The Application Of FPGA/CPLD In AC Servo System

The AC servo system based on permanent magnet synchronous motor (PMSM) is researched in this paper, for the PMSM servo system is numerically controlled by the hardware of the system made up of TMS320LF2407A designed by Texas Instruments as well as FPGA/CPLD designed by Altera. In this paper, it is introduced that how to design the main circuit and the controlling circuit of the DSP, failure detection diagnosis system, and the circuit for detect the current and the feed-back signal of the encoder, and the circuit of SCI is also designed so that the closed-loop control of PMSM is achieved deservedly.The feed-back signal of the servo system is researched in detail in this paper, for it is important for the discretional orthogonal frequency division of the pulses produced by the increamental optical-electrical encoder. In this paper, discretional decimal frequency division of the orthogonal pulses is achieved depending on the method of PLL frequency synthesizing and dividing, as well as integral frequency division with the same duty ratio. The results of the experiment prove that discretional frequency division is accurate and even worthy of a lot.The difference of the increamental optical-electrical encoder and the absolute Encoder is discussed at the end of the paper for position sensor with high precision is indispensable for servo control system with high precision, and the absolute Optical-electrical Encoder produce by Futju is also introduced while the absolute Optical-electrical Encoder id introduced in detail. At last, the module for receiving and sending are designed based on FPGA so that the decode of the serial data of the encoder and the communication interface of DSP are accomplished.