The report describes the development of a test procedure for evaluating the performance characteristics of automobiles in combined cornering-braking operation. The procedure involves a series of brake applications at varying levels of applied pedal force from an initial 40 mph and a lateral acceleration of 0.4g for both directions of turn on a dry road surface. The experimental and analytical studies covered initial speed, initial lateral acceleration, road surface skid number, brake pedal force, wheel lock-up patterns, loading, use of steering control, driver skill, vehicle characteristics, performance measurement parameters, and brake application techniques. Results of the experimental investigations of these factors are described in detail. It is shown that total performance in the maneuver may be determined by measurements of average deceleration and final lateral displacement and heading angle error referenced to the projected initial path. The effectiveness of driver steering control in panic stopping (i.e., high brake pedal forces) is seen to be restricted to a narrow range of deceleration for vehicles which tend to spin out.
Vehicle Directional Control During Braking-in-a-Turn. Volume I, Summary Report
1975
31 pages
Report
No indication
English
Road Transportation , Automobiles , Braking , Tests , Acceleration , Roads , Pavements , Skid resistance , Steering , Control , Safety , Maneuverability , Cornering maneuvers , DOT/5D , DOT/4DZ/DB , Road curves