Light tracking automatic navigation system

Claim 1

A navigation system for detecting the position and controlling the movement of a vehicle (1) which is intended to be automatically guided along a predetermined path (3; 20) on a supporting surface (2), such as a floor or the like, said system comprising at least one light source (4; 18) and at least one detector (5; 19) responsive to the light emitted from the light source (4; 18), one of said light source (4; 18) and said detector (5; 19) being mounted on and accompanying the vehicle (1) and the other of said light source (4; 18) and said detector (5; 19) being arranged substantially stationarily in relation to said supporting surface (2), said system further comprising a signal processing unit (10) having memory means (13) in which path control information (12) corresponding to said path (3) is stored, comparator means (11) adapted to compare the path control information (12) stored in said memory means (13) with positional information produced by said system and corresponding to the position of the vehicle (1) on said supporting surface (2), in order, when said path control information and said positional information differ from each other, to emit control signals (15) for controlling the movement of the vehicle (1), and signal transmission means (16) adapted to transmit said control signals (15) to the vehicle (1) to cause it to move along said path (3; 20), c h a r a c t e r i z e d in that the detector (5; 19) is a position-sensitive semiconductor detector having a substantially planar, extended continuous sensing area (7), said detector (5; 19) being adapted to receive the light which is emitted from the light source (4; 18) and is then incident on a restricted part (P) of said sensing area (7), the position of the vehicle (1) on said supporting surface (2) corresponding to the position of the illuminated part of the sensing area (7) on the detector (5; 19), said detector (5; 19) being adapted,in response to the light detected within said restricted part (P), to emit electric signals indicating where on said sensing area (7) the light emitted from the light source (4; 18) is incident, said positional information which is intended to be compared with the path control information (12) stored in said memory means (13), being derived from the electric signals emitted by said detector (5; 19).