Applying velocity specification techniques to control robotic positioning systems

Abstract

Abstract Residual vibration limits the terminal positioning precision of robotic manipulators. The residual vibration exhibited by robotic manipulators can be due to low frequency structural modes, self-excited by the manipulator during operations. In these cases, redesigning the structure to modify the resonant frequency(ies) causing residual vibration can be impractical or too costly. In this paper, an intelligent controller scheme is developed to measure and control residual vibration caused by the principal structural resonance. The controller tests the robot structure for critical resonant modes, calculates a drive profile using motion specification techniques to control the residual vibration, and then evaluates its effectiveness. A frequency domain interpretation is used to select the preferred input driver waveform. A breadboard controller is also developed for a single-degree-of-freedom drive system and it is used to validate the proposed strategy. Test results for a simple cantilever beam system and for a desktop articular-arm robot are presented.