A method for detecting collisions between an obstacle and an electromechanical system having a mechanical output controlled by a servo system includes inputting a forcing function xi to the servo system to direct the mechanical output to move in an intended manner. A difference signal is generated at...http://www.google.com/patents/US20050088132?utm_source=gb-gplus-sharePatent US20050088132 - Methods and systems for reducing unintentional collisions
