System for Sensing a Position of a First Member Relative to a Second Member Based on a Radio Frequency Characteristic of a Bias Member

Abstract

A system for sensing a position of a first member relative to a second member based on a radio frequency characteristic of a bias member is disclosed. The bias member may be configured to bias the second member relative to the first member. Radio frequency circuitry may be configured to apply a radio frequency signal to the bias member and provide one or more signals indicative of a position of the first member relative to the second member based on a radio frequency characteristic of the bias member.

What is claimed is: 
     
         1 . A position sensor system comprising:
 a first member:   a second member movable relative to the first member;   a bias member configured to bias the second member relative to the first member; and   radio frequency circuitry configured to apply a radio frequency signal to the bias member and provide one or more signals indicative of a position of the first member relative to the second member based on a radio frequency characteristic of the bias member.   
     
     
         2 . The position sensor system of  claim 1 , wherein the bias member is coupled to each of the first member and second member. 
     
     
         3 . The position sensor system of  claim 1 , wherein the bias member is configured to bias the second member away from the first member. 
     
     
         4 . The position sensor system of  claim 1 , wherein the second member is pivotally coupled to the first member. 
     
     
         5 . The position sensor system  claim 1 , wherein the bias member comprises a coil spring. 
     
     
         6 . The position sensor system of  claim 1 , wherein the radio frequency circuity comprises a radio frequency generator electrically coupled with the bias member at a first location of the bias member and configured to apply the radio frequency signal to the bias member at the first location. 
     
     
         7 . The position sensor system of  claim 6 , wherein the radio frequency circuity comprises a spectrum analyzer electrically coupled with the bias member at the first location of the bias member and configured to detect the radio frequency signal reflected by the bias member at the first location. 
     
     
         8 . The position sensor system of  claim 7 , further comprising a splitter having a first port, a second port, and a third port, and wherein the first port is connected to the bias member at the first location, and wherein the second port is connected to the frequency generator, and wherein the third port is connected to the spectrum analyzer such that each of the frequency generator and spectrum analyzer are electrically coupled with the bias member at the first location. 
     
     
         9 . The position sensor system of  claim 1 , wherein the radio frequency circuity comprises a spectrum analyzer configured to detect an amplitude of a reflected radio frequency signal reflected by the bias member. 
     
     
         10 . The position sensor system of  claim 9 , wherein the one or more signals indicative of the position of the first member relative to the second member provided by the radio frequency circuity are positively correlated with the amplitude detected by the spectrum analyzer. 
     
     
         11 . The position sensor system of  claim 1 , wherein the radio frequency signal comprises a fixed amplitude sinusoidal signal. 
     
     
         12 . The position sensor system of  claim 11 , wherein the fixed amplitude sinusoidal signal has a frequency that ranges from about 50 MHz to about 2 GHz. 
     
     
         13 . A position sensor system for a vehicle pedal comprising:
 a base member;   a pedal member movable relative to the base member;   a bias member configured to bias the pedal member away from the base member;   radio frequency circuitry configured to apply a radio frequency signal to the bias member and provide one or more signals indicative of a position of the base member relative to the pedal member based on a radio frequency characteristic of the bias member.   
     
     
         14 . The position sensor system of  claim 13 , wherein the pedal member comprises an accelerator pedal. 
     
     
         15 . The position sensor system of  claim 13 , wherein the bias member is coupled to each of the base member and pedal member, wherein the pedal member is pivotally coupled to the base member. 
     
     
         16 . The position sensor system of  claim 13 , wherein the bias member comprises a coil spring. 
     
     
         17 . The position sensor system of  claim 13 , wherein the radio frequency circuity comprises a radio frequency generator electrically coupled with the bias member at a first location of the bias member and configured to apply the radio frequency signal to the bias member at the first location. 
     
     
         18 . The position sensor system of  claim 17 , wherein the radio frequency circuity comprises a spectrum analyzer electrically coupled with the bias member at the first location of the bias member and configured to detect the radio frequency signal reflected by the bias member at the first location, wherein the position sensor system further comprises a splitter having a first port, a second port, and a third port, and wherein the first port is connected to the bias member at the first location, and wherein the second port is connected to the frequency generator, and wherein the third port is connected to the spectrum analyzer such that each of the frequency generator and spectrum analyzer are electrically coupled with the bias member at the first location. 
     
     
         19 . The position sensor system of  claim 13 , wherein the radio frequency circuity: comprises a spectrum analyzer configured to detect an amplitude of a reflected radio frequency signal reflected by the bias member, wherein the one or more signals indicative of the position of the base member relative to the pedal member are positively correlated with the amplitude detected by the spectrum analyzer. 
     
     
         20 . A method for sensing a position of a first member relative to a second member, the method comprising:
 applying a radio frequency signal to a bias member that is configured to bias the second member relative to the first member;   detecting a radio frequency characteristic of the bias member; and   providing one or more signals indicative of a position of the first member relative to the second member based on the radio frequency characteristic of the bias member.