| The feed support system of the 500-meters-diameter-radio-telescope adopts flexible instead of connecting rod drive. This makes it have the advantages of parallel structure and flexible drive. It has a high accuracy and load capability and can work in a larger space. Coupling effects exist between the six soft cable, its weight can not be ignored, at the same the time large-scale traction movement is vulnerable to the interference of wind load and the outside environment. Therefore, from control perspective, the feed supporting system is a multi-variable, time-varying, nonlinear and coupling dynamic systems with complex. Dynamic characteristics and control method of the control strategy are studied.For the feed support system, first, analyze its mathematical model, the six flexible catenary model is simplified as straight line.Analysis the feed support system by Lagrange equation to the second class. Simulate then the mathematical model by MATLAB software to verify the rationality of the model.For the feed support system characteristics such as strong coupling,time-varying, multivariable, and vulnerable to the influence of outside environment such as wind load disturbance. Base on the decentralized control strategy to realize the trajectory tracking control of feed tank.At the same time, put forward nonlinear adaptive interaction PID control strategy to achieve precise control of feed support system trajectory tracking.The control strategy bases on the traditional PID control algorithm,and combines with the adaptive interaction theory to form the adaptive interaction PID control strategy, which can control three parameters of PID based on the system error automatically. At the same time, combine with nonlinear PID control algorithm to alleviate system between static performance and dynamic performance and the contradiction between the stability and control performance.By writing and running the MATLAB, it is concluded that under the same interference sequence, compared with the traditional PID control algorithm, in the use of nonlinear adaptive interaction PID control algorithm, the maximum error is 23% of the former.In 3 m model test, the AB axis intersection point position error of themaximum average is 36.1% of the former, the response time is 65.5% of the former.So the nonlinear adaptive interaction PID control algorithm has faster response speed,smaller overshoot, higher robust performance, more suitable for the tracking control of feed support system.At the same time, the nonlinear adaptive interaction PID control algorithm can also be used for similar flexible drive system. |
