An optical object detection system for sensing obstructions to low speed vehicles

Abstract

An object detection system to sense obstructions in the path of low speed vehicles is described. The system uses a pulsed GaAs diode laser as an illuminator, and a PIN photodiode as a detector. Reliable detection of objects with an effective area as small as 2 0.5 ft was achieved. A signal processor using active filters and a phase-locked loop tone decoder was employed for both phase and frequency rejection of undesired signals, and detection of objects under high ambient light conditions.