NCJ Number
43754
Date Published
1977
Length
192 pages
Annotation
FIELD TRIALS AND ENGINEERING TESTS OF AN AUTOMATED SYSTEM FOR TRACKING VEHICLES ARE DOCUMENTED.
Abstract
THE FAIRCHILD LOCATION SUBSYSTEM TRACKS THE MOVEMENT OF RANDOM-ROUTE VEHICLES (POLICE PATROL CARS, TAXIS, FIRE-FIGHTING EQUIPMENT, TRUCKING FLEETS) AND FIXED-ROUTE VEHICLES (E.G., BUSES AND RAPID TRANSIT SYSTEMS). THE TRACKING SYSTEM USES SEMIPASSIVE SIGNPOSTS DEPLOYED AT KNOWN LOCATIONS. ELECTRONIC EQUIPMENT ONBOARD THE VEHICLES TRANSMITS CODES FROM EACH SIGNPOST VIA A RADIO LINK TO A CONTROL CENTER. THE SIGNPOST CODE ESTABLISHES THE VEHICLE'S LOCATION AT A FIXED REFERENCE, AND THE ONBOARD EQUIPMENT THEN ESTABLISHES THE VEHICLE'S CURRENT POSITION RELATIVE TO THE LAST SIGNPOST CODE SO THAT A VEHICLE LOCATION CAN BE ESTABLISHED UPON EACH POLLING REQUEST FROM THE CONTROL CENTER. THE CONTROL CENTER COMPUTER USES THE POLLED VEHICLE LOCATION INFORMATION TO ESTABLISH VEHICLE POSITIONS ON A STREET MAP. FOR FIXED-ROUTE VEHICLES, THE COMPUTER ALSO VERIFIES VEHICLE PROGRESS IN REFERENCE TO STORED ROUTE SCHEDULES. TEST PROCEDURES AND RESULTS ARE DESCRIBED FOR FIXED- AND RANDOM-ROUTE FIELD STUDIES AND FOR SPECIAL CASE TESTS (OPERATION IN PROXIMITY TO AN OIL TANK FARM AND AN AIRPORT, OPERATION WITH MISSING SIGNPOSTS AND WITH ROUTE DEVIATIONS). ENGINEERING TEST RESULTS ARE REPORTED FOR SIGNPOST BATTERY DRAIN, OPERATIONAL VOLTAGE, ADJACENT CHANNEL INTERFERENCE, AND OTHER TECHNICAL ASPECTS OF SYSTEM OPERATION. IMPROVEMENTS RESULTING FROM THE FIELD TESTS ARE NOTED. SUPPORTING DATA ARE APPENDED.