Implementation of Precision Force Control for an Electro-Hydraulic Servo Press System

2012 ◽  
Vol 190-191 ◽  
pp. 806-809 ◽  
Author(s):  
Hong Ming Chen ◽  
Chun Sheng Shen ◽  
Ting En Lee
Keyword(s):  
Control System ◽  
Force Control ◽  
Force Sensor ◽  
Hydraulic Cylinder ◽  
Relief Valve ◽  
Servo Valve ◽  
Composite Control ◽  
Servo Press ◽  
Control Scheme ◽  
Hydraulic Servo

Based on the fuzzy method, a PC-based precision force control scheme is proposed for the electro-hydraulic servo press system. The main feature of proposed scheme is to develop a composite control of relief valve and flow servo valve. With the feedback of force sensor, the fuzzy-based control system is realized by LabVIEW for achieving the precision force control of hydraulic cylinder. In the experiments, a practical platform of hydraulic servo press system is used to demonstrate the effectiveness of proposed scheme. The testing results indicate the accurate output responses.

Research on Flow Press Servo-Valve Controlling Electro-Hydraulic Force Control System and Nonlinear Performance Analysis

2011 ◽  
Vol 121-126 ◽  
pp. 4606-4612 ◽  
Author(s):  
Jian Ying Li ◽  
Jun Peng Shao ◽  
Xiao Jing Wang ◽  
Bai Qin ◽  
Yu Jing Qiao
Keyword(s):  
Control System ◽  
Force Control ◽  
System Performance ◽  
Mathematic Model ◽  
Basic Theory ◽  
Servo Valve ◽  
Hydraulic Force ◽  
Force Control System ◽  
Hydraulic Servo ◽  
Simulation And Experiment

The configuration and the work principle of the flow press hydraulic servo-valve was introduced in this paper, based on this and electromagnetic basic theory, the mechanics analysis of every main parts of the flow press hydraulic servo-valve and the liquid basic theory especially the flow continuity equation, the mathematic model of the flow press sever-valve was built, during the process of building the model, the author took into account the load moment brought by the pair of spray nozzles flow force and the load moment brought by the force couples back pole and the fundamental equation of the force moment motor. On the other hand, the author analyzed the influence of the nonlinear factor to system performance, and the nonlinear factor was valve port overlap length disaccord caused by machining error. The mathematic model of the electro-hydraulic force control system controlled by the flow press servo-valve with valve port error was built. The results of simulation and experiment showed that valve port error badly influenced the system performance, and that valve port error was the main reason of the pressure higher than the supply pressure, which is one of the two cylinder cavities. The simulation curve and the experiment curve were accord compared by system simulation and experiment results, so we can know that the mathematic model of the flow press sever-valve and of the electro-hydraulic force control system controlled by the flow press servo-valve is correct.

Design and Integrated Simulation of the Electro-Hydraulic Servo System Based on AMESim and Matlab

2010 ◽  
Vol 44-47 ◽  
pp. 1355-1359 ◽  
Author(s):  
Xiang Xu ◽  
Zhi Xiong Li ◽  
Hong Ling Qin
Keyword(s):  
Control System ◽  
Design Method ◽  
Design Procedure ◽  
Servo System ◽  
Hydraulic Cylinder ◽  
Fast Response ◽  
Simulation Design ◽  
Integrated Simulation ◽  
Hydraulic Servo ◽  
Hydraulic Servo System

Since electro-hydraulic servo system has fast response and highest control accuracy, it has been widely used in industrial application, including aircraft, mining, manufacturing, and agriculture, etc. With the fast development of computer science, it is feasible and available to evaluate the performance of the designed control system via virtual simulation before the practical usage of the system. In order to optimize the design procedure of the electro-hydraulic proportional controller, the co-simulation design method based on AMESim-Matlab is presented for the electro-hydraulic servo system in this paper. High accuracy of the mathematical model of electro-hydraulic servo system was full-fitted by the use of AMESim, and the advantage of high solving precision for large amount of calculation was full played using Matlab. The PID controller was employed to realize the efficient control of the motion of the hydraulic cylinder. The united simulation technique was adopted to verify the good performance of the designed control system. The simulation results suggest that the proposed method is effective for the design of electro-hydraulic servo systems and thus has application importance.

Analysis of an Opto-Pneumatic Control System and Improvement of its Control Performance

1999 ◽  
Vol 11 (4) ◽  
pp. 251-257 ◽  
Author(s):  
Tetsuya Akagi ◽  
◽  
Shujiro Dohta ◽  
Hisashi Matsushita ◽  
Keyword(s):  
Control System ◽  
Position Control ◽  
Sliding Mode ◽  
Pneumatic Cylinder ◽  
Control Performance ◽  
Pneumatic Control ◽  
Servo Valve ◽  
Proposed Model ◽  
Control Scheme

This paper describes an analysis of an opto-pneumatic control system and an improvement of control performance of the system. The opto-pneumatic system consists of an optical servo valve, a pneumatic cylinder and a cart. First, we built an analytical model of the system considering a nonlinear friction where exists in sliding parts. And we confirmed the validity of the proposed model by comparing theoretical results with experimental results of the characteristics of optical servo valve and cart position control. Then, we applied a sliding mode control scheme compensating a steady-state disturbance to multi- position control and follow-up control of a cart. By computer simulation, we confirmed that the control performance of opto-pneumatic control system was improved by using this control scheme.

Study Control System Based on Creep Test in High Density Baler

2010 ◽  
Vol 139-141 ◽  
pp. 1624-1627
Author(s):  
Wei Lee ◽  
Chun Guang Wang
Keyword(s):  
Control System ◽  
Data Acquisition ◽  
Creep Test ◽  
Hydraulic System ◽  
Electrical Contact ◽  
Hydraulic Cylinder ◽  
High Density ◽  
Hydraulic Control ◽  
Creep Tests ◽  
Relief Valve

Hydraulic transmission system controls hydraulic cylinder forward and backward movement freely, in order to achieve high density hydraulic baler work circulation. Creep test required hydraulic system to output constant stress, and study creep tests can not be completed when used succeeding the electrical contact style in the past time. The system used programmable logic controller (PLC) to instead of succeeding the electrical contact style and realized freely forward and backward movement of hydraulic cylinder, electro-hydraulic proportional relief valve can adjust hydraulic system and make it stepless pressure regulation and then degree of automation and reliability in hydraulic control system to be improved. This paper introduces aspects: including the selection, hardware configuration and program of PLC, meanwhile, giving specific realization method. Through the control system to study creep test in hydraulic baler, adopting the National Instrument (NI) company's multi-channel data acquisition card, which type is USB-6251,applying Labview8.2 to write data acquisition program on my own, the versatility and flexibility of system was verified, which was able to complete creep test successfully.

Application of Full-Digital Servo Valve in Auto-Discharge Control System for the Jig

2012 ◽  
Vol 542-543 ◽  
pp. 555-558
Author(s):  
Qing Mei Jia ◽  
Jun Jun Tai ◽  
Bin Xu
Keyword(s):  
Control System ◽  
Product Quality ◽  
Hydraulic Cylinder ◽  
Servo Valve ◽  
The Stability ◽  
Ensure Product Quality

In this paper, a full-digital Servo valve is built base on actual requirement of auto-discharge control system for the jig. Then the structure of full-digital Servo valve was introduced. Hydraulic cylinder was driven by the digital servo amplifier, to control the opening gate in auto-discharge control system for the jig. This jig can be maintained the stability of the bed chamber, to ensure product quality.

Suppression of Micro Stick-Slip Vibrations in Hydraulic Servo-System

1998 ◽  
Vol 122 (2) ◽  
pp. 249-256 ◽  
Author(s):  
Toshiyuki Hayase ◽  
Satoru Hayashi ◽  
Kazunori Kojima ◽  
Ikuro Iimura
Keyword(s):  
Feedback Linearization ◽  
Servo System ◽  
Hydraulic Cylinder ◽  
Feedback Gain ◽  
Stick Slip ◽  
Servo Valve ◽  
Wide Range ◽  
Order Of Magnitude ◽  
Hydraulic Servo ◽  
Hydraulic Servo System

This paper deals with suppression of two kinds of micro stick-slip vibrations occurring in a typical computer-controlled hydraulic servo-system. The relevant system consists of a single-rod hydraulic cylinder, an electrohydraulic servo-valve and a personal computer. The discontinuous control signal from a D/A converter causes a stick-slip vibration of micron order of magnitude over a wide range of the feedback gain. Increasing the feedback gain results in the other stick-slip vibration of nearly ten times larger amplitude due to the nonlinear pressure-flow characteristic of the servo-valve. The numerical simulation revealed the latter micro stick-slip vibration could be efficiently suppressed with the feedback linearization technique to compensate the nonlinearity of the servo-valve, while the former one reduced by improving the resolution of the D/A converter. Validities of both the methods were also confirmed with experiment. [S0022-0434(00)00102-7]

scholarly journals Research on the position–pressure cooperative control strategy for full-hydraulic leveler

2018 ◽  
Vol 10 (12) ◽  
pp. 168781401881739
Author(s):  
Dongping He ◽  
Tao Wang ◽  
Jun Wang ◽  
Zhongkai Ren ◽  
Xiangyu Gao
Keyword(s):  
Control Strategy ◽  
Cooperative Control ◽  
High Speed ◽  
Servo System ◽  
Hydraulic Cylinder ◽  
Relief Valve ◽  
Working Pressure ◽  
Pressure Signal ◽  
Hydraulic Servo ◽  
Hydraulic Servo System

The characteristics of electro-hydraulic servo system of full-hydraulic leveler are high speed, large inertia, high frequency response, and multi-degree of freedom. In order to improve the degree of automation of full-hydraulic leveler and achieve the simultaneous control between position and pressure, the position–pressure cooperative control strategy is presented in the article. In the working process, the dynamic working pressure signal of the hydraulic cylinder is turned into a real-time position signal by the pressure–position conversion gain and then compensates the converted signal into the position closed loop. Meanwhile, the pressure signal of the rear cavity of the hydraulic cylinder is fed back to the input of the proportional relief valve at the pump source, and then the system work pressure changes quickly according to the different thickness. In this article, the mathematical model of position–pressure cooperative control of hydraulic straightening machine is established. The simulation results in AMESim software verify the correctness of the control strategy. Finally, the feasibility and practicability of the control strategy are verified by the field prototype of 11-roller full-hydraulic leveler. The control strategy provides the theoretical basis for designing the electro-hydraulic servo system.

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