US4754208A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circular path control apparatus and method for multi-axis servomechanisms
Assignee: JFE Engineering Corp
•
Filing: 1987-07-22
•
Granted: 1988-06-28
•
Expires: 2007-07-22
Abstract
Abstract A circular path control apparatus and method for a multi-axis servomechanism having a plurality of driving shafts. Any disturbance to a command circular path is calculated from the amount of contour error of a circular path or a square of a circular-arc center angle error and a control for cancelling the disturbance is added, thereby improving the circular path accuracy of the multi-axis servomechanism.
Inventors
- 👤 Tatsuya Nakajima
- 👤 Yasushi Miura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 07:35
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; G05B2219/41177
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
333 words
In a circular path control apparatus for an orthogonal multi-axis servomechanism including, for each of a plurality of driving shafts of said servomechanism, a position signal adder, a position controller, a speed signal adder, a speed control amplifier, a drive motor, a rotation speed detector for said drive motor, and a position detector, said position signal adder calculating a difference between a command position signal and a present position signal of each said driving shaft, said position controller being responsive to a signal sent from said position signal adder to calculate a driving shaft speed command signal, said speed signal adder calculating a difference between said speed command signal calculated by said position controller and a driving shaft present speed signal detected by said drive motor rotation speed detector, and said speed control amplifier being responsive to a signal sent from said speed signal adder to rotate said drive motor, the improvement comprising: a contour error detector; a proportional plus integral controller and adder means which are additionally provided for each said driving axis; said contour error detector calculating a contour error vector from a response position on a command circular path and a response position on a response circular path, a cumulative absolute value of said contour error vector, and an angle made by each said driving shaft with a vector extending to said response position from a center of rotation; said proportional plus integral controller for each said driving shaft calculating a correction quantity by multiplying a corresponding shaft direction component value of said contour error vector by a constant and multiplying a product of said cumulative absolute value of said contour error vector and a cosine value of said angle made by each said driving shaft and said last-mentioned vector by another constant; and said adding means for each said driving shaft produces a sum of said correction quantity and the speed command signal from said position controller and applying the same as an input to said speed signal adder.
Claim 2
Dependent Claim
333 words
In a circular path control apparatus for an orthogonal multi-axis servomechanism including, for each of a plurality of driving shafts of said servomechanism, a position signal adder, a position controller, a speed signal adder, a speed control amplifier, a drive motor, a rotation speed detector for said drive motor, and a position detector, said position signal adder calculating a difference between a command position signal and a present position signal of each said driving shaft, said position controller being responsive to a signal sent from said position signal adder to calculate a driving shaft speed command signal, said speed signal adder calculating a difference between said speed command signal calculated by said position controller and a driving shaft present speed signal detected by said drive motor rotation speed detector, and said speed control amplifier being responsive to a signal sent from said speed signal adder to rotate said drive motor, the improvement comprising: a contour error detector; a proportional plus integral controller and adder means which are additionally provided for each said driving axis; said contour error detector calculating a contour error vector from a response position on a command circular path and a response position on a response circular path, a cumulative absolute value of said contour error vector, and an angle made by each said driving shaft with a vector extending to said response position from a center of rotation; said proportional plus integral controller for each said driving shaft calculating a correction quantity by multiplying a corresponding shaft direction component value of said contour error vector by a constant and multiplying a product of said cumulative absolute value of said contour error vector and a cosine value of said angle made by each said driving shaft and said last-mentioned vector by another constant; and said adding means for each said driving shaft produces a sum of said correction quantity and the speed command signal from said position controller and applying the same as an input to said speed signal adder.
Claim 3
Dependent Claim
303 words
A circular path control apparatus for an orthogonal multi-axis servomechanism including, for each of a plurality of driving shafts of said servomechanism, a position signal adder, a position controller, a speed signal adder, a speed control amplifier, a drive motor, a drive motor rotation speed detector, and a position detector, said position signal adder calculating a difference between a command position and a present position signal of each said driving shaft, said position controller calculating a driving shaft speed command signal in response to a signal sent from said position signal adder, said speed signal adder calculating a difference between said speed command signal calculated by said position controller and a driving shaft present speed signal detected by said drive motor rotation speed detector, and said speed control amplifier rotating said drive motor in response to a signal sent from said speed signal adder, the improvement comprising: a circular-arc center angle error detector; and a proportional controller and adding means provided additionally for each driving shaft; said circular-arc center angle error detector calculating a circular-arc center angle error from a command position on a command circular path and a response position on a response circular path, the square of said circular-arc center angle error, and an angle made by each said driving shaft with a vector extending to said response position from a center of rotation: said proportional controller calculating a correction quantity for each said driving shaft speed command as a quantity proportional to a product of said square of circular-arc center angle error and a cosine of said angle made by each said driving shaft with said last-mentioned vector; and said adding means producing a sum of said correction quantity and the speed command signal from said position controller and applying the same as an input to said speed signal adder.
Claim 4
Dependent Claim
303 words
A circular path control apparatus for an orthogonal multi-axis servomechanism including, for each of a plurality of driving shafts of said servomechanism, a position signal adder, a position controller, a speed signal adder, a speed control amplifier, a drive motor, a drive motor rotation speed detector, and a position detector, said position signal adder calculating a difference between a command position and a present position signal of each said driving shaft, said position controller calculating a driving shaft speed command signal in response to a signal sent from said position signal adder, said speed signal adder calculating a difference between said speed command signal calculated by said position controller and a driving shaft present speed signal detected by said drive motor rotation speed detector, and said speed control amplifier rotating said drive motor in response to a signal sent from said speed signal adder, the improvement comprising: a circular-arc center angle error detector; and a proportional controller and adding means provided additionally for each driving shaft; said circular-arc center angle error detector calculating a circular-arc center angle error from a command position on a command circular path and a response position on a response circular path, the square of said circular-arc center angle error, and an angle made by each said driving shaft with a vector extending to said response position from a center of rotation: said proportional controller calculating a correction quantity for each said driving shaft speed command as a quantity proportional to a product of said square of circular-arc center angle error and a cosine of said angle made by each said driving shaft with said last-mentioned vector; and said adding means producing a sum of said correction quantity and the speed command signal from said position controller and applying the same as an input to said speed signal adder.
References Cited (Backward Citations)
US4707780A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-06-28 | 1991-12-28 | 1992-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-06-28 | 1995-12-28 | 1996-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-06-28 | 1999-12-28 | 2000-06-28 | $7700.00 | Window Closed / Lapsed |