Development of the Anti-SideSlip Control for Motorcycles Using IMU

Motorcycles typically turn by generating camber thrust by leaning the body. However, in Competitions that emphasize speed like races, there is a technique to intentionally make the rear wheel slide laterally to reduce the turning radius, allowing for faster turns than using only camber thrust. While this technique is effective for faster riding, it is difficult to execute and carries risks such as falling. Therefore, the aim was to develop a control system that detects lateral sliding and controls the amount of slide, enabling natural and highly stable cornering. However, detecting lateral sliding in motorcycles presents challenges, particularly in detecting the slip angle. While electronic stability control (ESC) for preventing lateral sliding is already practical in four-wheeled vehicles, motorcycles differ as they turn by leaning the body, making it impossible to detect the slip angle using steering angle and yaw rate. To determine the slip angle in motorcycles, optical sensors like laser displacement meters are typically required, but equipping such sensors for riding is not practical. Therefore, a method was developed to detect lateral sliding using only IMU sensor signals by calculating parameters that represent the characteristics of the slip angle without directly determining the slip angle itself. When these slip angle characteristics exceed a threshold, the control system is activated. Once activated, the system suppresses lateral sliding by retarding ignition timing through PID control to approach the target slide amount. This control system successfully detects and suppresses lateral sliding, and it was confirmed by evaluation riders that the feeling during cornering improved.