Unconstrained and Constrained Motion Control of a Planar Two-Link Structurally Flexible Robotic Manipulator


Unconstrained and constrained motion control of a planar two-link structurally-flexible robotic manipulator are considered in this study. The dynamic model is obtained by using the extended Hamilton's principle and the Galerkin criterion. A method is presented to obtain the linearized equations of motion in Cartesian space for use in designing the control system. The approach to solving the control problem is to use feedforward and feedback control torques. The feedforward torques maneuver the flexible manipulator along a nominal trajectory and the feedback torques minimize any deviations from the nominal trajectory. The feedforward and feedback torques are obtained by solving the inverse dynamics problem for the rigid manipulator and designing linear quadratic Gaussian with loop transfer recovery (LQG/LTR) compensators, respectively. The LQG/LTR design methodology is exploited to design a robust feedback control system that can handle modeling errors and sensor noise, and operate on Cartesian space trajectory errors. Computer simulated results are presented for an example planar, two-link, structurally flexible robotic manipulator.


Mechanical and Aerospace Engineering

Keywords and Phrases

Computer simulation; Constraint theory; Control system synthesis; Equations of motion; Errors; Inverse problems; Linearization; Mathematical models; Motion control; Robotics; Robustness (control systems); Torque control; Cartesian space; Feedback control systems; Feedforward torque; Flexible robotic manipulator; Galerkin criterion; Hamiltons principle; Linear quadratic Gaussian; Loop transfer recovery; Planar two link manipulator; Trajectory errors; Manipulators

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version


File Type





© 1994 John Wiley & Sons Ltd, All rights reserved.

Publication Date

01 Sep 1994

This document is currently not available here.