US3736486A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Servo control system
Assignee: Teletronics International Inc
•
Filing: 1972-03-17
•
Granted: 1973-05-29
•
Expires: 1992-03-17
Abstract
Abstract A digital servo-motor control and drive system is disclosed. A control signal for changing the servo-motor position, and a position signal which is proportional to the servo-motor position are compared with one another by a comparator. A signal proportional to the difference between the control signal and the position signal is delivered to a full-wave rectifier using highgain differential operational amplifiers. The latter circuit produces a signal which is proportional to the absolute magnitude of the error signal. This error signal is delivered to a second comparator which compares the error signal with a reference signal. When the error signal is equal to or greater than the reference signal, The second comparator changes its output condition to indicate the ''''match''''. Logic circuitry is provided for detecting the coincidence between the latter condition of the second comparator and one condition of the first comparator. The detection of such a coincidence produces an output signal over a first lead which drives the servo-motor in one direction. A second drive signal for driving the servo-motor in the opposite direction is produced in response to the detection of coincidence between the match condition of the second comparator and the opposite output condition of the first comparator, thus indicating a reversal of polarity of the difference between the control and position signals. This servo control system has a very precisely controllable ''''deadband'''', and is relatively insensitive to electrical noise.
Inventors
- 👤 G Gould
- 👤 A Sarabia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 14:36
CPC Classifications
G; G05; G05D; G05D3/00; G05D3/12; G05D3/14; G05D3/16
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
198 words
A servo-motor control system comprising means for developing a control signal, means for developing a position signal for indicating the position of the servo-motor output relative to a reference position, first comparator means for producing a first output condition when one of said position and control signals is larger than the other, and for producing a second output condition when said other signal is larger than said one signal, means for producing an error signal proportional to the absolute value of the difference between said control and position signals, means for developing a reference signal, second comparator means for producing a match output condition when said error signal equals or exceeds said reference signal, means for delivering a first drive signal to said servo-motor to drive it in one direction in response to the coincident detection of a first output condition of said first comparator means and the match output condition of said second comparator means, and means for delivering a second drive signal to drive said servo-motor in the opposite direction in response to the coincident detection of the second output condition of said first comparator means and the match output condition of said second comparator means.
Claim 2
Dependent Claim
198 words
A servo-motor control system comprising means for developing a control signal, means for developing a position signal for indicating the position of the servo-motor output relative to a reference position, first comparator means for producing a first output condition when one of said position and control signals is larger than the other, and for producing a second output condition when said other signal is larger than said one signal, means for producing an error signal proportional to the absolute value of the difference between said control and position signals, means for developing a reference signal, second comparator means for producing a match output condition when said error signal equals or exceeds said reference signal, means for delivering a first drive signal to said servo-motor to drive it in one direction in response to the coincident detection of a first output condition of said first comparator means and the match output condition of said second comparator means, and means for delivering a second drive signal to drive said servo-motor in the opposite direction in response to the coincident detection of the second output condition of said first comparator means and the match output condition of said second comparator means.
Claim 3
Dependent Claim
38 words
A system as in claim 1 in which each of said comparator means comprises circuit means for producing an output signal in one of its output conditions, and no output signal in the other of its output conditions.
Claim 4
Dependent Claim
18 words
A system as in claim 1 in which each of said comparator means is an integrated circuit device.
Claim 5
Dependent Claim
34 words
A system as in claim 1 including means for developing a transient drive signal to drive said servo-motor in the opposite direction after movement in the one direction, in order to correct for over-shoot.
Claim 6
Dependent Claim
213 words
A servo-motor control system comprising means for developing a control signal, means for developing a position signal for indicating the position of the servo-motor output relative to a reference position, first comparator means for producing a first output condition when one of said position and control signals is larger than the other, and for producing a second output condition when said other signal is larger than said one signal, full-wave rectifier means connected for detecting and rectifying the difference between said control and position signals for producing an error signal proportional to the absolute value of the difference between said control and position signals, means for developing a reference signal, second comparator means for producing a match output condition when said error signal equals or exceeds said reference signal, means for delivering a First drive signal to said servo-motor to drive it in one direction in response to the coincident detection of a first output condition of said first comparator means and the match output condition of said second comparator means, and means for delivering a second drive signal to drive said servo-motor in the opposite direction in response to the coincident detection of the second output condition of said first comparator means and the match output condition of said second comparator means.
Claim 7
Dependent Claim
213 words
A servo-motor control system comprising means for developing a control signal, means for developing a position signal for indicating the position of the servo-motor output relative to a reference position, first comparator means for producing a first output condition when one of said position and control signals is larger than the other, and for producing a second output condition when said other signal is larger than said one signal, full-wave rectifier means connected for detecting and rectifying the difference between said control and position signals for producing an error signal proportional to the absolute value of the difference between said control and position signals, means for developing a reference signal, second comparator means for producing a match output condition when said error signal equals or exceeds said reference signal, means for delivering a First drive signal to said servo-motor to drive it in one direction in response to the coincident detection of a first output condition of said first comparator means and the match output condition of said second comparator means, and means for delivering a second drive signal to drive said servo-motor in the opposite direction in response to the coincident detection of the second output condition of said first comparator means and the match output condition of said second comparator means.
Claim 8
Dependent Claim
49 words
A system as in claim 5 in which said rectifier includes a pair of high-gain differential amplifiers, the input terminals of each being connected with opposite polarity to lines upon which said control and position signals appear, and the output of each being delivered to a common output terminal.
Claim 9
Dependent Claim
40 words
A system as in claim 6 in which said common output terminal is connected to one input terminal of said second comparator means, and said reference signal means is connected to a second input terminal of said second comparator means.
Claim 10
Dependent Claim
18 words
A system as in claim 6 in which each of said differential amplifiers is an integrated circuit device.
Claim 11
Dependent Claim
322 words
A servo-motor control system comprising means for developing a control signal, means for developing a position signal for indicating the position of the servo-motor output relative to a reference position, first comparator means for producing a first output condition when one of said position and control signals is larger than the other, and for producing a second output condition when said other signal is larger than said one signal, means for producing an error signal proportional to the absolute value of the difference between said control and position signals, means for developing a reference signal, second comparator means for producing a match output condition when said error signal equals or exceeds said reference signal, means for delivering a first drive signal to said servo-motor to drive it in one direction in response to the coincident detection of a first output condition of said first comparator means and the match output condition of said second comparator means, and means for delivering a second drive signal to drive said servo-motor in the opposite direction in response to the coincident detection of the second output condition of said first comparator means and the match output condition of said second comparator means, each of said comparator means comprising circuit means for producing an output signal in one of its output conditions, and no output signal in the other of its output conditions, said means for delivering said first and second drive signals to said servo-motor including a pair of AND gates, each receiving the output from said second comparator as one input, one AND gate receiving the uninverted output of said first comparator means, and the other AND gate receiving the inversion of the output of said first comparator means, the output of one of said AND gates being connected to the forward-drive input terminal of said servo-motor, and the output of the other AND gate being connected to the reverse-drive input terminal of said servo-motor.
Claim 12
Dependent Claim
322 words
A servo-motor control system comprising means for developing a control signal, means for developing a position signal for indicating the position of the servo-motor output relative to a reference position, first comparator means for producing a first output condition when one of said position and control signals is larger than the other, and for producing a second output condition when said other signal is larger than said one signal, means for producing an error signal proportional to the absolute value of the difference between said control and position signals, means for developing a reference signal, second comparator means for producing a match output condition when said error signal equals or exceeds said reference signal, means for delivering a first drive signal to said servo-motor to drive it in one direction in response to the coincident detection of a first output condition of said first comparator means and the match output condition of said second comparator means, and means for delivering a second drive signal to drive said servo-motor in the opposite direction in response to the coincident detection of the second output condition of said first comparator means and the match output condition of said second comparator means, each of said comparator means comprising circuit means for producing an output signal in one of its output conditions, and no output signal in the other of its output conditions, said means for delivering said first and second drive signals to said servo-motor including a pair of AND gates, each receiving the output from said second comparator as one input, one AND gate receiving the uninverted output of said first comparator means, and the other AND gate receiving the inversion of the output of said first comparator means, the output of one of said AND gates being connected to the forward-drive input terminal of said servo-motor, and the output of the other AND gate being connected to the reverse-drive input terminal of said servo-motor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |