Analysis of Wavelet Algorithm of Redundancy Denoising for Hydraulic System Signal

2008 ◽  
Vol 392-394 ◽  
pp. 341-346
Author(s):  
Chun Fu Gao ◽  
Xi Lin Zhu ◽  
Q.Y. Hu

Based on the theory of Wavelet decomposing algorithm, in this paper an algorithm of redundancy real-time denoising is presented, and the test of on-line identification mode of a hydraulic cylinder’s work load pressure signals was fulfilled. This method can improve the stability of the signal collection and the control accuracy of hydraulic cylinder pressure effectively, solve the crawling phenomenon of hydraulic cylinder when working, and reduce the signal collection error resulted from the load mutation. By means of controlling the wavelet decomposing depth, the calculation amount of real-time denoising is controled, thus the optimization of the signal, damping vibration and denoising are achieved.

2011 ◽  
Vol 383-390 ◽  
pp. 1202-1207
Author(s):  
Tao Ping Yan

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.


2010 ◽  
Vol 07 (03) ◽  
pp. 177-192 ◽  
Author(s):  
BEHNAM RAZAVI ◽  
CLARENCE W. DE SILVA

This paper develops a model-based technique based on the Unscented Kalman Filter (UKF) for on-line condition monitoring, and applies it to the hydraulic system of an automated industrial fish processing machine. First an analytical model of the hydraulic system is developed and the system parameters are identified (determined). Then the developed UKF approach is implemented in the machine. The UKF employs an unscented transformation to select a minimal set of sample points around the mean, which are then propagated through nonlinear functions, from which the mean and covariance of the estimate are recovered. This approach is known to be more accurate for nonlinear systems. For experimental investigation of the performance of the approach, four common hydraulic faults are deliberately introduced into the machine. The four faults are external leakage in the two chambers of the hydraulic cylinder; internal leakage; and dry friction build-up at the moving support plate of the cutter carriage. Three levels of leakage are manually introduced to the system for each fault scenario using needle valves. The criteria that are considered in fault diagnosing are residual moving average of the errors, chamber pressures, and actuator characteristics. The experimental results show that the developed technique is able to accurately determine the fault conditions of the machine.


2012 ◽  
Vol 433-440 ◽  
pp. 3852-3857
Author(s):  
Tao Ping Yan

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.


Author(s):  
Yong Xue ◽  
JunHong Yang ◽  
JianZhong Shang ◽  
HuiXiang Xie

In order to improve the efficiency of multi-actuator mobile robots hydraulic system, this paper proposes a new kind of cylinder whose effective area is variable. The new cylinder has multi chambers which can be connected with each other or to a main system circuit by controlling switching valves. On the one hand, the new cylinder can make sure that the load pressure of all actuators is almost equal through varying effective area. On the other hand, the new cylinder can realize the flow recovery through that return chambers are connected with feeding chambers. Therefore, the new cylinder can reduce overall machine energy consumption by reducing throttling losses and allowing energy recovery. The performance of the new cylinder is analyzed through building the mathematical model. Based on the evaluated results, in order to further improve the performance of the load match of the cylinder and avoid the deflection of the main piston, the structure of the cylinder is optimized. Finally, an optimized cylinder is shown in this paper which has well performance of the load match.


2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Fuqiang Chen ◽  
Rendong Wu ◽  
Chaolong Yuan ◽  
Wei Wei ◽  
Wei Jiao

In the extrusion machine with double booster cylinder hydraulic system, the stability of the extrusion velocity is affected because of the switching process of the two booster cylinders in the hydraulic system. In this paper, the analytical solution of the extrusion velocity fluctuation caused by the double booster cylinder hydraulic system is derived. Firstly, the model of the double booster cylinder hydraulic system was established, and the switching process of the two booster cylinders was studied under the condition of high pressure and high flow. Secondly, the traditional control method cannot obtain stable extrusion velocity under the condition of high pressure and high flow rate, and the new control method was proposed to significantly reduce the fluctuation of extrusion velocity. Thirdly, the fluctuation of extrusion velocity caused by the booster system was derived and the influence of the parameters of the hydraulic components such as the hydraulic cylinder and the hydraulic valve and the working conditions such as the flow rate and the pressure on the fluctuation of extrusion velocity was analyzed. Finally, based on the AMESIM software, the double booster cylinder hydraulic system of the 35 MN extrusion machine was simulated and analyzed. The numerical simulation results were used to verify the analytical solution of extrusion velocity fluctuation. The analytical solution can be applied to the engineering design of the hydraulic system and more in-depth optimization analysis.


1994 ◽  
Vol 33 (01) ◽  
pp. 60-63 ◽  
Author(s):  
E. J. Manders ◽  
D. P. Lindstrom ◽  
B. M. Dawant

Abstract:On-line intelligent monitoring, diagnosis, and control of dynamic systems such as patients in intensive care units necessitates the context-dependent acquisition, processing, analysis, and interpretation of large amounts of possibly noisy and incomplete data. The dynamic nature of the process also requires a continuous evaluation and adaptation of the monitoring strategy to respond to changes both in the monitored patient and in the monitoring equipment. Moreover, real-time constraints may imply data losses, the importance of which has to be minimized. This paper presents a computer architecture designed to accomplish these tasks. Its main components are a model and a data abstraction module. The model provides the system with a monitoring context related to the patient status. The data abstraction module relies on that information to adapt the monitoring strategy and provide the model with the necessary information. This paper focuses on the data abstraction module and its interaction with the model.


2010 ◽  
Vol 5 (3) ◽  
Author(s):  
Cheng-Nan Chang ◽  
Li-Ling Lee ◽  
Han-Hsien Huang ◽  
Ying-Chih Chiu

The performance of a real-time controlled Sequencing Batch Membrane Bioreactor (SBMBR) for removing organic matter and nitrogen from synthetic wastewater has been investigated in this study under two specific ammonia loadings of 0.0086 and 0.0045g NH4+-N gVSS−1 day−1. Laboratory results indicate that both COD and DOC removal are greater than 97.5% (w/w) but the major benefit of using membrane for solid-liquid separation is that the effluent can be decanted through the membrane while aeration is continued during the draw stage. With a continued aeration, the sludge cake layer is prevented from forming thus alleviating the membrane clogging problem in addition to significant nitrification activities observed in the draw stage. With adequate aeration in the oxic stage, the nitrogen removal efficiency exceeding 99% can be achieved with the SBMBR system. Furthermore, the SBMBR system has also been used to study the occurrence of ammonia valley and nitrate knee that can be used for real-time control of the biological process. Under appropriate ammonia loading rates, applicable ammonia valley and nitrate knee are detected. The real-time control of the SBMBR can be performed based on on-line ORP and pH measurements.


1999 ◽  
Vol 39 (9) ◽  
pp. 201-207
Author(s):  
Andreas Cassar ◽  
Hans-Reinhard Verworn

Most of the existing rainfall runoff models for urban drainage systems have been designed for off-line calculations. With a design storm or a historical rain event and the model system the rainfall runoff processes are simulated, the faster the better. Since very recently, hydrodynamic models have been considered to be much too slow for real time applications. However, with the computing power of today - and even more so of tomorrow - very complex and detailed models may be run on-line and in real time. While the algorithms basically remain the same as for off-line simulations, problems concerning timing, data management and inter process communication have to be identified and solved. This paper describes the upgrading of the existing hydrodynamic rainfall runoff model HYSTEM/EXTRAN and the decision finding model INTL for real time performance, their implementation on a network of UNIX stations and the experiences from running them within an urban drainage real time control project. The main focus is not on what the models do but how they are put into action and made to run smoothly embedded in all the processes necessary in operational real time control.


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