week 4 summary – Hitesh

The paper highlights some of the existing issues with location based tracking systems in a real world MR and wearable systems, that it requires the objects in the environment to be pre-mapped or marked thus not making the system extensible and robust. Computer vision tracking poses a lot of challenges and requires complex algorithms and corrections to be implemented. InterSense proposes to solve this issue through inertial sensors. The inertial cubes in the foot provide more accurate tracking than head-mounted orientation tracking because it enables Transfer Alignment based on acceleration/deceleration along an axis relative to the rest position.

The Navshoe improves accuracy by applying zero velocity update (ZUPT) to EKF when it detects a stance phase after each stride to correct the drift velocity error. The Navshoe provides considerable accuracy over short distances and has the ability to track height example each stair on a staircase. GPS can be used to extend range and correct yaw drift error. The information is also not affected by magnetic disturbances.  The system can be used in conjunction with MR and head tracking systems to improve yaw accuracy by providing reference points.