Abstract
This paper presents a sensor fusion algorithm of six-axis inertial sensors for power assisted applications. The algorithm is used to estimate attitude and acceleration of moving vehicles including bicycles and wheelchairs to achieve power assist. A six-axis inertial sensor includes a three-axis accelerometer and a three-axis gyroscope. Because accelerometers measure linear acceleration, gravitational acceleration and centrifugal acceleration at the same time, the proposed algorithm allows one to get high-bandwidth information on attitude and linear acceleration separately by fusing measurements from gyroscopes and the velocity sensor of the vehicle. Furthermore, this thesis also derives slip dynamics of vehicles and analyzes its characteristics. Then, an algorithm on slip detection is propose. For validation, we first verify the sensor fusion algorithm and slip detection algorithm using Simulink simulations. Afterward, the algorithms are implemented on the vehicles to achieve power-assist function. The vehicles include bicycles and wheelchairs. The power-assist function contains three compensations; mass compensation, damping compensation and gravity compensation. The performance of power-assist vehicles is verified experimentally.