abstract

• The stiffness controller proposed by Salisbury is an interaction control strategy designed to achieve a desired form of static behavior as regards the interaction of a robot manipulator with the environment. The main idea behind this approach is the simulation of a multidimensional linear spring - or linear elastic material - using the difference between the actual position of the end-effector and a constant position (relaxed point), multiplied by a constant stiffness matrix. In this paper, this idea is generalized with the objective of proposing a controller structure that includes a family of stiffness models based on the idea of linear elastic materials. The new controller structure also includes a damping term in order to have control over energy dissipation, as well as a term added for the purpose of compensating the gravity forces of the links. The stability analysis of the proposed controller was performed in the Lyapunov sense. The new stiffness controller is presented as a case study and compared to other cases, such as the Salisbury controller (Cartesian PD) and the tanh-tanh controller. Experimental results using a three degrees-offreedom direct-drive robot for the evaluation of controllers in a constrained motion task are presented.

authors

• Chávez-Olivares C.
• Gonzalez-Galvan Emilio J.
• Reyes F.

publication date

• 2015-01-01

published in

• International Journal of Advanced Robotic Systems  Journal

keywords

• Directdrive robot; Interaction control; Stiffness control Elasticity; Energy dissipation; Flexible manipulators; Gravitation; Industrial robots; Manipulators; Modular robots; Robot applications; Robots; Stiffness; Stiffness matrix; Degrees of freedom (mechanics); Constrained motion; Controller structures; Direct-drive robot; Interaction controls; Linear elastic material; Robot manipulator; Stability analysis; Stiffness control; Three degrees of freedom; Controllers

Digital Object Identifier (DOI)

• 10.5772/60054

start page

end page

volume

• 12