calculate the steering wheel torque, and its output end is connected to the hand torque calculation module. The torque angle sensor is used to collect the steering wheel torque signal and the angle signal, and its output end is connected to the hand torque calculation module. The hand force calculation module determines whether the steering wheel torque is within the range of the torque angle sensor. If so, the calculated steering wheel torque and the torque value collected by the torque angle sensor are weighted to obtain the weighted real-time torque and transmit it to the target hand force calculation module.

2. A steering-by-wire feel simulation system as claimed in claim 1, characterized in that: The system also includes a steering wheel angle calculation module and a motor angle conversion calculation module connected; the motor angle conversion calculation module calculates the calculated angle A2 based on the motor angle position, and the steering wheel angle signal A1 collected by the torque angle sensor is sent to the steering wheel angle calculation module; The steering wheel angle calculation module determines whether the steering wheel angle is within the range of the torque angle sensor. If so, the angles A2 and A1 are weighted and sent to the target rack position calculation module to achieve vehicle control.

3. A steering-by-wire feel simulation system as claimed in claim 1, characterized in that: When the steering wheel torque exceeds the measuring range of the torque angle sensor, the steering wheel torque calculated by the motor torque calculation module is output to the target hand force calculation module.

4. A steering-by-wire feel simulation system as claimed in claim 2, characterized in that: When the hand force torque calculation module determines that the torque acquisition function of the torque angle sensor fails, the steering wheel torque calculated by the motor torque calculation module is output to the target hand force calculation module.

5. The steering-by-wire feel simulation system according to claim 2, characterized in that: When the steering wheel angle exceeds the angle range of the torque angle sensor, the motor angle conversion calculation module calculates the calculated angle A2 based on the motor angle position and directly sends it to the target rack position calculation module.

6. A steering-by-wire feel simulation system as claimed in claim 2, characterized in that: When the steering wheel angle calculation module determines that the angle acquisition function of the torque angle sensor fails, the motor angle conversion calculation module directly sends the calculated angle A2 calculated based on the motor angle position to the target rack position calculation module.

7. A method for simulating the feel of a wire-controlled steering vehicle, characterized in that: The steps include: The torque value T1 of the steering wheel is collected by the torque angle sensor; the steering wheel torque value T2 is obtained by converting the motor torque calculation; the weights of the torque values ​​T1 and T2 are allocated according to the relationship between the torque value T1 and the torque range of the torque angle sensor, and then the hand torque value T3 is obtained by weighted calculation as the input value of the target hand force calculation module.

8. A method for simulating steering feel by wire according to claim 7, characterized in that: The method further includes collecting a steering wheel angle value A1 through a torque angle sensor, and converting it according to the motor rotation position to obtain a steering wheel angle A2 calculated based on the motor; The weights of angles A1 and A2 are allocated according to the relationship between the rotation angle A1 and the angle range of the torque angle sensor, and then the angle value A3 is obtained through weighted calculation, and the angle value A3 is used as the input of the target rack position calculation module.

9. A method for simulating steering-by-wire feel according to claim 7 or 8, characterized in that: When performing weight allocation, if the signal of the torque angle sensor is lost or invalid, the weight of the signal collected by the torque angle sensor is set to 0.

10. A steer-by-wire control system, characterized in that: The steer-by-wire control system comprises a steer-by-wire feel simulation system as described in any one of claims 1-6.

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