This project examines the feasibility of employing a cold-gas thruster (CGT) to arrest impending falls for individuals at fall risk. This work was partially inspired by the research of Heike Vallery’s research group, but rather than use a control moment gyroscope to arrest falls, we employed a thruster. The research has involved considerable mechatronic design of the microprocessor-controlled CGT system, and considerable controller development to determine when and how the CGT should fire to arrest an impending fall. The image below shows part of the CGT design, while the video shows some laboratory experiments on a rocking block. Current research entails human subject testing, which thus far has been surprisingly effective.
Figure: (a) CGT prototype (shown without refilling valves). The labels identify: 1) servo system, 2) custom piloted poppet valve, 3) thruster nozzle, 4) mounting plate, 5) carbon fiber tank; (b) CGT prototype in cross-section showing flow path of nitrogen gas when the CGT is triggered. Note that the nozzle is shown in-plane in order to illustrate the cold gas flow path.
Video of experiments conducted with the CGT, illustrating use of a phase-space fall controller, and the efficacy of the system in restoring upright balance following an impending fall.
Video of preliminary testing with human subjects