Algorithm for correcting sensor rotation during suspension movement of a two-wheeled vehicle

Abstract The stator–rotor principle is often used to measure rotational movements on full-suspension two-wheeled vehicles. The stator is attached to the frame of the two-wheeled vehicle, and the rotor is attached to the part to be measured. One example is the classic angle measurement with magnetic rings. As a result of the suspension movement, the kinematic bodies of the frame rotate, causing the attached stators to rotate accordingly. Postprocessing of the measurement data is essential to compensate for unwanted stator rotations. Without postprocessing, both rotations—the rotational movement of the kinematic body with the stator and the rotation of the part to be measured with the rotor—are used as rotation signals, which leads to a distorted measurement signal due to the rotation of the stator. This paper presents an algorithm for determining and eliminating the rotational movement of the stator. It can be used for any measurement that also works with a stator–rotor system in which the rotation of the stator is generated by ground contact (and not by lifting a wheel). By determining the rotations numerically, the algorithm can be transferred to different types of kinematics and frame parts. The paper also presents a bicycle sensor setup for measuring disturbance forces on the crank of a bicycle. This configuration can be used to analyze the influence of the chain movement and pedal kickback on the rider.