Combination capacitive and resistive obstacle sensor

Abstract

An obstacle sensor for a closure panel of a vehicle includes an elongate non-conductive case which encloses a first, second, and third elongate conductive electrodes. The first and second electrodes are separated by a portion of the case, with a capacitance between the first and second electrodes changing when an obstacle approaches the first electrode. The changed capacitance of the obstacle sensor provides a proximity indication of the obstacle to the obstacle sensor. The second and third electrodes are separated by an air gap formed in the case, with a resistance between the second and third electrodes changing when the second and third electrodes come into contact upon compression of the case by the obstacle. The changed resistance of the obstacle sensor provides a contact indication of the obstacle with the obstacle sensor.

What is claimed: 
     
         1 . An closure system for a motor vehicle comprising:
 a closure panel pivotably mounted to a body of the vehicle for movement between open and closed positions; and   an obstacle sensing system including an obstacle sensor having an elongate non-conductive case enclosing a first, second, and third elongate conductive electrodes, said first and second electrodes being separated by a portion of said case, a capacitance between said first and second electrodes changing when an obstacle approaches said first electrode to provide a proximity indication of the obstacle to the obstacle sensor, and said second and third electrodes being separated by an air gap formed in the case, a resistance between said second and third electrodes changing when the second and third electrodes come into contact upon compression of the case by the obstacle to provide a contact indication of the obstacle with the obstacle sensor, wherein said second and third electrodes are bounded by compressible spring side walls of said case to allow said second and third electrodes to contact one another when the obstacle sensor is contacted by the obstacle.