Capacitive detection systems and methods

Abstract

The invention is related to capacitive sensing and detection systems and methods. In one embodiment, a capacitive sensor system comprises a first electrode arrangement having a first characteristic and related to a first capacitance, a second electrode arrangement having a second characteristic different from the first characteristic and related to a second capacitance, and a control unit coupled to the first and second electrode arrangements and configured to identify an object-dependent variable from at least one of the first and second characteristics and first and second capacitances.

1 . A capacitive sensor system comprising:
 a first electrode arrangement having a first characteristic and related to a first capacitance;   a second electrode arrangement having a second characteristic different from the first characteristic and related to a second capacitance; and   a control unit coupled to the first and second electrode arrangements and configured to identify an object-dependent variable from at least one of the first and second characteristics and first and second capacitances.   
     
     
         2 . The system of  claim 1 , further comprising:
 at least one additional electrode arrangement having a third characteristic and related to a third capacitance, wherein the control unit is coupled to the third electrode arrangement and is configured to identify the object-dependent variable from at least one of the first, second and third characteristics and first, second and third capacitances.   
     
     
         3 . The system of  claim 2 , wherein the first, second and characteristics are each selected from the group consisting of an electrode size, an electrode dimension, a number of electrodes, an electrode stack configuration, an adjacent material deposit, an electrode distribution and an electrode orientation. 
     
     
         4 . The system of  claim 2 , wherein the first, second and at least one additional electrode are arranged along a length. 
     
     
         5 . The system of  claim 4 , wherein the length is related to a dimension of a vehicle component. 
     
     
         6 . The system of  claim 5 , wherein the vehicle component is a bumper or a fender. 
     
     
         7 . The system of  claim 1 , wherein the control unit comprises a sensor model configured to identify the object-dependent variable from at least one of the first, second and third characteristics and first, second and third capacitances. 
     
     
         8 . The system of  claim 7 , wherein the object-dependent variable is a distance. 
     
     
         9 . The system of  claim 7 , wherein the sensor model is a parallel plate capacitor model. 
     
     
         10 . A sensor system comprising:
 a first set of electrodes configured to direct a first electric field in a first direction relative to a vehicle;   a second set of electrodes configured to direct a second electric field in a second direction relative to a vehicle; and   a control unit coupled to the first and second sets of electrodes and configured to detect changes in the first and second electric fields.   
     
     
         11 . The system of  claim 10 , wherein the first and second sets of electrodes are mounted to one of a bumper or a fender of the vehicle. 
     
     
         12 . The system of  11 , further comprising a shield between the first and second sets of electrodes. 
     
     
         13 . The system of  claim 11 , wherein the first direction is outward and the second direction is inward relative to the vehicle. 
     
     
         14 . The system of  claim 10 , further comprising at least one capacitive sensor coupled to the control unit. 
     
     
         15 . The system of  claim 14 , wherein the at least one capacitive sensor is arranged near a shock absorber of the vehicle. 
     
     
         16 . A method comprising:
 configuring a first set of electrodes to detect a change in an electric field directed externally relative to a vehicle;   configuring a second set of electrodes to detect a change in an electric field directed internally relative to a vehicle; and   providing a path to communicate information from the first and second sets of electrodes.   
     
     
         17 . The method of  claim 16 , further comprising detecting a pre-crash event from information from the first set of electrodes. 
     
     
         18 . The method of  claim 17 , further comprising detecting an impact event from information from the second set of electrodes. 
     
     
         19 . The method of  claim 16 , further comprising:
 configuring a third set of electrodes to detect a change in a shock absorber of the vehicle; and   providing a path to communicate information from the third set of electrodes.   
     
     
         20 . The method of  claim 19 , further comprising detecting an impact event from information from the third set of electrodes.