GB1344082A - Vehicle location sensing means - Google Patents

Abstract

1344082 Positioning warehouse vehicle CLARK EQUIPMENT CO 20 May 1971 [15 June 1970] 15936/71 Heading G4H A system for positioning a vehicle at one of a plurality of discrete positions along a linear path comprises a binary coded plate placed at each position adapted to be read by a magnetic sensor comprising a plurality of permanent magnets associated each with a reed switch and mounted on the vehicle. As shown, a multibrator 160 generates clock pulses received by a counter 162 adapted to count through the number of available positions, to reset and start again. The code plate 50 of the station at which the vehicle is at rest or passing through is sensed and a binary signal emitted by 60 is presented at a comparator 168. The address of the desired station is inserted at 164 and presented at comparator 180, the other inputs to 168, 180 being from counter 162, outputs being derived upon coincidence of the count output and the respective comparator inputs. The outputs along lines 172, 182 are taken to a circuit 174 to sense which of the outputs arrives first and thereby to control a motor 194, 196 of the vehicle via a circuit 186 to drive in the appropriate direction. The two pulses also cause starting and stopping of a counter 198 adapted to receive pulses from the oscillator 160 via AND gate 200 enabled by the sensing of an element on the code plate 50 indicative of the correct juxtaposition of the items 50, 60. The count obtained is indicative of the distance of travel required and one of three speeds is selected at 212 accordingly. At the end of the count in 162, the resetting also resets the elements 174, 198 and the information at the control 194 is updated at each position sensing. The outputs of the comparators 168, 180 are also taken to an AND gate 176, enabled upon coincidence of the outputs. In that event, a fine positioning means 224 is enabled operative on the elements of the code plate 50 indicative of a correct alignment.