Multi-motor Synchronous System Control Based On Adaptive Backstepping Controller And Sliding Mode Observer

Multi-motor drive systems have been widely used in industrial production and automation equipments. It has significant meaning in high performance field like:production, quality, efficiency, reliability. Currently, most synchronous equipments use PID control strategy, PID control strategy is easy to apply but has the poor robustness. With the problems described above, this thesis designed the adaptive backstepping controller on a three-motor variable frequency system.On the basis of mathematical model of three-motor synchronous system, a adaptive backstepping controller is designed. And a adaptive backstepping controller together with a tension observer based on sliding mode theory is proposed to control three-motor synchronous system. The sliding mode surface of the observer is composed of actual velocity and observed velocity, with the switch signal acting on the state equations to adjust velocity and tension, the stability condition of the observer is also derived based on the Lyapunov stability theory.Designed the structure of adaptive backstepping controller and tension sliding-mode observer in MATLSAB/Simulink. Some experiments are tested on the model structured in Simulink: including speed synchronize experiment, tension decoupling control experiment,tension observe experiment. The simulation result indicated that the adaptive backstepping strategy has the smaller rising time and response time compared with PID strategy. The static error also meet the requirement. The tension sliding-mode observer can also observe the real tension accuratelly.Siemens S7-300 PLC and MM440 transducers was used as the core of the synchronous equipment. The basic control program on STEP7 was designed. The MPI communication technology was used to connect IPC(Industrial Personal Computer) and PLC.PROFIBUS network are connected to realize the communication between PLC and transducers. Win CC is applied in establishing monitoring picture of the synchronous system. The core of the arithmetic was running on MATLAB/Simulink, and then send to S7-300 after calculated,after that the control signal was send to MM440 transducers.The speed synchronize experiment was tested on the synchronous system. Including tension decoupling control experiment, tension observe experiment. The result indicated that the adaptive backstepping strategy has the smaller rising time and response time compared with PID strategy. The static error was also meet the requirement. The tension sliding-mode observer can also observe the real tension accuratelly. Finally, some conclusion and further research projects are presented.