Study On Drag Torque Tester And Control Method For Its Pneumatic Hydraulic Servo System

The brake is the main safety of car, its quality is directly effect the safe of driver and passerby. So with the development of auto industry, the requirements of brake performance tester is more strict.The article is based on disc brake drag torque tester reconstruction project of Jilin university Elec.-mech. Institute, on based of the analysis of the detection principle and test requirement of the disc brake drag torque, and aiming at the various problems of the drag torque tester and the requirements of test informatization and automation, redesigned the hardware and software of control system, reduce the production cost, improve the security and stability of tester, and have achieved good economic results.This machine has improved the speed control system, adopting mature AC servo control technology instead of the original manual frequency control system, the computer control the speed through the servo motor movement control card, and develops the corresponding control software, improves the shortcomings of speed can not automatically control and low accuracy, satisfy the test requirements.According to high cost, low stability of the original hydraulic pressure loading system, the article combining industrial pneumatic control technology and hydraulic servo technology, has developed a set of pneumatic hydraulic servo system. According to the character of strong nonlinear and hysteretic nature of pneumatic system , The article Focuses on fuzzy PID control method based on the analysis of the conventional PID control, and design a kind of fuzzy PID controller for pneumatic hydraulic servo device in the closed-loop control and also test in actual running. From the experiment results, the system can not only meet the requirement in the test, and also can promote on other automobile brake tester and production, it have broad application prospects and good economic benefit.