A Servo Control System Of A Shock Simulation Experiment Platform

Shock Simulation Experiment testing machine is widely used for testing product life, testing fatigue wear, precision analysis and so on. A servo control system of a shock simulation experiment platform is introduced in this paper. Servo system based on Modbus has obvious superiorities in applicability scope, in expansibility, in maintainability and in anti-malfunction ability.This servo control system uses FPGA as its main control chip, and it also consists of other main hardware devices such as 12-bit ADC which used for acquiring signals from the sensors, 12-bit DAC which used for outputting control signals to the hydroelectric servo, RS-485 interface chip which used for communicating with upper computer, E~2PROM based on I~2C interface which used for storing data after power down and so on.In the FPGA, there are mainly 3 modules. Modbus fieldbus protocol module applied to communication with upper computer. Direct Digital Synthesizer(DDS) module based on Cordic algorithm can generates many kinds of waveforms. PID controller module implements full digital PID control and adjustment.This servo control system can receive instructions and data from upper computer, acquire signals from the sensors, and control the hydroelectric servo. Test results show that the design meets the requirement of the shock simulation experiment platform environment, and has certain value to popularize in other kinds of application.