Experimental analysis of the dynamic stiffness in industrial robots

Abstract

Industrial robots are regularly being employed for machining tasks. As a key machining parameter, dynamic stiffness has a significant influence on robotic machining performance. This paper examines two experimental approaches for obtaining the dynamic stiffness of an industrial robot. One approach is based on experimental modal analysis. The other approach is a direct calculation with the acquisition of excitation forces and vibration displacement. Different excitation frequencies are planned to stimulate an industrial robot. The dynamic stiffnesses obtained by the two approaches are thoroughly evaluated. Large deviation appears between the dynamic stiffness measured by two approaches. The factors that result in variations in the measurements are discussed.