System friction compensation in vector plotters
US4935878A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 4, 1989 |
| Grant date | Jun 19, 1990 |
| Priority date | — |
| Expiry date | Jan 4, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D18/008
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and associated apparatus for frictionally compensating a vector plotter having an X-drive motor for driving plotting apparatus in +X and -X directions and a Y-drive motor for driving plotting apparatus in +Y and -Y directions and logic for applying positive and negative electrical drive currents to the respective motors to affect plotting. Plotter accuracy and associated plot quality are improved by the method which comprises the steps of, providing a memory for holding +X, -X, +Y, and -Y friction compensation factors; prior to the time of plotting with the vector plotter, calibrating the plotter by (1) causing the motors to move the plotting apparatus in +X, -X, +Y, and -Y directions, (2) measuring the friction during the +X, -X, +Y, and -Y directional movement, and (3) calculating and storing the +X, -X, +Y, and -Y friction compensation factors in the memory. At the time of plotting with the vector plotter, the method comprises adjusting the current applied to the drive motors by the plotter logic as a function of the proper friction compensation factor in the memory for the motor moved and the direction of motor movement.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.