| This thesis addresses the design procedure for biomechanical energy conversion systems. First, four motions---heel strike, joint motion, center-of-mass motion, and horizontal foot movement---are analyzed. Center-of-mass motion and horizontal foot movement are identified as the energetic motions. Based on the characteristics of the motions, a linear permanent magnet generator topology is proposed as the actuation topology. Magnetic equivalent circuits are developed for the linear generator. Linear generators are modeled and optimized for the maximum-power output. To transfer the energy into the battery load, a maximum-power extraction circuit is proposed as the interface between the generator and battery load. The circuit functions as a matched resistor to the generator internal resistance. A test generator for center-of-mass motion is built and tested with impedance matching circuit. Average power from 90 mW to 360 mW are measured for different walking conditions. |
