Modeling, Simulation And Control Study Of The Hydraulic System For The Double Gantry Lifter.

The car lifter is one of the most important and fundamental instruments in the auto-repairing industry. Lifting a car from a certain height to another is an indispensable procedure, so important that the lifter's normal operation not only determines the safety factor f the subject vehicle and workman, but also the prosperity of the auto-repairing industry.The double gantry hydraulic lifter is of several advantages, such as higher loading adaptive capacities, and easy maintenance, which suits repair requirements for different car types. With the development of the auto industry, the auto repairing equipments have also been improved to a new step.As to the double gantry hydraulic lifter, analyzing its hydraulic system, design method and application is of great significance to improving its working quality and economical properties technically.So it is necessary to study kinetics and dynamics for that machine, which offers great help for its successive development.According to the lifter's characteristics and tendency nowadays, based on the existing equipment, its hydraulic system is improved, and its dynamical mathematical model is brought out. Further, its static and dynamical properties are analyzed. Specific details are as follows,1. The hydraulic system is designed. The hydraulic circuit is confirmed, the control strategy is selected, and the pressure, flux are calculated respectively.2. The static characteristics of all the hydraulic engines, pumps and valves have been analyzed, including such main parameters as pressure, flux and their interactive relations.3. The vibration mechanism has been analyzed carefully during the ascending and descending processes. Its mathematical model is created and the solution is brought out.4. Based on the Power Band Graph method used in hydraulic modeling, the mathematical model is created, followed by converting into its dynamical model. The model is incorporated into the software Matlab and the simulator Simulink, which inverts the model into the simulation program, building up the simulation model for the hydraulic system.5. The double pumps'synchronous problem is worked out by adopting piston type cylinder and others.6. The PLC control method and implementation are adopted based on analyzing the relay system of the former equipment, as well as the typical control theories of that kind.