A Proximity Sensor for the Steering Wheel Based on Leaky Coaxial Cable

A practical readily embeddable proximity sensor based on a leaky coaxial cable (LCX) is proposed for detecting the presence and position of hands on a steering wheel. Different LCX configurations are analyzed both numerically and experimentally. For numeric simulations, the finite-difference time-domain (FDTD) method is applied to a square cross-section leaky coaxial cable. A comparable-sized 3D-printed LCX with various configurations is also measured to verify the design of the sensor. Based on those numerical and experimental results, a prototype steering wheel proximity sensor is designed, fabricated, and then embedded into a Honda 2013 Acura MDX steering wheel. Through the use of a network analyzer and the inverse discrete Fourier Transform, the hand position information is obtained.