说明：  经过老师的指导:速度采样用M法不适应低,所以对于调速范围大的就用M/T法,适合于高低测速!对测速还要加以数字滤波!可用一阶惯性/中值法,平均法等!
(After the teacher' s guide: the speed of the sampling method are not suited with M low speed range for the use of the M/T method, suitable for the level of gun! Gun would also like to be on the digital filter! Available to first-order inertial/median law, such as average!)