Research Of Ac Servo Control System For Multi-Motor Based On Network

AC servo with its good control performance has been gradually replaced DC servo and increasingly applied in the high precision of control system. The control method of AC servo is numerous, and the advanced study of various control algorithms also pushes forward the AC servo. But with the development of industry and the production line being large and complex increasingly, the demands of various mechanical properties increase gradually, only one motor control has not meet the requirements of modern high-tech development and industrial automation. And controlling with more motors that they can better coordinate operation has become a trend. Traditional multi-motor driven control system adopts a centralized parallel bus control method, which is a kind of centralized distributed control system. Along with the development of microelectronics technology, there are many high-speed, high-performance integrated control chips, the join of field bus technique makes AC servo edging towards digital and network. This design studies the combine of microelectronics technology and field-bus technology, using a CAN bus and DSP to make up the AC Servo Control System for Multi-motor Based on Network. The main research content includes:the AC servo control algorithm, the software and hardware design of CAN intelligent node and CAN adapter card, software and hardware design of the AC servo controller, and the experiment of the whole system.In AC servo control algorithm, the permanent magnet synchronous motor is controlled object.Analysis the model of traditional direct torque control system for permanent magnet synchronous motor. When considering the impact of stator resistance,the voltage vector selection choice has defect in the vicinity of the sector boundary,resulting in poor control performance.In view of the traditional direct torque control problems such as large torque ripple and the flux linkage deformity, the sector subdivision of the direct torque control system is putting forward. The space plane is divided into 12 sectors by opening six more sectors in the center of traditional 6-sectors boundaries. The voltage vector selection table is improved.Modeling and simulation for two kinds of control methods in MATLAB.The theoretical analysis and the results of simulation show that the the control method of sector subdivision can reduce torque ripple and has better control performance.In aspect of hardware design, the CAN bus adapter card and CAN bus intelligent node hardware structure are designed. Using the eCAN module and SCIA module of TMS320LF2812 to form a CAN bus adapter card which can be responsible for the data interchange between the PC and CAN bus. The CAN bus adapter card connect to PC by USB interface which can send command of PC to CAN network and receive feedback information from it. Using the eCAN module and event manager module of TMS320LF2812 to form a CAN bus intelligent node which can receive control commands from CAN network to drive PMSM and feedback the real-time running parameters of PMSM to PC. The hardware circui of ac servo is designed of the CAN bus intelligent node,including the peripheral circuit of TMS320LF2812、rectifier and inverter circuit、detection and protection circuit Etc.In aspect of software design, analysis the process of send and receive of the CAN bus adapter card and CAN bus intelligent node.The flow chart and some of the code to realize is given.The software of AC servo driven is introduced,mainly contain main program、interrupt service program and control algorithm program. All of the program code is writed by language C in Code Composer Studio 3.3 and the out documents is created to download to the flash of 2812.Finally, the hardware platform of system is built, as a result to conduct numerous experiments. The experimental results are consistent with the theoretical analysis and simulation results.