摘  要：伺服系统中采用电子齿轮来匹配指令脉冲当量和位置反馈脉冲当量。本文分析了电子齿轮的工作原理，提出了一种位置指令脉冲处理电路来把三种可能的脉冲输入形式转换成统一的可被接受的形式，并在Xilinx ISE开发环境下进行VHDL编程，用数字方法实现了电子齿轮比，最后利用Modelsim软件仿真验证了该设计的正确性和可行性。
关键词：电子齿轮比；位置指令脉冲；FPGA

Abstract: In servo system，electronic gear is used to adjust the instruction pulse equivalent and position feedback pulse equivalent．This article analysed the principle of electronic gear，proposed a position command pulse processing circuit which can transform three possible input pulse forms to an acceptable form．VHDL codes are programed and compiled in Xilinx ISE，and digital realization of electronic gear ratio is fulfilled．In the end，modelsim simulation result is provided to test the validity and feasibility of the design．
Key words: electronic gear ratio；position command pulse；FPGA