Rapidly Locating and Accurately Tracking the Center of Mass Using Statically Equivalent Serial Chains

Identifying the center of mass location (CoM) provides a significant aid in controlling the balance of humanoid robots. For human beings, the stability of motion is highly influenced by their ability to control their CoM and center of pressure (CoP). Additionally, computing the CoM can prove critical to assessing rehabilitation and in elite sports training. Human body segment parameters can be obtained from anthropometric tables. Their accuracy for a given individual is questioned due to differences in age, race, and fitness level from the sample population. This research presents an estimation technique that uses the statically equivalent serial chain (SESC). A SESC is a representation of any multilink branched chain, like a human or humanoid, whose end-effector locates the CoM. The SESC\u27s construction during an experimental phase depends on the node positions from a motion capture system (like the Microsoft Kinect), and the total mass and CoP from a force plate (like the Wii Balance Board). Additionally, the presence of a static body in the workspace (a walker or chair, for example) to create stability in test subjects is presented. The utility of the presented method as compared to other common methods for CoM estimation is that the force plate is not needed to track the CoM after the SESC is constructed.https://ecommons.udayton.edu/stander_posters/1661/thumbnail.jp