Multizone capacitive anti-pinch system

Abstract

An anti-pinch assembly is used for a closure panel supported by the motor vehicle. The closure panel is movable between an open position and a closed position. A controller is operably connected to the closure panel for controlling the operation of the closure panel. A position sensor is connected to the controller for indicating the position of the closure panel as the closure panel moves between the open and closed positions. A capacitive sensor is mounted on the frame of the vehicle and connected to the controller for providing an output signal to the controller indicative of the presence of a foreign object in the path of the closure panel. The controller varies the function of the capacitive sensor through a plurality of threshold levels as a function of the position of the closure panel as indicated by the position indicator. In a critical zone of travel, namely, travel of the closure panel nearing the closed position, the capacitive sensor can be utilized in either a contact mode or a non-contact mode or a combination of both.

1 . An anti-pinch assembly for a closure panel of a motor vehicle having a closure frame and said closure panel is movable between open and closed positions along a path using a closure motor, said anti-pinch assembly comprising: 
 a controller;    a position sensor operably connected to said controller, said position sensor generating a position signal indicative of a position of the closure panel as the closure panel moves; and    a capacitive sensor mounted on the motor vehicle and positioned to sense a capacitive field and operably connected to said controller to provide an output signal to said controller, said capacitive sensor operative to sense changes in the capacitive field resulting from an object extending between the closure frame and the closure panel and thereafter stops the closure panel from moving towards the closed position, wherein said controller operates said capacitive sensor at a plurality of threshold levels providing multiple sensitivity levels.    
   
   
       2 . An anti-pinch assembly as claimed in  claim 1  wherein said controller includes a threshold generator to alter said plurality of threshold levels upon changing ambient conditions.  
   
   
       3 . An anti-pinch assembly as claimed in  claim 2  wherein said threshold generator includes a threshold capacitor electrically connected to said controller in parallel with said capacitive sensor.  
   
   
       4 . An anti-pinch assembly as claimed in  claim 3  wherein said threshold generator further includes a pulse generator for generating a series of electrical pulses and for transmitting said series of electrical pulses to said capacitive sensor to charge same.  
   
   
       5 . An anti-pinch assembly as claimed in  claim 4  wherein said threshold generator includes a counter operably connected to said pulse generator to count each of said series of electrical pulses.  
   
   
       6 . An anti-pinch assembly as claimed in  claim 5  wherein said position sensor is disposed adjacent the closure panel to identify the position of the closure panel.  
   
   
       7 . An anti-pinch assembly as claimed in  claim 5  where said position sensor is disposed adjacent the closure motor.  
   
   
       8 . An anti-pinch assembly as claimed in  claim 7  wherein said position sensor is a Hall effect sensor.  
   
   
       9 . An anti-pinch assembly as claimed in  claim 8  wherein said capacitive sensor extends along a portion of the closure frame.  
   
   
       10 . An anti-pinch assembly as claimed in  claim 9  wherein said capacitive sensor is fabricated from an elongated conductor.  
   
   
       11 . An anti-pinch assembly as claimed in  claim 1  wherein said controller varies the function of the capacitive sensor through a plurality of threshold levels as a function of the position of the closure panel as indicated by the position indicator.  
   
   
       12 . An anti-pinch assembly as claimed in  claim 1  wherein the capacitive sensor operates in a contact mode, a non-contact mode or a combination of both.  
   
   
       13 . An anti-pinch assembly for a closure panel of a motor vehicle having a closure frame and said closure panel is movable between open and closed positions with respect to the closure frame using a closure motor, said anti-pinch assembly comprising: 
 a controller;    a position sensor disposed adjacent the closure motor and operably connected to said controller, said position sensor generating a position signal indicative of a position of the closure panel as the closure panel moves; and    a capacitive sensor mounted on the motor vehicle and operably connected to said controller to provide an output signal to said controller, wherein said controller operates said capacitive sensor at a plurality of sensitivity levels allowing said capacitive sensor to identify a foreign object extending through the closure frame and stops the closure panel from moving toward the closed position when said capacitive sensor identifies the foreign object extending through the closure frame.    
   
   
       14 . An anti-pinch assembly as claimed in  claim 13  wherein said position sensor is a Hall effect sensor.  
   
   
       15 . An anti-pinch assembly as claimed in  claim 14  wherein said controller includes a threshold generator to alter said plurality of threshold levels upon changing ambient conditions.  
   
   
       16 . An anti-pinch assembly as claimed in  claim 15  wherein said threshold generator includes a threshold capacitor electrically connected to said controller in parallel with said capacitive sensor.  
   
   
       17 . An anti-pinch assembly as claimed in  claim 16  wherein said threshold generator further includes a pulse generator for generating a series of electrical pulses and for transmitting said series of electrical pulses to said capacitive sensor to charge same.  
   
   
       18 . An anti-pinch assembly as claimed in  claim 17  wherein said threshold generator includes a counter operably connected to said pulse generator to count each of said series of electrical pulses.  
   
   
       19 . An anti-pinch assembly as claimed in  claim 18  wherein said capacitive sensor extends along a portion of the closure frame.  
   
   
       20 . An anti-pinch assembly as claimed in  claim 19  wherein said capacitive sensor is fabricated from an elongated conductor.  
   
   
       21 . A method for detecting the presence of an obstacle in a path of a closure panel movable by a motor between an open position and a closed position using a capacitive sensor, a threshold capacitor and a pulse generator, the method comprising the steps of: 
 generating a threshold signal;    measuring the dielectric in a field extending in the path of the closure panel to generate a measured signal;    comparing the measured signal with the threshold signal; and    stopping the closure panel from moving towards the closed position when the measured signal exceeds the threshold signal.    
   
   
       22 . A method as claimed in  claim 21  wherein the step of generating a threshold signal includes the step of producing a pulsed signal.  
   
   
       23 . A method as claimed in  claim 22  including the step of counting the pulses in the pulsed signal to create a pulse count.  
   
   
       24 . A method as claimed in  claim 23  including the step of comparing the pulse count to the threshold signal.  
   
   
       25 . A method as claimed in  claim 24  wherein the step of stopping the closure panel occurs when the pulse count exceeds the threshold signal.  
   
   
       26 . A method as claimed in  claim 25  wherein the threshold signal includes a plurality of threshold values.  
   
   
       27 . A method as claimed in  claim 26  including the step of using one of the plurality of threshold values based on the position of the closure panel along its path.  
   
   
       28 . A method as claimed in  claim 27  including the step of using the capacitive sensor to generate the measured signal.  
   
   
       29 . A method as claimed in  claim 28  including the step of using the threshold capacitor to generate the threshold signal.