Vehicle damping continuously-adjustable vibration reduction control method and system and vehicle

Abstract

The invention provides a vehicle damping continuously-adjustable vibration reduction control method and system and a vehicle, an IMU is used for replacing four sprung acceleration sensors, six-direction inertial signals, measured by the IMU, of a mounting position are converted into Z-direction acceleration signals of points on four vibration absorbers by utilizing a dynamic explicit integration method based on vector calculation, and the Z-direction acceleration signals are converted into Z-direction acceleration signals of points on the four vibration absorbers. According to the invention, the four shock absorbers and the telescopic speed of the four shock absorbers detected by the four unsprung acceleration / angle sensors are introduced into a Mixed-SH-ADD algorithm for calculation, and the control current of the solenoid valves of the four shock absorbers is output, so that the problems that the existing CDC sensors are many and high in cost and the existing sensing conversion method is poor in precision and few in applicable working conditions can be solved.

Description

Technical Field

[0001] The present application relates to the field of vehicle technology, and in particular to a damping continuously adjustable vibration reduction control technology for automobiles. Background Art

[0002] With the development of automobile technology and the improvement of users' demand for driving comfort, more and more models are equipped with CDC (Continuous Damping Control). At present, the mainstream CDC mostly adopts Mixed-SH-ADD algorithm (Mixed Algorithm of Skyhook and Acceleration Driven Damper Control skyhook and acceleration drive control mixed algorithm). Figure 1 As shown in the figure, the input required by the Mixed SH-ADD algorithm includes the sprung acceleration of the four shock absorbers (i.e., the Z-direction acceleration of the mounting point on the shock absorber) and the expansion and contraction speed of the four shock absorbers; the output is the target damping force of each shock absorber (or the control current of the solenoid valve in the shock absorber). In order to collect the above 8 input quantities, the traditional CDC usually sets 8 sensors, namely, four sprung acceleration sensors and four unsprung acceleration sensors (converting the expansion and contraction speed of the shock absorber through integration), and four unsprung angle sensors can also be used to replace the four unsprung acceleration sensors (converting the expansion and contraction speed of the shock absorber through the kinematic characteristics of the suspension). In this way, the large number of sensors has pushed up the price of CDC. Therefore, the industry urgently needs a technology to reduce the number of sensors required for CDC.

[0003] Patent documents CN212950025U and CN213007476U propose an ideal solution to the above problem, which is to cancel all sprung and unsprung sensors, but integrate IMU (Inertial Measurement Unit) inside the CDC controller to obtain sensor signals. However, IMU can only measure the translational acceleration and angular velocity signals at its location, and cannot provide the sprung acceleration and shock absorber extension and extension velocity signals required by the Mixed-SH-ADD algorithm. The above patent documents also do not provide a method for using IMU signals to convert the signals required by the Mixed-SH-ADD algorithm, so they lack practicality.

[0004] Patent document KR10-2007-0062053 also recognizes the problem of too many sensors required for CDC, and proposes to eliminate all sprung and unsprung sensors and only use the signals on CAN (Controller Area Network) to control CDC. However, this technology does not answer how to use the signals on CAN to convert the input signals required by the Mixed SH-ADD algorithm, so it lacks practicality.

[0005] Patent document CN115320310A proposes a new sensing system that uses a height sensor in an active headlight instead of a sprung acceleration sensor, and proposes an algorithm different from Mixed-SH-ADD to adapt to it. This method cannot be used in the mainstream CDC system based on Mixed-SH-ADD and has great limitations.

[0006] Patent document CN115871392A proposes a CDC control method that does not require a sprung acceleration sensor and only uses IMU and vehicle speed, steering wheel angle, brake and accelerator pedal position signals to control CDC. However, the patent does not propose a method for real-time conversion of the sprung acceleration of the shock absorber, so it cannot drive the Mixed SH-ADD algorithm to universally optimize the vehicle body vibration during driving. As described in the patent document, it can only be used for two working conditions: pitch suppression and roll suppression, which has great limitations.

[0007] Patent document CN116021939A proposes a simple algorithm for calculating sprung acceleration using IMU signals. However, the algorithm has good accuracy only under the following restrictions: 1) the IMU installation height is close to the height of the shock absorber top point, 2) the vehicle yaw rate is approximately zero, and 3) the vehicle lateral slip is approximately zero. That is, the algorithm has good accuracy only under relatively stable driving conditions, its application range is small, and the performance effect still needs to be optimized.

[0008] In summary, the industry is looking forward to a vehicle damping continuously adjustable vibration reduction control technology that can reduce the number of CDC sensors without affecting its scope of application and effect. Summary of the invention

[0009] The purpose of the present invention is to provide a vehicle damping continuously adjustable vibration reduction control method, system and vehicle, and design a unique CDC sensor signal conversion method to solve the problems of the existing CDC sensors being numerous and costly, and the existing sensor conversion methods being of poor accuracy and having few applicable working conditions.

[0010] The present invention achieves the above object through the following two aspects:

[0011] In a first aspect, the present invention provides a method for controlling a vehicle's continuously adjustable damping vibration reduction, the method comprising:

[0012] Step 1: Use the IMU to measure the six-directional inertial signals of its installation position in real time, and use four unsprung acceleration / angle sensors to detect the extension and retraction speeds of the four shock absorbers.

[0013] Step 2: The CDC controller obtains the signal measured by the IMU and converts it into the Z-direction acceleration signal of the four shock absorbers using a dynamic explicit integration method based on vector calculation, i.e., a z_LF 、a z_LR 、a z_RF 、a z_RR ; This step specifically includes:

[0014] Step 2.1, take the IMU point acceleration α IMU Integrate to calculate the IMU point velocity v IMU and position p IMU .

[0015] Step 2.2: Using the IMU point velocity, position and the position of the shock absorber point as input, obtain the instantaneous velocity v of each shock absorber point through vector calculation. i .

[0016] Step 2.3, take the instantaneous velocity v of the shock absorber point i Derivatively calculate its acceleration a i .

[0017] Step 2.4, using the time series as input, vector calculation as the form, and dynamic display integration as the method to continuously run the above steps 2.1 to 2.3 to obtain the real-time Z-direction acceleration of the point on the shock absorber during the entire time series.

[0018] Step 3: The extension and retraction speeds of the four shock absorbers in step 1 and the Z-axis accelerations of the points on the four shock absorbers obtained in step 2 are imported into the Mixed-SH-ADD algorithm for calculation, and finally the control currents of the solenoid valves of the four shock absorbers are output.

[0019] According to an embodiment of the present invention, the instantaneous velocity v of each point on the shock absorber is obtained by vector operation. i , the formula is as follows:

[0020] v i =v IMU +ω IMU ×(p i -p IMU );

[0021] All quantities in the formula are three-dimensional vectors, v is the translation velocity, ω is the angular velocity, p is the position, and the subscript i is LF, LR, RF or RR, representing the left front, left rear, right front and right rear points on the shock absorber, respectively.

[0022] According to an embodiment of the present invention, in the method, four sprung acceleration sensors are replaced by one IMU, and the IMU is integrated into a CDC controller or an ESC controller, or a controller at any position of the vehicle body.

[0023] In a second aspect, the present invention further provides a vehicle damping continuously adjustable vibration reduction control system, wherein the system comprises:

[0024] Four unsprung acceleration or angle sensors are arranged at the lower points of the left front, left rear, right front and right rear shock absorbers to detect the extension and contraction speeds of the four shock absorbers and input them to the CDC controller.

[0025] At least one IMU, which is integrated into the CDC or ESC controller, or installed in a controller at any other location on the vehicle body, is used to measure the six-directional inertial signals of its installation location in real time and input them to the CDC controller.

[0026] The CDC controller includes a sprung acceleration conversion module and a Mixed-SH-ADD algorithm module.

[0027] The sprung acceleration conversion module receives the signal measured by the IMU and converts it into the Z-direction acceleration signal of the four shock absorbers using a dynamic explicit integration method based on vector calculation, including: first, using the IMU point acceleration a IMU Integrate to calculate the IMU point velocity v IMU and position p IMU ; Then, using the IMU point velocity, position and the position of the shock absorber point as input, the instantaneous velocity v of each shock absorber point is obtained through vector calculation i ; Then take the instantaneous velocity v of the shock absorber top point i Derivatively calculate its acceleration a i Finally, the above process is continuously run with the time series as input, vector calculation as the form, and dynamic display integration as the method to obtain the real-time acceleration of the point on the shock absorber during the entire time series process.

[0028] The Mixed-SH-ADD algorithm module takes the extension and contraction speeds of the four shock absorbers and the Z-direction accelerations of the four shock absorbers obtained by the sprung acceleration conversion module as inputs, and finally outputs the control currents of the four shock absorber solenoid valves after calculation.

[0029] According to an embodiment of the present invention, in the control system, the sprung acceleration conversion module obtains the instantaneous velocity v of each point on the shock absorber through vector calculation. i , the formula is as follows:

[0030] v i =v IMU +ω IMU ×(p i -pIMU );

[0031] All quantities in the formula are three-dimensional vectors, v is the translation velocity, ω is the angular velocity, p is the position, and the subscript i is LF, LR, RF or RR, representing the left front, left rear, right front and right rear points on the shock absorber, respectively.

[0032] According to an embodiment of the present invention, in the control system, when the IMU is integrated in a non-CDC controller, the non-CDC controller sends the IMU signal to the CDC controller via CAN or CAN-FD or Ethernet.

[0033] The present invention further provides a vehicle in a third aspect, wherein the vehicle is equipped with the above-mentioned vehicle damping continuously adjustable vibration reduction control system.

[0034] The advantages of the present invention are as follows:

[0035] Traditional CDC needs to be equipped with four sprung acceleration sensors and four unsprung acceleration or angle sensors. However, the present invention adopts a unique sensor signal conversion method and combines it with a response sensor system to replace four sprung acceleration sensors with one IMU while still being able to obtain the high-precision, all-condition universal sprung acceleration signals required by the Mixed-SH-ADD algorithm in the CDC in real time, thereby significantly reducing the cost of CDC.

[0036] Figure 1 This is the block diagram of the traditional sensor system for CDC;

[0037] Figure 2 A diagram showing the steps of the vehicle damping continuously adjustable vibration reduction control method of the present invention;

[0038] Figure 3 The block diagram of the vehicle damping continuously adjustable vibration reduction control system for the CDC controller to call the IMU signal in the ESC;

[0039] Figure 4 It is the input and output block diagram of the sprung acceleration conversion algorithm module;

[0040] Figure 5 Schematic diagram of the sprung acceleration conversion algorithm. DETAILED DESCRIPTION

[0041] The specific implementation and principle of the present invention are further explained below in conjunction with the accompanying drawings and embodiments.

[0042] Figure 1The figure shows the sensor system of the traditional CDC. It contains four sprung acceleration sensors and four unsprung acceleration sensors (converted into shock absorber expansion and contraction speed through integration) or angle sensors (converted into shock absorber expansion and contraction speed through suspension kinematic characteristics) to obtain the eight real-time input quantities required by the Mixed-SH-ADD algorithm. The system composed of the above eight sensors is expensive, and the industry expects a more economical CDC sensor system.

[0043] Embodiment 1:

[0044] The following embodiment is a general implementation step of a vehicle damping continuously adjustable vibration reduction control method, such as

[0045] Figure 2 As shown:

[0046] In order to implement this control method, a new sensor system needs to be built, that is, an IMU replaces the four sprung acceleration sensors. The IMU can be integrated into the CDC controller or ESC controller, or into a controller at any position on the vehicle body.

[0047] Based on the newly constructed sensor system above, the steps of the control method are as follows:

[0048] Step 1: Use the IMU to measure the six-way inertial signals of its installation position in real time, including three-way translation acceleration and three-way acceleration signals. At the same time, use four unsprung acceleration / angle sensors to detect the extension and retraction speeds of the four shock absorbers.

[0049] Step 2: The CDC controller receives the above signal and converts the IMU signal into the Z-axis acceleration signal of the four shock absorbers using the dynamic explicit integration method based on vector calculation, that is, a z_LF 、a z_LR 、a z_RF 、a z_RR .

[0050] Step 3: The extension and retraction speeds of the four shock absorbers and the Z-direction accelerations of the four shock absorbers obtained in step 2 are imported into the Mixed-SH-ADD algorithm to finally output the control current of the solenoid valves of the four shock absorbers.

[0051] Embodiment 2;

[0052] The following embodiment is a specific implementation of a vehicle damping continuously adjustable vibration reduction control system. The system uses a CDC controller to call the IMU signal in the ESC, such as Figure 3 As shown, compared Figure 1The conventional solution shown in FIG. 1 does not include four sprung acceleration sensors in this embodiment. Most vehicles are equipped with ESC, and their controllers contain IMUs, which measure vehicle body inertia data. In this embodiment, the CDC controller obtains the sensor signals sent out by the ESC controller via CAN, CAN-FD, or Ethernet, and further converts them into four sprung acceleration signals required by the Mixed-SH-ADD algorithm. Therefore, the sensor arrangement scheme described in this embodiment has a significant cost advantage over the conventional scheme.

[0053] The specific structure of the system is as follows:

[0054] It includes four unsprung acceleration or angle sensors at the left front, left rear, right front and right rear, which are used to detect the extension and contraction speeds of the four shock absorbers and input them to the CDC controller. However, it does not include four sprung acceleration sensors at the left front, left rear, right front and right rear.

[0055] Contains at least one IMU. The IMU is integrated into the ESC (Electronic Stability Controller) controller to measure the six-way inertial signals of its installation position in real time and input them to the CDC controller.

[0056] A CDC controller includes a sprung acceleration conversion module and a Mixed-SH-ADD algorithm module.

[0057] The sprung acceleration conversion module converts the signal measured by the IMU into the Z-direction acceleration signal of the four shock absorbers using a dynamic explicit integration method based on vector calculation, including: first, using the IMU point acceleration a IMU Integrate to calculate the IMU point velocity v IMU and position p IMU ; Then, using the IMU point velocity, position and the position of the shock absorber point as input, the instantaneous velocity v of each shock absorber point is obtained through vector calculation i ; Then take the instantaneous velocity v of the shock absorber top point i Derivatively calculate its acceleration a i Finally, the above process is continuously run with the time series as input, vector calculation as the form, and dynamic display integration as the method to obtain the real-time acceleration of the point on the shock absorber during the entire time series process.

[0058] The Mixed-SH-ADD algorithm module takes the extension and contraction speeds of the four shock absorbers and the Z-direction accelerations of the four shock absorbers obtained by the sprung acceleration conversion module as inputs, and finally outputs the control currents of the four shock absorber solenoid valves after calculation.

[0059] Figure 4The input and output diagram of the sprung acceleration conversion module to realize the sensor signal conversion algorithm is shown in FIG. The required real-time input quantity of the algorithm is the vehicle body acceleration a IMU and angular velocity ω IMU The recommended measurement frequency is not less than 50Hz; the required fixed input is the initial position p of the IMU IMU , initial position of left front spring top point p LF , initial position of left rear spring top point p LR , initial position of the right front spring top point p RF , initial position of the right rear spring top point p RR The above inputs are all three-dimensional vectors. The output of the sensor signal conversion algorithm is the Z-direction acceleration a on the left front spring. z_LF , Z-direction acceleration a on the left rear spring z_LR , Z-direction acceleration a on the right front spring z_RF , Z-direction acceleration a on the right rear spring z_RR ,These four acceleration metrics are real-time scalars.

[0060] like Figure 5 As shown, the sprung acceleration conversion module performs sensor signal conversion calculation mainly including the following steps:

[0061] Step 2.1, take the IMU point acceleration a IMU Integrate to calculate the IMU point velocity v IMU and position p IMU .

[0062] Step 2.2, using the IMU point velocity, position and the position of the shock absorber point as input, obtain the instantaneous velocity of each shock absorber point through vector operation, that is:

[0063] v i =v IMU +ω IMU ×(p i -p IMU );

[0064] All quantities in the formula are three-dimensional vectors, v is the translation velocity, ω is the angular velocity, p is the position, and the subscript i can be LF, LR, RF, and RR, which represent the points on the left front, left rear, right front, and right rear shock absorbers, respectively.

[0065] Step 2.3, take the instantaneous velocity v of the shock absorber point i Derivatively calculate its acceleration a i ;

[0066] Step 2.4, using the time series as input, vector calculation as form, and dynamic display integration as method to continuously iterate the above 3 steps to obtain the real-time acceleration of the point on the shock absorber during the entire time series process.

[0067] The above-mentioned sensor signal conversion method does not restrict the installation position of the IMU sensor, does not limit the operating conditions, and has high accuracy under all driving conditions; therefore, it saves the sprung acceleration sensor while ensuring the output performance of the Mixed-SH-ADD algorithm, ultimately improving the cost and scope of use of the CDC system.

[0068] The above contents are only embodiments of the present invention and are not intended to limit the protection scope of the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of this application.

Claims

1. A vehicle damping continuously adjustable vibration reduction control method, characterized in that: The method comprises: Step 1: Use the IMU to measure the six-directional inertial signals of the installation position in real time, and use four unsprung acceleration / angle sensors to detect the extension and retraction speeds of the four shock absorbers; Step 2: The CDC controller obtains the signal measured by the IMU and converts it into the Z-direction acceleration signal of the points on the four shock absorbers using a dynamic explicit integration method based on vector calculation, including: Step 2.1, take the IMU point acceleration a IMU Integrate to calculate the IMU point velocity v IMU and position p IMU ; Step 2.2: Using the IMU point velocity, position and the position of the shock absorber point as input, obtain the instantaneous velocity v of each shock absorber point through vector calculation. i ; Step 2.3, take the instantaneous velocity v of the shock absorber point i Derivatively calculate its acceleration a i ; Step 2.4, using the time series as input, vector calculation as the form, and dynamic display integration as the method to continuously run the above steps 2.1 to 2.3, so as to obtain the real-time Z-direction acceleration of the points on the shock absorber during the entire time series; Step 3: The extension and retraction speeds of the four shock absorbers obtained in step 1 and the Z-direction accelerations of the four shock absorbers obtained in step 2 are imported into the Mixed-SH-ADD algorithm for calculation, and finally the control currents of the four shock absorber solenoid valves are output.

2. A vehicle damping continuously adjustable vibration reduction control method according to claim 1, characterized in that: The instantaneous velocity v of each point on the shock absorber is obtained by vector operation. i , the formula is as follows: v i =v IMU +ω IMU ×(p i -p IMU ); All quantities in the formula are three-dimensional vectors, v is the translation velocity, ω is the angular velocity, p is the position, and the subscript i is LF, LR, RF or RR, representing the left front, left rear, right front and right rear points on the shock absorber, respectively.

3. A vehicle damping continuously adjustable vibration reduction control method according to claim 1 or 2, characterized in that: In the method, four sprung acceleration sensors are replaced by one IMU, and the IMU is integrated into a CDC controller or an ESC controller, or into a controller at any position of the vehicle body.

4. A vehicle damping continuously adjustable vibration reduction control system, characterized in that: include: Four unsprung acceleration or angle sensors are arranged at the lower points of the four shock absorbers, namely the left front, left rear, right front and right rear, to detect the extension and retraction speeds of the four shock absorbers and input them to the CDC controller; At least one IMU, which is integrated into the CDC or ESC controller, or installed in a controller at any other location on the vehicle body, and is used to measure the six-directional inertial signals of its installation location in real time and input them to the CDC controller; CDC controller, including sprung acceleration conversion module and Mixed-SH-ADD algorithm module; The sprung acceleration conversion module receives the signal measured by the IMU and converts it into the Z-direction acceleration signal of the four shock absorbers using a dynamic explicit integration method based on vector calculation, including: first, using the IMU point acceleration a IMU Integrate to calculate the IMU point velocity v IMU and position p IMU ; Then, using the IMU point velocity, position and the position of the shock absorber point as input, the instantaneous velocity v of each shock absorber point is obtained through vector calculation i ; Then take the instantaneous velocity v of the shock absorber top point i Derivatively calculate its acceleration a i ; Finally, the above process is continuously run with the time series as input, vector calculation as form, and dynamic display integration as method to obtain the real-time acceleration of the point on the shock absorber during the entire time series process; The Mixed-SH-ADD algorithm module takes the extension and contraction speeds of the four shock absorbers and the Z-direction accelerations of the four shock absorbers obtained by the sprung acceleration conversion module as inputs, and finally outputs the control currents of the four shock absorber solenoid valves after calculation.

5. A vehicle damping continuously adjustable vibration reduction control system according to claim 4, characterized in that: The sprung acceleration conversion module obtains the instantaneous velocity v of each point on the shock absorber through vector calculation i , the formula is as follows: v i =v IMU +ω IMU ×(p i -p IMU ); All quantities in the formula are three-dimensional vectors, v is the translation velocity, ω is the angular velocity, p is the position, and the subscript i is LF, LR, RF or RR, representing the left front, left rear, right front and right rear points on the shock absorber, respectively.

6. A vehicle damping continuously adjustable vibration reduction control system according to claim 4 or 5, characterized in that: When the IMU is integrated in a non-CDC controller, the non-CDC controller sends the IMU signal to the CDC controller via CAN or CAN-FD or Ethernet.

7. A vehicle, characterized in that: The vehicle is equipped with the automobile damping continuously adjustable vibration reduction control system according to any one of claims 4-6.

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