US 7,321,801 B2 | ||
Automatic gain adjustment device and automatic gain adjustment method | ||
Yasushi Saito, Saitama (Japan) | ||
Assigned to Sony Corporation, (Japan) | ||
Filed on Mar. 30, 2004, as Appl. No. 10/813,454. | ||
Claims priority of application No. P2003-098480 (JP), filed on Apr. 01, 2003. | ||
Prior Publication US 2004/0199271 A1, Oct. 07, 2004 | ||
Int. Cl. G05B 13/02 (2006.01); H03L 7/06 (2006.01); H03D 3/24 (2006.01) |
U.S. Cl. 700—37 [327/147; 327/156; 375/373] | 4 Claims |
1. An automatic gain adjustment device of a feedback control system that uses a phase difference between an output signal
obtained from a controlled object and an input signal while controlling the object based on the input signal, the automatic
gain adjustment device comprising:
a disturbance generator for generating the input signal; the input signal being a sine wave of a predetermined frequency;
phase shifting means connected to an input stage of the feedback control system for shifting a phase of the input signal such
that a phase shift amount of the phase shifting means is set so that a frequency of the input signal to be supplied to a closed
loop coincides with a crossover frequency at which an open loop gain of the feedback control system becomes 0 db;
a band-pass filter for filtering the output signal to extract a component signal of the predetermined frequency;
a multiplier for multiplying the phase-shifted input signal from the phase shifting means and the component signal from the
band-pass filter;
an integrator for integrating product results of the multiplier over one cycle at the predetermined frequency and outputting
integrated product results; and
a gain setting unit for adjusting a gain of the feedback control system based on a sign of the integrated product results
from the integrator so that the open loop gain converges to 0 dB.
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