Single-link Flexible Arm Research Articles

Non-linear control and observation algorithms for a single-link flexible robot arm

Abstract The problem of controlling a single-link flexible arm is investigated. With reference to an approximate finite-dimensional model of the robot, a non-linear controller and observer are derived. A method to derive approximate asymptotic observers is proposed. Simulation tests to validate the effectiveness of the control/observation laws are included.

Non-linear control and observation algorithms for a single-link flexible robot arm

Non-linear control and observation algorithms for a single-link flexible robot arm

Tip control of a single-link flexible arm using a feedforward technique

This paper examines the problem of controlling the tip of a single-link flexible manipulator. A feedforward controller along with a P-D feedback controller are used to regulate the position of the arm's tip. It is shown analytically that the feedforward controller based on a precomputed torque provides an ‘almost’ pole-zero cancellation property which minimizes the residues of the dominant system poles, thus speeding up the response. Simulations are carried out to verify these properties and comparisons with standard error compensation methods (P-D) are conducted. An investigation is also conducted to determine the extent of system response degradation when the parameters of the feedforward controller are chosen inaccurately. This paper demonstrates that a combination of feedforward and feedback control is more adequate than methods based only on feedback control for controlling flexible link arms.

Optimal control of a flexible robot arm

This work is a computer simulation of the control of a flexible robot arm. The dynamic equations for a single-link flexible robot arm have been derived rigorously. This arm has two degrees of freedom in rotation and one in translation so that the workspace is three-dimensional. The payload is simulated by attaching additional mass to the arm at a specified location. The governing equations of the plant and the measurements are nonlinear. The process of control is divided into two stages: coarse control and fine control. Based on the optimal control theory, a linear observer is constructed for fine control. The numerical results are presented here.