Development Of A Controller For Electro-Hydraulic Servo Test Bench Based On Ethernet Communication

Controller is the core part in the electro-hydraulic servo control system. It isalso the key to run an algorithm and has a far reaching influence on response speedand precision. Traditional controller with communication mode of serial or field bushas a low rate, it’s hard to meet the trend of high speeding. To solve this problem,this paper takes the Electro-hydraulic servo test bench which is in mechanical-electric-hydraulic integration institute of technology and products in HarbinUniversity of Science and Technology as the control target, a controller for theelectro-hydraulic servo test bench based on Ethernet communication is developed. Itcan achieve closed-loop control of displacement and faster communication with hostcomputer. According to the functional requirement of controller for the electro-hydraulic servo test bench, the thesis provides total design proposal includinghardware, software and control algorithm.In view of hardware requirements, the controller is divided into signalacquisition module, servo valve driving module and Ethernet communication module.Floating point DSP as the core processor, power and clock circuit of DSP, A/Dacquisition circuit, D/A switching circuit, V/I switching circuit and Ethernetcommunication circuit are designed. The thesis develops main program and hardwaredriver of A/D, D/A and Ethernet with C language in CCS, the developmentenvironment of DSP. Fuzzy-PID compound controller based on fuzzy rule switchingis designed. Within the scope of small deviation PID control is carried out to ensuresteady state in the system. On the contrary, fuzzy control works to adjust the systemoscillations in a wide range of deviation.Each module of the designed controller will be verified through someexperiments, to prove the controller can realize the corresponding functions. The stepresponse of electro-hydraulic servo test bench under control of Fuzzy-PID is compared with PID and Fuzzy.Experiment results show that Fuzzy-PID compound controller based on fuzzyrules switching has the better performance. The controller for electro-hydraulic servotest bench based on Ethernet has important engineering application value to improvecommunication rate and control performance of electro-hydraulic servo system.