Frequency domain specifications

Frequency domain specifications

The resonant peak Mr is the maximum value of jM(jw)j.

The resonant frequency !r is the frequency at which the peak resonance Mr occurs.

The bandwidth BW is the frequency at which(jw) drops to 70:7% (3 dB) of its zero-frequency value.

Mr indicates the relative stability of a stable closed loop system.

A large Mr corresponds to larger maximum overshoot of the step response. Desirable value: 1.1 to 1.5

BW gives an indication of the transient response properties of a control system.

A large bandwidth corresponds to a faster rise time. BW and rise time tr are inversely proportional.

BW also indicates the noise-filtering characteristics and robustness of the system. Increasing wn increases BW.

BW and Mr are proportional to each other.