Reasearch On An Electro-Hydraulic Proportional Control System For Fast Capture

Catching a fast moving object is one of difficult tasks in control field. Eventhough a human is well trained, he or she cannot guarantee to be able to catch afast moving object every time. It is difficult for mechanical system as well.Successful capture demands interception in minimum time before targetmanoeuvre, tracking moving object, catching moving object in an instant, andbringing moving object to rest without damage.Based on the unique advantage of hydraulic cylinder in fast position control,a linear capture system which takes a hydraulic cylinder driven byelectro-hydraulic proportional directional valve as actuator is designed in thisthesis. This approach expands the application field of hydraulic technology intocapture system and overcome low-speed shortcoming of robotic capture systembased on mechanical transmission. Furthermore, through theoretical andexperimental analysis, it’s studied that tracking methods for random trajectoryand control strategies for servo hydraulic system.This thesis focuses on the proposed electro-hydraulic proportional controlsystem for fast capture. Firstly, the test rig model is constructed with Solidworks,and the target movement design is also completed. Secondly, to finish the designof hydraulic system circuit and control system, the appropriate high-speedhydraulic cylinder and electro-hydraulic proportional directional valve areselected respectively according to design object of fast capture system; inaddition, all of control functions are realized by xPC through hardware in loopsimulation. Thirdly，according to the system model, component-level modeling and simulation has been conducted by AMESim simulation, system-levelmodeling and simulation has been conducted by AMESim and Simulinkco-simulation. And both capture strategy based on Kalman filter estimation andcapture strategy based on adaptive fuzzy PID control have been proposed.Finally, these two strategies are verified through experiments and both areanalyzed.By experiments carried on fast capture system, it can be proved thathydraulic cylinder driven by electro-hydraulic proportional directional valveused in fast capture system is feasible. Meanwhile, for trajectory estimation andtracking problems in target tracking, Kalman filter estimation and adaptive fuzzyPID control have been proposed, and both have good performance. And thestudy is meaningful for hydraulic technology application in fast capture systemon theory study and practice.