Precise Control Of Turntable With Backlash

Turntable is widely used in aeronautics, astronautics and electronics communication as equippment for simulation and testing, whose function and performance is of great importance for industry and national defence.Backlash nonlinearity exists widely in turntable with large torque, which has great influence on the dynamic and static properties of turntanble. Due to the non-differentiable characteristics of backlash, the realization of compensation is very difficult. This brings great challenge to the design and realization of turntable system of good performance and high realibality. In this dissertation, the backlash nonlinearity in turntable system is studied and some control approach is brought forward.Firstly, this paper has analyzed the different influence to the servo system due to the different position of the backlash of the driving device, and related mechanical measures for reducing and releasing the backlash have been set forth.Then, based on drive system including dual sub-systems with pre-loaded torque bias, the paper presents study on backlash nonlinearity still existing in system. The kinetic model of dual-motor driving system is constructed via analyzing of its principles and anti-backlash schemes. By selecting control Lyapunov function through Backstepping approach, a state feedback scheme is developed to completely eliminate the influence of backlash in system. Then, an adaptive control scheme for backlash nonlinearity in such system with unknown parameters is proposed in the same way. Study and simulation show that the scheme can effectively keep tracking to the reference input while ensure the stability of overall system.Finally, the realization of an antenna test turntable control system is described, the design and development processes of the system control module and the servo module are clearly explained, some key technologies of them are depicted on hardware and software.