有被控对象的数学模型足够精确时，才能把特征根精确地配置在期望的位置上，而大多数实际系统一般无法得到系统的精确模型，因此理论设计的极点配置往往与实际系统不能精确匹配

-Manual Mode

　　　　 Controller output, p(t), is adjusted manually.

　 Manual Mode is very useful when unusual

　　　　 conditions exist:

plant start-up

plant shut-down

emergenciesjust becomes unstable. Define this gain to be Kr and measure the period of oscillation, Tr.