NCJ Number
42490
Date Published
1977
Length
78 pages
Annotation
THIS REPORT EXAMINES THE RESULTS OF A STUDY OF TWO ANTILOCK BRAKE SYSTEMS TO DETERMINE IF THESE WOULD OFFER SIGNIFICANT IMPROVEMENTS IN THE SAFETY, ECONOMY, AND PRODUCTIVITY OF THE POLICE PATROL FUNCTION.
Abstract
THE DEVELOPMENT OF A FOUR-WHEEL ANTILOCK BRAKE SYSTEM WAS PURSUED RATHER THAN UTILIZING A REAR-WHEEL-ONLY ANTILOCK SYSTEM BECAUSE OF THE SIGNIFICANT IMPROVEMENTS IN STOPPING AND HANDLING PERFORMANCE AFFORDED BY A FOUR-WHEEL SYSTEM. TWO SYSTEMS WERE DEVELOPED, ONE USING A HYDRAULIC ACTUATOR AND THE OTHER USING A PNEUMATIC ACTUATOR. THE SYSTEMS WERE INSTALLED AND TESTED ON LEASED VEHICLES WITH POLICE SUSPENSION AND SUSPENSION AND SUCCESSFULLY DEMONSTRATED ON SKID PADS. IN ADDITION, THE HYDRAULIC ACTUATOR SYSTEM WAS INSTALLED ON A PROTOTYPE POLICE VEHICLE WHICH SERVED AS THE INITIAL TEST BED FOR DEVELOPMENT OF THE IMPROVED POLICE PATROL CAR. THE TEST RESULTS SHOWED THAT WITH THE ANTILOCK BRAKE SYSTEM ON THE IMPROVEMENT IN STOPPING DISTANCE RANGED UP 36 PERCENT AS COMPARED TO THE STOPPING DISTANCE WITHOUT THE ANTILOCK FEATURE OPERATIVE. ALSO, FULL CONTROL OF THE VEHICLE WAS MAINTAINED THROUGHOUT A HARD-BRAKING APPLICATION TO A FULL STOP WHEN MAKING LANE CHANGES, STRAIGHT STOPS ON HOMOGENEOUS AND SPLIT COEFFICIENT SURFACES, AND STOPS ON A CURVE WHEN THE ANTILOCK SYSTEM WAS OPERATIVE AS COMPARED TO TOTAL LOSS OF CONTROL WITHOUT THE SYSTEM. ELECTROMAGNETIC COMPATABILITY AND RADIO FREQUENCY INTERFERENCE TESTS WERE CONDUCTED AND PROVED THAT THE ANTILOCK BRAKE SYSTEMS TESTED DID NOT MALFUNCTION WHEN SUBJECTED TO STRONG EXTRANEOUS ELECTROMAGNETIC FIELDS.(AUTHOR ABSTRACT MODIFIED)...EB