Dissertation Defense - Ahmed Fahmy Soliman (PHDME)

Ahmed Fahmy Soliman – Ph.D. Mechanical Engineering

Asst. Prof. Dr. Barkan Uğurlu – Advisor

Date: 28.12.2022

Time: 11.30

Location: AB4 B127

Optimal Trajectory Generation and Adaptive Control of an Underactuated and Self-Balancing Lower Body Exoskeleton

Asst. Prof. Dr. Barkan Uğurlu, Özyeğin University

Asst. Prof. Dr. Özkan Bebek, Özyeğin University

Assoc. Prof. Dr. Kemalettin Erbatur, Sabancı University

Asst. Prof. Dr. Ramazan Ünal, Özyeğin University

Assoc. Prof. Dr. Koray Kadir Şafak, Yeditepe University

Abstract:

The thesis presents a framework that enables us to obtain 3D dynamic self-balanced walking motion for an underactuated bipedal exoskeleton robot. In the proposed framework, we used the ZMP concept to generate a set of task trajectories. An optimization algorithm based on different task levels was included to enable a kinematic resolution without violating the balance condition. A set of locomotion controllers were added on top of the optimization algorithm to improve the robustness against external perturbations despite underactuation.

To improve the locomotion controller performance against the inertial parameters variation, an online identification algorithm was developed. A semidefinite programming optimization algorithm based on the interior point method was used to estimate the inertial parameters recursively in a complete physical consistency form. A set of simulation experiments were conducted either using distinct simulators to verify the feasibility of the developed algorithms.  Moreover, two locomotion control experiments were conducted on the actual robot Co-Ex, namely, squatting and swaying. The experiment results indicated the real-time applicability and feasibility of the proposed algorithms as well as the confirmation of the developed hardware.

Bio:

Ahmed Fahmy Soliman is an Egyptian researcher. He received his B.Sc. in Mechatronics engineering from Helwan University, Cairo, Egypt, in 2009. He received an M.Sc. in Electrical engineering from Cairo University, Cairo, Egypt, in 2015. He joined the Biomechatronics lab Research Group as a Research Assistant in 2017 working toward his doctorate under the supervision of Asst. Prof. Barkan Uğurlu at Özyeğin University, Istanbul, Turkey. His current research interests include Legged robots Kinematics, Dynamics Analysis, and Design, Assistive devices, Robot dynamics and control, Compliant  Manipulation, Human-Robot Interaction, and Path and Trajectory Planning.