Experimental Compliance Breakdown of Industrial Robots

Abstract

An engineering tool is described, enabling a static compliance breakdown of a machine (with fixed or varying geometry) from a modal analysis performed at a quasi-static frequency. The most interesting feature of the method is that the compliances of the constitutive machine components can be determined independent from the instantaneous configuration of the machine. Real-life test results on a fixed-configuration beamlike structure and on a variable-configuration industrial robot show the accuracy and the power of the method but also reveal some stringent requirements for the motion sensors needed. Some new results on the need for correction of the influence of gravity on the accelerometer signals at low frequencies are also included.