2016, Master's Thesis, RoMeLa UCLA
As a master's thesis research, I extended my undergraduate thesis project of the resistance mechanism with improved mechanical configuration and control strategies. The mechanism is designed to generate a controllable resistance force for exercise and rehabilitation by using a series elastic actuator. Instead of measuring force with a load cell, a series elastic actuator is used to measure resistance force by calculating force from spring deflection. By applying a SEA to generate resistance force, the mechanism has the following benefits:
1. Programmable resistance force.
2. Low manufacturing cost compared with the existing powered exercise devices.
3. Compact and lightweight structure.
4. Provides a user-interface via a smart-phone applications.
A prototype hardware of the resistance mechanism was manufactured, and an impedance control algorithm was implemented in order to simulate the effects of a virtual damper, spring and constant force. The hardware design and control algorithm were examined with dynamics simulation and a prototype hardware was used to further verify the ideas.