US3835360A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Numerical control system
Assignee: Tektronix Inc
•
Filing: 1972-03-20
•
Granted: 1974-09-10
•
Expires: 1992-03-20
Abstract
Abstract In a point-to-point control system of a modified, optimum, nonlinear type, a digital servomechanism employs an error counter receiving an input from a position-error-to-frequency-converter. The counter has a limited range, which, when exceeded, applies additional input to the servomechanism for producing rapid traverse. The error-to-frequency-converter normally receives a maximum input greater than the actual position error, until a deceleration range is detected, at which point the error-tofrequency-converter directs the servomechanism''s error counter for bringing about rapid deceleration. The normal counter limits are also exceeded during deceleration for bringing about increased servomechanism gain and braking toward final position. As soon as substantial deceleration has taken place, such that the counter limits are no longer exceeded, the counter directs a deceleration which is linear with respect to the distance-to-go, for final, accurate servomechanism positioning.
Inventors
- 👤 W Kiwiet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:52
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/19; G05B19/21; G05B19/25; G05B19/251; G05B19/253; G05B2219/00; G05B2219/30; G05B2219/41; G05B2219/41029; G05B2219/41243
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
107 words
In apparatus for moving a controlled device along a path between two points, rate command means for generating an output having a rate to which movement of said controlled device is responsive, digital servomechanism means, and a positioning motor operated thereby, responsive to the output of said rate command means to provide movement of said controlled device, said digital servomechanism means receiving feedback in accordance with movement of said controlled device, said digital servomechanism means having a first range of response to the difference between rate commanded and feedback, and means for non-proportionately increasing the response of said digital servomechanism means as said difference exceeds said range.
Claim 2
Dependent Claim
107 words
In apparatus for moving a controlled device along a path between two points, rate command means for generating an output having a rate to which movement of said controlled device is responsive, digital servomechanism means, and a positioning motor operated thereby, responsive to the output of said rate command means to provide movement of said controlled device, said digital servomechanism means receiving feedback in accordance with movement of said controlled device, said digital servomechanism means having a first range of response to the difference between rate commanded and feedback, and means for non-proportionately increasing the response of said digital servomechanism means as said difference exceeds said range.
Claim 3
Dependent Claim
49 words
The apparatus according to claim 1 including means for causing said rate command means to provide a first output, means for detecting when a given positional error remains, and means responsive to such detection for causing said rate command means to provide an output related to remaining positional error.
Claim 4
Dependent Claim
42 words
The apparatus according to claim 2 wherein said means for detecting when a given positional error remains includes register means for receiving input information and providiNg a digital positional error indication between input information and the actual position of the controlled device.
Claim 5
Dependent Claim
19 words
The apparatus according to claim 5 wherein said rate command means comprises an error-to-frequency-converter for supplying a pulse output.
Claim 6
Dependent Claim
15 words
The apparatus according to claim 1 wherein said digital servomechanism means includes an error counter.
Claim 7
Dependent Claim
42 words
The apparatus according to claim 5 including means for detecting a near center rest content of said error counter and in response thereto setting said error counter to the center rest value, said digital servomechanism means having increased gain in response thereto.
Claim 8
Dependent Claim
62 words
The apparatus according to claim 1 wherein said digital servomechanism means includes a counter having a normal capacity on each side of a center rest value, said means for non-proportionately increasing the response of said digital servomechanism means including means for detecting a count in said counter exceeding normal capacity and in response thereto increasing the gain of said digital servomechanism means.
Claim 9
Dependent Claim
40 words
The apparatus according to claim 7 wherein said means for detecting a count includes delay means operable when the contents of the counter exceeds normal capacity for providing an output of predetermined length each time the counter capacity is exceeded.
Claim 10
Dependent Claim
32 words
The apparatus according to claim 7 further including means for restoring the count in said counter to said normal capacity in response to a count in said counter exceeding said normal capacity.
Claim 11
Dependent Claim
22 words
The apparatus according to claim 7 wherein said counter is provided with an additional stage for detecting overflow beyond said normal capacity.
Claim 12
Dependent Claim
36 words
The apparatus according to claim 10 wherein said means for detecting a count includes delay means operable by said additional counter stage for providing an output of predetermined length each time the counter capacity is exceeded.
Claim 13
Dependent Claim
14 words
The apparatus according to claim 11 wherein said delay means comprises a one-shot multivibrator.
Claim 14
Dependent Claim
45 words
The apparatus according to claim 7 wherein said digital servomechanism means includes an amplifier and an analog servomechanism means driven by said amplifier for actuating said motor, and wherein the gain of said amplifier is increased by a count in said counter exceeding normal capacity.
Claim 15
Dependent Claim
47 words
The apparatus according to claim 13 wherein said digital servomechanism means further includes a digital-to-analog converter driven by said counter, wherein said amplifier comprises an operational amplifier normally having a first magnitude of feedback, and wherein the gain of said amplifier is increased by decreasing said feedback.
Claim 16
Dependent Claim
37 words
The apparatus according to claim 14 wherein said operational amplifier is provided with a feedback resistor, and means normally shunting said feedback resistor operable for increasing the gain of the amplifier through inhibition of its shunting action.
Claim 17
Dependent Claim
51 words
The apparatus according to claim 1 including register means for receiving input information and providing a digital positional error indication between input information and the actual position of the controlled device, and wherein said rate command means comprises an error-to-frequency-converter for supplying a pulse output proportional to said positional error indication.
Claim 18
Dependent Claim
25 words
The apparatus according to claim 16 further including means for applying feedback in said input register means in accordance with movement of said controlled device.
Claim 19
Dependent Claim
30 words
The apparatus according to claim 16 wherein said error-to-frequency-converter includes a register for providing an overflow output, and adding means for repetitively adding said positional error indication to said register.
Claim 20
Dependent Claim
78 words
The apparatus according to claim 18 further including means for inhibiting application of the positional error indication to said adding means when said positional error is more than a selected value while providing a fixed input to said adding means when said error indication exceeds said selected value, causing the output of said error-to-frequency-converter to be proportional to the positional error indication near the end point of point-to-point movement for said controlled device for bringing about deceleration thereof.
Claim 21
Dependent Claim
53 words
The apparatus according to claim 19 wherein said means, for inhibiting application of the positional error indication to said adding means when said positional error is more than a selected value, includes selector switch means for multiplying said positional error, and comparison means for comparing the multiplied positional error with a given value.
Claim 22
Dependent Claim
85 words
In apparatus for moving a controlled device along a path between two points, digital servomechanism means, and a positioning motor operated thereby, responsive to a commanded rate to provide movement of said controlled device, said digital servomechanism means receiving feedback in accordance with movement of said controlled device, said digital servomechanism means having a first range of response to the difference between the commanded rate and feedback, and means for non-proportionately increasing the response of said digital servomechanism means as said difference exceeds said range.
Claim 23
Dependent Claim
85 words
In apparatus for moving a controlled device along a path between two points, digital servomechanism means, and a positioning motor operated thereby, responsive to a commanded rate to provide movement of said controlled device, said digital servomechanism means receiving feedback in accordance with movement of said controlled device, said digital servomechanism means having a first range of response to the difference between the commanded rate and feedback, and means for non-proportionately increasing the response of said digital servomechanism means as said difference exceeds said range.
Claim 24
Independent Claim
112 words
The method of operating apparatus for moving a controlled device along a path between first and second points by means of a motor, said method comprising: rapidly traversing the controlled device from the first point generally toward the second point for a predetermined proportion of said path, applying predetermined reverse torque to said motor at the conclusion of said predetermined proportion of said path for decelerating said device, digitally determining the remaining distance-to-go to the second point, and digitally controlling the velocity of said controlled device to be in direct proportion to the remaining distance-to-go to the second point, as the velocity of said controlled device falls below a given low value.
Claim 25
Independent Claim
112 words
The method of operating apparatus for moving a controlled device along a path between first and second points by means of a motor, said method comprising: rapidly traversing the controlled device from the first point generally toward the second point for a predetermined proportion of said path, applying predetermined reverse torque to said motor at the conclusion of said predetermined proportion of said path for decelerating said device, digitally determining the remaining distance-to-go to the second point, and digitally controlling the velocity of said controlled device to be in direct proportion to the remaining distance-to-go to the second point, as the velocity of said controlled device falls below a given low value.
Claim 26
Dependent Claim
76 words
The method according to claim 22 including digitally detecting the ability of the controlled device to follow, within predetermined lag limits, a velocity proportional to said distance-to-go, and wherein the attainment of said given low value of velocity is detected according to said detected ability of the controlled device to follow, within said predetermined lag limits, a velocity proportional to said distance-to-go, after which said velocity of said controlled device becomes substantially proportional to said distance-to-go.
Claim 27
Independent Claim
71 words
The method of operating servomechanism apparatus for moving a controlled device along a path between first and second points, comprising traversing the controlled device from the first point generally toward the second point at a first value of servomechanism gain for a lag of the controlled device within predetermined limits, and substantially increasing the effective gain of the servomechanism apparatus to a second value when said lag exceeds said predetermined limits.
Claim 28
Independent Claim
71 words
The method of operating servomechanism apparatus for moving a controlled device along a path between first and second points, comprising traversing the controlled device from the first point generally toward the second point at a first value of servomechanism gain for a lag of the controlled device within predetermined limits, and substantially increasing the effective gain of the servomechanism apparatus to a second value when said lag exceeds said predetermined limits.
Claim 29
Independent Claim
149 words
The method of operating servomechanism apparatus for moving a controlled device along a path between first and second points, comprising traversing the controlled device from the first point generally toward the second point at a first value of servomechanism gain for a lag of the controlled device within predetermined limits, while substantially increasing the effective gain of the servomechanism apparatus to a second value when said lag exceeds said predetermined limits, and including decreasing the velocity of said controlled device as said device comes within a predetermined distance of said second point while continuing to provide said first value of servomechanism gain for a lag of the controlled device within predetermined limits and substantially increasing the effective gain of the servomechanism apparatus to a second value when said lag exceeds said predetermined limits, wherein said decreasing velocity is determined in accordance with the remaining distance-to-go within said predetermined distance.
Claim 30
Independent Claim
149 words
The method of operating servomechanism apparatus for moving a controlled device along a path between first and second points, comprising traversing the controlled device from the first point generally toward the second point at a first value of servomechanism gain for a lag of the controlled device within predetermined limits, while substantially increasing the effective gain of the servomechanism apparatus to a second value when said lag exceeds said predetermined limits, and including decreasing the velocity of said controlled device as said device comes within a predetermined distance of said second point while continuing to provide said first value of servomechanism gain for a lag of the controlled device within predetermined limits and substantially increasing the effective gain of the servomechanism apparatus to a second value when said lag exceeds said predetermined limits, wherein said decreasing velocity is determined in accordance with the remaining distance-to-go within said predetermined distance.
References Cited (Backward Citations)
US3389243A
Cited
US3651392A
Cited
US3629560A
Cited
US3729668A
Cited
US3731177A
Cited
US3693064A
Cited
US3737751A
Cited
US3721882A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |