转速可靠测量与精确控制是模拟原动系统设计中的一个重要环节，关系到整个系统的 稳态误差和动态响应性能。根据M/T 法测速的基本原理，提出了一种模拟原动系统中基于DSP 的电气转速测量的M/T 法实现方式，介绍了基本硬件组成及软件流程。该方法通过DSP的捕获功能，确保测速的计时和码盘脉冲计数的同步，提高了速度反馈精确度，并使系统具有良好的动态性能和鲁棒性。实验表明，该方案准确可靠，提高了系统的响应时间且适用的测速范围大。 关键词：原动机仿真；转速测量；M/T 法；TMS320LF240 Abstract: The dependable measurement and the accurate control of the rotational speed is an important part during the design of the prime movers simulated system. Which will influence the stable errors and the dynamic response function? According to the basically principles of the M/T speed measurement methods, the thesis proposes a kind of M/T method realizing way in the prime movers simulated system based on the DSP electric rotational measurement, introduces the basic hardware organization and the software process. This method makes full use of DSP resources and ensures synchronous counting for time and encoder pulses, which improves the accuracy of speed feedback and makes the system, has good dynamic function and robustness. Its reliability and accuracy are verified by experiment result. Key words: simulation of prime mover; rotational speed measuring; M/T method; TMS320LF240