Comparison of Kinect and Vicon Motion Capture of Upper-Body Joint Angle Tracking

Motion capture systems are an effective tool for generating realistic trajectory profiles for human-mimicking robots. For example, traffic police and aircraft marshals spend long hours directing car and plane traffic and are susceptible to the effects of pollution, as well as mental and physical fatigue. These jobs could be automated with the use of robots that mimic human upper-body motions. In order to develop such robotic systems, natural human motion must be studied. Vicon 3D Motion Capture systems involve multiple high-definition cameras that are accurate, but expensive, and infeasible to use in airports, aircraft carriers, and road settings. Microsoft Kinect V2 is a non-invasive, low-cost sensor primarily used in the video game industry which can be used for human-body motion analysis. This study focuses on various planar and non-planar upper-body motions typically performed in traffic and factory environments. The study compares the joint-tracking abilities of Kinect and Vicon Nexus. For several planar and non-planar motions, it was determined that the Kinect was an effective tool in tracking upper-body motions with low error in frequency and amplitude measurements of joint angles. The limitations of Kinect tracking were explored through rotation tests and weighted tests. The Kinect is sufficiently accurate to track upper-body joints in these conditions.