A Robust Controller for A 3‐DOF Flexible Robot with a Time Variant Payload

Abstract

This article describes a new control scheme designed for a three degree of freedom (3-DOF) flexible robot. The control scheme consists of two multi variable control loops. The inner loop is the motor's position control system, while the outer loop controls the robot tip's position, thus canceling vibrations which are originated by the structural flexibility of the manipulator during movement. As it will be shown, the outer control loop is robust to payload variations. The outer loop performance is based on a perfect cancelation of the inner loop dynamics. The effects of not achieving such perfect cancelation are also studied, and rules for designing a robust controller in this case are developed. Simulations assuming different payloads have been carried out with successful results for trajectory tracking. Trajectory tracking with a variable payload is also achieved.

Dedicated Nonlinear Control of Robot Manipulators in the Presence of External Vibration and Uncertain Payload

“…V, Feliu. et al [25] designed a control algorithm to cancel vibrations that are originated by the structural flexibility of the manipulator during movement. The control algorithm works efficiently for trajectory tracking without saturating the actuators, however, it requires a perfect kinematic model and a perfect knowledge of the compliance matrix.…”

Precision contouring control of five degree of freedom robot manipulators with uncertainty

“…In particular, one of the important tasks in manufacturing systems requires robot manipulators to make its end-effector follow the specific path, such as applications in painting robot, welding robot, and machine tool systems. [1][2][3][4][5] Actually, most of these tasks are so complicated that contouring control is subjected to the problem. For high-quality tasks, accuracy is the critical problem of contouring control for robot manipulators, especially under the operation in various environments.…”

Boundary and Distributed Control for a Nonlinear Three‐Dimensional Euler‐Bernoulli Beam Based On Infinite Dimensional Disturbance Observer

“…With advances in science and technology, control of complex systems and processes has developed rapidly , especially in the field of flexible systems. As a basic flexible system, the Euler‐Bernoulli beam can be used to model a number of mechanical systems in the engineering field, such as flexible manipulators , flexible marine riser , moving strips , bridge‐vehicle systems and train rails , etc. In addition, the Euler‐Bernoulli beam system can be regarded as the simplification of some simple systems and studies about it provide a basis for the further research of complex flexible systems.…”