Mechanical Engineering ETDs


Kevin Ruybal

Publication Date



Successful peg and hole insertion systems allow the peg to translate and rotate to accommodate contact forces that arise from different contact states between the peg and hole during assembly. Typically, a position or force controlled robotic insertion system is fitted with a specialized mechanically compliant wrist, known as a remote center compliance (RCC) device, to allow the system to accommodate the forces. Using design principles similar to those developed for the RCC, a variable compliance control system is produced in this thesis. This control system allows a dual seven degree of freedom robotic arm system to cooperatively perform rigid peg and hole assembly with human-like performance at a 100% success rate without the use of mechanically compliant attachments. Additionally, a novel finite state machine with visual feedback is developed to improve the positional accuracy of the robots impedance controllers and boost the reliability and performance of the entire system. Finally, a unique design process is developed to obtain the optimum variable compliance controller control law equations with respect to task success, reliability, and coupled robotic arm stability.'


Manipulators (Mechanism)--Automatic control, Assembling machines--Automatic control, Manipulators (Mechanism)--Optical equipment, Feedback control systems.

Degree Name

Mechanical Engineering

Level of Degree


Department Name

Mechanical Engineering

First Committee Member (Chair)

Ebrahimi, Nader

Second Committee Member

Russell, John


U.S. Department of Energy

Document Type