COMPARATIVE ANALYSIS OF BRAKE DATA OF VEHICLES ON DIFFERENT BRAKE ROLLER TESTERS FROM MINISTRY OF TRANSPORT

摘要

This research has been carried out by the mechanical engineering staffs at thernmechanical laboratory at the Miguel Hernández University in Elche.rnThis study gives a comparison between what occurs when braking on differentrnMinistry of Transport (MOT) brake tester. We have analysed mathematical formulasrnabout braking on bank of rolling and we indicate which factors should influence inrnbrake on rollers in theory.rnWe have already study what occurs when many other parameters were changed like:rntyre pressure, tyre tread, load etc... But now we study the influence of distancernbetween rollers in brake and slip.rnThe car stops on the bank of rollers. The emergency brake should not be actuated.rnThen the rollers move at 5km/h of speed and we have to press brake pedal until wernobtain 100% of slippage.This velocity is enough to obtain 100% of slippage. Thernpressure in the brake hydraulic circuit on the right wheel of the vehicle is alsornmeasured with a hydraulic sensor in hydraulic pipe of the right wheel. We can obtainrnthe slip if we measure the angular velocity of wheel and roller. We obtain angularrnvelocity from 2 encoders fitted one on the brake roller tester and the other one onrnwheel of the vehicle.rnIn Michel hernandez University we have two MOT bank of rollers, with differentrndistance between rollers, where we have mesured brake and slip and we haverncompared the resoults with others MOT station with other distance between rollers,rnand we analyce the diference. We compare data acquired with theoric formulas tornprovide a new formula that depends on distance of rollers.rnThis paper demonstrates that the MOT brake and slide data results depend on therndistance between rollers and we provide data and graphs to prove it.