Observations on the controllability of motion of two-wheelers

This paper presents an investigation into the motion of two-wheelers: every day motorcycles and bicycles. The emphasis is on controllability of the sys tem for small lateral deviations from straight running under idealized ride r control. After introduction, a discussion of the kinematics, assumptions and geometry of a rider-vehicle system is presented, followed by a statemen t of the equations of motion. The control systems analogy is briefly review ed, and state space methods formalize the concept of controllability. The d ifficulty in steered riding is quantified by the ratio of maximum to minimu m singular values of the controllability Grammian and rideability is invest igated for different designs of (a) a motorcycle from a well-known study an d (b) a bicycle from a recent investigation. New insight into controlled tw o-wheeler behaviour is shown, compared with traditional methods, and can pr ovide another means to design for a safety of vehicle performance.