Mechanical Engineering ETDs

Publication Date



The focus of much automation research has been to design controllers and robots that safely interact with the environment. One approach is to use impedance control to specify a relationship between a robot's motion and force and control a grasped object's apparent stiffness, damping, and inertia. Conventional impedance control practices have focused on position-based manipulators - which are inherently non-compliant - using constant, task-dependent impedances. In the event of large trajectory tracking errors, this implementation method generates large interaction forces that can damage the workcell. Additionally, these position-based devices require dedicated force/torque sensors to measure and apply forces. In this paper, we present an alternative impedance controller implemented on cooperating torque-based manipulators. Through the use of time-varying impedance parameters, this controller limits the interaction forces to ensure harmless manipulation. Successful completion of transport and insertion tasks demonstrated the effectiveness of the controller.


Manipulators (Mechanism)--Automatic control, Impedance (Electronics)

Degree Name

Mechanical Engineering

Level of Degree


Department Name

Mechanical Engineering

First Committee Member (Chair)

Lumia, Ron

Second Committee Member

Russell, John


Department of Energy - University Research Program in Robotics

Document Type