Researches On Application And Frequency Response Characteristics Of The Generalization Pulse Code Modulation Hydraulic Control

The generalization pulse code modulation (GPCM) hydraulic servo control is the way using the common on/off valves used as control components ,with characteristics such as low cost, high anti-polluted ability and others. It is used for hydraulic servoing and controlling situations that the controlling precision is not too high, but the working environment is bad. This study was the continue research of NSFC founded project. In this thesis, it deeply researched the frequency response characteristics of GPCM by using methods of mathematical modeling, computer simulating and experimental researching. In the experimentation, it used the GPCM hydraulic position servo controlling system to control multi-joint series robot and got satisfied results.In chapter one, it introduced the developing tendency of hydraulic controlling technology and hydraulic components, the electro-hydraulic digital technology, hydraulic modulation and methods, digital valve research and classification, and controlling system of multi-joint series robot. At last, it represented the research purpose of this research thesis.In chapter two, it described the pulse code modulating principle, pulse code modulation controlling hydraulic system methods, and GPCM hydraulic servoing controlling theorem. From analyzing results, it acquired that could efficiently increasing the output flow of PCM controlling valve by adopting GPCM modulation under the same bit of PCM controlling valve and the same minimum controlling flow of PCM controlling valve. It deeply introduced the structure and working principle of the GPCM controlling valve.In chapter three, it deeply analyzed the electromagnet, on/off throttle valve, reversing valve, and GPCM controlling valve, set up their mathematical models, and deduced out the transfer functions.In chapter four, according to the high non-linear characteristics of GPCM controlling valve, it set up the controlling simulating models of GPCM valve and GPCM hydraulic servoing valve, then analyzed their frequency response characteristics by adopting the AMESim and MATLAB/Simulink software. In simulating analysis, it input the step signal wave and scanning sine signal wave, the results proved that the frequency response of GPCM valve and GPCM hydraulic servoing valve were effected by coding methods, throttling units, frequency characteristics of valves, and others.In chapter five, it built a position servoing system with the GPCM controlling valve and hydraulic piston, then applied the system into a multi-joint series oil-paint spraying robot. Using the Simulink, RTW, XPC, and other toolbox of MATLAB software, it set up a real-time controlling experimental system based on the XPC target. Using the fuzzy-PID controlling policy, it realized the track control of the robot, ad acquired better track control effictiveness.At last, the author summarized the thesis and proposed the continue researches in the future.