动态系统
返回SISO或MIMO的电线杆dynamic system modelP
= pole(sys
)sys
。The output is expressed as the reciprocal of the time units specified insys.TimeUnit
。动态系统的极点确定了系统的稳定性和响应。
An open-loop linear time-invariant system is stable if:
在连续的时间内,转移函数的所有极点都具有负实际零件。当两极在复合物S平面上可视化时,它们都必须全部位于左半平面(LHP)中以确保稳定性。
In discrete-time, all the poles must have a magnitude strictly smaller than one, that is they must all lie inside the unit circle.
Multiple poles are numerically sensitive and cannot be computed with high accuracy. A poleλ具有多重性mtypically results in a cluster of computed poles distributed on a circle with centerλand radius of order
where ε is the relative machine precision (eps
).
有关多个电线杆的更多信息,请参阅Sensitivity of Multiple Roots。
Ifsys
有内部延迟,首先将所有内部延迟设置为零,从而获得了极点,以使系统具有有限数量的极点,从而创建零级的PADé近似。对于某些系统,将延迟设置为零会产生单数代数循环,从而导致不正确或不明显的零延迟近似值。对于这些系统,极
returns an error.