SUBJECT: M.S. Thesis Presentation
BY: Hsiang Hsu
TIME: Monday, April 22, 2019, 3:00 p.m.
PLACE: Love Building, 109
TITLE: Design, Control, and Human Subject Evaluation of Powered Hip Exoskeletons
COMMITTEE: Dr. Aaron Young, Chair (ME)
Dr. Gregory Sawicki (ME)
Dr. Anirban Mazumdar (ME)


Powered lower-limb exoskeletons have recently been popularized for industrial, military, and clinical applications. Currently, many lower-limb exoskeletons are complex multi-joint devices limited by its weight, convoluted controllers, and imperfect power transmissions. To make exoskeletons more robust, researchers and companies are re-focusing on single-joint devices and examining the effects of human-machine interaction. While both the ankle joint and hip joint are main torque contributors during level walking, the hip joint is less efficient due to the lack of spring-like tendons. As a result, providing hip joint assistance may be more impactful than aiding other joints.

In this thesis, the research team proposes a top-down approach towards wearable robotics by designing, building, and testing two versions of torque-controllable exoskeletons. First, both Hip Exo v1.0 and Hip Exo v2.0 utilize series elastic actuator designs to achieve closed-loop torque control. Hip Exo v2.0 solves many of the previous design flaws through a combination of new mechanical design, dedicated PCB layouts, and more efficient power management. Then, three distinct control strategies are developed and implemented. Each of the biological torque controller, proportional EMG controller, and EMG pattern recognition controller’s strengths and weakness are studied and summarized. Lastly, several human subject testings are carried out to further understand the complex human machine interactions. The findings of this thesis act as a comprehensive guide for design, control, and validate powered hip exoskeletons.