CN115289100A - Hydraulic cylinder deterioration trend evaluation method - Google Patents
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
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Abstract
The invention provides a method for evaluating the deterioration trend of a hydraulic cylinder, and belongs to the technical field of automatic control of hot-rolled strip steel. The method comprises the following steps: acquiring piston displacement signals of the hydraulic cylinder in different working time periods in real time; determining an LS algorithm format of a hydraulic cylinder motion model based on the collected piston displacement signal; estimating the Stribeck parameter based on the determined LS algorithm format of the hydraulic cylinder motion model to obtain the Stribeck parameter which is converged to be stable; and comparing the obtained stable Strebeck parameter with the Strebeck parameter in the initial state, establishing a deterioration index of the working state of the hydraulic cylinder, drawing a deterioration curve of the working state of the hydraulic cylinder, determining the deterioration trend of the hydraulic cylinder according to the drawn deterioration curve of the working state of the hydraulic cylinder, and determining the current deterioration degree of the hydraulic cylinder according to the deterioration index at the current moment. By adopting the invention, the deterioration degree of the hydraulic cylinder can be accurately evaluated.
Description
Technical Field
The invention relates to the technical field of automatic control of hot rolled strip steel, in particular to a method for evaluating the deterioration trend of a hydraulic cylinder.
Background
A large amount of industrial field data show that the hydraulic cylinder is always influenced by some disturbances during working, so that the force balance state is damaged, different amplitudes of flutter are generated, and equipment damage and plant production halt can be caused even in serious conditions. Therefore, the measures of fault diagnosis, life prediction, daily monitoring and maintenance of the hydraulic cylinder system should be considered. At the present stage, the research on the hydraulic cylinder fault diagnosis and the service life prediction is quite deep, a Shijiazhuang railway university Mashixiang professor team mainly researches the working states of two typical engineering machinery hydraulic systems, namely a shield machine and an excavator, labview software is applied to develop a fault diagnosis and health evaluation system of the engineering machinery hydraulic system by taking pressure, flow, vibration, temperature and oil signals as detection quantities, and the effect of the fault diagnosis and health prediction of the hydraulic system is remarkably improved. For daily monitoring and maintenance aspects of a hydraulic system, a friction model is introduced, and parameter changes of the friction model are analyzed to represent degradation trend of a hydraulic cylinder. Common friction models include: a coulomb model, a coulomb + viscous friction model, a Stribeck friction model, a Karnopp model, a LuGre model and the like; wherein, the Stribeck friction model has high utilization rate and wide application range. An article (mechanical system control of friction and rebound) researches the design problem of a controller based on the stick-slip phenomenon of a permanent magnet synchronous motor during low-speed operation, a Stribeck friction model is used for modeling a nonlinear friction torque, and the problems of system steady-state error and low-speed crawling are solved by designing a compensation controller.
At present, most of research is to analyze a Stribeck friction model from the aspect of how to influence the stability performance of a system, and the literature for researching the problem of hydraulic cylinder degradation by using the Stribeck friction model is rare.
Disclosure of Invention
The embodiment of the invention provides a hydraulic cylinder degradation trend evaluation method, which can accurately evaluate the degradation degree of a hydraulic cylinder. The method comprises the following steps:
acquiring piston displacement signals of the hydraulic cylinder in different working time periods in real time;
determining an LS algorithm format of a hydraulic cylinder motion model based on the collected piston displacement signal; wherein LS represents least squares;
estimating the Stribeck parameter based on the determined LS algorithm format of the hydraulic cylinder motion model to obtain the Stribeck parameter which is converged to be stable;
and comparing the obtained stable Stribeck parameter with the Stribeck parameter in the initial state, establishing a deterioration index of the working state of the hydraulic cylinder, drawing a deterioration curve of the working state of the hydraulic cylinder, determining the deterioration trend of the hydraulic cylinder according to the drawn deterioration curve of the working state of the hydraulic cylinder, and determining the current deterioration degree of the hydraulic cylinder according to the deterioration index at the current moment.
Further, the LS algorithm format of the determined hydraulic cylinder motion model is expressed as:
y(t)＝φ T (t)θ+d(t)
θ＝[m K f c f v f s ] T
wherein y (T) is LS algorithm output, phi (T) is LS algorithm input, theta is a parameter to be estimated, d (T) is measurement noise, superscript T represents matrix transposition, and p 1 、p 2 Respectively a rodless chamber pressure intensity and a rod chamber pressure intensity A 1 、A 2 Respectively, the effective area of the rodless cavity and the effective area of the rod cavity, p 1 A 1 and p2 A 2 Respectively representing the pressure of the rodless and rod chambers, F L Represents an external rolling force, c represents a viscous damping coefficient, x,
Respectively representing the displacement, the speed and the acceleration of the piston, sgn (-) is a symbolic function, m is the converted mass of the piston and a load, K represents the equivalent rigidity of the hydraulic cylinder system, f represents the equivalent rigidity of the hydraulic cylinder system c Is a Coulomb friction parameter, f v Is a viscous coefficient of friction, f s Is the Stribeck friction parameter.
Further, the step of estimating the Stribeck parameter based on the determined LS algorithm format of the hydraulic cylinder motion model to obtain the Stribeck parameter converged to be stable includes:
a1, in the LS algorithm parameter estimation process of an initial sampling time period, giving an initial parameter value theta 0 Initial value P of gain matrix 0 Initial value of displacement x 0 And initial value of velocity
A2, inputting a piston displacement signal x 1 Calculating the speed signal and the acceleration signal of the piston by adopting a differential algorithm, and constructing output y in an LS algorithm format of a hydraulic cylinder motion model k And input phi k Sequentially updating the calculation K k 、
P k A value of (d);
a3, updating and calculating K k 、
P k K = k +1, the process returns to step A2, and the piston displacement signal x at the next time is input 2 Recalculate K k 、
P k The value of (2) is continuously circulated until the corresponding sampling time period is obtained and the corresponding Stribeck parameter is converged to be stable, and the parameter estimation result of each sampling time period is used as the initial value of the next parameter estimation and added into the calculation; wherein the Stribeck parameters include: f. of c 、f v and fs The next time refers to the next sampling period.
Further, the calculating the speed signal and the acceleration signal of the piston by using a differential algorithm comprises:
by the formula
Solving the velocity signal v of the piston k (ii) a Where Δ is the differential spacing, x k The displacement signal of the piston at the kth moment;
by the formula
Solving the acceleration signal a of the piston k； wherein ,
is the acceleration signal of the piston at the time k.
Further, the K-th time K k 、
P k The update expression of (1) is:
wherein ,Kk and Pk Both represent the gain matrix at time k;
a parameter estimation value representing a k-th time; p k-1 A gain matrix representing the k-1 time instant; phi is a k An LS algorithm input representing a kth time instant;
representing the estimated value of the parameter at the k-1 th moment; y is k Represents the LS algorithm output at time k.
Further, the parameter estimation loop termination condition is:
wherein ,
and respectively obtaining parameter estimation values of the kth moment and the k-1 moment obtained by the nth parameter estimation, wherein epsilon is a stopping condition parameter.
Further, the step of comparing the obtained stable Stribeck parameter with the Stribeck parameter in the initial state, establishing a hydraulic cylinder working state degradation index, drawing a hydraulic cylinder working state degradation curve, and determining the current degradation degree of the hydraulic cylinder according to the drawn hydraulic cylinder working state degradation curve includes:
comparing the stable Stribeck parameter obtained each time with the Stribeck parameter in the initial state, and establishing a deterioration index J of the working state of the hydraulic cylinder n ：
wherein ,
representing the upper speed limit when the piston works; v represents a velocity signal of the piston;
respectively representing the coulomb friction parameter, viscous friction coefficient and Stribeck friction parameter obtained by the nth parameter estimation,
respectively representing the Coulomb friction parameter, the viscous friction coefficient, the Stribeck friction parameter and a function F in the initial state of the hydraulic cylinder d (.) is a linearized Stribeck friction model;
to be provided with
As the abscissa, J n Drawing a degradation curve of the working state of the hydraulic cylinder for a vertical coordinate; wherein, T i Denotes the time interval between the i-th estimated parameter and the i + 1-th estimated parameter, τ n Representing a sampling time period corresponding to a piston displacement signal used for the nth parameter estimation;
and determining the degradation trend of the hydraulic cylinder according to the drawn degradation curve of the working state of the hydraulic cylinder, and determining the current degradation degree of the hydraulic cylinder according to the degradation index at the current moment.
Further, function F d (. Cndot.) is expressed as:
wherein ,fc Is a Coulomb friction parameter, f v Is a viscous coefficient of friction, f s For the Stribeck friction parameter, sgn (·) is a sign function,
indicating the velocity of the piston.
The technical scheme provided by the embodiment of the invention has the beneficial effects that at least:
in the embodiment of the invention, piston displacement signals of the hydraulic cylinder in different working time periods are acquired in real time; determining an LS algorithm format of a hydraulic cylinder motion model based on the collected piston displacement signal; estimating the Stribeck parameter based on the determined LS algorithm format of the hydraulic cylinder motion model to obtain the Stribeck parameter which is converged to be stable; and comparing the obtained stable Strebeck parameter with the Strebeck parameter in the initial state, establishing a deterioration index of the working state of the hydraulic cylinder, drawing a deterioration curve of the working state of the hydraulic cylinder, determining the deterioration trend of the hydraulic cylinder according to the drawn deterioration curve of the working state of the hydraulic cylinder, and determining the current deterioration degree of the hydraulic cylinder according to the deterioration index at the current moment. Therefore, the hydraulic cylinder degradation degree can be accurately evaluated through the established hydraulic cylinder degradation trend evaluation method based on the Stribeck curve, the daily monitoring and maintenance of the hydraulic system are assisted, and the method has important significance for monitoring and evaluating the performance of the hydraulic system and improving the working efficiency of the production process, so that the problem that the hydraulic cylinder degradation degree cannot be evaluated in the prior art is solved.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
Fig. 1 is a schematic flow chart of a hydraulic cylinder degradation trend evaluation method provided by an embodiment of the invention;
FIGS. 2 (a) - (f) are schematic diagrams of piston displacement signals for the 1 st to 6 th parameter estimation and velocity and acceleration signals obtained by solving the signals by using a differential algorithm, according to an embodiment of the present invention;
fig. 3 (a) - (f) are schematic diagrams of estimated values and true value curves of Stribeck parameters obtained from the 1 st to 6 th parameter estimation provided by the embodiment of the present invention;
FIG. 4 is a schematic diagram of a Stribeck friction model curve at different sampling periods according to an embodiment of the present invention;
fig. 5 is a broken line schematic view of the deterioration trend of the hydraulic cylinder provided by the embodiment of the invention.
Detailed Description
To make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
As shown in fig. 1, an embodiment of the present invention provides a method for evaluating a deterioration tendency of a hydraulic cylinder, including:
s101, acquiring piston displacement signals of the hydraulic cylinder in different working time periods in real time;
s102, determining an LS (Least square) algorithm format of a hydraulic cylinder motion model based on the collected piston displacement signals; wherein LS represents least squares;
in this embodiment, the LS algorithm format of the determined hydraulic cylinder motion model is expressed as:
y(t)＝φ T (t)θ+d(t)
θ＝[m K f c f v f s ] T
wherein y (T) is LS algorithm output, phi (T) is LS algorithm input, theta is a parameter to be estimated, d (T) is measurement noise, superscript T represents matrix transposition, and p 1 、p 2 Respectively a rodless chamber pressure intensity and a rod chamber pressure intensity, A 1 、A 2 Respectively, the effective area of the rodless cavity and the effective area of the rod cavity, p 1 A 1 and p2 A 2 Respectively representing the pressure in the rodless and rod chambers, F L Represents an external rolling force, c represents a viscous damping coefficient, x,
Respectively represents the displacement, the speed and the acceleration of the piston, sgn (-) is a symbolic function, m is the reduced mass of the piston and a load, K represents the equivalent stiffness of the hydraulic cylinder system, and f c Is a Coulomb friction parameter, f v Is a viscous coefficient of friction, f s Is the Stribeck friction parameter.
In this embodiment, d (t) is measurement noise, which is assumed to follow a 0-mean gaussian distribution; from the formula "pressure = pressure x surface area", p 1 A 1 and p2 A 2 The pressure of the rodless cavity and the pressure of the rod cavity are respectively represented, and the pressures of the two cavities change along with the displacement change of the piston and can be measured by a pressure sensor; external rolling force F L The design can be carried out according to different working conditions; the viscous damping coefficient c is considered to be a known constant in a real system,thereby the viscous force
Are known.
In the embodiment, the LS algorithm output is formed by piston displacement derivation to obtain piston speed, pressure of a rodless cavity and a rod cavity, external rolling force and viscous force; from x,
The regression vector is composed, i.e.: and inputting an LS algorithm.
S103, estimating the Stribeck parameters based on the determined LS algorithm format of the hydraulic cylinder motion model to obtain the Stribeck (Sterlibeck) parameters which are converged to be stable; the method specifically comprises the following steps:
a1, in the LS algorithm parameter estimation process of an initial sampling time period, an initial parameter value theta is given 0 Initial value P of gain matrix 0 Initial value of displacement x 0 And initial value of velocity
A2, inputting a piston displacement signal x 1 Calculating the speed signal and the acceleration signal of the piston by adopting a differential algorithm, and constructing output y in an LS algorithm format of a hydraulic cylinder motion model k And input phi k Sequentially updating the calculation K k 、
P k A value of (d);
in this embodiment, the calculating the speed signal and the acceleration signal of the piston by using a differential algorithm may specifically include the following steps:
by the formula
Solving the velocity signal v of the piston k (ii) a Wherein Δ is a differential interval, x k The displacement signal of the piston at the kth moment;
by the formula
Solving the acceleration signal a of the piston k； wherein ,
is the acceleration signal of the piston at the k-th time.
In this embodiment, the piston displacement signals used for the 1 st to 6 th parameter estimation and the velocity and acceleration signal curves obtained by solving with a differential algorithm are shown in fig. 2 (a) - (f).
In this embodiment, the LS algorithm format and the hydraulic cylinder dynamic equation of the known hydraulic cylinder motion model are as follows:
y(t)＝φ T (t)θ+d(t)
obtaining the K time K through calculation k 、
P k The update expression of (c) is:
wherein ,Kk and Pk Both represent the gain matrix at time k;
an estimated value, an initial value, of a parameter indicating the k-th time
P k-1 A gain matrix representing the k-1 th time instant; phi is a k An LS algorithm input representing a kth time instant;
representing the estimated value of the parameter at the k-1 th moment; y is k Representing the LS algorithm output at time k.
A3, updating and calculating K k 、
P k K = k +1, the process returns to step A2, and the piston displacement signal x at the next time is input 2 Recalculating K k 、
P k The value of (2) is continuously circulated until the corresponding sampling time period is obtained and the corresponding Stribeck parameter is converged to be stable, and the parameter estimation result of each sampling time period is used as the initial value of the next parameter estimation and added into the calculation; wherein the Stribeck parameters include: f. of c 、f v and fs The next time refers to the next sampling period.
In this embodiment, the parameter estimation cycle termination condition is:
wherein ,
and the parameter estimation values at the k-th time and the k-1 time obtained by the nth parameter estimation respectively, wherein epsilon is a stopping condition parameter and is generally close to 0.
In this embodiment, schematic diagrams of estimated values and truth curves of the Stribeck parameters obtained from the 1 st to 6 th parameter estimation are shown in fig. 3 (a) - (f).
S104, comparing the obtained stable Stribeck parameter with the Stribeck parameter in the initial state, establishing a degradation index of the working state of the hydraulic cylinder, drawing a degradation curve of the working state of the hydraulic cylinder, determining a degradation trend of the hydraulic cylinder according to the drawn degradation curve of the working state of the hydraulic cylinder, and determining a current degradation degree of the hydraulic cylinder according to the degradation index at the current time, which may specifically include the following steps:
b1, comparing the stable Stribeck parameter obtained each time with the Stribeck parameter in the initial state, and establishing a hydraulic cylinder working state degradation index J n ：
wherein ,
representing the upper speed limit when the piston works; v represents a velocity signal of the piston;
respectively representing the coulomb friction parameter, viscous friction coefficient and Stribeck friction parameter obtained by the nth parameter estimation,
respectively representing the Coulomb friction parameter, the viscous friction coefficient, the Stribeck friction parameter and a function F in the initial state of the hydraulic cylinder d () is a linearized Stribeck friction model;
in this embodiment, function F d (. Cndot.) is expressed as:
wherein ,fc Is a Coulomb friction parameter, f v Is a viscous coefficient of friction, f s For the Stribeck friction parameter, sgn (·) is a sign function,
indicating the velocity of the piston.
In this embodiment, stribeck friction model curves at different sampling periods are shown in fig. 4.
B2, in order
As the abscissa, J n Drawing a degradation curve of the working state of the hydraulic cylinder as a vertical coordinate; wherein, T i Denotes the time interval between the i-th estimated parameter and the i + 1-th estimated parameter, τ n Representing the sampling time period corresponding to the piston displacement signal used for the nth parameter estimation;
and B3, determining the deterioration trend of the hydraulic cylinder according to the drawn deterioration curve of the working state of the hydraulic cylinder, and determining the current deterioration degree of the hydraulic cylinder according to the deterioration index at the current moment.
In the present embodiment, 4 threshold ranges may be empirically set, so as to divide the degree of degradation into: slight loss, moderate loss, equipment failure and complete rejection. In this embodiment, the current degradation degree of the hydraulic cylinder is obtained by determining the threshold range to which the degradation index of the hydraulic cylinder at the current time belongs.
In the present embodiment, a broken line diagram illustrating the deterioration tendency of the hydraulic cylinder is shown in fig. 5.
In this embodiment, the current degradation degree of the hydraulic cylinder can be determined by analyzing the degradation curve of the working state of the hydraulic cylinder, so as to provide a basis for whether to replace a system component.
According to the method for evaluating the degradation trend of the hydraulic cylinder, piston displacement signals of the hydraulic cylinder in different working time periods are collected in real time; determining an LS algorithm format of a hydraulic cylinder motion model based on the collected piston displacement signal; estimating the Stribeck parameter based on the determined LS algorithm format of the hydraulic cylinder motion model to obtain the Stribeck parameter which is converged to be stable; and comparing the obtained stable Strebeck parameter with the Strebeck parameter in the initial state, establishing a deterioration index of the working state of the hydraulic cylinder, drawing a deterioration curve of the working state of the hydraulic cylinder, determining the deterioration trend of the hydraulic cylinder according to the drawn deterioration curve of the working state of the hydraulic cylinder, and determining the current deterioration degree of the hydraulic cylinder according to the deterioration index at the current moment. Therefore, the hydraulic cylinder degradation degree can be accurately evaluated through the established hydraulic cylinder degradation trend evaluation method based on the Stribeck curve, the daily monitoring and maintenance of the hydraulic system are assisted, and the method has important significance for monitoring and evaluating the performance of the hydraulic system and improving the working efficiency of the production process, so that the problem that the hydraulic cylinder degradation degree cannot be evaluated in the prior art is solved.
The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.
Claims (8)
1. A hydraulic cylinder deterioration tendency evaluation method is characterized by comprising the following steps:
acquiring piston displacement signals of the hydraulic cylinder in different working time periods in real time;
determining an LS algorithm format of a hydraulic cylinder motion model based on the collected piston displacement signal; wherein LS represents least squares;
estimating the Stribeck parameter based on the determined LS algorithm format of the hydraulic cylinder motion model to obtain a Stribeck parameter which is converged to be stable;
and comparing the obtained stable Strebeck parameter with the Strebeck parameter in the initial state, establishing a deterioration index of the working state of the hydraulic cylinder, drawing a deterioration curve of the working state of the hydraulic cylinder, determining the deterioration trend of the hydraulic cylinder according to the drawn deterioration curve of the working state of the hydraulic cylinder, and determining the current deterioration degree of the hydraulic cylinder according to the deterioration index at the current moment.
2. The hydraulic cylinder degradation tendency evaluation method according to claim 1, wherein the LS algorithm format of the determined hydraulic cylinder motion model is expressed as:
y(t)＝φ T (t)θ+d(t)
θ＝[m K f c f v f s ] T
wherein y (T) is LS algorithm output, phi (T) is LS algorithm input, theta is a parameter to be estimated, d (T) is measurement noise, superscript T represents matrix transposition, and p 1 、p 2 Respectively a rodless chamber pressure intensity and a rod chamber pressure intensity A 1 、A 2 Respectively, the effective area of the rodless cavity and the effective area of the rod cavity, p 1 A 1 and p2 A 2 Respectively representing the pressure of the rodless and rod chambers, F L Represents an external rolling force, c represents a viscous damping coefficient, x,
Respectively represents the displacement, the speed and the acceleration of the piston, sgn (-) is a symbolic function, m is the reduced mass of the piston and a load, K represents the equivalent stiffness of the hydraulic cylinder system, and f c Is a Coulomb friction parameter, f v Is a viscous coefficient of friction, f s Is the Stribeck friction parameter.
3. The hydraulic cylinder degradation trend evaluation method according to claim 2, wherein the estimating the Stribeck parameter based on the determined LS algorithm format of the hydraulic cylinder motion model to obtain the Stribeck parameter converging to a stable state comprises:
a1, in the LS algorithm parameter estimation process of an initial sampling time period, giving an initial parameter value theta 0 Initial value P of gain matrix 0 Initial value of displacement x 0 And initial value of velocity
A2, inputtingPlug displacement signal x 1 Calculating the speed signal and the acceleration signal of the piston by adopting a differential algorithm, and constructing an output y in an LS algorithm format of a hydraulic cylinder motion model k And input phi k Sequentially updating the calculation K k 、
P k A value of (d);
a3, updating and calculating K k 、
P k K = k +1, the process returns to step A2, and the piston displacement signal x at the next time is input 2 Recalculating K k 、
P k The value of (2) is continuously circulated until the corresponding sampling time period is obtained and converged to the stable Stribeck parameter, and the parameter estimation result of each sampling time period is used as the initial value of the next parameter estimation to be added into the calculation; wherein the Stribeck parameters include: f. of c 、f v and fs The next time refers to the next sampling period.
4. The hydraulic cylinder degradation trend evaluation method according to claim 3, wherein the calculating the speed signal and the acceleration signal of the piston by using the differential algorithm comprises:
by the formula
Solving the velocity signal v of the piston k (ii) a Where Δ is the differential spacing, x k A displacement signal of the piston at the kth moment;
by the formula
Solving the acceleration signal a of the piston k； wherein ,
is the acceleration signal of the piston at the time k.
5. The hydraulic cylinder deterioration tendency evaluation method according to claim 1, characterized in that K-th time K k 、
P k The update expression of (c) is:
wherein ,Kk and Pk Both represent the gain matrix at time k;
a parameter estimation value representing a k-th time; p k-1 A gain matrix representing the k-1 th time instant; phi is a k An LS algorithm input representing a kth time instant;
representing the estimated value of the parameter at the k-1 th moment; y is k Representing the LS algorithm output at time k.
6. The hydraulic cylinder deterioration tendency evaluation method according to claim 1, wherein the parameter estimation cycle end condition is:
wherein ,
and respectively obtaining parameter estimation values of the kth moment and the k-1 moment obtained by the nth parameter estimation, wherein epsilon is a stopping condition parameter.
7. The method for evaluating the deterioration trend of the hydraulic cylinder according to claim 1, wherein the step of comparing the obtained stable Stribeck parameter with the Stribeck parameter in the initial state, establishing a deterioration index of the working state of the hydraulic cylinder, drawing a deterioration curve of the working state of the hydraulic cylinder, and determining the current deterioration degree of the hydraulic cylinder according to the drawn deterioration curve of the working state of the hydraulic cylinder comprises the following steps:
comparing the stable Stribeck parameter obtained each time with the Stribeck parameter in the initial state, and establishing a deterioration index J of the working state of the hydraulic cylinder n ：
wherein ,
representing the upper speed limit when the piston works; v represents a velocity signal of the piston;
respectively represents the coulomb friction parameter, the viscous friction coefficient and the Stribeck friction parameter obtained by the nth parameter estimation,
respectively represents the Coulomb friction parameter, the viscous friction coefficient and the Stribeck friction parameter in the initial state of the hydraulic cylinder, and a function F d (. Is) isA linearized Stribeck friction model;
to be provided with
As the abscissa, J n Drawing a degradation curve of the working state of the hydraulic cylinder as a vertical coordinate; wherein, T i Denotes the time interval between the i-th estimated parameter and the i + 1-th estimated parameter, τ n Representing a sampling time period corresponding to a piston displacement signal used for the nth parameter estimation;
and determining the degradation trend of the hydraulic cylinder according to the drawn degradation curve of the working state of the hydraulic cylinder, and determining the current degradation degree of the hydraulic cylinder according to the degradation index at the current moment.
8. The hydraulic cylinder deterioration tendency evaluation method according to claim 7, characterized in that the function F d (. Cndot.) is expressed as:
wherein ,fc Is a Coulomb friction parameter, f v Is a viscous coefficient of friction, f s For the Stribeck friction parameter, sgn (·) is a sign function,
indicating the velocity of the piston.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080228329A1 (en) * | 2007-03-13 | 2008-09-18 | Honeywell International Inc. | Methods and systems for friction detection and slippage control |
| CN102635597A (en) * | 2012-05-02 | 2012-08-15 | 武汉理工大学 | Health management system and method of engineering machinery hydraulic system |
| US20130276516A1 (en) * | 2012-04-20 | 2013-10-24 | Kent Tabor | Actuator predictive system |
| CN103410809A (en) * | 2013-08-01 | 2013-11-27 | 中冶赛迪工程技术股份有限公司 | System and method for testing hydraulic cylinder Stribeck model friction parameters |
| CN203374559U (en) * | 2013-08-01 | 2014-01-01 | 中冶赛迪工程技术股份有限公司 | Test system for hydraulic cylinder stribeck model friction parameter |
| CN104678763A (en) * | 2015-01-21 | 2015-06-03 | 浙江工业大学 | Friction compensation and dynamic surface control method based on least squares support vector machine for electromechanical servo system |
| JP2016089961A (en) * | 2014-11-05 | 2016-05-23 | 国立大学法人 東京大学 | Electrostatic hydraulic actuator and parameter estimation method in electrostatic hydraulic actuator |
| JP5990729B1 (en) * | 2015-04-03 | 2016-09-14 | トライボテックス株式会社 | General-purpose deterioration curve creation method and machine life prediction method, and general-purpose deterioration curve creation program and machine life prediction program |
| CN106093782A (en) * | 2016-06-03 | 2016-11-09 | 哈尔滨工业大学 | The least square method supporting vector machine SOC method of estimation of dynamic modeling |
| US20190257327A1 (en) * | 2018-02-22 | 2019-08-22 | Caterpillar Inc. | Hydraulic cylinder health monitoring and remaining life system |
| CN110296833A (en) * | 2019-07-22 | 2019-10-01 | 齐鲁工业大学 | A kind of flexible measurement method and system of Hydraulic Cylinder combined test stand |
| CN112507487A (en) * | 2020-11-30 | 2021-03-16 | 中国长江电力股份有限公司 | Reliability evaluation method and system for hydraulic turbine speed governor servomotor |
-
2022
- 2022-07-28 CN CN202210901662.0A patent/CN115289100B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080228329A1 (en) * | 2007-03-13 | 2008-09-18 | Honeywell International Inc. | Methods and systems for friction detection and slippage control |
| US20130276516A1 (en) * | 2012-04-20 | 2013-10-24 | Kent Tabor | Actuator predictive system |
| CN102635597A (en) * | 2012-05-02 | 2012-08-15 | 武汉理工大学 | Health management system and method of engineering machinery hydraulic system |
| CN103410809A (en) * | 2013-08-01 | 2013-11-27 | 中冶赛迪工程技术股份有限公司 | System and method for testing hydraulic cylinder Stribeck model friction parameters |
| CN203374559U (en) * | 2013-08-01 | 2014-01-01 | 中冶赛迪工程技术股份有限公司 | Test system for hydraulic cylinder stribeck model friction parameter |
| JP2016089961A (en) * | 2014-11-05 | 2016-05-23 | 国立大学法人 東京大学 | Electrostatic hydraulic actuator and parameter estimation method in electrostatic hydraulic actuator |
| CN104678763A (en) * | 2015-01-21 | 2015-06-03 | 浙江工业大学 | Friction compensation and dynamic surface control method based on least squares support vector machine for electromechanical servo system |
| JP5990729B1 (en) * | 2015-04-03 | 2016-09-14 | トライボテックス株式会社 | General-purpose deterioration curve creation method and machine life prediction method, and general-purpose deterioration curve creation program and machine life prediction program |
| CN106093782A (en) * | 2016-06-03 | 2016-11-09 | 哈尔滨工业大学 | The least square method supporting vector machine SOC method of estimation of dynamic modeling |
| US20190257327A1 (en) * | 2018-02-22 | 2019-08-22 | Caterpillar Inc. | Hydraulic cylinder health monitoring and remaining life system |
| CN110296833A (en) * | 2019-07-22 | 2019-10-01 | 齐鲁工业大学 | A kind of flexible measurement method and system of Hydraulic Cylinder combined test stand |
| CN112507487A (en) * | 2020-11-30 | 2021-03-16 | 中国长江电力股份有限公司 | Reliability evaluation method and system for hydraulic turbine speed governor servomotor |
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