US3555254A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Error correcting system and method for use with plotters, machine tools and the like
Assignee: Gerber Systems Corp
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Filing: 1967-04-17
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Granted: 1971-01-12
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Expires: 1987-04-17
Abstract
Abstract A method and system is provided for positioning a marking instrument, cutting tool or other driven part of a numerically controlled device and for overcoming, in such positioning, repeatable errors due to mechanical limitations such as, for example, lack of perfect straightness in guide ways or lead screws. A memory device forming part of the computer associated with the system is filled with a table of error correction values corresponding to different points or areas in the field of movement of the driven part and as the part is moved to such points or areas corrections are made in accordance with the table of error correction values.
Inventors
- 👤 Heinz Joseph Gerber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:16
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/404; G05B19/19; G05B19/27; G05B19/29; G05B19/291; G05B2219/00; G05B2219/30; G05B2219/33; G05B2219/33078; G05B2219/37; G05B2219/37619; G05B2219/41; G05B2219/41036; G05B2219/41037; G05B2219/41055; G05B2219/41062; G05B2219/49; G05B2219/49195
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
126 words
A method for reducing errors in a device for positioning a driven part relative to a reference member and including a computer for converting input commands into output commands having arguments related to the positions to which said driven part is to be moved, said method comprising the steps of storing a table of error values versus reference positions in a memory device associated with said computer, and thereafter operating said computer in accordance with such a program that as said driven part is moved to different points of its field of movement as a result of input commands supplied to said computer said memory device is interrogated and values of error corresponding to said points are extracted therefrom and used to correct said output cOmmands.
Claim 2
Independent Claim
126 words
A method for reducing errors in a device for positioning a driven part relative to a reference member and including a computer for converting input commands into output commands having arguments related to the positions to which said driven part is to be moved, said method comprising the steps of storing a table of error values versus reference positions in a memory device associated with said computer, and thereafter operating said computer in accordance with such a program that as said driven part is moved to different points of its field of movement as a result of input commands supplied to said computer said memory device is interrogated and values of error corresponding to said points are extracted therefrom and used to correct said output cOmmands.
Claim 3
Dependent Claim
54 words
The method as defined in claim 1 further characterized by said step of operating said computer including the use of such a program that said error values obtained from said memory are used to effect discrete changes in said output commands as said driven part passes the various reference positions included in said table.
Claim 4
Dependent Claim
82 words
The method as defined in claim 1 further characterized by said step of operating said computer including the use of such a program that at any position of said driven part the amount of error correction required in said output commands is interpolated from the error values given by said table for adjacent reference positions and so that corrections are made in accordance with such interpolated error values as said driven part is moved between various reference positions included in said table.
Claim 5
Independent Claim
202 words
A method for reducing errors in a device for positioning a driven part relative to a reference member and including a computer for converting input commands into output commands having arguments related to the positions to which said driven part is to be moved, said method comprising the steps of providing input commands to said computer commanding movement of said driven part to different reference positions spread over its field of movement, accurately measuring the actual positions of said driven part after it supposedly reaches each of said different reference positions and from such measurements calculating the values of the errors between the positions commanded by said input commands and the measured positions to obtain a table of error values versus reference positions, inserting said table of error values versus reference positions into a memory device associated with said computer, and thereafter operating said computer in accordance with such a program that as said driven part is moved to different points of its field of movement as a result of input commands supplied to said computer said memory device is interrogated and values of error corresponding to said points are extracted therefrom and used by said computer to correct said output commands.
Claim 6
Independent Claim
202 words
A method for reducing errors in a device for positioning a driven part relative to a reference member and including a computer for converting input commands into output commands having arguments related to the positions to which said driven part is to be moved, said method comprising the steps of providing input commands to said computer commanding movement of said driven part to different reference positions spread over its field of movement, accurately measuring the actual positions of said driven part after it supposedly reaches each of said different reference positions and from such measurements calculating the values of the errors between the positions commanded by said input commands and the measured positions to obtain a table of error values versus reference positions, inserting said table of error values versus reference positions into a memory device associated with said computer, and thereafter operating said computer in accordance with such a program that as said driven part is moved to different points of its field of movement as a result of input commands supplied to said computer said memory device is interrogated and values of error corresponding to said points are extracted therefrom and used by said computer to correct said output commands.
Claim 7
Dependent Claim
145 words
The method as defined in claim 4 as used with a positioning device wherein said driven part is independently movable along two axes so as to be capable of being moved to any point on a given area of said reference member, said method being further characterized by said step for providing input commands to said computer commanding movement of said driven part to different reference positions spread over its field of movement consisting of providing input signals to said computer commanding movement of said driven part through a number of reference points spaced along one of said axes by given intervals and a number of reference points spaced along the other of said axes by given intervals, and by setting up said table of error values so as to have for each axis a single error value for each reference point along such axis.
Claim 8
Dependent Claim
174 words
The method as defined in claim 4 as used with a positioning device wherein said driven part is independently movable along two axes so as to be capable of being moved to any point on a given area of said reference member, said method being further characterized by said step of providing input commands to said computer commanding movement of said driven part to different positions spread over its field of movement consisting of providing input signals to said computer commanding movement of said driven part through a grid of reference positions separated from one another along both of said axes by given intervals and spread generally over the entire extent of said given area of said reference member, and by setting up said table of error values so as to have for each of said reference positions an associated error value for each of said two axes with the result that the error values supplied by said memory device are dependent on the position of said driven part along both of said axes.
Claim 9
Dependent Claim
132 words
In a part positioning system for moving a part relative to a given Reference member, the combination comprising a memory device having stored therein a table of error values versus part positions, a drive system for said driven part operable to move said driven part to different positions relative to said reference member in response to input commands thereto, means providing primary input commands commanding movement of said driven part to various driven positions, and a computer operable to convert said primary input commands into input commands transmitted to said drive system, said computer including means for interrogating said memory device to obtain therefrom error values corresponding to the position of said driven part and for using the error value so obtained to correct said input commands transmitted to said drive system.
Claim 10
Dependent Claim
132 words
In a part positioning system for moving a part relative to a given Reference member, the combination comprising a memory device having stored therein a table of error values versus part positions, a drive system for said driven part operable to move said driven part to different positions relative to said reference member in response to input commands thereto, means providing primary input commands commanding movement of said driven part to various driven positions, and a computer operable to convert said primary input commands into input commands transmitted to said drive system, said computer including means for interrogating said memory device to obtain therefrom error values corresponding to the position of said driven part and for using the error value so obtained to correct said input commands transmitted to said drive system.
Claim 11
Dependent Claim
76 words
The combination defined in claim 7 further characterized by said drive system including a stepping motor for driving said driven part, and a driver for said stepping motor, said input commands transmitted to said drive system consisting of electrical pulses transmitted to said driven, and said computer including means for adding pulses to or subtracting pulses from said input commands in accordance with the magnitude and sign of the error values obtained from said memory device.
Claim 12
Dependent Claim
41 words
The combination defined in claim 8 further characterized by said means for adding pulses to or subtracting pulses from said input commands including means for performing such an operation in a discrete fashion as said driven part passes given reference positions.
Claim 13
Dependent Claim
42 words
The combination defined in claim 8 further characterized by said means for adding pulses to or subtracting pulses from said input commands including means for performing such an operation in a proportional manner as said driven part moves between given reference positions.
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) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |