Semester

Fall

Date of Graduation

2021

Document Type

Thesis

Degree Type

MS

College

Statler College of Engineering and Mineral Resources

Department

Mechanical and Aerospace Engineering

Committee Chair

Sergiy Yakovenko

Committee Member

Victor Mucino

Committee Member

Gregory Thompson

Abstract

Prosthetic limbs have aided in the restoration of both cosmetic and functional capabilities of the human hand; however, structural and control limitations hinder widespread adoption. One example of these limitations addressed in this study is the lack of wrist degrees of freedom (DOF) in robotic hands. Using the mechanical model-driven design, I developed a hand with cable-driven actuation of fingers and direct actuation of the wrist pronation-supination and flexion-extension DOFs. An inverse dynamic simulation determined torque requirements in common tasks manipulating a 1 kg mass with rotational speeds up to 60 deg/s, setting a minimum limitation of 0.76 Nm on the wrist servomotors. The performance of the manufactured robotic hand was validated using motion capture. Kinematic errors were 19 deg on average with the best and worst values spanning 2 to 55 deg (thumb CMC and third digit PIP DOFs, respectively). The execution delays computed with the cross-correlation of the command-movement relationship were 200 to 400 ms in 6 DOF movements. This performance was appropriate for the functional use of the device and serves as the framework for testing future controller designs.

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