Dynamic Simulation and Experimental Validation of a Single Stage Thermocompressor for a Pneumatic Ankle-Foot Orthosis

The mechanical design, modeling, and partial experimental validation of a prototype Stirling thermocompressor is presented in this paper. The thermocompressor is intended to serve as a compact and quiet, untethered 50 W, pneumatic power supply for an ankle foot orthosis. The goal of high efficiency at the target power density is pursued through the use of novel heat exchangers and high operating temperature and frequency. The motion of the displacer piston is controlled utilizing a brushless DC motor driving a continuous linear reciprocating screw. This paper presents the experimental validation of the heat transfer and pressure dynamics portions of the thermocompressor, leaving the modeling and validation of mass transfer to future work.