Design And Research Of Control System Of The Paper Tensile Strength Tester

Paper as the important carrier of information culture has become an integral part of human supplies. With the rapid development of industrial technology, people on the increasing demand for paper and the quality requirements of the paper has also improved. In order to ensure the parameters of paper meet the requirements of national standards, it needs to test the production of paper. Domestic tensile testing machine used machinery primarily in measurement methods, testing accuracy is not high and the operation is so complicated that cannot satisfy the requirement of modern. In view of the above the weaknesses of the testing machine, this paper adopts the modern servo drive technology and designs a kind of high precision of paper portable tensile testing machine, it has high precision and simple operation and real-time processing capability characteristics.Paper tensile testing machine’s hardware structure is mainly composed of force sensor, micro processor, a high precision AD converter, keyboard, nixie tube display, dc servo motors and drives, power supply, etc. This machine use ATMEGA16chip as the core of the system control, A chip is used to receive the collect tension value of AD converter,and displaying, printing and accepting the keyboard preinstall function, and the other one regulate PWM duty cycle to control the motor speed; We used to take the high precision converter ADS1211what have self-revised Σ-Δ modulator as the AD converter; We use the national semiconductor company produces what have interior has electric current detection function of LMD18200as Dc servo motor driving device.According to 《the paper and cardboard tensile testing machine》、《the tensile strength mensuration of Paper and board)) and 《the constant speed stretching method》, paper tensile testing machine in measuring tension process must be constant speed, but as the tensile testing paper test, the force on chuck is changed by the minute. This led to drag motor load torque is constantly change and the motor load torque increase gradually, when it will reach a maximum and diminishes quickly to zero. In addition, motor tensile load torque of the different material paper are also different. This is put forward higher requirement to control strategyt of the speed control system. First we are compared the conventional PID with the fuzzy control of intelligent algorithm, and analyze the advantages and disadvantages of each. And then, based on the tensile testing machine with degeneration of load factor,we put forward the fuzzy control and the conventional PID control combination, namely fuzzy PID control algorithm. Through the Matlab software we make the simulation of dc speed control system, and compare with the former two algorithm, fuzzy PID control algorithm has a fast response system, small overshoots, and also does not rely on the controlled object mathematical, for the time-varying system has good control effect and robustness.