When the phase angle of the open-loop taste characteristic is-180, the corresponding angular frequency is Wg, and the amplitude G(Jw)H(Jw) of the open-loop frequency characteristic can indicate the degree of the closed-loop system approaching critical stability, so remember that the amplitude margin of Kg is Kg= 1/G(Jw)H(Jw).

Maximum distance from the equilibrium position. Commonly used in mathematics, physics, current, electromagnetism, machinery and other fields. For example, the maximum absolute value of alternating current in a period is called the amplitude of alternating current, which is also called the maximum value, amplitude and peak value.

Allowance refers to the degree to which a certain margin is left and a certain error is allowed. The tolerance range is defined according to the statistical object and range.

Extended data:

In the principle of automatic control, the frequency response is often described by Porter diagram. There are two parameters to judge stability, namely amplitude margin and phase margin. The latter is usually used to judge that the system is stable when the phase margin is greater than zero and unstable when it is not. But for the amplitude margin, it refers to the corresponding amplitude (in this case, dB) when the phase angle is-180 degrees.

In a period, the maximum absolute value of instantaneous alternating current is also a sine wave, which is half of the distance from the peak to the trough. The parameters of the signal are generally expressed by amplitude and frequency; Frequency is the number of cycles per unit time.

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