An active damper pressure loss compensation algorithm

Abstract

This invention discloses an algorithm for compensating pressure loss in an active damper, belonging to the technical field of automotive active dampers. Specifically, it includes the following steps: S1, the host computer sends the required force value Fcmd to the electric hydraulic pump, which drives the actuator to ensure its force value meets the required force value Fcmd; S2, calculate the pressure difference ΔPp on both sides of the electric hydraulic pump; S3, calculate the leakage amount Qleak of the electric hydraulic pump; S4, calculate the actual pump flow rate; S5, calculate the throttle valve flow rate; S6, calculate the throttle valve pressure drop ΔPh; S7, calculate the feedback force value Fb; S8, calculate the difference value Ferro, and then use PID control to adjust the pressure sensor value based on the difference Ferro; S9, output an accurate actuation force value. This invention compensates for the attenuation of the main force caused by pressure loss by appropriately increasing or decreasing the motor torque, ensuring that the final output main force meets the requirements and guaranteeing the accuracy of the active damper's output force value.

Description

Technical Field

[0001] This invention belongs to the field of automotive active damper technology, specifically relating to an active damper pressure loss compensation algorithm. Background Technology

[0002] In some existing active dampers, the electric hydraulic pump is directly connected to the lower chamber of the active damper on one side, and the other side first passes through a throttle valve before reaching the upper chamber of the actuator. Due to the presence of the throttle valve, there will be a certain pressure drop, which will cause the pressure difference of the electric hydraulic pump to be unequal to the pressure difference on both sides of the piston, ultimately resulting in inaccurate output of the actuating force.

[0003] Therefore, there is an urgent need for an active damper pressure loss compensation algorithm that can accurately calculate the force output by the active damper. Summary of the Invention

[0004] To address the problem in existing technologies where pressure drop occurs as oil flows through the throttle valve inside the active suspension during operation, leading to a decrease in the main power output of the active suspension, this invention provides an active suspension pressure loss compensation algorithm. By appropriately increasing or decreasing the motor torque, the algorithm compensates for the decrease in main power caused by pressure loss, ensuring that the final output main power meets the requirements and guaranteeing the accuracy of the active suspension's output main force value.

[0005] This invention is achieved through the following technical solution:

[0006] An algorithm for compensating pressure loss in an active vibration damper includes the following steps:

[0007] S1. The host computer sends the required force value Fcmd to the electric hydraulic pump, and the electric hydraulic pump drives the actuator to make its force value meet the required force value Fcmd.

[0008] S2. Calculate the pressure difference ΔPp on both sides of the electric hydraulic pump;

[0009] S3. Calculate the leakage Qleak of the electric hydraulic pump based on the pressure difference △Pp obtained in step S2;

[0010] S4. Calculate the actual pump flow rate Qactual = Qleak based on the electro-hydraulic pump leakage amount Qleak obtained in step S3. 理论 -Qleak=n*D / 60–Qleak, where D is the displacement of the cycloidal pump and n is the speed of the motor;

[0011] S5. Calculate the throttle valve flow rate based on the actual pump flow rate Q obtained in step S4.

[0012] S6. Calculate the pressure drop ΔPh of the throttle valve based on the throttle valve flow rate obtained in step S5.

[0013] S7. Calculate the feedback force value Fb based on the pressure drop obtained in step S6;

[0014] S8. Calculate the difference Ferro based on the feedback force value Fb in step S7 and the demand force value Fcmd sent by the host computer in step S1, and then use PID control to adjust the pressure value of the pressure sensor based on the difference Ferro.

[0015] S9 outputs accurate working power values.

[0016] Furthermore, in step S2, the pressure difference ΔPp on both sides of the electric hydraulic pump is obtained by subtracting the known accumulator pressure value and the pressure sensor reading.

[0017] Furthermore, step S3 specifically includes the following:

[0018] The electric hydraulic pump was placed on a test bench for the PQ characteristics of the valve. Different flow rates were applied to the electric hydraulic pump, and the corresponding pressure drop was tested. Then, the function of pressure drop versus flow rate was fitted.

[0019] Furthermore, in step S4, the motor speed is obtained by the motor speed sensor.

[0020] Furthermore, in step S5, the actual pump flow rate Q is equal to the throttle valve flow rate.

[0021] Furthermore, step S6 specifically includes the following:

[0022] The throttle valve is placed on a test bench for the valve's PQ characteristics. Different flow rates are applied to the throttle valve, and the corresponding pressure drop is tested. Then, the function of pressure drop versus flow rate is fitted.

[0023] Further, in step S7, the feedback force value Fb = -△Pp*Ap + △Ph*(Ap-Ar), where △Pp is the pressure drop of the electric hydraulic pump, Ap is the piston area, △Pp is the pressure drop of the throttle valve, and Ar is the area of ​​the piston rod.

[0024] Further, in step S8, the pressure value of the pressure sensor is adjusted by PID control of the difference Ferro, specifically, the feedback force value Fb = Kp*(Fcmd-△Pp*Ap)+Ki*(Fcmd-△Pp*Ap)*1 / s+Kd*(Fcmd-△Pp*Ap)*s, where Kp is the proportional coefficient, Ki is the integral coefficient, and Kd is the derivative coefficient.

[0025] Compared with the prior art, the advantages of the present invention are as follows:

[0026] The present invention provides an active vibration damper pressure loss compensation algorithm, which compensates for the main power attenuation caused by pressure loss by appropriately increasing or decreasing the motor torque, so that the final output main power meets the requirements and ensures the accuracy of the active vibration damper output main power value. Attached Figure Description

[0027] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0028] Figure 1 This is a flowchart illustrating an active vibration damper pressure loss compensation algorithm according to the present invention.

[0029] Figure 2 This is a schematic diagram of the pressure difference across an electric hydraulic pump.

[0030] Figure 3 This is a schematic diagram illustrating the relationship between pressure drop and flow rate.

[0031] Figure 4 This is a schematic diagram of the PID control principle. Detailed Implementation

[0032] To clearly and completely describe the technical solution and its specific working process of the present invention, the specific embodiments of the present invention are as follows, in conjunction with the accompanying drawings:

[0033] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0034] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0035] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0036] Example 1

[0037] This embodiment provides an algorithm for compensating pressure loss in an active vibration damper, which specifically includes the following steps:

[0038] S1. The host computer sends the required force value Fcmd to the electric hydraulic pump, and the electric hydraulic pump drives the actuator to make its force value meet the required force value Fcmd.

[0039] S2. Calculate the pressure difference ΔPp on both sides of the electric hydraulic pump;

[0040] The pressure difference ΔPp on both sides of the electric hydraulic pump is obtained by subtracting the known accumulator pressure value and the pressure sensor reading.

[0041] S3. Calculate the leakage Qleak of the electric hydraulic pump based on the pressure difference △Pp obtained in step S2;

[0042] Specifically, the electric hydraulic pump is placed on a test bench for the PQ characteristics of the valve, different flow rates are applied to the electric hydraulic pump, and the corresponding pressure drop is tested. Then, the function of pressure drop and flow rate is fitted.

[0043] S4. Calculate the actual pump flow rate Qactual = Qleak based on the electro-hydraulic pump leakage amount Qleak obtained in step S3. 理论-Qleak=n*D / 60–Qleak, where D is the displacement of the cycloidal pump and n is the motor speed; the motor speed is obtained through the motor speed sensor.

[0044] S5. Calculate the throttle valve flow rate based on the actual pump flow rate Q obtained in step S4; the actual pump flow rate Q is equal to the throttle valve flow rate.

[0045] S6. Calculate the pressure drop ΔPh of the throttle valve based on the throttle valve flow rate obtained in step S5.

[0046] Specifically, it includes the following:

[0047] The throttle valve is placed on a test bench for the valve's PQ characteristics. Different flow rates are applied to the throttle valve, and the corresponding pressure drop is tested. Then, the function of pressure drop versus flow rate is fitted.

[0048] S7. Calculate the feedback force value Fb based on the pressure drop obtained in step S6;

[0049] The feedback force value Fb = -△Pp*Ap + △Ph*(Ap-Ar), where △Pp is the pressure drop of the electric hydraulic pump, Ap is the piston area, △Pp is the pressure drop of the throttle valve, and Ar is the area of ​​the piston rod.

[0050] S8. Calculate the difference Ferro based on the feedback force value Fb in step S7 and the demand force value Fcmd sent by the host computer in step S1, and then use PID control to adjust the pressure value of the pressure sensor based on the difference Ferro.

[0051] The pressure value of the pressure sensor is adjusted by PID control of the difference Ferro. Specifically, the feedback force value Fb = Kp*(Fcmd-△Pp*Ap)+Ki*(Fcmd-△Pp*Ap)*1 / s+Kd*(Fcmd-△Pp*Ap)*s, where Kp is the proportional coefficient, Ki is the integral coefficient, and Kd is the derivative coefficient.

[0052] S9 outputs accurate working power values.

[0053] Example 2

[0054] like Figure 1 As shown, this embodiment provides a pressure loss compensation algorithm for an active vibration damper without a solenoid valve, characterized by the following steps:

[0055] S1. The host computer sends the required force value Fcmd. The electric hydraulic pump receives this force value command and then uses its algorithm to ensure that the actuator's force value meets the requirement of Fcmd.

[0056] S2. Calculate the pressure difference ΔPp on both sides of the electric hydraulic pump.

[0057] The pressure difference ΔPp is calculated by subtracting the known accumulator pressure value from the pressure sensor reading. Figure 2 As shown;

[0058] S3. Calculate the leakage Qleak of the electric hydraulic pump based on the pressure difference ΔPp obtained in step S2. The specific calculation process is as follows:

[0059] Because there is a fixed relationship between the electro-hydraulic pressure difference and the leakage of the electro-hydraulic pump (Qleak), the horizontal axis represents the pressure difference, and the vertical axis represents the leakage amount. The curve of the pressure difference and leakage amount on both sides of the pump is obtained by placing the electro-hydraulic pump on a test bench for valve PQ characteristics, applying different flow rates to the electro-hydraulic pump, testing the corresponding pressure drop, and then fitting a function of pressure drop and flow rate.

[0060] S4. Based on the rotational speed ω, pump displacement D, and the electro-hydraulic pump leakage Qleak calculated in step S3, calculate the actual pump flow rate Qactual = Q 理论 -Qleak=n*D / 60–Qleak, where D is the displacement of the cycloidal pump, n is the speed of the motor, and Q is the flow rate of the electric hydraulic pump; the speed of the motor is obtained by the motor speed sensor.

[0061] S5. Calculate the throttle valve flow rate based on the actual flow rate of the pump calculated in S4. This flow rate is the same as the flow rate through the throttle valve, so the flow rate of the throttle valve can be calculated.

[0062] S6. Calculate the pressure drop ΔPh of the throttle valve based on the flow rate obtained in step S5. Since the relationship between the flow rate and pressure difference of the throttle valve is known, the pressure drop ΔPh can be calculated by looking up a table. The curve of pressure difference versus flow rate on both sides of the throttle valve is obtained by placing the throttle valve on a test bench for its PQ characteristics, applying different flow rates to the throttle valve, testing the corresponding pressure drop, and then fitting a function of pressure drop versus flow rate. The horizontal axis represents flow rate, and the vertical axis represents pressure difference; for example... Figure 3 As shown;

[0063] S7. Calculate the feedback force value Fb based on the pressure drop in step S6. The specific calculation formula is Fb=-△Pp*Ap+△Ph*(Ap-Ar), where △Pp is the pressure drop of the electric hydraulic pump, Ap is the piston area, △Pp is the pressure drop of the throttle valve, and Ar is the area of ​​the piston rod.

[0064] S8. Calculate the difference Ferro based on the feedback force value Fb from step S7 and the required force value Fcmd sent by the host computer in step S1. Then, use PID control to adjust the pressure sensor value based on the difference Ferro. The controller calculates the force value in S7 and compares it with Fcmd: Ferro = Fcmd - Fb. The electric hydraulic pump then increases or decreases the torque to increase or decrease the pressure sensor reading, ensuring Ferro approaches 0. A schematic diagram of the PID control principle is shown below. Figure 4 As shown:

[0065] Fb=Kp*(Fcmd-△Pp*Ap)+Ki*(Fcmd-△Pp*Ap)*1 / s+Kd*(Fcmd-△Pp*Ap)*s, where Kp is the proportional coefficient, Ki is the integral coefficient, and Kd is the differential coefficient;

[0066] S9 outputs an accurate actuation force value. As described in S8, the pressure sensor reading is adjusted using PID control.

[0067] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0068] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0069] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. An algorithm for compensating pressure loss in an active vibration damper, characterized in that, Specifically, the steps include the following: S1. The host computer sends the required force value Fcmd to the electric hydraulic pump, and the electric hydraulic pump drives the actuator to make its force value meet the required force value Fcmd. S2. Calculate the pressure difference ΔPp on both sides of the electric hydraulic pump; S3. Calculate the leakage Qleak of the electric hydraulic pump based on the pressure difference △Pp obtained in step S2; S4. Calculate the actual flow rate of the electric hydraulic pump based on the leakage amount of Qleak obtained in step S3. Where D is the displacement of the cycloidal pump and n is the speed of the motor; S5. Calculate the throttle valve flow rate based on the actual pump flow rate Q obtained in step S4. S6. Calculate the pressure drop ΔPh of the throttle valve based on the throttle valve flow rate obtained in step S5. S7. Calculate the feedback force value Fb based on the pressure drop obtained in step S6; S8. Calculate the difference Ferro based on the feedback force value Fb in step S7 and the demand force value Fcmd sent by the host computer in step S1, and then use PID control to adjust the pressure value of the pressure sensor based on the difference Ferro. S9. Outputs accurate working power value; In step S7, the feedback force value Fb = -△Pp*Ap + △Ph*(Ap-Ar), where △Pp is the pressure drop of the electric hydraulic pump, Ap is the piston area, △Ph is the pressure drop of the throttle valve, and Ar is the area of ​​the piston rod. In step S8, the pressure value of the pressure sensor is adjusted by PID control of the difference Ferro. Specifically, the pressure value is Kp*Ferro+Ki*∫Ferrodt+Kd*d / dtFerro, where Kp is the proportional coefficient, Ki is the integral coefficient, and Kd is the derivative coefficient. The electric hydraulic pump increases or decreases the pressure sensor reading by increasing or decreasing the torque, ensuring that Ferro approaches 0.

2. The active vibration damper pressure loss compensation algorithm as described in claim 1, characterized in that, In step S2, the pressure difference ΔPp between the two sides of the electric hydraulic pump is obtained by subtracting the known accumulator pressure value and the pressure sensor reading.

3. The active vibration damper pressure loss compensation algorithm as described in claim 1, characterized in that, Step S3 specifically includes the following: The electric hydraulic pump was placed on a test bench for the PQ characteristics of the valve. Different flow rates were applied to the electric hydraulic pump, and the corresponding pressure drop was tested. Then, the function of pressure drop versus flow rate was fitted.

4. The active vibration damper pressure loss compensation algorithm as described in claim 1, characterized in that, In step S4, the motor speed is obtained by the motor speed sensor.

5. The active vibration damper pressure loss compensation algorithm as described in claim 1, characterized in that, In step S5, the actual pump flow rate Q is equal to the throttle valve flow rate.

6. The active vibration damper pressure loss compensation algorithm as described in claim 1, characterized in that, Step S6 specifically includes the following: The throttle valve is placed on a test bench for the valve's PQ characteristics. Different flow rates are applied to the throttle valve, and the corresponding pressure drop is tested. Then, the function of pressure drop versus flow rate is fitted.

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