Electro-hydraulic Tension Control System

Tension control is a very important part of process control in many industrial applications, and plays an important role in improving product quality ^ enhancing system control security and etc. In this paper, electro-hydraulic proportional control methods are applied to control the export tension of the hydraulic motor and also the related winding machine by modulating the pressure difference between the inlet and outlet of the hydraulic motor, and the control methods are proven feasible. System instability caused by damp ratio of the control system can be resolved by adding mechanical damper or compensating through PID control segment. Theoretical analysis and experimental results are presented on system structure and control principles of the cable tension control system and the jigger tension control system, mathematic module is built up and corresponding simulation by MATLAB is executed, the simulation results aid to decide the structural parameters. The experiment results show that the mathematic module can reflect the dynamic process of the tension control, and the system is stable and reliable. So the theoretical analysis and the experiment conclusions in this paper can be practical and directive to the design and research of the later electro-hydraulic proportional/servo control system. Details are as follows:The first chapter introduces the applied areas of the tension control, the main methods applied presently, the electro-hydraulic proportional control technology anr subjects of the thesis.The second chapter discusses the structure and principles of the system. First pan discusses cable tension control system, begins with system structure and principle: i" whole, and then its constitutes includes hydraulic system and microprocessor control system. Second part discusses jigger tension control system, mainly on its working principles and system structures. Finally the main factors which affects tension centre 1 are discussed.The third chapter analyzes the detect segment. Detect segments of the two sysien^ are both studied. First build up the mathematic module of the able tension control system, analyze its static and dynamic response, testify its stability :md veracity. Second study the detect segment of the jigger tension control system. Finally compare between the two segments are presented.The fourth chapter introduces the simulation and experiments analysis. First study cable tension control system, begins with analysis on its physical environments and the a mathematic module are built up, accordingly static and dynamic response with MATLAB tool is executed to improve system stability and control precision. Fieldworks are performed to solve the demarcation, resort emendation, advanced PID control algorithm and signal interference. Second build up the mathematic module of the jigger tension control system, analyze its control type and emendation methods, perform experiments and draw some conclusions.The fifth chapter gives a brief summarize on electro-hydraulic tension control system and a expectation on future work.