Development of a low power motion tracking wireless node for IoT applications

Abstract

Motion tracking technology offers the ability to detect and record movements of an object or human. This technology has been widely used in many fields such as gaming industry, sports and biomedical. Motion tracking typically uses sensors such as accelerometer, gyroscope and magnetometer to measure movements of humans’ joints. This project aims to develop motion tracking node using Inertial Measurement Unit (IMU) interfaced with low power microcontroller. IMU is a device that measures the change in orientation, angular rate and magnetic field surrounding the moving body. Multiples of this tracking node can be attached to human body parts, such as knees, hips or ankles. These tracking nodes then regularly send sensors’ movement data to a central device, which in this case is a Raspberry Pi for further processing. Fusion of data from multiple tracking nodes can hence be used to track the joint orientation of body parts that they are attached to, such as knees, hips or ankles. All the data processing are performed in the Raspberry Pi. Drifts and offset will appear during the sensors’ data transfer from multiple motion tracking nodes to the central device. As a result, the joint orientation will not be accurate due to these offsets. As such, time synchronization between the devices is implemented to enable monitoring the drift.