Electricity: motive power systems – Braking – Automatic and/or with time-delay means
Patent
1981-12-17
1984-05-15
Weldon, Ulysses
Electricity: motive power systems
Braking
Automatic and/or with time-delay means
318327, 318329, 318618, G05B 500
Patent
active
044490828
ABSTRACT:
In a system for controlling within a very tight tolerance the speed of a DC motor, a first servo loop servos the motor to a speed which is close to ideal but not perfect. A second servo loop, operating in concert with the first servo loop, acts as a vernier or fine tuning adjustment to add any necessary correction needed to bring the motor into substantially perfect positional alignment.
The first servo loop utilizes ramp and velocity feedback techniques to achieve constant acceleration by tracking or following a speed command signal profiled to have a linear velocity ramp portion and a final constant velocity portion where acceleration terminates and speed remains constant. Once the motor has accelerated up to the desired speed the second servo loop begins to function in concert with the first servo loop.
The second servo loop utilizes "phase-lock" techniques wherein a phase error signal is derived by comparing the phase of a reference signal generated from a crystal oscillator with the phase of a digital tachometer signal obtained from the motor. This causes the tachometer to phase-lock to the reference oscillator, thereby allowing the long term speed variation of the motor to be controlled with an accuracy approaching that of the crystal utilized to derive the reference signal.
REFERENCES:
patent: 1880367 (1932-10-01), Stansbury et al.
patent: 3309597 (1967-03-01), Gabor et al.
patent: 3518516 (1970-06-01), Pawletko
patent: 3536975 (1970-10-01), Hough
patent: 3543115 (1970-11-01), Grygera
patent: 3843914 (1974-10-01), Carlson et al.
patent: 3917989 (1974-11-01), Bereisa, Jr.
patent: 4160197 (1979-07-01), Rothman et al.
patent: 4211967 (1980-07-01), Akiyama et al.
patent: 4232257 (1980-11-01), Harshberger
patent: 4249119 (1981-02-01), Robbi
patent: 4259698 (1981-03-01), Takada
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