CN115289100B - Hydraulic cylinder degradation trend evaluation method - Google Patents
Hydraulic cylinder degradation trend evaluation method Download PDFInfo
- Publication number
- CN115289100B CN115289100B CN202210901662.0A CN202210901662A CN115289100B CN 115289100 B CN115289100 B CN 115289100B CN 202210901662 A CN202210901662 A CN 202210901662A CN 115289100 B CN115289100 B CN 115289100B
- Authority
- CN
- China
- Prior art keywords
- hydraulic cylinder
- parameter
- degradation
- stribeck
- piston
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000015556 catabolic process Effects 0.000 title claims abstract description 93
- 238000006731 degradation reaction Methods 0.000 title claims abstract description 93
- 238000011156 evaluation Methods 0.000 title claims abstract description 11
- 238000006073 displacement reaction Methods 0.000 claims abstract description 34
- 238000000034 method Methods 0.000 claims abstract description 24
- 230000001133 acceleration Effects 0.000 claims description 17
- 238000005070 sampling Methods 0.000 claims description 17
- 239000011159 matrix material Substances 0.000 claims description 9
- 230000008569 process Effects 0.000 claims description 6
- 230000006866 deterioration Effects 0.000 claims description 5
- 238000005096 rolling process Methods 0.000 claims description 5
- 238000004364 calculation method Methods 0.000 claims description 4
- 238000013016 damping Methods 0.000 claims description 4
- 238000005259 measurement Methods 0.000 claims description 4
- 230000017105 transposition Effects 0.000 claims description 3
- 230000001351 cycling effect Effects 0.000 claims description 2
- 229910000831 Steel Inorganic materials 0.000 abstract description 2
- 239000010959 steel Substances 0.000 abstract description 2
- 238000012544 monitoring process Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000003745 diagnosis Methods 0.000 description 4
- 238000012423 maintenance Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 238000013461 design Methods 0.000 description 2
- 230000036541 health Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000009193 crawling Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B19/00—Testing; Calibrating; Fault detection or monitoring; Simulation or modelling of fluid-pressure systems or apparatus not otherwise provided for
- F15B19/005—Fault detection or monitoring
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B19/00—Testing; Calibrating; Fault detection or monitoring; Simulation or modelling of fluid-pressure systems or apparatus not otherwise provided for
- F15B19/007—Simulation or modelling
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F17/00—Digital computing or data processing equipment or methods, specially adapted for specific functions
- G06F17/10—Complex mathematical operations
- G06F17/11—Complex mathematical operations for solving equations, e.g. nonlinear equations, general mathematical optimization problems
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06Q—INFORMATION AND COMMUNICATION TECHNOLOGY [ICT] SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES; SYSTEMS OR METHODS SPECIALLY ADAPTED FOR ADMINISTRATIVE, COMMERCIAL, FINANCIAL, MANAGERIAL OR SUPERVISORY PURPOSES, NOT OTHERWISE PROVIDED FOR
- G06Q10/00—Administration; Management
- G06Q10/06—Resources, workflows, human or project management; Enterprise or organisation planning; Enterprise or organisation modelling
- G06Q10/063—Operations research, analysis or management
- G06Q10/0639—Performance analysis of employees; Performance analysis of enterprise or organisation operations
- G06Q10/06393—Score-carding, benchmarking or key performance indicator [KPI] analysis
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Business, Economics & Management (AREA)
- Human Resources & Organizations (AREA)
- General Physics & Mathematics (AREA)
- General Engineering & Computer Science (AREA)
- Mathematical Physics (AREA)
- Theoretical Computer Science (AREA)
- Economics (AREA)
- Mechanical Engineering (AREA)
- Operations Research (AREA)
- Fluid Mechanics (AREA)
- Strategic Management (AREA)
- Entrepreneurship & Innovation (AREA)
- Data Mining & Analysis (AREA)
- Pure & Applied Mathematics (AREA)
- Educational Administration (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Development Economics (AREA)
- Game Theory and Decision Science (AREA)
- Algebra (AREA)
- General Business, Economics & Management (AREA)
- Databases & Information Systems (AREA)
- Software Systems (AREA)
- Tourism & Hospitality (AREA)
- Quality & Reliability (AREA)
- Marketing (AREA)
- Fluid-Pressure Circuits (AREA)
Abstract
The invention provides a hydraulic cylinder degradation trend evaluation method, and belongs to the technical field of hot rolled strip steel automatic control. 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 acquired piston displacement signals; estimating the Stribeck parameters based on the LS algorithm format of the determined hydraulic cylinder motion model to obtain the stable Stribeck parameters; 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 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. By adopting the method and the device, the degradation 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 degradation trend of a hydraulic cylinder.
Background
A large amount of industrial field data show that the hydraulic cylinder is always affected by some disturbance in working, so that the force balance state is damaged, chatter with different amplitudes is generated, and even equipment damage and factory production stoppage are caused in severe cases. Therefore, the means of fault diagnosis, life prediction, daily monitoring, maintenance and the like of the hydraulic cylinder system should be considered with great importance. At present, the research aiming at the fault diagnosis and life prediction of the hydraulic cylinder is very in depth, the university of railway of Shijia Ma Huaixiang teaches the team to mainly research the working states of two typical engineering machinery hydraulic systems of a shield machine and an excavator, and the effect of the fault diagnosis and health prediction of the hydraulic system is obviously improved by using pressure, flow, vibration, temperature and oil signals as detection amounts and applying Labview software to develop the engineering machinery hydraulic system fault diagnosis and health assessment system. For daily monitoring and maintenance aspects of the hydraulic system, the degradation trend of the hydraulic cylinder is represented by introducing a friction model and analyzing parameter changes of the model. Common friction models include: coulomb model, coulomb + viscous friction model, stribeck friction model, karnopp model, lu gre model, etc.; the Stribeck friction model has high utilization rate and wide application range. The design problem of a controller based on the stick-slip phenomenon of a permanent magnet synchronous motor during low-speed operation is researched, a Stribeck friction model is utilized to model nonlinear friction moment, and the steady-state error and the low-speed crawling problem of the system are solved through designing a compensation controller.
At present, most researches are to analyze the Stribeck friction model from the perspective of how to influence the stability performance of the system, and the literature for researching the degradation problem of the hydraulic cylinder by using the Stribeck friction model is quite available.
Disclosure of Invention
The embodiment of the invention provides a method for evaluating the degradation trend of a hydraulic cylinder, which can accurately evaluate the degradation degree of the 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 acquired piston displacement signals; wherein LS represents least squares;
estimating the Stribeck parameters based on the LS algorithm format of the determined hydraulic cylinder motion model to obtain the stable Stribeck parameters;
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 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, the LS algorithm format of the determined hydraulic cylinder movement model is expressed as follows:
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 parameter to be estimated, d (T) is measurement noise, the superscript T represents matrix transposition, and p 1 、p 2 The pressure of the rodless cavity and the pressure of the rod cavity are respectively, A 1 、A 2 The effective area of the rodless cavity and the effective area of the rod cavity, p 1 A 1 and p2 A 2 Representing the pressure of the rodless and rodless chambers, respectively, F L Represents external rolling force, c represents viscous damping coefficient, x,
Respectively representing the displacement, the speed and the acceleration of the piston, sgn (·) is a sign function, m is the folded mass of the piston and the load, K represents the equivalent stiffness of the hydraulic cylinder system, f c For Coulomb friction parameter, f v F is the coefficient of viscous friction s Is the Stribeck friction parameter.
Further, the estimating the Stribeck parameter based on the determined LS algorithm format of the hydraulic cylinder motion model, where obtaining the Stribeck parameter converged to a stable value includes:
a1, in the LS algorithm parameter estimation process of the initial sampling time period, giving an initial value theta of a parameter 0 Initial value P of gain matrix 0 Initial value x of displacement 0 And initial value of velocity
A2, inputting piston displacement signal x 1 Calculating a speed signal and an acceleration signal of a piston by adopting a differential algorithm, and constructing an LS algorithm format output y of a hydraulic cylinder motion model k And input phi k Sequentially updating and calculating K k 、
P k Is a value of (2);
a3, updating and calculating K k 、
P k After the value of (1), 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 Continuously cycling until the corresponding sampling time period is converged to a stable Stribeck parameter, and taking the parameter estimation result of each sampling time period as the initial value of the next parameter estimation to be added into calculation; wherein, the Stribeck parameters include: f (f) c 、f v and fs The next time refers to the next sampling period.
Further, the calculating the velocity signal and the acceleration signal of the piston by using the differential algorithm includes:
by the formula
Solving for velocity signal v of piston k The method comprises the steps of carrying out a first treatment on the surface of the Wherein delta is the differential spacing, x k The displacement signal of the piston at the kth moment;
by the formula
Solving acceleration signal a of piston k； wherein ,
Is the acceleration signal of the piston at the kth moment.
Further, at the kth time K k 、
P k The update expression of (2) is:
wherein ,Kk and Pk All represent gain matrices at time k;
a parameter estimation value indicating a kth time; p (P) k-1 A gain matrix representing the k-1 time; phi (phi) k LS algorithm input representing the kth time;
A parameter estimation value representing the k-1 time; y is k The LS algorithm output at time k is represented.
Further, the parameter estimation cycle termination condition is:
wherein ,
the parameter estimated values at the kth time and the k-1 time obtained by the nth parameter estimation are respectively, and epsilon is a stop condition parameter.
Further, 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 comprises:
comparing the stable Stribeck parameter obtained each time with the Stribeck parameter in the initial state to establish a deterioration index J of the working state of the hydraulic cylinder n ：
wherein ,
indicating an upper speed limit for the piston when in operation; v represents the velocity signal of the piston;
Respectively represents the Coulomb friction parameter, the viscous friction coefficient and the Stribeck friction parameter obtained by the n-th parameter estimation,
respectively represent coulomb friction parameter, viscous friction coefficient and Stribeck friction parameter in the initial state of the hydraulic cylinder, and function F d (. Cndot.) is the linearized Stribeck friction model;
to be used for
In abscissa, J n Drawing a hydraulic cylinder working state degradation curve by taking the hydraulic cylinder working state degradation curve as an ordinate; wherein T is i Representing the time interval between the i-th estimated parameter and the i+1th estimated parameter, τ n Representing a sampling time period corresponding to a piston displacement signal used for n-th parameter estimation;
according to the drawn degradation curve of the working state of the hydraulic cylinder, determining the degradation trend 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 For Coulomb friction parameter, f v F is the coefficient of viscous friction 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 collected in real time; determining an LS algorithm format of a hydraulic cylinder motion model based on the acquired piston displacement signals; estimating the Stribeck parameters based on the LS algorithm format of the determined hydraulic cylinder motion model to obtain the stable Stribeck parameters; 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 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. Therefore, by the established hydraulic cylinder degradation trend evaluation method based on the Stribeck curve, the degradation degree of the hydraulic cylinder can be accurately evaluated, the daily monitoring and maintenance of the hydraulic system are assisted, and the method has important significance for the performance monitoring and evaluation of the hydraulic system and the improvement of the working efficiency of the production process, so that the problem that the degradation degree of the hydraulic cylinder cannot be evaluated in the prior art is solved.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic flow chart of a hydraulic cylinder degradation trend evaluation method according to an embodiment of the present invention;
FIGS. 2 (a) - (f) are schematic diagrams of velocity and acceleration signal curves obtained by solving the piston displacement signals used for 1 st-6 th parameter estimation and using a differential algorithm according to the embodiments of the present invention;
FIGS. 3 (a) - (f) are schematic diagrams of the estimated values and true curves of the Stribeck parameters obtained by the 1 st-6 th parameter estimation according to the embodiments of the present invention;
fig. 4 is a schematic diagram of a Stribeck friction model under different sampling periods according to an embodiment of the present invention;
fig. 5 is a schematic diagram of degradation trend broken lines of a hydraulic cylinder according to an embodiment of the present invention.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the embodiments of the present invention will be described in further detail with reference to the accompanying drawings.
As shown in fig. 1, an embodiment of the present invention provides a method for evaluating a degradation trend of a hydraulic cylinder, including:
s101, acquiring piston displacement signals of a 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 an acquired piston displacement signal; wherein LS represents least squares;
in this embodiment, the format of the LS algorithm 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 parameter to be estimated, d (T) is measurement noise, the superscript T represents matrix transposition, and p 1 、p 2 The pressure of the rodless cavity and the pressure of the rod cavity are respectively, A 1 、A 2 The effective area of the rodless cavity and the effective area of the rod cavity, p 1 A 1 and p2 A 2 Representing the pressure of the rodless and rodless chambers, respectively, F L Represents external rolling force, c represents viscous damping coefficient, x,
Respectively representing the displacement, the speed and the acceleration of the piston, sgn (·) is a sign function, m is the folded mass of the piston and the load, K represents the equivalent stiffness of the hydraulic cylinder system, f c For Coulomb friction parameter, f v F is the coefficient of viscous friction s Is the Stribeck friction parameter.
In this embodiment, d (t) is the measurement noise, which is assumed to follow a gaussian distribution of 0 mean; from the formula "pressure=pressure×surface area", p is known 1 A 1 and p2 A 2 The pressure of the rodless cavity and the pressure of the rod cavity are respectively represented, the pressure of the two cavities changes along with the displacement change of the piston, and the pressure 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 practical systems, and therefore the viscous force
Is known.
In the embodiment, the LS algorithm output is formed by deriving the piston displacement to obtain the piston speed, the pressures of the rodless cavity and the rod cavity, the external rolling force and the viscous force; from x,
The regression vector is composed, namely: LS algorithm input.
S103, estimating the Stribeck parameters based on the LS algorithm format of the determined hydraulic cylinder motion model to obtain stable Stribeck parameters; the method specifically comprises the following steps:
a1, in the LS algorithm parameter estimation process of the initial sampling time period, giving an initial value theta of a parameter 0 Initial value P of gain matrix 0 Initial value x of displacement 0 And initial value of velocity
A2, inputting piston displacement signal x 1 Calculating a speed signal and an acceleration signal of a piston by adopting a differential algorithm, and constructing an LS algorithm format output y of a hydraulic cylinder motion model k And input phi k Sequentially updating and calculating K k 、
P k Is a value of (2);
in this embodiment, a differential algorithm is used to calculate a velocity signal and an acceleration signal of the piston, which specifically includes the following steps:
by the formula
Solving for velocity signal v of piston k The method comprises the steps of carrying out a first treatment on the surface of the Wherein delta is the differential spacing, x k The displacement signal of the piston at the kth moment;
by the formula
Solving acceleration signal a of piston k； wherein ,
Is the acceleration signal of the piston at the kth moment.
In this embodiment, the piston displacement signals used for parameter estimation for the 1 st to 6 th times and velocity and acceleration signal curves obtained by solving by using a differential algorithm are shown in fig. 2 (a) - (f).
In this embodiment, the LS algorithm format and the hydraulic cylinder dynamics 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 (2) is:
wherein ,Kk and Pk All represent gain matrices at time k;
parameter estimation value, initial value, representing the kth time
P k-1 A gain matrix representing the k-1 time; phi (phi) k LS algorithm input representing the kth time;
A parameter estimation value representing the k-1 time; y is k The LS algorithm output at time k is represented.
A3, updating and calculating K k 、
P k After the value of (1), 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 Is continuously cycled until a corresponding sampling period is obtained that converges to a stable Stribeck parameter, and each timeThe parameter estimation result in the sampling time period is used as an initial value of the next parameter estimation to be added into calculation; wherein, the Stribeck parameters include: f (f) c 、f v and fs The next time refers to the next sampling period.
In this embodiment, the parameter estimation cycle termination conditions are:
wherein ,
parameter estimation values at the kth time and the k-1 time obtained by the nth parameter estimation are respectively, epsilon is a stop condition parameter, and epsilon is generally close to 0.
In this embodiment, the strabeck parameter estimation values and the truth curves obtained by 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 hydraulic cylinder working state degradation index, drawing a hydraulic cylinder working state degradation curve, determining a hydraulic cylinder degradation trend according to the drawn hydraulic cylinder working state degradation curve, and determining the current degradation degree of the hydraulic cylinder according to the degradation index at the current moment, wherein the method specifically comprises the following steps:
b1, comparing the stable Stribeck parameter obtained each time with the Stribeck parameter in the initial state to establish a hydraulic cylinder working state degradation index J n ：
wherein ,
indicating an upper speed limit for the piston when in operation; v represents the velocity signal of the piston;
Respectively represents the Coulomb friction parameter, the viscous friction coefficient and the Stribeck friction parameter obtained by the n-th parameter estimation,
respectively represent coulomb friction parameter, viscous friction coefficient and Stribeck friction parameter in the initial state of the hydraulic cylinder, and function F d (. Cndot.) is the linearized Stribeck friction model;
in the present embodiment, function F d (. Cndot.) is expressed as:
wherein ,fc For Coulomb friction parameter, f v F is the coefficient of viscous friction s For the Stribeck friction parameter, sgn (·) is a sign function,
indicating the velocity of the piston.
In this embodiment, the Stribeck friction model curves are shown in fig. 4 for different sampling periods.
B2 to
In abscissa, J n Drawing a hydraulic cylinder working state degradation curve by taking the hydraulic cylinder working state degradation curve as an ordinate; wherein T is i Representing the time interval between the i-th estimated parameter and the i+1th estimated parameter, τ n Representing a sampling time period corresponding to a piston displacement signal used for n-th parameter estimation;
and B3, determining a 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.
In the present embodiment, 4 threshold ranges may be empirically set, thereby dividing 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 this embodiment, a schematic diagram of a degradation trend broken line of the hydraulic cylinder is shown in fig. 5.
In this embodiment, by analyzing the degradation curve of the working state of the hydraulic cylinder, the current degradation degree of the hydraulic cylinder can be determined, and a basis is provided for whether to replace the system components.
According to the method for evaluating the degradation trend of the hydraulic cylinder, disclosed by the embodiment of the invention, 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 acquired piston displacement signals; estimating the Stribeck parameters based on the LS algorithm format of the determined hydraulic cylinder motion model to obtain the stable Stribeck parameters; 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 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. Therefore, by the established hydraulic cylinder degradation trend evaluation method based on the Stribeck curve, the degradation degree of the hydraulic cylinder can be accurately evaluated, the daily monitoring and maintenance of the hydraulic system are assisted, and the method has important significance for the performance monitoring and evaluation of the hydraulic system and the improvement of the working efficiency of the production process, so that the problem that the degradation degree of the hydraulic cylinder cannot be evaluated in the prior art is solved.
The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.
Claims (7)
1. A hydraulic cylinder degradation tendency evaluation method, characterized by comprising:
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 acquired piston displacement signals; wherein LS represents least squares;
estimating the Stribeck parameters based on the LS algorithm format of the determined hydraulic cylinder motion model to obtain the stable Stribeck parameters;
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 the current degradation degree of the hydraulic cylinder according to the degradation index at the current moment;
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, wherein the determining the current degradation degree of the hydraulic cylinder comprises the following steps:
comparing the stable Stribeck parameter obtained each time with the Stribeck parameter in the initial state to establish a deterioration index J of the working state of the hydraulic cylinder n ：
wherein ,
indicating an upper speed limit for the piston when in operation; v represents the velocity signal of the piston;
Respectively represent the Coulomb friction parameter, the viscous friction coefficient and the Stribeck friction parameter obtained by the n-th parameter estimation,>
respectively showing the initial state of the hydraulic cylinderCoulomb friction parameter, viscous friction coefficient, stribeck friction parameter, function F d (. Cndot.) is the linearized Stribeck friction model;
to be used for
In abscissa, J n Drawing a hydraulic cylinder working state degradation curve by taking the hydraulic cylinder working state degradation curve as an ordinate; wherein T is i Representing the time interval between the i-th estimated parameter and the i+1th estimated parameter, τ n Representing a sampling time period corresponding to a piston displacement signal used for n-th parameter estimation;
according to the drawn degradation curve of the working state of the hydraulic cylinder, determining the degradation trend of the hydraulic cylinder, and determining the current degradation degree of the hydraulic cylinder according to the degradation index at the current moment.
2. The hydraulic cylinder degradation trend evaluation method according to claim 1, wherein the LS algorithm format of the determined hydraulic cylinder movement 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 parameter to be estimated, d (T) is measurement noise, the superscript T represents matrix transposition, and p 1 、p 2 The pressure of the rodless cavity and the pressure of the rod cavity are respectively, A 1 、A 2 The effective area of the rodless cavity and the effective area of the rod cavity, p 1 A 1 and p2 A 2 Representing the pressure of the rodless and rodless chambers, respectively, F L Represents external rolling force, c tableShowing the viscous damping coefficient, x,
Respectively representing the displacement, the speed and the acceleration of the piston, sgn (·) is a sign function, m is the folded mass of the piston and the load, K represents the equivalent stiffness of the hydraulic cylinder system, f c For Coulomb friction parameter, f v F is the coefficient of viscous friction s Is the Stribeck friction parameter.
3. The method for evaluating the degradation trend of the hydraulic cylinder according to claim 2, wherein the estimating the Stribeck parameter based on the LS algorithm format of the determined hydraulic cylinder motion model, to obtain the Stribeck parameter that converges to a stable one includes:
a1, in the LS algorithm parameter estimation process of the initial sampling time period, giving an initial value theta of a parameter 0 Initial value P of gain matrix 0 Initial value x of displacement 0 And initial value of velocity
A2, inputting piston displacement signal x 1 Calculating a speed signal and an acceleration signal of a piston by adopting a differential algorithm, and constructing an LS algorithm format output y of a hydraulic cylinder motion model k And input phi k Sequentially updating and calculating K k 、
P k Is a value of (2);
a3, updating and calculating K k 、
P k After the value of (1), 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 Continuously cycling until the corresponding sampling time period is converged to a stable Stribeck parameter, and taking the parameter estimation result of each sampling time period as the initial value of the next parameter estimation to be added into calculation; wherein, the Stribeck parameters include: f (f) c 、f v and fs The next time refers to the next sampling period.
4. The method for evaluating the degradation tendency of a hydraulic cylinder according to claim 3, wherein the calculating the velocity signal and the acceleration signal of the piston using the differential algorithm includes:
by the formula
Solving for velocity signal v of piston k The method comprises the steps of carrying out a first treatment on the surface of the Wherein delta is the differential spacing, x k The displacement signal of the piston at the kth moment;
by the formula
Solving acceleration signal a of piston k； wherein ,
Is the acceleration signal of the piston at the kth moment.
5. The method for evaluating a deterioration trend of a hydraulic cylinder according to claim 1, characterized in that the kth time K k 、
P k The update expression of (2) is:
wherein ,Kk and Pk All represent gain matrices at time k;
a parameter estimation value indicating a kth time; p (P) k-1 A gain matrix representing the k-1 time; phi (phi) k LS algorithm input representing the kth time;
A parameter estimation value representing the k-1 time; y is k The LS algorithm output at time k is represented.
6. The hydraulic cylinder deterioration trend evaluating method according to claim 1, characterized in that the parameter estimation cycle termination condition is:
wherein ,
the parameter estimated values at the kth time and the k-1 time obtained by the nth parameter estimation are respectively, and epsilon is a stop condition parameter.
7. The hydraulic cylinder deterioration trend evaluation method according to claim 1, characterized in that the function F d (. Cndot.) is expressed as:
wherein ,fc For Coulomb friction parameter, f v F is the coefficient of viscous friction s For the Stribeck friction parameter, sgn (·) is a sign function,
indicating the velocity of the piston. />
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210901662.0A CN115289100B (en) | 2022-07-28 | 2022-07-28 | Hydraulic cylinder degradation trend evaluation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210901662.0A CN115289100B (en) | 2022-07-28 | 2022-07-28 | Hydraulic cylinder degradation trend evaluation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115289100A CN115289100A (en) | 2022-11-04 |
| CN115289100B true CN115289100B (en) | 2023-05-02 |
Family
ID=83823686
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210901662.0A Active CN115289100B (en) | 2022-07-28 | 2022-07-28 | Hydraulic cylinder degradation trend evaluation method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115289100B (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
Family Cites Families (11)
| 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 |
| US9128008B2 (en) * | 2012-04-20 | 2015-09-08 | Kent Tabor | Actuator predictive system |
| CN102635597B (en) * | 2012-05-02 | 2015-02-04 | 武汉理工大学 | Health management system and method of engineering machinery hydraulic system |
| CN103410809B (en) * | 2013-08-01 | 2016-01-20 | 中冶赛迪工程技术股份有限公司 | The test system of oil hydraulic cylinder Stribeck model friction parameter and test method |
| JP6502063B2 (en) * | 2014-11-05 | 2019-04-17 | 国立大学法人 東京大学 | Electrohydrostatic actuator and parameter estimation method for electrohydrostatic actuator |
| CN104678763B (en) * | 2015-01-21 | 2017-02-22 | 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 |
| US10837472B2 (en) * | 2018-02-22 | 2020-11-17 | Caterpillar Inc. | Hydraulic cylinder health monitoring and remaining life system |
| CN110296833B (en) * | 2019-07-22 | 2020-08-18 | 齐鲁工业大学 | Soft measurement method and system for hydraulic cylinder comprehensive test board |
| CN112507487B (en) * | 2020-11-30 | 2023-06-27 | 中国长江电力股份有限公司 | Reliability evaluation method and system for hydraulic turbine governor servomotor |
-
2022
- 2022-07-28 CN CN202210901662.0A patent/CN115289100B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115289100A (en) | 2022-11-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104111607B (en) | A kind of control method of the electric machine position servo system considering input delay | |
| CN104345638A (en) | ADRAC (active-disturbance-rejection adaptive control) method for hydraulic motor position servo system | |
| CN104345639A (en) | Robust adaptive control (RAC) method of electro-hydraulic position servo control system | |
| CN110456646B (en) | Design method of anchor rod drilling machine drill arm swing angle self-adaptive sliding mode control system based on EKF | |
| CN103941589B (en) | A kind of nonlinear model predictive control method of piezo actuator | |
| CN110500339B (en) | Additive fault detection method for electro-hydraulic servo system | |
| CN109334376B (en) | Time-varying compensation control system for mechanical property of shock absorber of magneto-rheological semi-active suspension and construction method thereof | |
| CN111367173B (en) | High-speed railway pantograph robust prediction control method based on state estimation | |
| CN109334377B (en) | Magneto-rheological semi-active suspension equivalent replacement Taylor series LQG time lag compensation control system and construction method thereof | |
| CN104698844A (en) | Uncertainty compensatory sliding-mode control method of hydraulic position servo system | |
| CN110107563B (en) | Multi-hydraulic servo actuator distribution cooperative control method under load interference condition | |
| CN115289100B (en) | Hydraulic cylinder degradation trend evaluation method | |
| CN105931130A (en) | Improved ensemble Kalman filtering estimation method considering measurement signal loss | |
| Dong et al. | Robust fault diagnosis based on nonlinear model of hydraulic gauge control system on rolling mill | |
| CN111025904B (en) | Magnetic levitation ball continuous sliding mode control method based on extended state observer | |
| Guo et al. | Disturbance observer based position tracking of electro-hydraulic actuator | |
| CN105538310A (en) | Electro-hydraulic servo control method based on fading memory filtering and 2-DOF mechanical arm | |
| CN109902357B (en) | Method for analyzing dynamic response sensitivity of complex-variant differential smooth nonlinear structure | |
| CN114186595B (en) | Time-varying structure parameter identification method, storage medium and equipment | |
| CN108843654A (en) | A kind of valve control cylinder mode leakage judgment means and method based on Subspace Identification | |
| CN108804721B (en) | Oil pumping machine fault diagnosis method based on self-adaptive unscented Kalman filtering and RBF neural network | |
| CN115729171A (en) | Excavator friction compensation control method based on stroke characteristics | |
| CN115478574A (en) | Excavator load prediction method based on radial basis function neural network | |
| Zhou et al. | Model-based trajectory tracking control for an electrohydraulic lifting system with valve compensation strategy | |
| Feng et al. | Robotic excavator identification model based on recursive least squares algorithm with forgetting factor |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |