The Research On Control Methods Of Small Stable Platform For Vehicles

Small-size stable platforms have a broad prospect, but small stable platform with low-cost relatively has little research. In the dissertation, a small stable platform with two two-axis frame structure has been developed. And structural design and selection of key components (such as:servo drive system, inertial measuring instrument) are described. A digital servo motor controller with CAN bus and RS232 has been developed. The system can share real-time data through CAN bus and RS232 communication network. The mathematical model of servo motor drive system is derived. The characteristics of the servo motor with current loop, velocity loop, and position loop were tested. The servo motor controlled by PID controller with three loops has been studied by the simulation and experiments. The special vector model between the stable platform attitude and two motor driver systems have been established. The feedback control algorithm is employed to decouple 2 degrees of freedom. The experiments show the decoupling algorithm validity. In order to deal with time-varying parameters of the servo motor drive system, the QFT controller design has been completed, including:plant model generation, constraint condition establishment, loop shaping and pre-filter design. The simulation results show that the QFT controller has a suppressive effect on time-varying parameters. To overcome internal parameter variability and external parameter disturbances effects on the servo motor control system, the optimal sliding mode variable structure control algorithm with fuzzy proportional approaching rate is studied. And simulation and experimental results show the rapid response ability of the motor drive system was improved, and the effects of the nonlinearity, hysteresis on the control system are restricted. An experimental research platform has been developed. The experimental study of the algorithms has been performed. And experiments show the algorithms validity.