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CN-116181741-B - Method for detecting leakage in hydraulic cylinder and application of method in TBM shoe supporting hydraulic cylinder

CN116181741BCN 116181741 BCN116181741 BCN 116181741BCN-116181741-B

Abstract

The invention discloses a method for detecting leakage in a hydraulic cylinder and application of the method in a TBM shoe supporting hydraulic cylinder, and the method comprises the following steps of S1, obtaining travel data of the hydraulic cylinder within a preset time t 1 , S2, cleaning and dividing the obtained travel data of the hydraulic cylinder, S3, obtaining pressure data of the hydraulic cylinder within each preset time period and screening, S4, respectively carrying out wavelet decomposition and reconstruction on each screened set of pressure data, S5, calculating the ratio of energy of each-order high-frequency reconstruction signals in the total energy of original pressure signals, and judging whether the hydraulic cylinder suffers from internal leakage or not. According to the invention, the detection of leakage in the TBM shoe supporting hydraulic cylinder is completed only by the pressure data and the stroke data of the TBM shoe supporting hydraulic cylinder, a complex physical model is not required to be established according to the information such as the geometric parameters of the TBM shoe supporting hydraulic cylinder, and the calculation speed and the detection efficiency are improved.

Inventors

  • CHAO QUN
  • SHAO YUECHEN
  • LIU CHENGLIANG

Assignees

  • 上海交通大学

Dates

Publication Date
20260505
Application Date
20221229

Claims (8)

  1. 1. The method for detecting the leakage in the hydraulic cylinder is characterized by comprising the following steps of: s1, acquiring travel data of a hydraulic cylinder in a preset time t 1 ; S2, cleaning and dividing the acquired hydraulic cylinder travel data; s3, acquiring pressure data of the hydraulic cylinder in each appointed time period and screening; S4, performing wavelet decomposition and reconstruction on each group of pressure data selected respectively; S5, calculating the duty ratio of the energy of each-order high-frequency reconstruction signal in the total energy of the original pressure signal, and judging whether the internal leakage of the hydraulic cylinder occurs or not; The step S2 specifically comprises the following steps: S2.1, detecting whether a maximum stroke point exists in the section of data, if no maximum stroke point exists in the section of data, judging that the stroke data acquired in the step S1 are invalid data, returning to the step S1, and adjusting the preset time t 1 in the step S1; S2.2, sequentially judging whether each stroke maximum value point in the step S2.1 is an initial timing point for hydraulic cylinder recovery; S2.3, finding a travel minimum value point corresponding to each travel maximum value point obtained in the step S2.2, and if the travel minimum value point corresponding to a certain travel maximum value point cannot be found, judging that the travel maximum value point is invalid and removing the travel minimum value point; S2.4, if any one set of travel maximum value points and travel minimum value points meeting the conditions cannot be obtained after the steps S2.2 and S2.3, judging that the travel data acquired in the step S1 are invalid data, returning to the step S1 and adjusting the preset time t 1 in the step S1; The judgment in the step S2.2 is based on the requirement that the following conditions are satisfied simultaneously: a. The stroke value s 1 of the stroke peak point is not less than 95% of the maximum stroke s max of the hydraulic cylinder, namely s 1 ≥0.95s max ; b. Starting from a timing point corresponding to the maximum stroke point, the stroke value of the hydraulic cylinder is in a continuously descending state within a preset time t 2 , wherein the preset time t 2 is between 70% and 90% of the average time t s required by the hydraulic cylinder to retract from the maximum stroke point to the starting position, and the average time is 0.7t s ≤t 2 ≤0.9t s ; c. Starting from the timing point corresponding to the maximum stroke point, the range deltas of the stroke value of the hydraulic cylinder falling within the preset time t 2 is not less than 70% of the maximum stroke s max of the hydraulic cylinder, wherein deltas is more than or equal to 0.7s max , t 2 is consistent with the preset time t 2 in the step b, and s max is consistent with the maximum stroke s max of the hydraulic cylinder in the step a.
  2. 2. The in-cylinder leakage detection method according to claim 1, wherein in step S1, the predetermined time t 1 is set to at least ensure that the cylinder can undergo a process of returning to the vicinity of the start position from the vicinity of the maximum stroke point.
  3. 3. The method for detecting leakage in a hydraulic cylinder according to claim 1, wherein the method for finding the stroke minimum point in step S2.3 is required to satisfy the following conditions simultaneously: a. the stroke value of the point is lower than that of the previous adjacent sampling point and is not higher than that of the next adjacent sampling point; b. The stroke value s 2 of the point is not more than 5% of the maximum stroke s max of the hydraulic cylinder, s 2 ≤0.05s max ; c. the sampling time corresponding to the point is after the sampling time corresponding to the corresponding maximum stroke point.
  4. 4. The method for detecting leakage in a hydraulic cylinder according to claim 1, wherein the screening in step S3 simultaneously satisfies the following conditions according to need: a. The maximum value p max of the selected pressure data is between the threshold p 1 and the threshold p 2 , p 1 ≤p max ≤p 2 ; b. The value change range delta p of the selected pressure data in the previous n 1 seconds is not less than 90 percent of the maximum value p max of the selected pressure data, wherein delta p is more than or equal to 0.9p max ; c. The value of the selected pressure data at the last data point should not be greater than the threshold p 3 .
  5. 5. The method according to claim 1, wherein the basis function selected for wavelet decomposition and reconstruction in step S4 is db8 wavelet.
  6. 6. The method for detecting leakage in a hydraulic cylinder according to any one of claims 1 to 5, characterized in that the number of times the pressure signal is subjected to wavelet decomposition is 4.
  7. 7. The method according to claim 6, wherein in step S5, for a discrete signal, the calculation formula of the energy contained in the discrete signal is: ; wherein E is the energy of the segment signal, N is the number of sampling points of the segment signal, and x (i) is the number of the ith sampling point of the segment signal; After 4 times of wavelet decomposition and reconstruction are carried out on the original pressure signal, the formula for calculating the energy ratio q k of the high-frequency reconstruction signal of each order in the original pressure signal is as follows: ; Wherein E k represents the energy of the kth order high frequency reconstruction signal, E 0 represents the energy of the original pressure signal; To sum up, the final energy duty ratio calculation formula is: ; Wherein N represents the number of groups of original pressure signals, N represents the number of sampling points of each group of pressure signals, p 0 (i, j) represents the value of the jth group of original pressure signals at the ith sampling point, and p k (i, j) represents the value of the jth group of k-order high-frequency reconstruction signals at the ith sampling point; When judging whether the hydraulic cylinder is in internal leakage or not, selecting the energy ratio of the 4-order high-frequency reconstruction signal in the original pressure signal as a main index parameter, and when the energy ratio of the 4-order high-frequency reconstruction signal is smaller than a threshold value r, judging that the hydraulic cylinder is in internal leakage.
  8. 8. Use of the method for detecting leakage in a hydraulic cylinder according to any one of claims 1 to 7 in a TBM shoe-supporting hydraulic cylinder.

Description

Method for detecting leakage in hydraulic cylinder and application of method in TBM shoe supporting hydraulic cylinder Technical Field The invention relates to the technical field of tunnel boring machine and hydraulic cylinder internal leakage detection, in particular to a hydraulic cylinder internal leakage detection method and application thereof in a TBM supporting shoe hydraulic cylinder. Background The shoe supporting hydraulic cylinder is an important component in a full-face Tunnel Boring Machine (TBM) supporting system, and is not only used for providing enough supporting force for the TBM in the TBM tunneling process, but also used for adjusting the pose of the TBM. Because prop boots pneumatic cylinder often work under strong vibration and high pressure's state, over time, elements such as sealing member, piston rod, cylinder body of pneumatic cylinder are very easily damaged, and then lead to prop the boots pneumatic cylinder and appear leaking, support power is not enough, the poor trouble of stability, seriously influence the normal tunneling of TBM, cause economic loss and the potential safety hazard of inestimable. Therefore, it is necessary to timely perform internal leakage detection on the TBM shoe hydraulic cylinder. Although some methods for detecting leakage in hydraulic cylinders exist in the prior art, most of the methods are only suitable for hydraulic cylinders under experimental conditions, the hydraulic cylinders usually reciprocate under constant load and working cycle, and various sensors such as flow, vibration, strain and the like are additionally arranged, wherein some methods need to further rely on geometric parameters and working condition information of the hydraulic cylinders to establish an accurate internal leakage physical model. The TBM shoe supporting hydraulic cylinder is affected by site construction, a definite working period is not available in the working process, redundant sensors are difficult to install, collected data are easily interfered by noise and tunneling working conditions, and therefore larger errors are often generated in internal leakage detection by using the current diagnosis method. Therefore, how to provide an internal leakage detection method suitable for a TBM shoe supporting hydraulic cylinder and capable of being popularized to other hydraulic cylinders is a problem to be solved by those skilled in the art. Disclosure of Invention In view of the above, the invention provides a method for detecting leakage in a hydraulic cylinder and application of the method in a TBM shoe supporting hydraulic cylinder, and aims to solve the technical problems. In order to achieve the above purpose, the present invention adopts the following technical scheme: A method for detecting leakage in a hydraulic cylinder comprises the following steps: s1, acquiring travel data of a hydraulic cylinder in a preset time t 1; S2, cleaning and dividing the acquired hydraulic cylinder travel data; s3, acquiring pressure data of the hydraulic cylinder in each appointed time period and screening; S4, performing wavelet decomposition and reconstruction on each group of pressure data selected respectively; S5, calculating the duty ratio of the energy of each-order high-frequency reconstruction signal in the total energy of the original pressure signal, and judging whether the hydraulic cylinder has internal leakage or not. Preferably, in the above-described in-cylinder leakage detecting method, in step S1, the predetermined time t 1 is set to at least ensure that the cylinder can undergo a process of returning to the vicinity of the start position from the vicinity of the maximum stroke point. Preferably, in the above-mentioned method for detecting leakage in a hydraulic cylinder, step S2 specifically includes the steps of: S2.1, detecting whether a maximum stroke point exists in the section of data, if no maximum stroke point exists in the section of data, judging that the stroke data acquired in the step S1 are invalid data, returning to the step S1, and adjusting the preset time t 1 in the step S1; S2.2, sequentially judging whether each stroke maximum value point in the step S2.1 is an initial timing point for hydraulic cylinder recovery; S2.3, finding a travel minimum value point corresponding to each travel maximum value point obtained in the step S2.2, and if the travel minimum value point corresponding to a certain travel maximum value point cannot be found, judging that the travel maximum value point is invalid and removing the travel minimum value point; And S2.4, if any one set of travel maximum value points and travel minimum value points meeting the conditions cannot be obtained after the steps S2.2 and S2.3, judging that the travel data acquired in the step S1 are invalid data, returning to the step S1, and adjusting the preset time t 1 in the step S1. Preferably, in the above method for detecting leakage in a hydraulic cylinder, the judging in step S2.2 is b