Research Of Electro-hydraulic Position Servo System Of The Large Hydraulic Cylinder Assembling Equipment

With the development of science technology and mechanical industry, hydraulic cylinder as important machinery parts, is enhanced in product quantity and product quality. So its traditional assembly methods and assembly equipments can not be satisfied with the market demand requirement. Especially the largely hydraulic cylinder assembling equipment. In the assembling process of hydraulic cylinders, the focal point and difficult point to ensure the seal capability and boost the productivity is to seek the centre line of the cylinder barrel and the modular piston rod raPIDly.To resolve the concentric problem, according as assembling demands of the hydraulic cylinder, new specialized assembling equipment is investigated in electro-hydraulic servo valve. It adopts the self-centering and clamping organization, which hydraulic motor driving a combination of one gear and two racks to make two V-shaped slides centered synchronously to ensure seeking the centre line of the cylinder barrel and the modular piston rod raPIDly at the Y direction. On the other hand, electro-hydraulic position feedback servo systems is designed, which math model is built and predigested, using PID control to adjust the precise place of the controlled cylinder barrel and the modular piston rod at the Z direction. Gain a simplified formula through mathematical fitting tools and keep the error in allowed limits.For characters of the system such as lime-variable, nonlinear and no accurate math model, the electro-hydraulic position servo control systems are studied on the electro-hydraulic servo valve and the hydraulic cylinder as the driving device, which is the controlled object. The model reference self-adapting PID controller. Then, the systems are simulated and analyzed with various damping ratios and disturbances through Matlab7.0, proving the self-adapting PID controllers are best in robustness, dynamic characteristics and static characteristics. At last, through simulation analysis proving the self-adapting PID controllers is best. The using needs of the assembling equipment of hydraulic cylinder, and provides credibility for the model machine manufacture. The research on the specialized assembling equipment of hydraulic cylinder and the electro-hydraulic servo control systems has practical meaning and theoretic value, resolving the bottle-neck problem that restricts the hydraulic cylinder’s product. Inducing the factories can enhance the quality of product and the productivity, reduce the fault ratio and the after-service charge, debase work-labor intension, and increase the product competition in its own profession.