Functionality and Performance of HS ABS through Computer Simulation

This section explains the theoretical functionality and basic performance of the HS ABS through computer simulation of one wheel¡¯s dynamic behavior during the braking phase of a motorcycle in order to demonstrate the ABS effects by the braking pressure restriction HS ABS valve

50km/h on dry asphalt
55km/h on dry asphalt
60km/h on wet asphalt

Conclusions on Test Results

During sudden braking maneuvers, for the motorcycle without an ABS valve, the master cylinder pressure was above 50 bar which passed fully to the wheel cylinder. This caused front wheel locking that could be seen in the rapid wheel speed reduction (angular deceleration) in Table 1. Notice that more rapid speed reduction occurred for the higher driving speed and for wet road conditions. However, for the motorcycle with the HS ABS valve, the wheel cylinder pressure was maintained to a unlocking value of 40 bar by the pressure restriction function of the HS ABS valve, which results in anti-locking of the front wheel until the motorcycle completely stops. This anti-locking phenomenon is seen in a smoother and almost constant wheel speed reduction of ?14 rad/sec2 in Table 1. Table 2 shows average wheel angular deceleration and braking distnace at each speed condition. Every average wheel angular deceleration is similar and much less than that in case of

wheel locking condition ( i.e. much less than ?23 rad/s2 ) and the higher initial speed, the longer braking distance. In conclusion, real motorcycle test results show that the HS ABS is functioning robustly in varying driving speeds on varying road conditions such as dry and wet asphalt roads.
 

<Table 1> Angular Decelerations

<Table 2> Angular Decelerations and Braking Distances