Study On The Fuzzy Sliding Mode Control Of The Hydraulic Driving Unit Of Quadruped Robot

With the progress and development of the Leg Robot Control Technology andComputer Technology, Quadruped Robot has a good application prospect in emergencerescue, military reconnaissance, adventure and entertainment, etc. So the research ofQuadruped Robot has attracted much attention of domestic and international researchers.In recent years, Quadruped Robot has been brought into National High TechnologyResearch and Development Program (namely863Program) in our country,which aims tobreak through the core technology of bionic mechanism, high power density hydraulicdrive, state of perception and environmental adaptation, bionic gait planning, etc, and topromote the development of the intelligent robot technology in China.This paper mainly studies the control strategy of the electro-hydraulic position servosystem of Quadruped Robot hydraulic drive unit. Compared with the traditional servomotor drive of Quadruped Robot, the hydraulic drive has smaller volume and largercarrying capacity, faster response, higher precision, but there are also the disadvantages ofnon-linearity and parameter uncertainty. According to the characteristics of QuadrupedRobot hydraulic drive unit, this paper proposes a control strategy which combines theSliding Mode Control based on the Exponential Approach Law and Fuzzy Control.Mechanism modeling method and system identification method are combined toestablish the accurate mathematical model of the Quadruped Robot hydraulic drive unit,which makes the simulation research more practical guiding significance.Based on thetheoretical analysis of the Sliding Mode Control and Fuzzy Control, first the mathematicalmodel of the hydraulic drive unit, PID controller and Sliding Mode Controller have beenbuilt by MATLAB/Simulink software to do the simulation analysis on the robustness ofthe PID control and Sliding Mode Control and the effect of the Exponential Approach Lawparameters to Sliding Mode Control properties. Then Fuzzy Sliding Mode Controller hasbeen set up further to do simulation analysis and the system response performance hasbeen significantly improved.The experiment system of Quadruped Robot hydraulic drive unit is built in thelaboratory to do experiment research, which includes electro-hydraulic position servo system and loading system of the hydraulic drive unit. At the same loading conditions, theeffect of Exponential Approach Law parameters to Sliding Mode Control properties hasbeen analyzed by experiment research and the experiment proves that the Fuzzy SlidingMode Control can improve the steady precision and dynamic quality of the system.