Device for suppressing steering wheel shimmy during high speed driving of a vehicle

Abstract

The application discloses a device for suppressing steering wheel shaking during high-speed driving of a vehicle, comprising an ABS system, an EPS angle sensor, an EPS torque sensor, an EPS controller and an EPS motor; the ABS system is used for collecting a vehicle speed signal, a left front wheel speed signal and a right front wheel speed signal; the EPS controller obtains a hand torque signal and a rotation angle signal applied on the steering wheel by a driver from the EPS torque sensor and the EPS angle sensor; the EPS controller controls the EPS motor to execute a motor control instruction; compared with the prior art, the application can suppress the steering wheel shaking during high-speed driving of the vehicle, and improves driving comfort and safety.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobiles, in particular to a device for suppressing steering wheel shaking during high-speed driving of a vehicle. BACKGROUND

[0002] During high-speed driving of a vehicle, the driver can directly perceive the shaking of the steering wheel, which directly affects the operation stability and driving smoothness of the vehicle. When the vehicle is driving straight on a smooth road, even if there is no obvious road shaking input, the steering wheel shaking problem can still occur due to poor dynamic balance of the wheel tire and other reasons. The steering wheel of the vehicle is mechanically connected to the wheels through the steering column and the steering gear, so that the road excitation or poor balance of the tire during the service life of the tire can be transmitted to the steering wheel through the steering mechanical system, such as the steering column and the steering gear, to cause the steering wheel to vibrate, thereby affecting the operation of the driver, causing the driver to complain, and affecting the driving experience and driving safety. In severe cases, the shaking of the steering wheel can cause the driver's arms to be numb and the mood to be upset, which poses a serious safety hazard. SUMMARY

[0003] The technical problem to be solved by the present application is to provide a method for suppressing steering wheel shaking during high-speed driving of a vehicle.

[0004] To solve the above technical problem, the present application provides a device for suppressing steering wheel shaking during high-speed driving of a vehicle, which comprises an ABS system, an EPS angle sensor, an EPS torque sensor, an EPS controller and an EPS motor.

[0005] The ABS system is used to collect a vehicle speed signal, a left front wheel speed signal and a right front wheel speed signal; the EPS controller obtains a hand torque signal and a steering angle signal applied by the driver on the steering wheel from the EPS torque sensor and the EPS angle sensor; and the EPS controller controls the EPS motor to execute a motor control instruction.

[0006] The EPS controller comprises a signal preprocessing module, a function state machine, an adaptive torque controller and a current controller.

[0007] The signal preprocessing module calculates a wheel rotation frequency according to the left front wheel speed signal and / or the right front wheel speed signal, and calculates a steering wheel vibration amplitude and a steering wheel vibration frequency according to the hand torque signal.

[0008] The function state machine is used to start or stop the adaptive torque controller according to a preset condition.

[0009] The adaptive torque controller is used to generate an adaptive torque compensation wave, the adaptive torque compensation wave is generated according to a same-frequency excitation wave and a steering wheel vibration wave, the same-frequency excitation wave is generated according to the wheel rotation frequency, and the steering wheel vibration wave is generated according to the steering wheel vibration amplitude.

[0010] The current controller converts the adaptive torque compensation wave into a current signal for controlling the EPS motor.

[0011] Preferably, the formula for calculating the wheel rotation frequency is f=v / 2πR, where f is the wheel rotation frequency, v is the average of the left front wheel speed signal and / or the right front wheel speed signal, and R is the wheel rolling radius.

[0012] Preferably, the hand torque signal is filtered using mean filtering before calculating the steering wheel vibration amplitude and frequency, and the steering wheel vibration amplitude and frequency are also filtered using mean filtering after calculation.

[0013] Preferably, the adaptive torque compensation wave is generated according to the same-frequency excitation wave and the steering wheel vibration wave through an adaptive algorithm.

[0014] Preferably, the adaptive algorithm is as follows:

[0015] Y(n) = W T (n)X(n)

[0016] e(n) = d(n) - W T (n)X(n)

[0017] W(n+1) = W(n) + 2ue(n)X(n)

[0018] where Y(n) is the adaptive torque compensation wave; X(n) is the input signal vector at time n, X(n) = [X(n), X(n-1),..., X(n-L+1)], i.e., the same-frequency excitation wave; W T (n) is the transpose of the tap weight vector of the filter; d(n) is the steering wheel vibration wave; e(n) is the error signal; W(n) is the tap weight vector of the filter; and u is the step parameter. The adaptive torque controller automatically adjusts the tap weight vector W(n) through the error signal e(n) to make the adaptive torque compensation wave Y(n) close to the steering wheel vibration wave d(n).

[0019] Preferably, the preset condition is a first condition, when the first condition is met, the function state machine opens the adaptive torque controller, when the first condition is not met, the function state machine closes the adaptive torque controller; the meeting of the first condition refers to meeting all of the following: the absolute value of the steering angle signal is less than the target steering angle value; the vibration amplitude is greater than the first target vibration value and less than the second target vibration value; the wheel rotation frequency is greater than the first target frequency value and less than the second target frequency value; the vehicle speed signal is greater than the first target vehicle speed value and less than the second target vehicle speed value; the absolute value of the difference between the wheel rotation frequency and the steering wheel vibration frequency is less than the target frequency value; the absolute value of the difference between the minimum value of the hand torque signal and the steering wheel vibration amplitude is less than the target preset value.

[0020] Preferably, the preset condition further includes a second condition, when the second condition is met, the function state machine closes the adaptive torque controller; the meeting of the second condition refers to meeting any of the following: the absolute value of the steering angle signal is greater than or equal to the target steering angle value; the vibration amplitude is less than the first target vibration value or greater than the second target vibration value; the wheel rotation frequency is less than the first target frequency value and greater than the second target frequency value; the absolute value of the difference between the left front wheel speed signal and the right front wheel speed signal is greater than the target wheel speed value; the vehicle speed signal is less than the first target vehicle speed value or greater than the second target vehicle speed value.

[0021] Preferably, the preset condition further includes a third condition, when the third condition is met, the function state machine closes the adaptive torque controller; the meeting of the third condition refers to meeting any of the following: the absolute value of the steering angle signal is greater than or equal to the target steering angle value; the wheel rotation frequency is less than the first target frequency value and greater than the second target frequency value; the absolute value of the difference between the left front wheel speed signal and the right front wheel speed signal is greater than the target wheel speed value; the vehicle speed signal is less than the first target vehicle speed value or greater than the second target vehicle speed value; the adaptive torque compensation wave is greater than the target preset value.

[0022] Preferably, the preset condition further includes a fourth condition, when the fourth condition is met, the function state machine closes the adaptive torque controller; the meeting of the fourth condition refers to meeting any of the following: the vibration amplitude is greater than the third target vibration value; the adaptive torque compensation wave is greater than the target preset value.

[0023] Compared with the prior art, the present application can suppress steering wheel shaking when the vehicle is running at high speed, improve driving comfort and safety. BRIEF DESCRIPTION OF DRAWINGS

[0024] The present application will be further described in detail below in conjunction with the specific embodiments and the accompanying drawings:

[0025] Figure 1 The device structure diagram for suppressing steering wheel shaking when the vehicle of Example 1 is running at high speed;

[0026] Figure 2 This is a schematic diagram of the power steering system involved in Example 1;

[0027] Figure 3 This is a schematic diagram of the steering wheel torque signal before the adaptive torque controller of Example 1 is activated;

[0028] Figure 4 This is a schematic diagram showing the adaptive torque compensation wave generated by the adaptive torque controller in Example 1 after it is turned on for a period of time.

[0029] Figure 5 A schematic diagram of the steering wheel hand torque signal after applying a compensating torque of the same frequency but opposite direction to the steering wheel in Example 1. Detailed Implementation

[0030] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can fully understand other advantages and technical effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through different specific embodiments, and the details in this specification can also be applied based on different viewpoints, with various modifications or changes made without departing from the overall design concept of the invention. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. The following exemplary embodiments of the present invention can be implemented in many different forms and should not be construed as being limited to the specific embodiments set forth herein. It should be understood that these embodiments are provided to make the disclosure of the present invention thorough and complete, and to fully convey the technical solutions of these exemplary embodiments to those skilled in the art.

[0031] Example 1

[0032] like Figure 1 As shown, this embodiment provides a device for suppressing steering wheel vibration when a vehicle is traveling at high speed, including an ABS system 1, an EPS angle sensor 2, an EPS torque sensor 3, an EPS controller 4, and an EPS motor 5.

[0033] The ABS system 1 and the EPS controller 4 communicate via a CAN bus. The EPS angle sensor 2 and the EPS torque sensor 3 are connected to the EPS controller 4 via hard wires, and the EPS controller 4 is connected to the EPS motor 5 via hard wires.

[0034] The ABS system 1 is used to collect the vehicle speed signal, the left front wheel speed signal and the right front wheel speed signal and send them to the CAN bus; the EPS controller 4 obtains the vehicle speed signal, the left front wheel speed signal and the right front wheel speed signal from the CAN bus; the EPS controller 4 obtains the hand torque signal and the steering wheel angle signal applied by the driver to the steering wheel from the EPS torque sensor 3 and the EPS angle sensor 2; the EPS controller 4 controls the EPS motor 5 to execute the motor control instruction.

[0035] The EPS controller 4 comprises a signal preprocessing module, a function state machine, an adaptive torque controller and a current controller.

[0036] The signal preprocessing module is used to process the signals obtained by the EPS controller. For example, the wheel rotation frequency is calculated according to the left front wheel speed signal and / or the right front wheel speed signal. Exemplarily, the calculation formula of the wheel rotation frequency is: f = v / 2πR, wherein f is the wheel rotation frequency, v is the average value of the left front wheel speed signal and / or the right front wheel speed signal, and R is the rolling radius of the wheel. For example, the steering wheel vibration amplitude (including the maximum value and the minimum value) and the steering wheel vibration frequency are calculated according to the hand torque signal. Preferably, the hand torque signal is filtered by using the mean filter before calculating the steering wheel vibration amplitude and the steering wheel vibration frequency, and the steering wheel vibration amplitude and the frequency are also filtered by using the mean filter after calculation.

[0037] The function state machine is used to start or stop the adaptive torque controller according to the preset conditions.

[0038] The adaptive torque controller is used to generate an adaptive torque compensation wave, which is generated by the adaptive LMS algorithm according to a same-frequency excitation wave and a steering wheel vibration wave. The same-frequency excitation wave is generated according to the wheel rotation frequency, and the steering wheel vibration wave is generated according to the steering wheel vibration amplitude.

[0039] Exemplarily, the adaptive LMS algorithm is as follows:

[0040] Y(n) = W T (n)X(n)

[0041] e(n) = d(n) - W T (n)X(n)

[0042] W(n + 1) = W(n) + 2ue(n)X(n)

[0043] wherein Y(n) is the adaptive torque compensation wave; X(n) is the input signal vector at time n, X(n) = [X(n), X(n - 1), …, X(n - L + 1)], i.e. the same-frequency excitation wave; W T(n) is the transpose of the filter tap weight vector; d(n) is the steering wheel vibration wave; e(n) is the error signal; W(n) is the filter tap weight vector; u is the step size parameter, which determines the convergence speed and stability of the update algorithm.

[0044] The current controller converts the adaptive torque compensation wave into a current signal to control the EPS motor.

[0045] More specifically, the preset condition is a first condition. When the first condition is met, the functional state machine activates the adaptive torque controller; when the first condition is not met, the functional state machine deactivates the adaptive torque controller.

[0046] The first condition being met means satisfying all of the following: the absolute value of the steering angle signal is less than the target steering angle value; the vibration amplitude is greater than the first target vibration value and less than the second target vibration value; the wheel rotation frequency is greater than the first target frequency value and less than the second target frequency value; the vehicle speed signal is greater than the first target vehicle speed value and less than the second target vehicle speed value; the absolute value of the difference between the wheel rotation frequency and the steering wheel vibration frequency is less than the target frequency value; and the absolute value of the difference between the hand torque signal and the minimum value of the steering wheel vibration amplitude is less than the target preset value.

[0047] The technical effects of the device for suppressing steering wheel vibration when the vehicle is traveling at high speed, as described in this embodiment, are explained in detail below. Figure 2 The schematic diagram of the power steering system including the device of this embodiment shows that the driver operates the power steering system by applying a force called "steering torque" on the steering wheel 1. The steering wheel 1 is mounted on the steering column 13, which is guided to rotate in the vehicle. The steering column 13 is engaged with a rack via a steering pinion, and the rack itself is fixed in the steering housing 11 of the vehicle and guided to translate. The ends of the rack are each connected to a connecting rod, which is connected to the steering knuckles on the wheels 9 and 12, so that the longitudinal displacement of the rack translation can perform lateral rotation, and thus modify the steering angle of the wheels 9 and 12. The gear 4 of the EPS motor 5 can be engaged with the steering column via a gear reducer type 3. The ECU 6 includes an EPS controller. The ECU 6 receives torque and angle information from the steering wheel torque and angle sensor 2. The ECU 6 receives vehicle speed signals, left front wheel speed signals, and right front wheel speed signals from the vehicle ABS system 8 via the CAN bus 7, calculates an adaptive torque compensation wave, and transmits the torque to be applied to the EPS motor 5.

[0048] Before the adaptive torque controller is activated, the steering wheel torque signal fluctuates significantly, such as... Figure 3 As shown. After the adaptive torque controller is activated, it generates an adaptive torque compensation wave for a period of time, as shown below. Figure 4The fluctuation of the steering wheel hand torque signal is obviously reduced after the steering wheel applies the compensation torque of the same frequency in the opposite direction, as shown in FIG. 2. The steering wheel hand torque signal is shown in FIG. 3. Figure 5

[0049] Embodiment 2

[0050] The difference between this embodiment and embodiment 1 is that the function state machine contains four different states, and the adaptive torque controller is turned on or off according to different states. The remaining technical features are the same as those of embodiment 1. The following describes in detail how to turn on or off the adaptive torque controller according to the four different states.

[0051] The four different states are Off, Ready, Active, and Error. Among the four states, the system can enable the compensation of the steering wheel swing array, turn on the adaptive torque controller, and generate adaptive torque compensation waves in the Active state. In the Error state, the system prohibits the compensation of the steering wheel swing array, turns off the adaptive torque controller, and cannot generate adaptive torque compensation waves. In addition, the function state machine cannot be normally switched in this ignition cycle, and the next ignition cycle is required. The initial state of the system function state machine is the Off state. The Ready state is a transition state from the Off state to the Active state. The switching between the states needs to meet the relevant conditions, such as

[0052] The switching between each state is as follows: Off-Ready-Active, which needs to meet the first condition of embodiment 1, which is not described here again.

[0053] Ready-Off, which needs to meet the second condition, that is, any of the following conditions is met:

[0054] The absolute value of the steering angle signal is greater than or equal to the target steering angle value;

[0055] The vibration amplitude is less than the first target vibration value or greater than the second target vibration value;

[0056] The wheel rotation frequency is less than the first target frequency value and greater than the second target frequency value;

[0057] The absolute value of the difference between the left front wheel speed signal and the right front wheel speed signal is greater than the target wheel speed value;

[0058] The vehicle speed signal is less than the first target vehicle speed value or greater than the second target vehicle speed value.

[0059] Active-Off, which needs to meet the third condition, that is, any of the following conditions is met:

[0060] The absolute value of the steering angle signal is greater than or equal to the target steering angle value;

[0061] ​the wheel rotation frequency is less than the first target frequency value and greater than the second target frequency value;

[0062] the absolute value of the difference between the left front wheel speed signal and the right front wheel speed signal is greater than the target wheel speed value;

[0063] the vehicle speed signal is less than the first target vehicle speed value or greater than the second target vehicle speed value;

[0064] the adaptive torque compensation wave is greater than the target preset value.

[0065] Off-Error, or Ready-Error, or Active-Error, needs to meet the fourth condition, which means meeting any one of the following:

[0066] the vibration amplitude is greater than the third target vibration value;

[0067] the adaptive torque compensation wave is greater than the target preset value.

[0068] The application has been described in detail through specific embodiments and examples, but these do not constitute a limitation on the application. Those skilled in the art can also make many modifications and improvements without departing from the principles of the application, and these should also be considered as falling within the scope of protection of the application.

Claims

1. A device for suppressing steering wheel vibration when a vehicle is traveling at high speed, characterized in that, The ABS system, the EPS angle sensor, the EPS torque sensor, the EPS controller and the EPS motor are included. The ABS system is used to collect the vehicle speed signal, the left front wheel speed signal and the right front wheel speed signal. The EPS controller obtains the hand torque signal and the steering angle signal from the EPS torque sensor and the EPS angle sensor, and controls the EPS motor to execute the motor control instruction. The EPS controller includes a signal preprocessing module, a function state machine, an adaptive torque controller and a current controller. The signal preprocessing module calculates the wheel rotation frequency according to the left front wheel speed signal and / or the right front wheel speed signal, and calculates the steering wheel vibration amplitude and the steering wheel vibration frequency according to the hand torque signal. The function state machine is used to start or stop the adaptive torque controller according to a preset condition. The adaptive torque controller is used to generate an adaptive torque compensation wave, which is generated according to a same-frequency excitation wave and a steering wheel vibration wave, the same-frequency excitation wave is generated according to the wheel rotation frequency, and the steering wheel vibration wave is generated according to the steering wheel vibration amplitude. The current controller converts the adaptive torque compensation wave into a current signal for controlling the EPS motor. The adaptive torque compensation wave is generated according to the same-frequency excitation wave and the steering wheel vibration wave through an adaptive algorithm, and the adaptive algorithm is specifically as follows: Y(n) = W T (n) X(n) e(n) = d(n) - W T (n) X(n) W(n+1)=W(n)+2ue(n)X(n) where Y(n) is an adaptive torque compensation wave; X(n) is an input signal vector at n moment, X(n) = [X(n), X(n-1), …, X(n-L+1)], that is, a same frequency excitation wave; W T (n) is a transpose of a tap weight vector of a filter; d(n) is a steering wheel vibration wave; e(n) is an error signal; W(n) is a tap weight vector of a filter; and u is a step parameter. The adaptive torque controller automatically adjusts the tap weight vector W(n) through the error signal e(n), so that the adaptive torque compensation wave Y(n) approaches the steering wheel vibration wave d(n).

2. The device for suppressing the steering wheel shimmy of a vehicle during high speed travel according to claim 1, characterized by The calculation formula of the wheel rotation frequency is f=v / 2πR, wherein f is the wheel rotation frequency, v is the average value of the left front wheel speed signal and / or the right front wheel speed signal, and R is the wheel rolling radius.

3. The device for suppressing the steering wheel shake of a vehicle during high-speed travel according to claim 1, characterized by The mean filter is used to filter the hand torque signal before calculating the steering wheel vibration amplitude and the steering wheel vibration frequency, and the mean filter is also used to filter the steering wheel vibration amplitude and the frequency after calculation.

4. The device for suppressing the steering wheel shake during high-speed running of a vehicle according to claim 1, characterized by The preset condition is a first condition, the function state machine starts the adaptive torque controller when the first condition is met, and the function state machine stops the adaptive torque controller when the first condition is not met. The first condition is met when all of the following conditions are met: the absolute value of the steering angle signal is less than a target steering angle value; the vibration amplitude is greater than a first target vibration value and less than a second target vibration value; the wheel rotation frequency is greater than a first target frequency value and less than a second target frequency value; the vehicle speed signal is greater than a first target vehicle speed value and less than a second target vehicle speed value; the absolute value of the difference between the wheel rotation frequency and the steering wheel vibration frequency is less than a target frequency value; and the absolute value of the difference between the minimum value of the hand torque signal and the steering wheel vibration amplitude is less than a target preset value. The preset condition also includes a second condition, the function state machine stops the adaptive torque controller when the second condition is met.

5. The device for suppressing the steering wheel shake of a vehicle during high speed travel according to claim 4, characterized in that, ​ The second condition is satisfied when any of the following conditions is met: the absolute value of the steering angle signal is greater than or equal to a target steering angle value; the vibration amplitude is less than a first target vibration value or greater than a second target vibration value; the wheel rotation frequency is less than a first target frequency value and greater than a second target frequency value; the absolute value of the difference between the left front wheel speed signal and the right front wheel speed signal is greater than a target wheel speed value; the vehicle speed signal is less than a first target vehicle speed value or greater than a second target vehicle speed value.

6. The device for suppressing the steering wheel shake of a vehicle during high speed travel according to claim 4, characterized in that, The preset condition further includes a third condition, and the function state machine turns off the adaptive torque controller when the third condition is met; The third condition is met when any of the following conditions is met: the absolute value of the steering angle signal is greater than or equal to a target steering angle value; the wheel rotation frequency is less than a first target frequency value and greater than a second target frequency value; the absolute value of the difference between the left front wheel speed signal and the right front wheel speed signal is greater than a target wheel speed value; the vehicle speed signal is less than a first target vehicle speed value or greater than a second target vehicle speed value. The adaptive torque compensation wave is greater than a target preset value.

7. The device for suppressing the steering wheel shake of a vehicle during high speed travel according to claim 4, characterized in that, The preset condition further includes a fourth condition, and the function state machine turns off the adaptive torque controller when the fourth condition is met; The fourth condition is met when any of the following conditions is met: the vibration amplitude is greater than a third target vibration value; and the adaptive torque compensation wave is greater than a target preset value.

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