CONTACT DETECTION BY MEANS OF AN ULTRASONIC SENSOR SYSTEM

A method for contact detection for an ultrasonic sensor system installed in a concealed or unconcealed manner is disclosed. The method involves detecting reference surroundings information, comprising a time profile of a signal with: noise signal information relating to a wall material and/or airborne sound signal information, using an ultrasonic sensor of the ultrasonic sensor system; storing the reference surroundings information; detecting real-time surroundings information, comprising a time profile of a signal with: noise signal information relating to the wall material and/or airborne sound signal information and/or object sound signal information relating to an object in contact with the wall material, using the ultrasonic sensor; and forming a difference signal between the surroundings information of reference surroundings information and real-time surroundings information, using a computational unit. The difference signal can be interpreted in a further step.