Electronic Material Testing Machine Closed Loop Control System Research

As the polymer materials are limited in a small stress loading scope and complicated objects, the project builds a miniature electrical testing machine, including the design of the mechanical structure, the set-up of the controlling system, the implement of the measurement scheme and the programming of the upper computer software. It controls the loading of the testing machine mainly from three aspects:displacement control, speed control and material stress control. Among the three aspects, the paper mainly focuses on the study of the stress loading control of the testing machine system, and it adopts the fuzzy adaptive PID control algorithm and makes contrastive analysis with that of conventional PID control and of integral apart PID control based on simulation and experimental study.Firstly, the paper studies and explores the basic operating principles and the organization of the controlling system of the electrical testing machine and works out the final design proposal of the testing machine structure and controlling system based on various comparisons with other plans.Secondly, according to the controlling proposal of the testing machine and analysis of the operating principles of the stepper motor and the driver, it determines the measurement scheme of medium force, deformation and displacement and provides the mathematical models of each part of the system.Thirdly, in stress loading control, as emphasis, the project puts forward the two-dimensional fuzzy adaptive PID controlling strategy and provides detailed analysis on the controller’s design.Finally, it builds a simulation model of the stress loading control of the testing machine system based on MATLAB/Simulink simulation software and the dynamic responding performances with different control algorithms are contrastively analyzed by experiments and simulations which presents the superiority and stability of the fuzzy adaptive PID the project adopts.