Patent CH323839A successfully refreshed from Google Patents.
US3569814A
Expired / Lapsed
US
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Programmed digital servo control including repeated command updating whereby output function becomes smoothly varying
Assignee: International Business Machines Corp
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Filing: 1969-01-17
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Granted: 1971-03-09
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Expires: 1989-01-17
Abstract
Abstract Digital numerical control for a machine tool. A plurality of digitally encoded signals or words, each representing an axis of the machine tool, are periodically supplied to a servo for each axis at a rate of less than 200 per axis per second. The digitally encoded signals update the servo by an amount equal to the value thereof to indicate a new desired position of the machine tool along that axis at that point in time. The servo continuously supplies an error signal representing the difference between the desired and actual position of the machine tool. A drive motor for each axis responds to the corresponding error signal to drive the machine tool along that axis. The error signal is updated at a sufficiently high rate that the inertia of the driven tool operates to smooth the motion thereof.
Inventors
- 👤 Jack Rosenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:00
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/19; G05B19/33; G05B19/37; G05B19/371
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
198 words
A system for controlling the movement of at least one member of a device along at least one axis in a coordinate system to describe a resulting desired path comprising: processor means periodically providing at least one digitally encoded word signal, each signal representing, by the encoded value thereof, a predetermined measure of distance to be travelled by a moving member of said device along an associated axis to describe said desired path, said periods comprising relatively long, predetermined, uniform time intervals; servo error means for each said member of said device, each responsive to each of said word signals from said processor means for that axis to accordingly update a current representation of the desired position of said member along said axis by said predetermined measure of distance, each continuously comparing said representation of said desired position with the actual position of said member, and each continuously supplying an error signal representing the direction and difference therebetween; and servomotive means for each said member of said device operative to continuously urge said member along said axis in response to said error signal for that axis in accordance with the direction and difference represented by said error signal.
Claim 2
Independent Claim
198 words
A system for controlling the movement of at least one member of a device along at least one axis in a coordinate system to describe a resulting desired path comprising: processor means periodically providing at least one digitally encoded word signal, each signal representing, by the encoded value thereof, a predetermined measure of distance to be travelled by a moving member of said device along an associated axis to describe said desired path, said periods comprising relatively long, predetermined, uniform time intervals; servo error means for each said member of said device, each responsive to each of said word signals from said processor means for that axis to accordingly update a current representation of the desired position of said member along said axis by said predetermined measure of distance, each continuously comparing said representation of said desired position with the actual position of said member, and each continuously supplying an error signal representing the direction and difference therebetween; and servomotive means for each said member of said device operative to continuously urge said member along said axis in response to said error signal for that axis in accordance with the direction and difference represented by said error signal.
Claim 3
Dependent Claim
81 words
The control system of claim 1 wherein: said device has a plurality of axes; and said processor means periodically provides a plurality of digitally encoded word signals, each said signal of said plurality representing a different one of said axes of said device, the encoded value of each of which signals represents a predetermined measure of distance to be travelled by said member along said associated axis to describe said desired path, said periods comprising relatively loNg, predetermined, uniform time intervals.
Claim 4
Dependent Claim
77 words
The control system of claim 1 wherein: said periods at said processor means comprise a predetermined rate of occurrence of less than 200 per second and greater than the minimum at which the inertial characteristics of said member and said servo means for said axis smooths the motion of said member along said axis to a nearly constant velocity, and only one of said word signals is provided for any one axis in one of said periods.
Claim 5
Dependent Claim
56 words
The control system of claim 3 for a device having low velocity ripple wherein: said periods at said processor means additionally comprise a rate of occurrence of more than the maximum upper cutoff frequency of the electromechanical filters comprising, for each said axis, the electrical and driven mechanical servo portion of said device for that axis.
Claim 6
Dependent Claim
72 words
The control system of claim 2 wherein: each of said digitally encoded word signals provided by said processor means additionally includes a designation of the axis of said device represented by said signal; and additionally including: distribution means which responds to said designation included in each of said signals to distribute the digitally encoded portion of each of said signals to the one of said servo error means for said designated axis.
Claim 7
Dependent Claim
79 words
The control system of claim 5 wherein: said periods at said processor means comprise a predetermined rate of occurrence of less than 200 per second and greater than the minimum at which the inertial characteristics of each said member and said servomeans for said associated axis smooths the motion of said member along said axis to a nearly constant velocity and only one of said word signals is provided for each of said axes in one of said periods.
Claim 8
Dependent Claim
57 words
The control system of claim 6 for a device having low velocity ripple wherein: said periods at said processor means additionally comprise a rate of occurrence of more than the maximum effective upper cutoff frequency of the electromechanical filters comprising, for each said axis, the electrical and driven mechanical servo portion of said device for that axis.
Claim 9
Dependent Claim
22 words
The control system of claim 5 additionally including: transmission means for transmitting said signals from said processor means to said distribution means.
Claim 10
Dependent Claim
83 words
The control system of claim 8 wherein: said processor means is additionally arranged to supply a special signal to said transmission means in each said period indicating that all said digitally encoded signals for that period have been supplied; and said distribution means is additionally arranged to temporarily store said digitally encoded signals from said transmission means and is responsive to the receipt therefrom of said special signal to then cause transmission of said stored digitally encoded signals to said servo error means.
Claim 11
Dependent Claim
58 words
The control system of claim 9 wherein: said processor means is additionally arranged to supply said signals in the form of words, each word comprising an axis designation and a digitally encoded signal for that axis, serially by word to said transmission means such that one word is transmitted for each axis of said device in said period.
Claim 12
Independent Claim
228 words
A method for controlling the movements of members of a device along separate axes in the coordinate system to describe a resulting desired path having servo motive means for each said axis operative to drive said associated member along said associated axis, comprising the following steps: periodically providing a plurality of digitally encoded word signals, each said signal of said plurality representing a different one of said axes of said device, the encoded value of each of which signals represents a predetermined measure of distance to be travelled by said member along said associated axis to describe said desired path, said periods comprising relatively long, predetermined, uniform time intervals; updating current representations of the desired position of said member along each of said axes by said predetermined measures of distance in accordance with the corresponding ones of said plurality of digitally encoded word signals; continuously comparing, at each of said axes, said representation of said desired position with the actual position of said member along the axis and thereby supplying an error signal representing the direction and difference therebetween; and operating said servo motive means for each said axis in accordance with said error signal for that axis to thereby continuously urge said member along said axis in accordance with the difference represented by said error signal in a direction tending to reduce said error signal to zero.
Claim 13
Independent Claim
228 words
A method for controlling the movements of members of a device along separate axes in the coordinate system to describe a resulting desired path having servo motive means for each said axis operative to drive said associated member along said associated axis, comprising the following steps: periodically providing a plurality of digitally encoded word signals, each said signal of said plurality representing a different one of said axes of said device, the encoded value of each of which signals represents a predetermined measure of distance to be travelled by said member along said associated axis to describe said desired path, said periods comprising relatively long, predetermined, uniform time intervals; updating current representations of the desired position of said member along each of said axes by said predetermined measures of distance in accordance with the corresponding ones of said plurality of digitally encoded word signals; continuously comparing, at each of said axes, said representation of said desired position with the actual position of said member along the axis and thereby supplying an error signal representing the direction and difference therebetween; and operating said servo motive means for each said axis in accordance with said error signal for that axis to thereby continuously urge said member along said axis in accordance with the difference represented by said error signal in a direction tending to reduce said error signal to zero.
Claim 14
Dependent Claim
94 words
The method of controlling the operation of a device of claim 11 wherein: said step of periodically providing a plurality of digitally encoded words signals additionally comprises providing said plurality of signals at a predetermined rate of less than 200 per axis per second and greater than the minimum at which the inertial characteristics of each said member and said servo motive means for said associated axis smooths the motion of said member along said axis to a nearly constant velocity, and only one word signal is provided for each axis in one period.
Claim 15
Dependent Claim
66 words
The method of claim 12 for controlling the operation of a device having low velocity ripple wherein: said step of periodically providing a plurality of digitally encoded word signals additionally comprises providing said signals to each said axis at a rate of more than the upper cutoff frequency of the electromechanical filter comprising the electrical and driven mechanical servo portion of said device for that axis.
Claim 16
Dependent Claim
80 words
The method for controlling operation of a device of claim 11 wherein: said step of periodically providing a plurality of digitally encoded word signals additionally comprises providing, with each of said signals, a designation of the axis of said device represented by said signal; and said altering step comprises responding to each of said axis designations to alter a stored representation of the desired position of said member along said designated axis in accordance with said corresponding digitally encoded signal.
References Cited (Backward Citations)
US2900586A
Cited
US3365634A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-03-08 | 1974-09-07 | 1975-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-08 | 1978-09-07 | 1979-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-08 | 1982-09-07 | 1983-03-09 | $7700.00 | Window Closed / Lapsed |