Development of a Test Bed System for Robot Actuators

Abstract

This paper describes the design and utilization of an advanced dynamic dynamometer test bed for electromechanical robot actuators. Typically actuators are tested at steady state under continuous load, but this is insufficient to characterize the nonlinear properties of actuators. The test bed was specifically designed with the capability to emulate high bandwidth complex duty cycle loads. Furthermore, the test bed is modular which enables rapid reconfiguration of test components. The test bed is comprised of a servo motor which serves as a dynamic load emulator, a brake, a clutch, full sensor array for comprehensive monitoring of test variables, and supporting motion control hardware. Two preliminary tests of a permanent magnet synchronous motor (PMSM) were conducted to demonstrate some of the test bed’s capabilities. These included a torque ripple test and a test to determine torque variation for a sinusoidal load at constant speed. The results show increased torque ripple for increasing speed. The sinusoidal loading test demonstrates the nonlinearities associated with actuator dynamics. Future testing will focus on the full characterization of an actuator.