Development And Research On Testing Press Machine

Testing press machine is used to test the stress and strain of the pressure, its key technology is double cylinder synchronous control. The accuracy of the synchronization impairs the accuracy of detection directly, and affects further quality and safety of the product. This thesis designs100T press machine, and mainly researches and develops the technology of synchronous control, control algorithm, the control system of PC.Firstly, the paper introduces the working process of testing press machine, and then introduces the present situation and the development trend of research on synchronization techniques at home and abroad. Then according to the working need of testing press machine, the paper designs the hydraulic system of100T testing press machine based on proportional directional valve, and analyzes the working process and order of execution of hydraulic system, then designs the electrical schematic diagram, and calculates detailedly the size, flow and pressure of the main hydraulic system components, and selects the electrical and hydraulic components. In order to demonstrate the feasibility of practice, the paper establishes a mathematical model of spool movement on proportional directional valve and mathematical model of proportional directional valve controlling asymmetric cylinder, and obtains the transfer function of position control system. By establishing the simulation of the position control and analyzing bode map, it shows that the system is stable and feasible, which provides an important theoretical basis for the development and research of testing press machine.Secondly, the paper discusses mainly that the incremental PID controller and the fuzzy adaptive PID controller about the hydraulic system, simulates and compares this two controllers using the fuzzy control toolbox and simulink toolbox of MATLAB. The simulation results show that the fuzzy adaptive PID controller is superior to the incremental PID controller.Finally, the TT&C software achieving the normal communication between PC and PLC is developed basing on LabVIEW and Modbus communication protocol. And corresponding control algorithm is written to the TT&C software by the method of mixed programming. Lastly it is applied to testing press machine. The debugging result curves indicate that the control has the characteristics of strong stability and high precision. It can meet the client’s requirements on the performance of the testing press machine, meanwhile it validates the correctness of the simulation and the feasibility of the design of hydraulic system and TT&C software.The paper combines mechanical, hydraulic, electrical, control, software and other disciplines. It completes the development and research of testing press machine. And the testing press machine has been handed over to the customer. To sum up, the research has strong theoretical and practical value.