Bank angle detecting device and headlight device for motorcycle

A bank angle detecting device for a motorcycle, which comprises:

• a roll rate sensor for detecting a angular velocity about a longitudinal axis of the motorcycle;
• a yaw rate sensor for detecting a angular velocity about a vertical axis of the motorcycle;
• a bank angle detecting unit for detecting a motorcycle bank angle for calibration use based on the angular velocity, detected by the yaw rate sensor, about the vertical axis of the motorcycle and a traveling velocity of the motorcycle;
• and
• a bank angle correcting unit for correcting a basic motorcycle bank angle, determined from an output of the yaw rate sensor, so as to approach the motorcycle bank angle for calibration use that is detected by the bank angle detecting unit, to thereby determine an estimated bank angle.