A pre-compensation control method for valve control system based on the difference of solenoid valve flow characteristics

Abstract

The present invention discloses a pre-compensation control method for a valve control system based on the difference in solenoid valve flow characteristics. In response to the problem that solenoid valves of the same model and specification have different performances when leaving the factory, the present invention proposes a pre-compensation control method for a valve control system. By detecting the pressure difference-duty cycle-flow characteristics of each solenoid valve and analyzing the differences in the flow characteristics of each valve, the duty cycle compensation value required for each solenoid valve to achieve the same flow output value under the same control signal is calculated. The duty cycle control module in the controller superimposes the original duty cycle value with the duty cycle compensation value required to compensate for the flow difference. When the user gives the target motion parameters of the hydraulic actuator, the controller outputs a control signal that is processed by the duty cycle control module and then outputs the corresponding duty cycle value to control the required solenoid valves. After pre-compensation, the flow output of each solenoid valve under the same control signal remains consistent, and the solenoid valve flow output value is linearly correlated with the control signal.

Description

Technical Field

[0001] The present invention belongs to the field of solenoid valve control, and in particular relates to a pre-compensation control method for a valve control system based on differences in flow characteristics of solenoid valves. Background Art

[0002] Solenoid valves are the core control components of digital hydraulic technology. Their high-frequency opening and closing operations generate discrete fluids that merge in the pipeline, mimicking the control of continuous fluids. Solenoid valves are widely used in hydraulic systems due to their high-frequency response, high control accuracy, and strong resistance to contamination.

[0003] In hydraulic systems, multiple solenoid valves often work together. When solenoid valves of the same model and specification are used, the control algorithm that drives these solenoid valves often assumes that the performance of the solenoid valves is consistent. However, the actual situation is that even if solenoid valves of the same model and specification are used, there may be slight differences in the performance of each solenoid valve due to factors such as production batch, manufacturing differences, material differences, and usage environment.

[0004] The differential pressure-duty cycle-flow characteristic is a crucial performance parameter of solenoid valves, directly impacting the performance and stability of hydraulic systems. Different valve differential pressure-duty cycle-flow characteristic curves may exhibit differences in maximum flow, flow gain, deadband, nonlinearity, linearity, and saturation regions. Failure to compensate for these differences in differential pressure-duty cycle-flow characteristics can lead to unstable system motion, increased position control errors, oscillation, and vibration, all of which can degrade system performance and reliability. Therefore, in practical hydraulic systems, compensation should be made for differences in duty cycle-flow characteristics among solenoid valves of the same model and specification. Summary of the Invention

[0005] To address the problems in the prior art, the present invention proposes a pre-compensation control method for a valve control system based on differences in solenoid valve flow characteristics. In an actual valve control system, the present invention detects the pressure differential-duty cycle-flow characteristics of each solenoid valve. The controller analyzes the differences in the flow characteristics of each valve and calculates the duty cycle compensation value required for each solenoid valve to achieve the same flow output value under the same control signal. The duty cycle control module in the controller superimposes the original duty cycle value with the duty cycle compensation value required to compensate for the flow difference. The resulting superimposed duty cycle value controls the corresponding solenoid valve, thereby achieving pre-compensation. When the user specifies the target motion parameters of the hydraulic actuator, the controller outputs the final duty cycle value, superimposed by the duty cycle control module, to control the required solenoid valves. After pre-compensation, the flow output of the solenoid valves remains consistent under the same control signal, and the solenoid valve flow output value is completely linearly correlated with the control signal. Furthermore, the system is highly flexible. Based on the pre-compensation method, different flow output ranges can be selected to control the solenoid valves, adapting to different operating conditions and meeting a wide range of industrial application needs. The technical solutions of the present invention are as follows:

[0006] The present invention provides a pre-compensation control method for a valve control system based on the difference in flow characteristics of a solenoid valve, the method comprising the following steps:

[0007] S1: Obtain the pressure difference-duty cycle-flow characteristic curve of each solenoid valve in the valve control system;

[0008] S2: Under each pressure difference, according to the duty cycle-flow characteristic curve of each solenoid valve, the controller selects the solenoid valve with the smallest maximum output flow as the reference valve, and sets the line where the control signal and flow output are linearly correlated as the reference line;

[0009] S3: The controller compares the duty cycle-flow characteristic curve of each solenoid valve under the same pressure difference with the baseline, obtains the duty cycle compensation value required for each solenoid valve to achieve the flow output of the baseline under each control signal, and stores the duty cycle compensation value in each duty cycle control module within the controller. Each duty cycle control module controls each solenoid valve by outputting the duty cycle;

[0010] S4: After the controller obtains the target motion parameters of the hydraulic actuator input by the user, it outputs a control signal, which is a flow command signal; each duty cycle control module superimposes the duty cycle compensation value and the original duty cycle value to control its corresponding solenoid valve, so that the actual flow output of each solenoid valve under the same control signal under the pressure difference is consistent and the control signal is linearly correlated with the flow output value, thereby realizing pre-compensation control.

[0011] Compared with the prior art, the present invention has the following beneficial effects:

[0012] 1) After precompensation using the present method, each solenoid valve achieves consistent flow output values ​​under the same control signal, resolving the issue of actual performance differences among the solenoid valves. Based on the user-set target motion parameters, the duty cycle control module in the controller outputs the desired duty cycle to the corresponding solenoid valve. Precompensation helps improve system control accuracy, reduce system oscillations and errors, and enhance system stability and reliability.

[0013] 2) The present invention offers a wider range of applications and greater flexibility. Based on the pre-compensation method, any range within the linear correlation between the control signal and the flow output value can be selected as the baseline, allowing the desired flow output range of the solenoid valve to be adjusted according to different operating conditions. Users can select different flow output ranges to meet the needs of various industrial applications. This allows the system to be more flexible in different applications without having to replace hardware.

[0014] 3) The present method simplifies the controller design and manufacturing process, allowing manufacturers to develop universal controllers, eliminating the need for customized design and manufacturing for different situations, which reduces manufacturing costs. The compensation method standardizes and unifies the flow characteristics of each solenoid valve, making their performance more consistent and enabling the selection of flow output ranges based on demand. Manufacturers can mass-produce controllers without the need for complex customized design.

[0015] 4) After pre-compensation, the control signal and flow output value are completely linearly correlated. By adjusting the mapping between the control signal and the duty cycle value, when the user specifies the actuator's target motion parameters, the controller's output control signal is processed by its internal duty cycle control modules to generate a duty cycle signal for each solenoid valve. The control signal is linearly correlated with the solenoid valve's flow output value. This linear relationship simplifies the controller's calculation process and reduces the complexity of the control algorithm, which will help improve system performance, stability, and usability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of a valve control system based on compensation for flow characteristic differences of a solenoid valve according to the present invention;

[0017] Figure 2 is the solenoid valve pressure difference-duty cycle-flow characteristic curve;

[0018] Figure 3 This is a comparison diagram of the actual pressure difference-duty cycle-flow characteristics of solenoid valves of the same model and specification;

[0019] Figure 4 This is a schematic diagram of an ideal flow characteristic in which the flow command and the output flow are completely linearly related;

[0020] Figure 5This is a comparison chart of the control effect before and after compensation of the solenoid valve duty cycle-output flow difference;

[0021] Figure 6 This is the control system flow chart. DETAILED DESCRIPTION

[0022] The present invention will be further described and illustrated below in conjunction with specific embodiments. The embodiments are merely illustrative of the present disclosure and do not limit its scope. The technical features of the various embodiments of the present invention may be combined accordingly, provided that there is no conflict between them.

[0023] like Figure 1 As shown in the figure, the present invention illustrates a valve control system applicable to the present invention, the valve control system includes a hydraulic actuator, the hydraulic actuator has two oil chambers, each oil chamber is provided with an oil inlet solenoid valve and an oil outlet solenoid valve, corresponding to Figure 1 The solenoid valves 3, 4, 9, and 10 are normally closed. Solenoid valves 3 and 10 are inlet valves, while solenoid valves 4 and 9 are outlet valves. In the figure, 1 is the hydraulic pump, and 2 is the relief valve. Relief valve 2 controls the pressure upstream of solenoid valves 3 and 10 and ensures system safety. Adjustable throttle valves 5 and 8 mitigate the effects of pressure pulsations generated by the normally closed solenoid valves.

[0024] The valve control system also includes a controller 6, which obtains the pressure difference before and after each solenoid valve, the motion parameters of the hydraulic actuator, and the target motion parameters set by the user, and controls each solenoid valve by outputting the duty cycle through each duty cycle control module inside the controller. Figure 1 In the structure shown, the controller 6 receives signals from each pressure detection module and the speed detection module, and outputs signals to the first duty cycle control module (duty cycle α1, 0-100%), the second duty cycle control module (duty cycle α2, 0-100%), the third duty cycle control module (duty cycle α3, 0-100%) and the fourth duty cycle control module (duty cycle α4, 0-100%), and the solenoid valves 3, 4, 9, and 10 respectively receive drive signals from the corresponding duty cycle control modules.

[0025] Hydraulic actuators can be various types of actuators, such as hydraulic motors and hydraulic cylinders. This system uses two sets of symmetrical solenoid valves to control the two chambers of an asymmetrical hydraulic cylinder. By adjusting the duty cycle of these solenoid valves, the following operations can be achieved:

[0026] Forward movement: solenoid valve 3 and solenoid valve 9 are open, solenoid valve 4 and solenoid valve 10 are closed. By properly setting the duty cycle of the solenoid valve, the rodless chamber of the hydraulic cylinder can receive high-pressure oil, while the rod chamber discharges low-pressure oil, thereby pushing the rod of the hydraulic cylinder to move to the right.

[0027] Reverse movement: solenoid valve 3 and solenoid valve 9 are closed, solenoid valve 4 and solenoid valve 10 are opened. By adjusting the duty cycle of the solenoid valve, the rodless chamber discharges high-pressure oil and the rod chamber receives low-pressure oil, thereby causing the rod of the hydraulic cylinder to move to the left.

[0028] Stop movement: Close all solenoid valves to stop the movement of the hydraulic cylinder.

[0029] The above is the principle of controlling an asymmetric hydraulic cylinder with four solenoid valves. This valve control system can control both the linear motion of the hydraulic cylinder and the rotational motion of the hydraulic motor. The speed detection module can detect the speed of the hydraulic cylinder or the rotational speed of the hydraulic motor.

[0030] like Figure 6 As shown, the pre-compensation control method proposed by the present invention is:

[0031] S1: Obtain the pressure difference-duty cycle-flow characteristic curve of each solenoid valve in the valve control system;

[0032] S2: Under each pressure difference, according to the duty cycle-flow characteristic curve of each solenoid valve, the controller selects the solenoid valve with the smallest maximum output flow as the reference valve, and sets the line where the control signal and flow output are linearly correlated as the reference line;

[0033] S3: The controller compares the duty cycle-flow characteristic curve of each solenoid valve under the same pressure difference with the baseline, obtains the duty cycle compensation value required for each solenoid valve to achieve the flow output of the baseline under each control signal, and stores the duty cycle compensation value in each duty cycle control module within the controller. Each duty cycle control module controls each solenoid valve by outputting the duty cycle;

[0034] S4: After the controller obtains the target motion parameters of the hydraulic actuator input by the user, it outputs a control signal, which is a flow command signal; each duty cycle control module superimposes the duty cycle compensation value and the original duty cycle value to control its corresponding solenoid valve, so that the actual flow output of each solenoid valve under the same control signal under the pressure difference is consistent and the control signal is linearly correlated with the flow output value, thereby realizing pre-compensation control.

[0035] According to a preferred embodiment of the present invention, the pressure difference-duty cycle-flow characteristic curve of the solenoid valve is obtained by the following method:

[0036] When the solenoid valve on the test side is the oil inlet solenoid valve, close the oil outlet solenoid valve in the same oil chamber, close the oil inlet solenoid valve of the other oil chamber, and fully open the oil outlet solenoid valve of the other oil chamber; gradually adjust the duty cycle of the solenoid valve to be tested from 0 to 100% with a step value a, detect the pressure difference before and after the solenoid valve to be tested, and obtain the output flow of the solenoid valve to be tested through the motion parameters of the hydraulic actuator; after obtaining the test data, the pressure difference-duty cycle-flow characteristic curve of the solenoid valve to be tested is obtained by interpolation fitting; Figure 2 shown.

[0037] If the solenoid valve on the test side is the outlet solenoid valve, close the inlet solenoid valve in the same oil chamber, close the outlet solenoid valve in the other oil chamber, and fully open the inlet solenoid valve in the other oil chamber. The duty cycle of the solenoid valve under test is gradually adjusted from 0 to 100% with a step value a. The pressure differential between the valve and the outlet of the solenoid valve under test is measured, and the output flow rate of the solenoid valve under test is obtained using the motion parameters of the hydraulic actuator. After obtaining the test data, the pressure differential-duty cycle-flow rate characteristic curve of the solenoid valve under test is obtained through interpolation fitting. Once the pressure differential is selected, the duty cycle-flow rate characteristic curve of the solenoid valve under a certain pressure differential can be further obtained.

[0038] Specific to Figure 1 In the illustrated embodiment, for example, to measure the pressure differential-duty cycle-flow characteristic curve of solenoid valve 3, solenoid valves 3 and 9 are open, while solenoid valves 4 and 10 are closed. Solenoid valve 9 is fully open, and the duty cycle of solenoid valve 3 is gradually adjusted from 0 to 100% in steps of value a. Pressure detection modules 1 and 4 measure the pressure differential before and after solenoid valve 3, while the speed detection module measures the output flow rate. This method, combined with interpolation and fitting techniques, yields the pressure differential-duty cycle-flow characteristic curve of solenoid valve 3.

[0039] When measuring solenoid valve 9: solenoid valves 3 and 9 are open, solenoid valves 4 and 10 are closed, solenoid valve 3 is fully open, and the duty cycle of solenoid valve 9 is adjusted;

[0040] When measuring solenoid valve 4: solenoid valves 3 and 9 are closed, solenoid valves 4 and 10 are opened, solenoid valve 10 is fully opened, and the duty cycle of solenoid valve 4 is adjusted;

[0041] When measuring solenoid valve 10: solenoid valves 3 and 9 are closed, solenoid valves 4 and 10 are opened, solenoid valve 4 is fully opened, and the duty cycle of solenoid valve 10 is adjusted; the controller can finally obtain the pressure difference-duty cycle-flow characteristic curves of the four valves.

[0042] The duty cycle-flow characteristic curve of a solenoid valve typically exhibits distinct regions, including a deadband, a nonlinear region, a linear region, a nonlinear region, and a saturation region. These regions are related to the solenoid valve's operating principle and performance characteristics. These characteristics are inherent to the solenoid valve and may vary even among valves of the same model and specifications. These characteristics are crucial for effectively controlling solenoid valves and integrating them into hydraulic systems. In practical applications, the appropriate solenoid valve must be selected based on specific operating requirements and control system requirements, and a control strategy must be implemented to address characteristics such as deadband, nonlinearity, and saturation to ensure system stability and performance.

[0043] After testing, under a certain pressure difference, the duty cycle-flow characteristics of each solenoid valve must be different. For example, when the pressure difference is 0.1Mpa, the duty cycle-flow characteristics of each solenoid valve are as follows: Figure 3 As shown, each solenoid valve has different maximum flow rates, flow gains, dead zones, nonlinear zones, linear zones, and saturation zones. The differences in duty cycle-flow characteristics of each solenoid valve may have the following effects on the solenoid valve:

[0044] Reduced control accuracy: Differences in duty cycle-flow characteristic curves may result in different output flows for each valve under the same control input. This may reduce the control accuracy of the system, especially in applications requiring high-precision control.

[0045] Increased position control error: If the hydraulic system is used for position control, differences in the pressure differential-duty cycle-flow characteristics may cause increased position control error, resulting in inaccurate actuator positioning and affecting system performance.

[0046] Oscillation and vibration: Differences in the characteristics of different valves may cause oscillation or vibration in the system. This may introduce instability into the hydraulic system and affect the smooth operation of the system.

[0047] In summary, it is necessary to pre-compensate the actual pressure difference-duty cycle-flow characteristics of each solenoid valve before the hydraulic system works to improve the system control accuracy and reliability.

[0048] S2 of the present invention is to select the reference valve and set the reference line, such as Figure 3 and Figure 4 As shown. S2 is specifically:

[0049] The duty cycle-flow characteristic curve of the solenoid valve under each pressure differential is divided into a dead zone, a first nonlinear zone, a linear zone, a second nonlinear zone, and a saturated zone. The controller analyzes the duty cycle-flow characteristic curves of each solenoid valve under different pressure differentials. Since the maximum output flow value of each solenoid valve is determined by its structure and can only be adjusted downward, the controller selects the solenoid valve with the smallest maximum output flow value as the reference valve, whose maximum output flow value is Q0.

[0050] The control signal generated by the controller for each solenoid valve is standardized and designed to be in the range of [0, 1]. The output flow range of each solenoid valve is [0, Q0]. The line that is linearly related to the control signal and the flow output is set as the baseline. When the baseline control signal is t, the corresponding output flow Q = t × Q 0。

[0051] S3 of the present invention is that the controller compares the duty cycle-flow characteristic curve of each solenoid valve under the same pressure difference with the baseline, obtains the duty cycle compensation value required for each solenoid valve to reach the flow output of the baseline under each control signal, and stores the duty cycle compensation value in each duty cycle control module inside the controller. Each duty cycle control module controls each solenoid valve by outputting the duty cycle.

[0052] Mapping the ideal flow characteristic to the slope (baseline), users can select the maximum output flow rate of the solenoid valve according to changing operating conditions. Within the maximum output flow rate range of the benchmark solenoid valve, they can then select the desired flow range to control each valve. By selecting different flow output ranges, valve performance can be tailored to actual operating conditions. This increases system flexibility, making it easier to adapt to different applications and changing operating conditions, and more easily achieve precise flow control. Users can dynamically adjust controller parameters to meet varying flow requirements based on specific operating requirements.

[0053] This feature is very useful for adapting to a variety of application scenarios, as different operating conditions may require different flow outputs. For example, when the system requires high-speed movement, the user can choose to control the output flow rate within a larger range, from 0 to a base valve flow output. In cases where lower flow requirements are required, the user can choose to control the output flow rate within a smaller range, from 0 to a smaller value. This adjustable flow range and control flexibility make the controller more versatile in different applications, able to meet a wide range of industrial needs and improve system performance and efficiency. At the same time, users can more easily adapt to different working conditions without having to replace or readjust controllers with different configurations. This improves the adaptability of the system and the convenience of operation.

[0054] And by mapping to the oblique line (baseline) of the ideal flow characteristic, the control algorithm can be simplified: after mapping the nonlinear flow characteristic to a linear relationship, the controller can more easily calculate the required duty cycle value without having to process nonlinear mathematical operations, which reduces the complexity of the control algorithm; linear relationships are usually easier to control accurately because they follow a simple proportional relationship. By mapping the nonlinear flow characteristic to a linear relationship, the accuracy of the control system can be improved, ensuring that the relationship between the output flow and the flow command signal is more accurate; after mapping to a linear relationship, the user can more easily select the required flow range without the need for complex calculations, which increases the adjustability and applicability of the system.

[0055] The S4 of the present invention is specifically:

[0056] According to the target motion parameters of the hydraulic actuator set by the user, the controller calculates the target output flow value Q of each solenoid valve required to work n ;

[0057] The controller sets the target output flow value Q of each solenoid valve n Compare with the maximum output flow value Q0 of the reference valve to obtain the control signal n of each solenoid valve, n = Q n / Q 0；

[0058] The controller superimposes the original duty cycle value corresponding to the control signal n and the corresponding duty cycle compensation value to obtain the superimposed duty cycle value of each solenoid valve. 叠加 =Duty cycle 原始 ±Duty cycle 补偿 The original duty cycle value is the duty cycle value corresponding to the solenoid valve control signal without any compensation or adjustment;

[0059] The final superimposed duty cycle value is output by the corresponding duty cycle control module to control the corresponding solenoid valve to ensure that its output flow meets expectations and that the flow output of the entire system is linearly related to the duty cycle.

[0060] After pre-compensation, when the user gives the actuator target motion parameters, the controller outputs the control signal to the duty cycle control modules inside it. Each duty cycle module superimposes the original duty cycle value with the duty cycle compensation value, and then adjusts the solenoid valve to achieve the duty cycle value required for the output flow. Taking the control of an asymmetric cylinder as an example, after compensation, it can achieve Figure 5 The control effect shown.

[0061] After pre-compensation, the actual pressure differential, duty cycle, and flow characteristics of each solenoid valve remain consistent, addressing the issue of actual performance variations among the solenoid valves. Based on the user-defined actuator target motion parameters, the controller calculates the input signal for each valve. Compensating for differences in flow characteristics among solenoid valves helps improve system control accuracy, reduce oscillations and errors, and enhance system stability and reliability. After pre-compensation, the control signal is completely linearly correlated with the flow target value, simplifying the controller's calculation process and reducing the complexity of the control algorithm, ultimately improving system performance, stability, and availability.

[0062] The above-described embodiments merely illustrate several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. Persons skilled in the art will readily appreciate that variations and modifications may be made without departing from the scope of the present invention, all of which fall within the scope of protection of the present invention.

Claims

1. A pre-compensation control method for a valve control system based on the difference in flow characteristics of a solenoid valve, characterized in that: The steps include: S1: Obtain the pressure difference-duty cycle-flow characteristic curve of each solenoid valve in the valve control system; S2: Under each pressure difference, according to the duty cycle-flow characteristic curve of each solenoid valve, the controller selects the solenoid valve with the smallest maximum output flow value as the reference valve, and sets the line with a linear correlation between the control signal and the flow output as the reference line; S3: The controller compares the duty cycle-flow characteristic curve of each solenoid valve under the same pressure difference with the baseline, obtains the duty cycle compensation value required for each solenoid valve to achieve the flow output of the baseline under each control signal, and stores the duty cycle compensation value in each duty cycle control module within the controller. Each duty cycle control module controls each solenoid valve by outputting the duty cycle; S4: After the controller obtains the target motion parameters of the hydraulic actuator input by the user, it outputs a control signal, which is a flow command signal; each duty cycle control module superimposes the duty cycle compensation value and the original duty cycle value to control its corresponding solenoid valve, so that the actual flow output of each solenoid valve under the same control signal under the pressure difference is consistent and the control signal is linearly correlated with the flow output value, thereby realizing pre-compensation control.

2. The valve control system pre-compensation control method based on the difference in solenoid valve flow characteristics according to claim 1 is characterized in that: The valve control system includes a hydraulic actuator, which has two oil chambers, each of which is provided with an oil inlet solenoid valve and an oil outlet solenoid valve; the valve control system also includes a controller, which obtains the pressure difference before and after the valve of each solenoid valve, the motion parameters of the hydraulic actuator, and the target motion parameters set by the user, and outputs a control signal to each duty cycle control module therein, and each duty cycle control module outputs a duty cycle to control each solenoid valve; the duty cycle control module stores the duty cycle compensation value required for each solenoid valve to reach the baseline flow output under each control signal.

3. The valve control system pre-compensation control method based on the difference in solenoid valve flow characteristics according to claim 2 is characterized in that: The pressure difference-duty cycle-flow characteristic curve of the solenoid valve is obtained by the following method: When the solenoid valve on the test side is the oil inlet solenoid valve, close the oil outlet solenoid valve in the same oil chamber, close the oil inlet solenoid valve of the other oil chamber, and fully open the oil outlet solenoid valve of the other oil chamber; gradually adjust the duty cycle of the solenoid valve to be tested from 0 to 100% with a step value a, detect the pressure difference before and after the solenoid valve to be tested, and obtain the output flow of the solenoid valve to be tested through the motion parameters of the hydraulic actuator; after obtaining the test data, the pressure difference-duty cycle-flow characteristic curve of the solenoid valve to be tested is obtained through interpolation fitting; When the solenoid valve on the test side is an oil outlet solenoid valve, close the oil inlet solenoid valve in the same oil chamber, close the oil outlet solenoid valve of the other oil chamber, and fully open the oil inlet solenoid valve of the other oil chamber; gradually adjust the duty cycle of the solenoid valve to be tested from 0 to 100% with a step value a, detect the pressure difference before and after the solenoid valve to be tested, and obtain the output flow of the solenoid valve to be tested through the motion parameters of the hydraulic actuator; after obtaining the test data, the pressure difference-duty cycle-flow characteristic curve of the solenoid valve to be tested is obtained by interpolation fitting.

4. The valve control system pre-compensation control method based on solenoid valve flow characteristic difference according to claim 1, characterized in that: The S2 is specifically: The duty cycle-flow characteristic curve of the solenoid valve under each pressure differential is divided into a dead zone, a first nonlinear zone, a linear zone, a second nonlinear zone, and a saturated zone. The controller analyzes the duty cycle-flow characteristic curves of each solenoid valve under different pressure differentials. Since the maximum output flow value of each solenoid valve is determined by its structure and can only be adjusted downward, the controller selects the solenoid valve with the smallest maximum output flow value as the reference valve, whose maximum output flow value is Q0. The control signal generated by the controller for each solenoid valve is standardized and designed to be in the range of [0, 1]. The output flow range of each solenoid valve is [0, Q0]. The line that is linearly related to the control signal and the flow output is set as the baseline. When the baseline control signal is t, the corresponding output flow Q=t×Q 0。 5. The valve control system pre-compensation control method based on solenoid valve flow characteristic difference according to claim 1, characterized in that: The S4 is specifically: According to the target motion parameters of the hydraulic actuator set by the user, the controller calculates the target output flow value Q of each solenoid valve required to work n ; The controller sets the target output flow value Q of each solenoid valve n Compare with the maximum output flow value Q0 of the reference valve to obtain the control signal n of each solenoid valve, n=Q n / Q 0； The controller superimposes the original duty cycle value corresponding to the control signal n and the corresponding duty cycle compensation value to obtain the superimposed duty cycle value of each solenoid valve. 叠加 =Duty Cycle 原始 ±Duty cycle 补偿 ; The final superimposed duty cycle value is output by the corresponding duty cycle control module to control the corresponding solenoid valve to ensure that its output flow meets expectations and that the flow output of the entire system is linearly related to the duty cycle.

6. The valve control system pre-compensation control method based on solenoid valve flow characteristic difference according to claim 1 or 5, characterized in that: The original duty cycle value is a duty cycle value corresponding to the solenoid valve control signal without any compensation or adjustment.

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