闭环传递函数公式的应用条件

实例表明，一些自动控制理论的专著中所介绍的闭环传递函数公式具有应用上的局限性。为了完善该公式，以便正确无误地应用它，需要准确地界定其应用范围。因此，提出并根据著名的梅逊（ＭａｓｏｎＳＪ）增益定理从理论上推证了应用该公式时控制系统应具备的两个条件：控制系统必须无相互独立的反馈回环，无独立于任一反馈回环的前向通道。

Application Conditions of the Closed-Loop Transfer Function Formula

Demonstrations have showed that the transfer function formula for closed-loop control system introduced in some books on automatic control has certain application limits. In order to improve the formula and use it correctly, it is required to limit its scope of application. Thus the two necessary conditions of the control system in using this formula have put forward and deduced theoritically based on the well-knows Mason Gain S J theorem. The conditions are that in studied control system there are no mutually independent feed-back loops and no forward path independent on any a feed-back loop.