Analysis of Passenger's Posture Change Effect on Motorcycles and Disturbance Rejection Control

Abstract

In 2005, the ban on riding tandem on motorcycles along expressways in Japan was lifted. Since this is likely to increase tandem riders, there is a need to improve the motorcycle stability of tandem riding from the perspectives of safety and comfort. A motorcycle becomes unstable at low speed. Thus, this study investigates the stability and handling properties in tandem riding on motorcycles at low speed. First, we did experiments and obtained the time responses of motorcycle behaviors and rider control after a passenger changes posture. Next, we constructed a multi-body model for a human-motorcycle tandem riding system that contains a controller that imitates the rider's driving operation. From simulation results, we obtained the effect of passenger's posture changes and such individual differences as upper-body mass and length. Finally, we designed a control system that applies a sliding mode control theory to reduce the effects of passenger's posture changes. After comparing the rider control model and the sliding mode control, the latter shows better control. This system also has robustness to uncertainty of passenger properties.