TDR-Based System for Detection of Hand Touch Positionings on an Object, Particularly on a Steering Wheel for the Purpose of Hand Gesture Recognition

A method of recognizing a hand gesture established by a sequence of hand touch positionings on an object, particularly on a steering wheel (38) by operating a sensing system (10) comprising at least one electrically conducting signal line (12), which is arranged to extend along a part of a surface of the object with a priori knowledge about a relation between a distance of any portion of the at least one signal line (12) from a reference point (44) and information on a position on the object, a signal voltage source (26) that is operatively connectable to each signal line (12), and a control and evaluation unit (28) that is operatively connectable to each signal line (12). The method comprises at least steps of: providing (50) to a signal line (12) a time- dependent measurement signal; receiving (52) the measurement signal after being at least partially reflected by at least one portion of the signal line (12); determining (54) positions on the object of the portions of the signal line (12) that have reflected the measurement signal; comparing an obtained plurality of stored successively determined positions on the object with at least one predefined pattern of successive positions to derive (60) a measure of similarity; and providing (64) an output signal that is indicative of the predefined pattern of successive positions if the derived measure of similarity is lower than a predefined threshold value (Thr).