Abstract: An electro-optical detection system for detecting objects within the boundaries of a monitored zone, comprises a plurality of LED emitter and photodetector pairs. Each emitter (12) emits a beam of pulses of light energy into the monitored zone, and its paired photodetector (14) detects light energy including light energy from the beam that is reflected from an object within the monitored zone and generates light detection signals. A controller (10) operates the emitter and photodetector pairs and evaluates the light detection signals to discriminate between light energy of beams reflected from an object within the monitored zone and other light energy. The controller can selectively adjust the evaluation of the light detection signals to adjust the effective boundaries of the monitored zone.

Abstract: A method of defining a sensing system for detecting the presence of an object in a volume of space under surveillance by determining the optimal placement of a plurality of energy beams which are projected into the volume which comprises the steps of (A) placing the object at a preselected position within the space; (B) directing a plurality of sample beams of energy, which have a predetermined orientation, from a source onto the object; (C) detecting the reflections of the sample beam energy from points on the object by energy detectors; (D) recording the preselected position of the object, the predetermined orientation of sample beams, and the detection status of the energy detectors; (E) changing the equatorial and azimuthal angles of each of the beams and repeating steps (B), (C) and (D); (F) moving the source of the sample beams relative to the object; (G) repeating steps (B) through (F) to produce spatial maps of the locations at which the object is positioned when each of the energy detectors detect re

Abstract: A collision avoidance system includes an object detection module (50) mounted on a vehicle (54) for detecting the presence of an object (68) within a monitored zone of space (56) adjacent the vehicle (54). The detection unit (50) emits a plurality of beams (66) of infrared energy and detects the reflection of such energy from objects (68) within the zone. The detection module (50) is typically activated by the host vehicle's electrical turn signal, The detection module (50) includes a plurality of associated pairs of light emitting diodes (134) and photosensitive detectors (128) for sensing the reflected light.

Abstract: Apparatus for detecting the presence of an object within an area under surveillance employs an electro-optical emitter for directing light into the area and an electro-optical receiver for sensing light reflected from the object which originates from the emitter. The emitter emits light energy of a preselected wavelength and is modulated at a preselected frequency to provide the emanating light energy with a characteristic signature. Light reflected by an object within the area under surveillance is filtered and converted to an electrical signal which varies in accordance with the magnitude of the filtered light having the preselected wavelength and modulation frequency. A selected portion of the electrical signal is amplified by a band-pass amplifier and is synchronously sampled in accordance with the modulation frequency to determine the magnitude of the filtered light which originated from the emitter.

Abstract: Apparatus for detecting the presence of an object within an area under surveillance employs an electro-optical emitter for directing light into the area and an electro-optical receiver for sensing light reflected from the object which originates from the emitter. The emitter emits light energy of a preselected wavelength and is modulated at a preselected frequency to provide the emanating light energy with a characteristic signature. Light reflected by an object within the area under surveillance is filtered and converted to an electrical signal which varies in accordance with the magnitude of the filtered light having the preselected wavelength and modulation frequency. A selected portion of the electrical signal is amplified by a band-pass amplifier and is synchronously sampled in accordance with the modulation frequency to determine the magnitude of the filtered light which originated from the emitter.