Body Pose Measurement System (BPMS): An Inertial Motion Capture System for Biomechanics Analysis and Robot Control from Within a Pressure Suit.

摘要

A novel system has been developed at the University of Maryland Space System Laboratory with the goal of providing the researcher with a new view of the human inside a space suit. Based on an array of microprocessors and microelectromechanical (MEMS) inertial measurement units (IMUs), the system allows monitoring of the kinematics of the suit occupant in an unobtrusive, light weight and compact fashion, without requiring any external equipment such as would be necessary with video-based motion tracking. The instrumented system is composed mainly of three blocks: the acquisition system, the receiver element, and the recording and visualization software. It includes seven microprocessors that acquire accelerations, angular rates and magnetic field measurements from 18 different IMUs positioned on a conformal garment that is worn by the suit wearer. The garment can be either equipped with a liquid cooling system as a standalone liquid cooling garment (LCG), or can worn under conventional LCGs. The system does not induce any apparent mobility constraint on the test subject, and does not require any external wired connections. The IMUs are located on the body garment, and measure the attitude of the major long bones of the suit subject at a 50 Hz frequency. The acquisition system sends the acquired data wirelessly over Bluetooth to a receiver element that is connected to a remote computer that records, filters and visualizes the data. The wireless system allows communications at distances up to 100 m in line of sight, making it an ideal choice for field trials where operations should not be constrained. This work will expand on the design and manufacturing of the system, and will then introduce the results of a preliminary data acquisition sessions conducted at David Clark Incorporated, where range of motion of a suited and unsuited test subject is analyzed in two very different pressure suits. This work will mainly focus on giving the reader a feel for what is possible with a system like BPMS once it has been validated and advanced from a working prototype to a usable unit. Lastly the outline of the current SSL vision for BPMS is described hence setting the first stone is a series of future publications.