说明：  增量式PID的例程,后面附有对PID算法的简要说明和参数整定的步骤方法,使用增量式PID比用普通PID在某些场合具有更好的效果.
(The incremental PID routines, followed with a brief description and parameters of the PID algorithm tuning step method, the incremental PID than ordinary PID has better results in some cases.)