Implementation methods of FPGA-based shaft angle demodulation

摘要

The resolver is used as the angle sensor of the shaft angle encoder unit in the shipboard servo system at present, and three methods are used to demodulate it. These are the sampling peak method, the coherent demodulation and filter method and the dedicated chip method, but there are many disadvantages for these three methods. A method learned from the digital signal processing is presented in the paper, in which the axis angle modulation is direct demodulated to be digital, FPGA is applied for the digital processing, filtering, coding and error correction. This method solves the complex demodulation problem, and reduces the costs, which embodies the design ideas of economic and practical. The method has been successfully applied to the shipboard servo system.