Algorithm for compensating for changes in actuation force caused by temperature changes in an active suspension

Abstract

This invention relates to an algorithm for compensating for changes in driving force caused by temperature variations in active suspension. The algorithm includes determining temperature and oil viscosity by testing the relationship between torque and pressure difference; slowly applying a constant torque to the motor under set conditions and recording pressure sensor readings; establishing a table showing the relationship between pressure sensor readings, temperature, and oil viscosity at a given torque; estimating oil temperature and then calculating oil viscosity from the table using torque and pressure; estimating the leakage of the electric hydraulic pump based on oil viscosity; estimating the throttle valve pressure drop based on leakage and oil viscosity, calculating the driving force, and calculating the actual pump flow rate based on speed and displacement information; obtaining the flow rate through the throttle valve; calculating the throttle valve pressure drop from the table; and calculating the driving force using a formula. This invention utilizes existing sensors on the active damper for temperature compensation, eliminating the need for additional sensors, accurately determining the valve pressure drop, and calculating the output driving force.

Description

Technical Field

[0001] This invention belongs to the field of active damper technology, specifically relating to an algorithm for compensating for changes in action force caused by temperature variations in active suspension. Background Technology

[0002] like Figure 1 As shown, the active damper includes an accumulator structure, an electro-hydraulic pump structure, a pressure sensor, a throttle valve, and an actuator. The viscosity of the hydraulic fluid changes with the operation of the active damper or variations in ambient temperature, causing changes in the throttle valve's PQ (flow-to-pressure) characteristic and the pump's leakage characteristic P-Qleak (pressure-leakage) characteristic, ultimately leading to changes in the output.

[0003] Therefore, to accurately obtain the actuator output force value, it is necessary to accurately assess the viscosity of the oil and perform PQ calibration of the throttle valve and pump characteristics. Since there is a one-to-one correspondence between temperature and oil viscosity, the active damper needs to be calibrated using temperature parameters to determine the PQ curve.

[0004] However, the active damper lacks a temperature sensor that directly measures the oil temperature, and the actual oil temperature differs from the ambient temperature. Although the active damper control system has sensors that directly measure the temperature of the circuit board and the MOSFETs, these temperatures do not match the actual oil temperature. Therefore, an algorithm is needed to predict the temperature. Summary of the Invention

[0005] The purpose of this invention is to provide an algorithm for compensating for changes in driving force caused by temperature variations in active suspension, in order to solve the problem of changes in damping force caused by changes in oil viscosity due to temperature variations.

[0006] The objective of this invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides an algorithm for compensating for changes in action force of an active suspension caused by temperature variations, comprising the following steps:

[0008] A. Determine temperature and oil viscosity by testing the relationship between torque and pressure difference.

[0009] A1. Under set conditions, slowly apply a constant torque to the motor and record the pressure sensor readings;

[0010] A2. Establish a table showing the relationship between the readings of a specific torque pressure sensor, temperature, and oil viscosity;

[0011] A3. The oil temperature can be estimated by looking up the table using torque and pressure, and then the oil viscosity can be calculated.

[0012] B. Estimate the leakage of the electric hydraulic pump based on the oil viscosity;

[0013] C. Estimate the pressure drop of the throttle valve based on the leakage amount and oil viscosity, and calculate the operating power.

[0014] C1. Calculate the actual flow rate of the pump based on the speed and displacement information;

[0015] C2. Calculate the flow rate through the throttle valve;

[0016] C3. Calculate the pressure drop of the throttle valve by referring to the table;

[0017] C4. Calculate the power source according to the formula.

[0018] Further, in step A1, the conditions are set as follows: the suspension vibration speed is less than a certain threshold or the vehicle is stationary.

[0019] Further, step A2 specifically involves: at a constant temperature, matching the torque with the readings of the pressure sensor one by one, then calibrating the relationship between pressure P and temperature T, as well as the relationship between temperature T and oil viscosity, establishing a table of the relationship between a given torque pressure sensor reading, temperature, and oil viscosity, fitting the above results into a curve, and performing linear interpolation to obtain the temperature and viscosity.

[0020] Further, step B specifically involves: different viscosities will have different leakage amounts when flowing through the pump. The leakage amount flowing through the electric hydraulic pump is tested on a bench, a table corresponding to viscosity and leakage amount is generated, and a curve corresponding to viscosity and leakage amount is fitted to generate the relationship curve. The leakage amount of the electric hydraulic pump can be estimated from the oil viscosity.

[0021] Furthermore, step C1 specifically involves: based on the above curves, the leakage amount under different pressures can be obtained, and then the actual flow rate through the pump can be calculated based on the rotational speed.

[0022] Furthermore, step C2 specifically involves connecting the pump and the throttle valve in series to calculate the actual flow rate through the throttle valve.

[0023] Furthermore, step C3 specifically involves: different viscosities will result in different pressure drops when flowing through the throttle valve, and the pressure drop of the throttle valve can be estimated through the calibration curve.

[0024] Furthermore, bench tests were conducted to measure the PQ characteristics of valves with different viscosities. The test results were then compiled into a MAP and input into software for linear interpolation to obtain an accurate pressure drop.

[0025] Furthermore, in step C4, the formula for calculating the power is: F=-△Pp*Ap+△Ph(Ap-Ar), where F is the main output power, △Pp is the pressure difference of the electric hydraulic pump, △Ph is the pressure difference across the valve, Ap is the piston area, and Ar is the piston rod area.

[0026] In a second aspect, the present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements an algorithm for compensating for changes in action force of an active suspension caused by temperature changes, as described in any of the embodiments of the present invention.

[0027] Thirdly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements an algorithm for compensating for changes in action force of an active suspension caused by temperature variations, as described in any of the embodiments of the present invention.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] The present invention provides an algorithm for compensating for changes in the driving force of an active suspension caused by temperature variations, including torque and pressure calibration to estimate temperature, temperature to estimate oil viscosity, oil viscosity to estimate leakage of the electric hydraulic pump, and leakage and oil viscosity to estimate throttle valve pressure drop; the method is used for compensating for changes in the driving force of an active suspension caused by temperature variations.

[0030] The greatest advantage of this method is that it determines temperature and oil viscosity by testing the relationship between torque and pressure difference. This test can be performed in detail on a bench to ensure accuracy. The test results are then compiled into a MAP (Position Map), which is input into software for linear interpolation to obtain the viscosity. The leakage rate through the electro-hydraulic pump is then measured on a bench. Based on the leakage rate of the electro-hydraulic pump, the actual flow rate of the pump can be accurately calculated. The actual flow rate of the pump is equal to the flow rate through the valve. The PQ (Pressure-to-Quantity) characteristics of valves with different viscosities are then tested on a bench. The test results are then compiled into a MAP and input into software for linear interpolation to obtain an accurate pressure drop.

[0031] This method utilizes existing sensors on the active damper for temperature compensation, eliminating the need for additional sensors. Specifically, the torque is obtained by using a current sensor, which is proportional to the torque. A pressure sensor is used to obtain the pressure drop of the electric hydraulic pump, from which the temperature value is calculated. The viscosity value is then determined by the correlation between temperature and viscosity, leading to the actual flow rate through the pump. Based on the flow rate and temperature, the valve pressure drop is calculated. The output power can then be accurately determined using the mathematical formula F = -ΔPp*Ap + ΔPh(Ap - Ar). Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram illustrating the internal workings of an active vibration damper. Figure 2 The curve showing the relationship between viscosity and leakage amount; Figure 3 The pressure drop varies with the flow rate through the throttle valve for different viscosities;

[0034] Figure 4 A flowchart of an algorithm for compensating for changes in dynamic force caused by temperature variations in active suspension;

[0035] Figure 5 This is a schematic diagram of the structure of an electronic device according to Embodiment 3 of the present invention. Detailed Implementation

[0036] The present invention will be further described below with reference to embodiments:

[0037] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0038] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this invention, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0039] like Figure 1 As shown, the active damper includes an accumulator, an electro-hydraulic pump, a pressure sensor, a throttle valve, and an actuator cylinder. The active damper drives the actuator cylinder to move using pressure generated by the electro-hydraulic pump. Therefore, pressure control of the active damper is particularly important. To ensure rapid, accurate, and stable pressure control of the electro-hydraulic pump, precise control of the torque of the motor in the electro-hydraulic pump is required.

[0040] The algorithm of this invention for compensating for changes in action force caused by temperature variations in active suspension includes the following steps:

[0041] 1. Torque and pressure calibration estimation based on temperature and viscosity.

[0042] When the vehicle is stationary or the suspension vibration speed is below a certain threshold, a constant torque is slowly applied to the motor, and the pressure sensor readings are recorded. The temperature and oil viscosity are determined by testing the relationship between torque and pressure difference. Specifically, at a constant temperature, the torque is mapped one-to-one with the pressure sensor readings. The relationship between pressure P and temperature T, and between temperature T and oil viscosity, is then calibrated, creating a table showing the relationship between pressure sensor readings, temperature, and oil viscosity at a given torque, as shown in Table 1. T = f(P), ν = f(T). The results are fitted to a curve, and linear interpolation is used to obtain the temperature and viscosity. Table 1 is integrated into the control model, which, within the electric hydraulic pump, uses linear interpolation and table lookup to output the temperature and viscosity.

[0043] Table 1

[0044]

[0045] The oil temperature can be estimated from the torque and pressure by referring to Table 1, and then the oil viscosity can be calculated.

[0046] 2. Estimating the leakage of an electric hydraulic pump based on oil viscosity.

[0047] Different viscosities will result in different leakage rates when flowing through the pump. A table mapping viscosity to leakage rate is generated during calibration. The leakage rate of the electric hydraulic pump corresponding to the oil viscosity can be calculated by referring to the table. The viscosity-leakage rate curve is shown below. Figure 2 As shown, this relationship curve is integrated into the control model.

[0048] 3. Estimate the pressure drop of the throttle valve based on the leakage and oil viscosity, and calculate the operating power.

[0049] Based on the curve obtained in step 3, the leakage amount under different pressures can be obtained, and then the actual flow rate through the pump can be calculated based on the pump displacement and speed.

[0050] Since the pump and the throttle valve are connected in series, the actual flow rate through the throttle valve can be calculated.

[0051] Different viscosities will result in different pressure drops when flowing through a throttle valve; accurate calibration is necessary to address this. Figure 3 By integrating the curve into the control model, the pressure drop of the throttle valve can be accurately estimated. Based on the formula: F=-△Pp*Ap+△Ph(Ap-Ar), the magnitude of the working force can be accurately calculated.

[0052] Where F is the main output power, △Pp is the pressure difference of the electric hydraulic pump, △Ph is the pressure difference across the valve, Ap is the piston area, and Ar is the piston rod area.

[0053] Example 1

[0054] An algorithm for compensating for changes in action force caused by temperature variations in active suspension includes the following steps:

[0055] 1. The test is conducted on a bench test stand, when the suspension vibration speed is less than a certain threshold or when the vehicle is stationary;

[0056] 2. Slowly apply a constant torque to the motor;

[0057] 3. Take pressure sensor readings.

[0058] 4. Under constant temperature, the torque and pressure sensor readings correspond one-to-one. The relationship between pressure P and temperature T, and between temperature T and oil viscosity, is calibrated. A table showing the relationship between pressure sensor readings, temperature, and oil viscosity for a given torque is established and integrated into the control model. By referring to the table, the oil temperature can be estimated from the torque and pressure, and thus the oil viscosity can be accurately estimated.

[0059] Specifically, the test results are compiled into a MAP and input into the software for linear interpolation to obtain the viscosity.

[0060] 5. Different viscosities will result in different leakage rates when flowing through the pump. A table mapping viscosity to leakage rate is generated. By referring to the table, the leakage rate of the electric hydraulic pump corresponding to the oil viscosity estimated in step 2 can be calculated. The viscosity-leakage relationship curve is shown below. Figure 2 As shown, this relationship curve is integrated into the control model.

[0061] 6. Based on the above curves, the leakage amount under different pressures can be obtained, and then the actual flow rate through the pump can be calculated according to the rotational speed.

[0062] 7. Since the pump and the throttle valve are connected in series, the actual flow rate through the throttle valve can be calculated.

[0063] 8. Different viscosities will result in different pressure drops when flowing through a throttle valve. Accurate calibration is necessary to address this. Figure 3 The curve will Figure 3 The pressure drop of the throttle valve can be accurately estimated by integrating the curve into the control model.

[0064] Specifically, bench tests are conducted to measure the PQ characteristics of valves with different viscosities. The test results are then compiled into a MAP and input into software for linear interpolation to obtain an accurate pressure drop.

[0065] 9. Perform dynamic calculations:

[0066] Based on the formula: F=-△Pp*Ap+△Ph(Ap-Ar), the magnitude of the working force can be accurately calculated.

[0067] Where F is the main output power, △Pp is the pressure difference of the electric hydraulic pump, △Ph is the pressure difference across the valve, Ap is the piston area, and Ar is the piston rod area.

[0068] Example 2

[0069] Figure 5 This is a schematic diagram of the structure of a computer device in Embodiment 2 of the present invention. Figure 5 A block diagram of an exemplary computer device 12 suitable for implementing embodiments of the present invention is shown. Figure 5 The computer device 12 shown is merely an example and should not impose any limitation on the functionality and scope of use of the embodiments of the present invention.

[0070] like Figure 5 As shown, the computer device 12 is represented in the form of a general-purpose computing device. The components of the computer device 12 may include, but are not limited to: one or more processors or processing units 16, system memory 28, and a bus 18 connecting different system components (including system memory 28 and processing unit 16).

[0071] Bus 18 represents one or more of several bus architectures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus using any of the various bus architectures. For example, these architectures include, but are not limited to, the Industry Standard Architecture (ISA) bus, the Micro Channel Architecture (MAC) bus, the Enhanced ISA bus, the Video Electronics Standards Association (VESA) local bus, and the Peripheral Component Interconnect (PCI) bus.

[0072] Computer device 12 typically includes a variety of computer system readable media. These media can be any available media that can be accessed by computer device 12, including volatile and non-volatile media, removable and non-removable media.

[0073] System memory 28 may include computer system readable media in the form of volatile memory, such as random access memory (RAM) 30 and / or cache memory 32. Computer device 12 may further include other removable / non-removable, volatile / non-volatile computer system storage media. By way of example only, storage system 34 may be used to read and write non-removable, non-volatile magnetic media (…). Figure 5 Not shown; usually referred to as a "hard drive"). Although Figure 5Not shown, a disk drive for reading and writing to a removable non-volatile disk (e.g., a "floppy disk") and an optical disk drive for reading and writing to a removable non-volatile optical disk (e.g., a CD-ROM, DVD-ROM, or other optical media) may be provided. In these cases, each drive may be connected to bus 18 via one or more data media interfaces. Memory 28 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments of the present invention.

[0074] A program / utility 40 having a set (at least one) of program modules 42 may be stored, for example, in memory 28. Such program modules 42 include—but are not limited to—an operating system, one or more application programs, other program modules, and program data. Each or some combination of these examples may include an implementation of a network environment. Program modules 42 typically perform the functions and / or methods described in the embodiments of the present invention.

[0075] The computer device 12 can also communicate with one or more external devices 14 (e.g., keyboard, pointing device, display 24, etc.), and with one or more devices that enable a user to interact with the computer device 12, and / or with any device that enables the computer device 12 to communicate with one or more other computing devices (e.g., network card, modem, etc.). This communication can be performed via the input / output (I / O) interface 22. Furthermore, in this embodiment, the display 24 of the computer device 12 is not an independent entity, but is embedded in a mirror, so that when the display surface of the display 24 is not displayed, the display surface of the display 24 and the mirror surface visually blend together. Moreover, the computer device 12 can also communicate with one or more networks (e.g., local area network (LAN), wide area network (WAN), and / or public networks, such as the Internet) via the network adapter 20. As shown, the network adapter 20 communicates with other modules of the computer device 12 via the bus 18. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with computer device 12, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0076] The processing unit 16 executes various functional applications and data processing by running programs stored in the system memory 28, such as implementing an algorithm provided in this embodiment of the invention for compensating for changes in action force caused by temperature changes in active suspension.

[0077] Example 3

[0078] Embodiment 3 of the present invention provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, it implements an algorithm for compensating for changes in action force of an active suspension caused by temperature changes, as provided in all embodiments of the present application.

[0079] Any combination of one or more computer-readable media may be used. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples (a non-exhaustive list) of computer-readable storage media include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in connection with an instruction execution system, apparatus, or device.

[0080] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including—but not limited to—electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of transmitting, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0081] The program code contained on a computer-readable medium may be transmitted using any suitable medium, including—but not limited to—wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0082] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0083] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. An algorithm for compensating for changes in action force caused by temperature variations in active suspension, characterized in that, Includes the following steps: A. Determine temperature and oil viscosity by testing the relationship between torque and pressure difference. A1. Under set conditions, slowly apply a constant torque to the motor and record the pressure sensor readings; A2. Establish a table showing the relationship between the readings of a specific torque pressure sensor, temperature, and oil viscosity; A3. The oil temperature can be estimated by looking up the table using torque and pressure, and then the oil viscosity can be calculated. B. Estimate the leakage of the electric hydraulic pump based on the oil viscosity; C. Estimate the pressure drop of the throttle valve based on the leakage and oil viscosity, and calculate the power required; C1. Calculate the actual flow rate of the pump based on the speed and displacement information; C2. Calculate the flow rate through the throttle valve; C3. Calculate the pressure drop of the throttle valve by referring to the table; C4. Calculate the power source according to the formula; Step C2, specifically: the pump and the throttle valve are connected in series, thereby calculating the actual flow rate through the throttle valve; Step C4, the formula for calculating the power is: F = -△Pp*Ap + △Ph(Ap-Ar), where F is the main output power, △Pp is the pressure difference of the electric hydraulic pump, △Ph is the pressure drop across the throttle valve, Ap is the piston area, and Ar is the piston rod area.

2. The algorithm for compensating for changes in action force caused by temperature variations in active suspension according to claim 1, characterized in that: Step A1 sets the condition as the suspension vibration speed being less than a certain threshold or the vehicle being stationary.

3. The algorithm for compensating for changes in action force caused by temperature variations in active suspension according to claim 1, characterized in that, Step A2 is as follows: Under constant temperature, the torque and pressure sensor readings are matched one by one, and the relationship between pressure P and temperature T, as well as the relationship between temperature T and oil viscosity, are calibrated. A table is established showing the relationship between a certain torque pressure sensor reading, temperature and oil viscosity. The above results are fitted into a curve, and linear interpolation is performed to obtain the temperature and viscosity.

4. The algorithm for compensating for changes in action force caused by temperature variations in active suspension according to claim 1, characterized in that, Step B specifically involves: different viscosities will have different leakage amounts when flowing through the pump. The leakage amount of the electric hydraulic pump is tested on a bench, a table corresponding to viscosity and leakage amount is generated, and a curve corresponding to viscosity and leakage amount is fitted. The leakage amount of the electric hydraulic pump can be estimated from the oil viscosity.

5. The algorithm for compensating for changes in action force caused by temperature variations in an active suspension, as described in claim 4, is characterized in that... Step C1 is as follows: Based on the above curves, the leakage amount under different pressures can be obtained, and then the actual flow rate through the pump can be calculated according to the rotational speed.

6. The algorithm for compensating for changes in action force caused by temperature variations in an active suspension, as described in claim 1, is characterized in that... Step C3 is as follows: Different viscosities will result in different pressure drops when flowing through the throttle valve. The pressure drop of the throttle valve can be estimated by calibration curves. Specifically, bench tests are conducted to test the PQ characteristics of valves with different viscosities. The test results are then compiled into a MAP and input into software for linear interpolation to obtain an accurate pressure drop.

7. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements an algorithm for compensating for changes in action force of an active suspension caused by temperature variations, as described in any one of claims 1-6.

8. A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements an algorithm for compensating for changes in action force of an active suspension caused by temperature variations, as described in any one of claims 1-6.

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