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)
Level of Degree
First Committee Member (Chair)
Second Committee Member
Department of Energy - University Research Program in Robotics
Courtney, Matthew. "Cooperative impedance control with time-varying stiffness." (2011). https://digitalrepository.unm.edu/me_etds/50