Continuously adaptive moisture sensor system for wiper control
US4916374A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1989 |
| Grant date | Apr 10, 1990 |
| Priority date | — |
| Expiry date | Feb 28, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S318/02
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
An adaptive moisture sensor system includes a moisture sensor unit having a moisture sensor, which produces a moisture signal, a reference signal generating circuit and a comparator circuit for comparing the moisture signal with the reference signal and for producing an indication to the vehicle's wiper control of the relationship between the signals. The reference signal generating circuit indicates a fast positive signal processing circuit for rapidly processing changes in the moisture signal representing decreasing moisture and a slow signal processing circuit to process changes of the moisture signal in both directions at a slow rate. The fast positive signal processing circuit is only enabled during rain conditions due to a contaminant film on the sensed window. The reference signal generating circuit further includes a fast negative signal processing circuit which responds to a stable moisture signal occuring during rain conditions by rapidly offsetting the reference signal to discontinue wiper operation. Multiple sensing assemblies, each including a sensor, a reference signal generating circuit and a comparator, are combined with a master control unit, which responds to any …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.