Patent ID: 7822575

Claim:
A tilt-angle detecting apparatus for a motorcycle, said apparatus comprising: a steering-angle sensor for detecting a steering angle of the motorcycle; a vehicle speed sensor for detecting a vehicle speed; a turning-radius calculation unit for calculating a turning radius corresponding to a steering angle detected by the steering-angle sensor, wherein said turning radius is determined based on a predetermined relationship between measured steering angle values and turning radius; and a tilt-angle calculation unit for obtaining a tilt angle of a vehicle body during a regular turning of the motorcycle, wherein said tilt angle is calculated based on the turning radius calculated by the turning-radius calculation unit and the vehicle speed detected by the vehicle speed sensor; wherein the turning-radius calculation unit includes one of a map and a function of steering angle vs. turning radius, the map and the function each representing a predetermined relationship between the steering angle and the turning radius; and wherein the turning radius is obtained either by searching the map of steering angle vs. turning radius or by using the function of steering angle vs. turning radius, and the tilt angle calculated by the tilt-angle calculating unit is used for searching the map or for using the function.