CN-121978436-A - Rapid and accurate prediction method for duty ratio-equivalent output flow characteristic of high-speed switch valve

CN121978436ACN 121978436 ACN121978436 ACN 121978436ACN-121978436-A

Abstract

The invention discloses a rapid and accurate prediction method for the duty ratio-equivalent output flow characteristic of a high-speed switch valve, and belongs to the field of high-speed switch valves. The method comprises the steps of firstly obtaining dynamic characteristic parameters of a high-speed switching valve to be detected, including opening lag time, opening movement time, closing lag time, closing movement time and current adjustment time, then establishing a mathematical model of the equivalent output flow of the high-speed switching valve and a switching duty ratio based on the dynamic characteristic parameters, deducing duty ratio boundaries of dead zones, linear zones and saturation zones in the duty ratio-equivalent output flow characteristics, obtaining actual measurement equivalent output flow data of upper and lower limits of the linear zones through a small amount of experiments, substituting the actual measurement equivalent output flow data into the mathematical model, and combining the duty ratio boundaries to generate a duty ratio-equivalent output flow characteristic curve. According to the invention, the quick and accurate prediction of the duty ratio-equivalent output flow characteristic of the high-speed switch valve can be realized only through one-time dynamic behavior and current characteristic measurement and a small amount of experiments.

Inventors

ZHONG QI
GUO ZIHAO
PAN LICHENG
LI HAORAN
XU ENGUANG
LI YANBIAO

Assignees

浙江工业大学

Dates

Publication Date: 20260505
Application Date: 20260123

Claims (10)

1. A rapid and accurate prediction method for the duty ratio-equivalent output flow characteristic of a high-speed switch valve is characterized by comprising the following steps: 1) Under a selected driving mode, periodically opening and closing the to-be-detected high-speed switching valve, recording the starting and ending time of each movement state of the valve core and the coil current change time, and obtaining the dynamic time parameters of the high-speed switching valve, wherein the dynamic time parameters comprise opening lag time, opening movement time, opening current adjustment time, closing lag time, closing movement time and closing current adjustment time; 2) Calculating duty cycle boundaries of different intervals in duty cycle-equivalent output flow characteristics of the high-speed switching valve to be detected according to the obtained dynamic time parameters and the start-stop period, wherein the duty cycle boundaries comprise a dead zone upper limit alpha 1 , a linear zone lower limit alpha 1 +α 2 , linear zone upper limits 1-alpha 3 -α 4 and saturation zone lower limits 1-alpha 4 , and nonlinear zones are arranged between the dead zone upper limit and the linear zone lower limit and between the linear zone upper limit and the saturation zone lower limit; 3) Establishing a relation between duty ratio and flow characteristic by combining the measured equivalent output flow value, wherein the duty ratio is in a dead zone, and determining the relation with the constant equivalent output flow value of 0; establishing a linear fitting relation according to the actually measured equivalent output flow values of the upper limit and the lower limit of the linear region when the duty ratio is in the linear region, and determining the relation that the equivalent output flow is constant at 100 percent when the duty ratio is in the saturated region; 4) And combining the equivalent output flow and the duty ratio relation between different duty ratio intervals, establishing a coordinate system by taking the duty ratio as a horizontal axis and the equivalent output flow as a vertical axis, wherein the dead zone is represented by a horizontal line with the constant equivalent output flow being 0, the linear zone is represented by a linear fitting straight line, the saturation zone is represented by a horizontal line with the constant equivalent output flow being 100%, and a duty ratio-equivalent output flow characteristic curve of the high-speed switch valve without the nonlinear zone is obtained, wherein the duty ratio-equivalent output flow characteristic curve is a relation curve of the duty ratio and the equivalent output flow under the duty ratio.
2. The method of claim 1, wherein the selected driving mode in step 1) causes a start-stop cycle of the high-speed switching valve to be divided into an on-phase and an off-phase, wherein a preset voltage is applied during the on-phase to provide sufficient electromagnetic force for opening the valve core, and wherein a voltage source applies zero voltage or reverse voltage to the high-speed switching valve coil during the off-phase to cause the valve core to be reset and closed by spring force.
3. The method of claim 2, wherein the dynamic time parameter in step 1) is obtained by direct detection, specifically, a laser displacement sensor is additionally arranged on the high-speed switch valve, a valve core displacement curve is acquired in real time through the laser displacement sensor, and the complete opening time, the complete closing time and the complete closing time of the valve core starting opening time are determined according to the slope abrupt change point of the displacement curve.
4. The method according to claim 2, wherein the dynamic time parameter in step 1) is obtained through indirect detection, specifically, a coil current curve of the high-speed switch valve is collected through a current collection card, and the valve element starting opening time, the full opening time, the starting closing time and the full closing time are obtained through correlation by utilizing corresponding characteristic points of coil current characteristics and valve element displacement.
5. The method according to claim 2, wherein the dynamic time parameter in step 1) is calculated as follows: opening lag time t don is the difference between the valve core starting opening time and the initial time of the opening stage; The opening movement time t mon is the difference between the complete opening time and the starting opening time of the valve core; The opening current adjusting time t aon is the difference value between the moment when the coil current reaches a stable constant value in the opening stage of the high-speed switch valve and the moment when the valve core is completely opened; closing lag time t doff is the difference between the valve core starting closing time and the closing stage initial time; closing movement time t moff is the difference between the complete closing time and the starting closing time of the valve core; Closing current adjusting time t aoff is the difference between the moment when the coil current decays to zero in the closing stage of the high-speed switch valve and the moment when the valve core is completely closed.
6. The method of claim 1, wherein the periodic opening and closing test of step 1) is continued for at least 5 continuous opening and closing cycles, and when the dynamic time parameter of the high-speed switch valve is obtained, the parameter values of the continuous 5 opening and closing cycles are averaged to offset the influence of the fluctuation of the oil pressure on the dynamic performance of the high-speed switch valve.
7. The method of claim 1, wherein the actual measurement equivalent output flow value of the upper and lower limits of the linear region in step 3) is obtained by controlling the high-speed switching valve to stably operate under the condition that the duty ratio is equal to the lower limit alpha 1 +α 2 of the linear region and the upper limit 1-alpha 3 -α 4 of the linear region, respectively, collecting the output oil volume v within a fixed time t through the measuring cup, and measuring the equivalent output flow according to the actual measurement And (5) calculating to obtain the product.
8. The method according to claim 1, wherein the linear fitting relation of the linear region of step 3) is specifically: wherein q is the predicted equivalent output flow corresponding to any duty ratio in the linear region, q low is the actual measured equivalent output flow corresponding to the lower limit of the linear region, q high is the actual measured equivalent output flow corresponding to the upper limit of the linear region, and alpha is any duty ratio value in the linear region.
9. The method of claim 1, wherein the selected drive mode comprises a single voltage drive mode, a three voltage drive mode, and a preloaded voltage drive mode.
10. A rapid and accurate prediction system for a duty cycle-equivalent output flow characteristic of a high-speed switching valve, which is applicable to the rapid and accurate prediction method for the duty cycle-equivalent output flow characteristic of the high-speed switching valve according to any one of claims 1 to 9, and is characterized by comprising the following steps: The on-off test system is used for periodically on-off testing the high-speed switching valve to be detected in a single-voltage driving mode and comprises a collecting device and a measuring cup, wherein the collecting device is used for collecting valve core displacement data and outputting a dynamic time parameter t don 、t mon 、t aon 、t doff 、t moff 、t aoff ; The duty ratio boundary calculating unit is used for calculating duty ratio boundaries alpha 1 、α 1 +α 2 、1-α 3 -α 4 and 1-alpha 4 of a duty ratio-equivalent output flow characteristic region according to the dynamic time parameter output by the on-off test system and the set switching frequency f; The duty ratio-equivalent output flow curve generation module is used for establishing a duty ratio-equivalent output flow relation formula comprising a dead zone, a linear zone and a saturation zone according to the duty ratio boundary and the actually measured equivalent output flow value obtained by the measuring cup, and generating a duty ratio-equivalent output flow characteristic curve comprising the dead zone, the linear zone and the saturation zone after combination.

Description

Rapid and accurate prediction method for duty ratio-equivalent output flow characteristic of high-speed switch valve Technical Field The invention belongs to the field of high-speed switch valves, and particularly relates to a quick and accurate prediction method for the duty ratio-equivalent output flow characteristic of a high-speed switch valve. Background The high-speed switch valve (HSV) is used as a core control element of a Digital Hydraulic System (DHS), and by virtue of the remarkable advantages of compact structure, quick response, low cost and strong pollution resistance, the Equivalent Output Flow (EOF) is regulated by means of the duty cycle (SDR) of an adjusting switch through two discrete working states of full-on and full-off, so that the flow and pressure control of the DHS are realized, the high-speed switch valve is widely applied to various industrial hydraulic control scenes, and is a key basic device for guaranteeing the accurate operation of the DHS. In the DHS operation process, a duty cycle-equivalent output flow (SDR-EOF) characteristic curve of HSV is a core index for measuring control performance of the DHS, and the curve naturally has a dead zone, a linear zone and a saturation zone, wherein the dead zone corresponds to a zone with a valve core not opened and an EOF constant of 0 when the duty cycle is too small, the saturation zone corresponds to a zone with a valve core continuously fully opened and an EOF reaching a maximum value and stable when the duty cycle is too large, and the linear zone is a core zone with the equivalent output flow uniformly changed along with the duty cycle and most suitable for DHS stable control. The SDR-EOF characteristic curve is accurately obtained, a basis can be provided for the DHS to select the linear working range of HSV, the problems of unresponsiveness of the system, excessive flow caused by a saturation region and the like caused by dead zones can be effectively avoided, and the importance is placed on improving the overall control precision and stability of the DHS. In the prior art, SDR-EOF characteristic detection of HSV mainly depends on two methods, namely direct test and indirect test. The direct test method uses a flowmeter, a measuring cup, a weighing tank and the like as core tools, and adopts the principle that the EOF under a specific duty ratio is measured through experiments, for example, the equivalent output flow of an HSV saturation region is tested under different pressures by using the flowmeter, or the equivalent output flow is obtained through indirect conversion by collecting the output oil volume in a fixed time and monitoring the oil quality change of the weighing tank by using the measuring cup, so that flow data corresponding to different duty ratios are obtained step by step, and the indirect test method is used for reversely deducing the EOF of the HSV by monitoring the motion state (displacement and speed) of an HSV controlled object (such as a proportional valve core and a hydraulic cylinder) and combining the correlation between the performance of the controlled object and the equivalent output flow, for example, by detecting the change of the valve core after the motion is influenced by liquid damping, or analyzing the resistance and pressure difference in the cylinder motion process, so as to indirectly estimate the flow characteristics. However, the existing detection method has obvious limitations, so that the actual application requirements are difficult to meet, firstly, the test efficiency is extremely low, whether the direct test is performed by traversing 0-100% of full-range duty ratio points (30-50 experimental points are usually needed), each point is subjected to repeated experiments to ensure data stability, or the indirect test is performed by adjusting the duty ratio for many times to construct a complete curve, a large amount of time is required, the traditional method takes up 40 minutes for single test, high-efficiency research and development and field debugging scenes are difficult to adapt, secondly, the test precision is interfered by multiple factors, the flow discrete fluctuation caused by an HSV high-frequency switch in the direct test can cause errors in measuring the flowmeter, the internal residual pressure of HSV further influences the accuracy of the result, and the indirect test can change the resistance and the pressure difference of the controlled object during the monitoring, so that the original equivalent output flow is offset, the accuracy is difficult to ensure, and thirdly, the long-time test is easy to cause additional errors, the continuous experiment can cause the temperature rise of the HSV coil, further change the dynamic performance, the duty ratio-equivalent output flow curve is offset, and the reliability and consistency of the test result are further reduced. Therefore, the existing duty ratio-equivalent output flow characteristic detection method has defects