Addressing Valves With Pressure Ripple

2018 ◽  
Author(s):  
Ryan J. Foss ◽  
Mengtang Li ◽  
Eric J. Barth ◽  
Kim A. Stelson ◽  
James D. Van de Ven
Keyword(s):  
Hydraulic System ◽  
Experimental Validation ◽  
Resonant Peak ◽  
Elastic Membrane ◽  
System Parameters ◽  
System Validation ◽  
System Pressure ◽  
Pressure Ripple ◽  
Specific Frequency ◽  
Linear And Nonlinear

Pressure ripple can be purposely used to transmit information within a hydraulic system. For example, introducing ripple at specific frequencies into a fluid line can activate a valve, eliminating electrical wires. A key element of this system is the hydraulic resonator that activates the valve when a specific frequency pressure ripple is present in the line. This paper presents a linear and nonlinear model of the hydraulic resonator with experimental validation. The hydraulic resonator consists of an inertance tube, a series capacitor, made up of a deforming elastic membrane, and an orifice. For system validation, displacement of a valve, the capacitor, and system pressure are measured. The model was effective at predicting the natural frequency of the system and the narrowness of the resonant peak. Different effects were also shown experimentally by changing the fluid’s viscosity and system parameters.

Reinforcement Learning for Active Noise Control in a Hydraulic System

2021 ◽  
Vol 143 (6) ◽  
Author(s):  
Eric R. Anderson ◽  
Brian L. Steward
Keyword(s):  
Reinforcement Learning ◽  
Hydraulic System ◽  
Noise Control ◽  
Control Method ◽  
Active Noise Control ◽  
Operating Point ◽  
Hydraulic Pressure ◽  
Hydraulic Systems ◽  
Active Noise ◽  
Pressure Ripple

Abstract Hydraulic pressure ripple in a pump, as a result of converting rotational power to fluid power, continues to be a problem faced when developing hydraulic systems due to the resulting noise generated. In this paper, we present simulation results from leveraging an actor-critic reinforcement learning method as the control method for active noise control in a hydraulic system. The results demonstrate greater than 96%, 81%, and 61% pressure ripple reduction for the first, second, and third harmonics, respectively, in a single operating point test, along with the advantage of feed forward like control for high bandwidth response during dynamic changes in the operating point. It also demonstrates the disadvantage of long convergence times while the controller is effectively learning the optimal control policy. Additionally, this work demonstrates the ancillary benefit of the elimination of the injection of white noise for the purpose of system identification in the current state of the art.

Nonlinear Transient Response and its Sensitivity Using Finite Elements in Time

1995 ◽  
Author(s):  
Rakesh K. Kapania ◽  
Sungho Park
Keyword(s):  
Finite Elements ◽  
Transient Response ◽  
Legendre Polynomials ◽  
Design Parameters ◽  
Algebraic Equations ◽  
System Parameters ◽  
Nonlinear Transient ◽  
Linear And Nonlinear ◽  
Bilinear Formulation ◽  
The One

Abstract The bilinear formulation proposed earlier by Peters and Izadpanah to develop finite elements in time to solve undamped linear systems, is extended (and found to be readily amenable) to develop time finite elements to obtain transient responses of both linear and nonlinear, and damped and undamped systems. The formulation is used in the h-, p- and hp-versions. The resulting linear and nonlinear algebraic equations are differentiated to obtain the sensitivity of the transient response with respect to various design parameters. The present developments were tested on a series of linear and nonlinear examples and were found to yield, when compared with results obtained using other methods, excellent results for both the transient response and its sensitivity to system parameters. Mostly, the results were obtained using the Legendre polynomials as basis functions, though, in some cases other orthogonal polynomials namely, the Hermite, the Chebyshev, and integrated Legendre polynomials were also employed (but to no great advantage). A key advantage of the time finite element method, and the one often overlooked in its past applications, is the ease in which the sensitivity of the transient response with respect to various system parameters can be obtained.

scholarly journals Nonlinear modeling and stability analysis of a pilot-operated valve-control hydraulic system

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401881066 ◽  
Author(s):  
Wei Wei ◽  
Hongchao Jian ◽  
Qingdong Yan ◽  
Xiaomei Luo ◽  
Xuhong Wu
Keyword(s):  
Dynamic Model ◽  
Hydraulic System ◽  
Nonlinear Modeling ◽  
Orifice Diameter ◽  
Operating Pressure ◽  
Nonlinear Dynamic Model ◽  
System Parameters ◽  
Excited Vibration ◽  
The Stability ◽  
Valve Control

A nonlinear dynamic model is developed to analyze the stability of a pilot-operated valve-control hydraulic system. The dynamic model includes motion of the valve spool and fluid dynamics in the system. Characteristics such as pressure flow across the valve port and orifices, pressure, and flow rate in valve chambers are taken into consideration. Bifurcation analysis is proposed and examined by numerical simulation results when the feedback orifice diameter changes. The effects of different system parameters such as pilot-operating pressure, spring stiffness, and overlap of inlet port on the stability border of the system are studied by two-dimensional bifurcation analyses. The study identifies that bifurcation can occur in the system and lead to sustained self-excited vibration with parameters in certain region of the parameter space. It suggests that the vibration can be effectively predicted and prevented by selecting system parameters from the asymptotic stable parameter region.

The Air Controlled Hydraulic System Design of 3201z-Type Dump Truck Lifting Mechanisms

2011 ◽  
Vol 383-390 ◽  
pp. 1202-1207
Author(s):  
Tao Ping Yan
Keyword(s):  
Hydraulic System ◽  
Hydraulic Cylinder ◽  
Dump Truck ◽  
Gear Pump ◽  
Technical Parameters ◽  
Technical Performance ◽  
System Pressure ◽  
Working Principle ◽  
The Stability ◽  
Hydraulic System Design

3201Z-type dump truck is modification desiged by EQ3208GJ dump truck chassis which the technical performance parameters are known, and using a lifting mechanism of air controlled hydraulic system. By analyzing the composition and working principle of air controlled hydraulic system and referring to similar models, the design of the tank, the limiting mechanism and power taker are conducted. By calculating the main technical parameters, including in the performances of the hydraulic cylinder and the hydraulic pump, the dump truck's special oil cylinder HG-E180X780 and gear pump CBT-E563 are selected. By the stability of the piston rod, the system pressure and cars lifting time are checked; the reasonability and safty of the design can be proved.

Huge Forging Equipment Hydraulic System Dynamic Analysis

2012 ◽  
Vol 619 ◽  
pp. 459-462 ◽  
Author(s):  
Miao Xie ◽  
Jun Meng ◽  
Wen Xin Xu ◽  
Rong Bao Dong ◽  
Jian Liang Wang
Keyword(s):  
Hydraulic System ◽  
Simulation Models ◽  
Simulation Software ◽  
Hydraulic Systems ◽  
System Pressure ◽  
Hydraulic Hammer ◽  
Hammer Head ◽  
Working Principle ◽  
Switching Characteristics ◽  
Hammer Forging

In order to optimize the dynamic characteristic of hydraulic system of large forging equipment. It based on the model of one company of a certain aero-engine hydraulic system of hydraulic hammer forging, analysis the composition and working principle of hydraulic systems. Using simulation software AMESim, simulate the model of hydraulic systems and by changing the system pressure, flow and effect of the hammer-head stroke to explore this kind of switching characteristics of forging equipment’s hydraulic system. The result shows that this kind of simulation models can reflect the working status of hydraulic hammer well, and provide a technical reference for analysis and tuning equipment that with similar to forging equipment.

The Reduction of Gear Pump Pressure Ripple

1987 ◽  
Vol 201 (2) ◽  
pp. 99-106 ◽  
Author(s):  
K A Edge ◽  
B R Lipscombe
Keyword(s):  
Hydraulic System ◽  
Pressure Fluctuations ◽  
Gear Pump ◽  
Noise Levels ◽  
Flow Ripple ◽  
Flow Fluctuation ◽  
Accurate Knowledge ◽  
Airborne Noise ◽  
Pressure Ripple ◽  
Pump Pressure

Pressure fluctuations in a hydraulic system may be substantially reduced by cancelling the flow ripple produced by the pump. This paper describes a secondary flow ripple generating mechanism which introduces an equal and opposite flow fluctuation to that generated by the pump. Tests have shown that the mechanism can virtually cancel four harmonics of pressure ripple but success is dependent on an accurate knowledge of the pump flow fluctuation characteristic. This is best determined experimentally. Similar improvements can be achieved using a mechanism in a motor. This has the additional benefit of reducing torque fluctuations. The reduction in gear pump pressure ripple achieved with the mechanism has been shown to reduce overall airborne noise levels from a hydraulic system by as much as 10 dB, although the airborne noise radiated from the pump casing was not affected.

Analysis and Troubleshooting of the Hydraulic System about Bicycle Assembly Line

2014 ◽  
Vol 1006-1007 ◽  
pp. 139-141
Author(s):  
Hong Yang ◽  
Xiao Guang Yu ◽  
Ze Ning Xu ◽  
Ming Xu
Keyword(s):  
Hydraulic System ◽  
Assembly Line ◽  
Design Standard ◽  
System Pressure

This paper analyzes hydraulic system of the bicycle assemply line,Aiming at the problem of the hydraulic system pressure not up to design standard when there is only a hydraulic pupm in the oil supperly system. Put forward to replaced two throttle valves by two check valves. The results show validity of the method.

A redesigned DCAL controller without velocity measurements: theory and demonstration

Robotica ◽  
1997 ◽  
Vol 15 (3) ◽  
pp. 337-346 ◽  
Author(s):  
T. Burg ◽  
D. Dawson ◽  
P. Vedagarbha
Keyword(s):  
Experimental Validation ◽  
Parameter Estimates ◽  
Direct Drive ◽  
Velocity Measurements ◽  
System Parameters ◽  
Position Signal ◽  
Fixed Parameter ◽  
Filtering Technique ◽  
The Individual ◽  
Velocity Tracking

A link position tracking controller is formulated for an n-link, rigid, revolute, serially-connected robot. The controller generates torque commands to the individual robot links based on adaptive estimates of the system parameters and measurements of only link positions. A filtering technique, based on the link position signal, is used to alleviate the need for velocity measurements. A complete development of the controller is presented along with a proof of semiglobal asymptotic link position-velocity tracking performance. Experimental validation of the proposed controller on the Integrated Motion Inc. (IMI) two-link direct drive robot is also presented. Several extensions to the basic controller are described that consider the use of fixed parameter estimates.

Nonlinear Model Based Estimation of Rigid-Body Motion Via an Indirect Measurement of an Elastic Appendage

2010 ◽  
Vol 132 (1) ◽  
Author(s):  
M. Senesh ◽  
A. Wolf ◽  
O. Gottlieb
Keyword(s):  
Nonlinear System ◽  
Rigid Body ◽  
Nonlinear Model ◽  
Estimation Procedure ◽  
Indirect Measurement ◽  
Body Motion ◽  
System Parameters ◽  
Model Based ◽  
Proposed Model ◽  
Linear And Nonlinear

In this paper, we develop and implement a nonlinear model based procedure for the estimation of rigid-body motion via an indirect measurement of an elastic appendage. We demonstrate the procedure by motion analysis of a compound planar pendulum from indirect optoelectronic measurements of markers attached to an elastic appendage that is constrained to slide along the rigid-body axis. We implement a Lagrangian approach to derive a theoretical nonlinear model that consistently incorporates several generalized forces acting on the system. Identification of the governing linear and nonlinear system parameters is obtained by analysis of frequency and damping backbone curves from controlled experiments of the decoupled system elements. The accuracy of the proposed model based procedures is evaluated and its results are compared with those of a previously reported point cluster estimation procedure. Two cases are investigated to yield 1.7% and 3.4% errors between measured motion and its model based estimation for experimental configurations, with a slider mass to pendulum frequency ratios of 12.8 and 2.5, respectively. Motion analysis of system dynamics with the point cluster method reveals a noisy signal with a maximal error of 3.9%. Thus, the proposed model based estimation procedure enables accurate evaluation of linear and nonlinear system parameters that are not directly measured.

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