Soft landing method for probe assembly
US5952589A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 11, 1996 |
| Grant date | Sep 14, 1999 |
| Priority date | — |
| Expiry date | Jan 11, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05B2219/50109
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method and device for moving a probe assembly into soft contact with a work surface includes initially placing the probe into an approach position. Advancement of the probe along a substantially perpendicular path toward the work surface is then controlled by applying a restraining force on the probe. This resisting force is decreased until the weight of the probe assembly just overcomes the static friction forces that are acting on the probe. After the static friction forces are overcome, the probe advances along a path toward the work surface. By monitoring this advancement, soft contact of the probe with the work surface can be determined when the velocity of the probe changes to zero. First, the position of the probe can be monitored to advance the probe along the path through a known travel distance. Second, the velocity of probe advancement can be monitored to indicate soft contact when velocity changes to zero. Third, accelerations of the probe can be monitored to indicate soft contact when the acceleration exceeds a predetermined threshold. Fourth, a load sensor can be placed on the probe to indicate soft contact when the load sensor generates a predetermined value. And, …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.