Based On The Extension Control Strategy For Testing And Materials Electrohydraulic Proportional Control System

Based on studies on current developments of the material testing machine control system, a new project about electro-hydraulic proportional control system for material testing machine based on extension control strategy is proposed. After a lot of creative projective basic and systematic study on control system of material testing machine, many important conclusions have been drawn.In order to solve the problems that large energy consumption, temperature variation, high, cost trouble maintenance in current electro-hydraulic servo control system for material testing machine, a new design scheme that electro-hydraulic proportional control system for material testing machine based on extension control strategy is proposed. The design scheme is successful by means of designing new main frame system, hydraulic cylinder system, digital electro-hydraulic micro-fluid proportional valve and electrical control system, and its results lay a foundation for material testing machine industries in our country.In order to solve the problems of low accuracy and stability in domestic material testing machine and complicate structure, high cost and trouble maintenance in foreign material testing machine, a high quality and low cost digital measure and control system for material testing machine based on ISA bus has been presented in this thesis and its performance indexes have been achieved and overachieved comparing with foreign advanced products, and it is important for the development of material testing machine industries in our country.As the variable stiffness of testing specimen affects load stiffness, the theoretical analysis and simulation study of the effect of variable load stiffness on the system are done. The degree and tendency of the effect of variable load stiffness on the control quality and accuracy are given, furthermore, a new extension control algorithm for material testing machine is presented in this thesis. By these algorithm, the problem existed and confused in testing machine engineering in a long term can be solved completely.In order to solve the problems of narrow application range and unwieldy control mode in current material testing machine, a set of control modes and constraint conditions fitting whole material testing machine industries have been proposed for the first time, furthermore, a new software CARIES, which shows new design method for material testing machine, has been developed, and it submits reference for the automatic control system design of material testing machine industries.A new method with high accuracy and wide application solving the dynamic characteristic of measurement system based on graph bank is proposed for the first time and it is suitable for automatic solving dynamic characteristic various system with computer.The thesis includes eight chapters.Chapter 1 is a survey. The current development of material testing machine is expounded. The basic component and application of material testing machine are introduced. Main characteristics and several typical design schemes of material testing machine are analyzed. In the last part of the chapter, the research method of the overall thesis is proposed.In chapter 2,the overall design scheme of electro-hydraulic proportional controlsystem of material testing machine is introduced. Main frame system, hydraulic control system and electronic controller design method are presented in detail.In chapter 3,the precious mathematics model about electro-hydraulic proportional control system of material testing machine is proposed. The digital simulation and theoretical analysis of load control system, position control system and extension control system are discussed according to various load type.In chapter 4, the CAPIES of material testing machine is introduced. The organization and realization method of CAPIES software system are presented in detail.In chapter 5, the design principle of extension control is introduced, and the extension control algorithm of electro-hydraulic proportional control sys...