Research On Stabilization And Tracking System In Electro-optical Tracking And Pointing Platform

Electro-optical tracking platform as a key part of inertial navigation andguidance system, the stability and control precision have great effect on the holeprecise guidance system.So,research on electro-optical tracking-pointing platformcontrol system has important practical significance and theoretical guidance.The workenvironment of platform is complex and serious disruption, Between the ring frameexist strong coupling relationship, electro-optical sensor and video tracker give rise tothe large delay can also cause a lot of dynamic error and reduce the stability of thesystem. So, to improve the control performance of electro-optical tracking-pointingplatform need to research from robustness of the stability control, anti-interferencecapability and tracking precision and so on.First, on the basis of the analysis of the three-axis gimbal electro-opticalctracking-pointing platform in working principle and structure, regardless of couplingbetween the ring frame, according to each part of the machinery, force and circuitequation, set up corresponding transfer of each part, then get the mathematical modelof the ring frame.PID controller is designed in stabilizing loop, simulation results show that thesystem control effect is better, overshoot quantity becomes small, but stability andanti-interference ability are poor. Using variable structure control of proportionstrategy, inferring the existence condition of the synovial membrane, choosingappropriate parameters, and designing the reaching law(u (x1x2)sgn(s)) ofsynovial variable structure controller. Variable structure controller in combination withPID control is used to control the stabilizing loop of the platform framework.Simulation results show that the steady-state error of platform framework withproportion variable structure PID control decreases, and has a higher steady-stateprecision and response speed, the control performance improves obviously than PID control.Put the ideas of variable universe in the theory of fuzzy PID controller, selectreasonable flexible factors, respectively design the variable universe fuzzy PIDtracking controller of the three rings. Simulation results show that the system anti-interference ability strengthen, in comparison with the fuzzy PID control, the timeentering into the steady state becomes short, overshoot quantity becomes small and thecontrol performance get some advance. With the Smith estimates joining in trackingloop to compensate the pure lag caused by photoelectric sensor and video tracker.Studies show that Smith forecasting device can compensate the system delayeffectively, and reduce the system overshoot quantity and adjusting time.Above all, Using the proportion variable structure PID control in stabilizing loop,and variable universe fuzzy PID controller in tracking loop, at the same time, blendingin Smith estimated compensation system delay, a satisfying control effect ofphotoelectric tracking and pointing platform is achieved.