Steer-by-wire feel simulation system, method, and steering control system

Abstract

The application discloses a kind of steer-by-wire steering feel simulation system, method and steering control system, the simulation system includes target hand force calculation module, torque angle sensor, the system also includes motor torque calculation module, hand torque calculation module, the motor torque calculation module is used to calculate steering wheel torque, its output end is connected to hand torque calculation module, the torque angle sensor is used to collect rotating steering wheel torque signal, angle signal, its output end is connected to hand torque calculation module;The hand torque calculation module judges whether steering wheel torque is in torque angle sensor range, if yes, then the calculated steering wheel torque and the torque value of torque angle sensor acquisition are weighted to obtain weighted real-time torque and transmit to target hand force calculation module.The scheme increases steer-by-wire redundancy backup, improves the safety of steer-by-wire.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobile steering systems, in particular to a steer-by-wire steering feel simulation system and method and a steering control system. BACKGROUND

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

[0003] The steer-by-wire system cancels the mechanical connection between the steering wheel and the wheels, is the core of the steer-by-wire chassis for controlling lateral movement, and is the actuator for realizing high-order automatic driving. The steer-by-wire system relies on electric energy to realize steering. In the working process, the driver's steering intention and the vehicle's running state are detected by sensors, and the data are transmitted to the electronic control unit in the form of electric signals. After the calculation and processing of the electronic control unit, the electric signals are sent to the motor to complete the driving operation.

[0004] Since the steering wheel and the wheels are decoupled, the steer-by-wire system has higher requirements for safety and reliability. In the case of single-point failure, the steering system is still required to have certain road feel feedback and steering ability. Redundant steer-by-wire technology helps to solve the driving risk problem caused by the failure of power assistance during driving and ensures the safety of the vehicle and passengers.

[0005] The existing steer-by-wire system mainly includes a feel simulation actuator and a steering actuator. The feel simulator includes a steering wheel, a dual-redundant torque and angle sensor, a road feel motor, a first ECU, and a second ECU. The steering actuator is composed of a first motor unit, a second motor unit, and a steering gear. When any one of the first motor module and the second motor module fails, the other one can work normally.

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

[0007] ①The current steering industry generally uses ±10Nm sensors, while the torque required for the soft stop or locking function of the steer-by-wire system is 40Nm or more, which results in the inability to measure the true steering wheel torque when a large steering wheel torque is required. If the torque sensor range is increased, it will also cause a decrease in precision at low torque and an increase in cost.

[0008] ②When the torque and angle sensor redundancy circuit fails, the driver loses effective control of the vehicle, and the redundancy design is not sufficient. SUMMARY

[0009] The present application aims to overcome the deficiencies of the prior art, and provide a steer-by-wire steering feel simulation system, method and steering control system, which improves the steer-by-wire steering feel simulator, adds a hand torque calculation module and a steering wheel angle calculation module, calculates the torque and angle of the steering wheel by using the motor torque and angle, as a supplement and redundancy scheme of the torque and angle sensor, and realizes four redundancies of the torque and angle signals on the basis of the double-redundancy torque sensor.

[0010] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows: a steer-by-wire steering feel simulation system, the system comprising a target hand force calculation module and a torque and angle sensor, the system further comprising a motor torque calculation module and a hand torque calculation module, the motor torque calculation module being used to calculate the steering wheel torque, and the output end of the motor torque calculation module being connected to the hand torque calculation module, and the torque and angle sensor being used to collect the steering wheel torque signal and the angle signal, and the output end of the torque and angle sensor being connected to the hand torque calculation module.

[0011] The hand torque calculation module judges whether the steering wheel torque is within the torque and angle sensor range, if yes, the calculated steering wheel torque and the torque value collected by the torque and angle sensor are weighted to obtain the weighted real-time torque, and the weighted real-time torque is transmitted to the target hand force calculation module.

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

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

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

[0015] When the torque collection function of the torque and 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 and angle sensor, the calculation angle A2 calculated by the motor angle conversion calculation module based on the motor angle position is directly sent to the target rack position calculation module.

[0017] When the steering wheel angle calculation module judges that the angle acquisition function of the torque angle sensor is invalid, the motor angle conversion calculation module calculates a calculated angle A2 based on the motor angle position and directly sends the calculated angle A2 into the target rack position calculation module.

[0018] A steer-by-wire feel simulator method, comprising 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 motor torque conversion, 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, then the hand torque value T3 is obtained by weighted calculation, and the hand torque value T3 is taken as the input value of the target hand force calculation module.

[0020] The method further comprises collecting the angle value A1 of the steering wheel by the torque angle sensor, and obtaining the steering wheel angle A2 calculated based on the motor according to motor rotation position conversion;

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

[0022] When the weights are allocated, 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, wherein the steer-by-wire control system comprises the steer-by-wire feel simulator.

[0024] The advantages of the present application are as follows: the steer-by-wire feel simulator is improved, the hand torque calculation module and the steering wheel angle calculation module are added, the torque and the angle of the steering wheel are calculated by using the motor torque and the motor angle, which is a complementary and redundant scheme of the torque angle sensor, on the basis of the double-redundant torque sensor, four-redundant torque and angle signals are realized, the hand feel simulator hand force closed-loop control of super-sensor range is realized without increasing the hardware cost, the hand feel simulator hand feel control and vehicle control are realized after the torque angle is invalid, the steer-by-wire redundancy backup is increased, and the steer-by-wire safety is improved. BRIEF DESCRIPTION OF DRAWINGS

[0025] The content expressed by each figure in the specification of the present application and the marks in the figures are briefly described as follows:

[0026] Fig. 1 It is a structure block diagram of the steer-by-wire system of the present application.

[0027] Fig. 2 It is a schematic diagram of the hand torque calculation module of the present application.

[0028] Fig. 3 The steering wheel rotation angle calculation module schematic diagram of the present application. DETAILED DESCRIPTION

[0029] The specific embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0030] In the prior art, the hand feeling 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 corresponding matched control torque required by the ECU of the steer-by-wire system according to the torque of the steering wheel to realize the control of the steering torque, and the target rack position calculation module is used to calculate the current position used to control the tire according to the rotation angle, and the rack position is used to provide a control parameter for the subsequent steer-by-wire. Since both modules can be realized according to the accurate rotation angle and torque, the present scheme mainly controls the torque and rotation angle input into the two modules to realize accurate and reliable input of torque and rotation angle into the two modules.

[0031] As shown in Figs. 1-3 The hand feeling simulation system provided by the present scheme includes a target hand force calculation module, a torque rotation angle sensor, a motor torque calculation module, and a hand torque calculation module.

[0032] The torque rotation angle sensor is used to collect the torque value and rotation angle data when the steering wheel is rotated, and in order to be safe and reliable, it can be provided in a double-redundancy manner, that is, a double-redundancy torque rotation angle sensor is used to reduce the risk of torque sensor failure. The output end of the torque rotation 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 the output end thereof 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 feeling motor through calculation and conversion, and the steering wheel torque T2 is input to the hand torque calculation module.

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

[0035] The hand torque calculation module judges whether the steering wheel torque is within the torque angle sensor range. If yes, 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 transmitted to the target hand force calculation module. The judgment of the range is to avoid the inaccuracy of the torque angle sensor caused by the range problem. In this scheme, the torque T1 collected by the torque angle sensor is used to judge the relationship between the torque and the range. If the torque is within the range, the hand torque is weighted by the torque T1 and the torque T2 to obtain the corresponding torque T3 as the input torque value of the target hand force calculation module.

[0036] When the weight distribution is performed, whether the torque T2 exceeds the sensor range is judged. If the value of the steering wheel torque T2 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 according to the input torque value. Since the T1 value collected by the sensor after exceeding the range cannot be accurate, T2 is used to judge whether the range is exceeded, and the torque T2 is directly used as the input of the target force calculation module after judging that the range is exceeded.

[0037] In a preferred embodiment, when the torque collection function of the torque angle sensor is judged to be invalid by the hand torque calculation module, 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 the following modes: the output data of the sensor is obviously abnormal, exceeds the range, is not within the normal range, etc. Any mode can be used to judge the abnormality of the sensor or the failure of the sensor collection function. After the failure of the sensor function, in order to achieve the purpose of redundancy and safety and reliability, the torque T2 is directly transmitted to the target hand force calculation module.

[0038] In this embodiment, the system further comprises 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.

[0039] The torque angle sensor is a two-in-one sensor, which can collect the torque and the angle of the steering wheel respectively, and the angle output end is connected to the steering wheel angle calculation module, which is used to send the collected steering wheel angle to the steering wheel angle calculation module. The motor angle conversion calculation module obtains the calculated steering wheel angle A2 by 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 representing the steering wheel can also be calculated by converting the motor position.

[0040] The steering wheel angle calculation module inputs the angles A1 and A2, judges whether the steering wheel angle is within the range of the torque angle sensor, if yes, performs weighted calculation on the angles A2 and A1 and sends the result to the target rack position calculation module to control the vehicle. The steering wheel angle calculation module judges whether the steering wheel angle is within the range of the torque angle sensor, if yes, performs weighted calculation on the calculated steering wheel angle A2 and the angle value A1 collected by the torque angle sensor to obtain the weighted real-time angle A3 and transmits it to the target rack position calculation module. The judgment of the range is to avoid the inaccuracy of the torque angle sensor caused by the range problem. In this scheme, the angle A1 collected by the torque angle sensor is used to judge the relationship between the angle and the range. If the angle is within the range, the corresponding angle A3 is obtained by weighted calculation of the angles A1 and A2 and is used 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 angle A2 based on the motor angle position and directly sends it to the target rack position calculation module. When the angle collection function of the torque angle sensor fails, the motor angle conversion calculation module calculates the angle A2 based on the motor angle position and directly sends it to the target rack position calculation module.

[0042] When performing weight distribution, it is judged whether the angle A2 exceeds the sensor range. 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 judge whether the range is exceeded and the torque A2 is directly used as the input of the target rack position calculation module after judging that the range is exceeded.

[0043] The embodiment also provides a steer-by-wire steering feel simulation method, which includes the following steps:

[0044] The torque value T1 of the steering wheel is collected by the torque angle sensor, and the steering wheel torque value T2 is calculated and converted by the motor torque;

[0045] The weights of the torque values T1 and T2 are distributed 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 calculated by weighted calculation and used as the input value of the target hand torque calculation module.

[0046] The simulation method also includes collecting the steering wheel angle value A1 by the torque angle sensor and calculating and converting the steering wheel angle A2 based on the motor rotation position.

[0047] According to the relationship between the angle A1 and the angle range of the torque angle sensor, the weight of the angle A1 and A2 is allocated, and then the angle value A3 is calculated by weighting, and the angle value A3 is taken as the input of the target rack position calculation module.

[0048] When the weight is allocated, 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 in the range, the coefficients of the two weightings can be calibrated as follows:

[0049] The hand torque calculation module includes:

[0050] a) The motor torque T 机 is multiplied by the transmission ratio i1 from the steering wheel to the motor, and then divided by the transmission efficiency g to obtain the hand torque T2.

[0051] T2 = T 机 × i1 ÷ g

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

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

[0054] ② When T1 is less than 90% (calibratable) of the torque sensor range T 量 , 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] ③ When the T1 signal is lost or invalid, the weight Q1 of T1 is 0, and the weight of T2 is 1.

[0056] c) The hand torque T3 = T1 × Q1 + T2 × (1-Q1)

[0057] The hand torque T3 is used as the input to the target hand torque 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 completed on the vehicle, the steering wheel is centered, the steering wheel zero position is initialized, and the motor angle A 0, is memorized. This motor angle is used as the initial angle for calculating the steering wheel zero position.

[0060] b) The motor angle position A 机 is subtracted from A 0, , and then divided by the transmission ratio i1 from the steering wheel to the motor to obtain the steering wheel angle A2 calculated based on the motor

[0061] A2=(A 机 -A0) / i1

[0062] c) The weighting coefficient module assigns weights to A1 and A2 based on the size of the steering wheel angle A1:

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

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

[0065] ③ When 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 input into the target rack position calculation module. Angle A3 is weighted according to the above calculation scheme to obtain the angle and then sent into the target rack position calculation module.

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

[0069] In this plan, the following approach was adopted:

[0070] (a) The steering wheel torque is calculated using the motor torque. When the steering wheel torque is within the range of mass-produced sensors, it is related to the sensor...

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

[0072] (ii) 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] Calculation 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] The output is sent 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 the output

[0077] The target rack position calculation module realizes control of the vehicle.

[0078] The above scheme can realize the hand feeling simulator hand force closed loop control without increasing the cost. After the torque angle fails, the hand feeling simulator hand feeling control and vehicle control are realized, the redundant backup of the steer-by-wire is increased, and the safety of the steer-by-wire is improved.

[0079] Obviously, the specific implementation of the present application is not limited by the above manner, and various non-essential improvements made by adopting the method concept and technical scheme of the present application are within the protection scope of the present application.

Claims

1. A steer-by-wire feel emulation system, the system comprising a target hand force calculation module, a torque-to-angle sensor, characterized in that: The system further comprises a motor torque calculation module and a hand torque calculation module, the motor torque calculation module is based on the torque of the road feel motor to obtain the calculated steering wheel torque by calculation and conversion, and an output end of the motor torque calculation module 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 an output end of the torque angle sensor is connected to the hand torque calculation module; The hand torque calculation module judges whether the steering wheel torque is within the torque angle sensor range, if yes, 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 are transmitted to the target hand force calculation module.

2. A by-wire steering feel simulation system as recited in claim 1, characterized by: The system further comprises a steering wheel angle calculation module and a motor angle conversion calculation module; the motor angle conversion calculation module is based on the motor angle position to obtain the calculated angle A2, 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 judges whether the steering wheel angle is within the torque angle sensor range, if yes, the angles A2 and A1 are weighted and then are sent to the target rack position calculation module to realize the control of the vehicle.

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

4. A by-wire steering feel simulation system as recited in claim 2, characterized by: When the torque collection 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. A by-wire steering feel simulation system as recited in claim 2, characterized by: When the steering wheel angle exceeds the angle range of the torque angle sensor, the calculated angle A2 obtained by the motor angle conversion calculation module based on the motor angle position is directly sent to the target rack position calculation module.

6. A by-wire steering feel simulation system as recited in claim 2, characterized by: When the angle collection function of the torque angle sensor fails, the calculated angle A2 obtained by the motor angle conversion calculation module based on the motor angle position is directly sent to the target rack position calculation module.

7. A steer-by-wire feel emulation method characterized by: The method comprises the following steps: The torque value T1 of the steering wheel is collected by the torque angle sensor; the steering wheel torque value T2 is obtained by calculation and conversion based on the torque of the road feel motor; 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, which is used as the input value of the target hand force calculation module.

8. A steer-by-wire feel simulator method as described in claim 7, wherein: The method further comprises collecting the steering wheel angle value A1 by the torque angle sensor, and converting the steering wheel angle A2 based on the motor calculation according to the motor rotation position; The weights of the angles A1 and A2 are allocated according to the relationship between the angle A1 and the angle range of the torque angle sensor, and then the angle value A3 is obtained by weighted calculation, which is used as the input of the target rack position calculation module.

9. A steer-by-wire feel simulator method according to claim 7 or 8, characterized in that: When the weights are allocated, 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 by: The steer-by-wire control system comprises the steer-by-wire hand feeling simulation system according to any one of claims 1-6.

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