Kinematic State Estimation Using Multiple DGPS/MEMS-IMU Sensors

摘要

Inertial measurement unit based motion capture (MOCAP) technology has put an end to subjective gait analysis and has allowed researchers to obtain quantitative measurements of the kinematic and kinetic variables associated with gait. However, these systems are prone to drift in the inertial frame, especially under conditions of high acceleration, which naturally occur during rapid maneuveres. In an effort to circumvent this, we explore the possibility of integrating differential global positioning systems (DGPSs) on each limb of interest. This novel configuration is compared to a traditional inertial based system as well as a popular method of differential global positioning systems (DGPS) processing (RTKLIB) by means of an extended Kalman smoother. The configurations are experimentally validated on a mechanical test rig with the effect of nonline of sight of the global navigation satellite systems antennae explored. The results demonstrate that the combination of multiple DGPS receivers facilitate improved accuracy of the multibody system during rapid acceleration movements and can improve the accuracy of future Motion capture (MOCAP) systems.