Techniques for vibration control of a flexible robot manipulator

Abstract

This paper presents investigations into the applications and performance of positive and negative input shapers in command shaping techniques for the vibration control of a flexible robot manipulator. A constrained planar single-link flexible manipulator is considered and the dynamic model of the system is derived using the finite element method. An unshaped bang-bang torque input is used to determine the characteristic parameters of the system for design and evaluation of the input shaping control techniques. The positive and specified amplitude negative input shapers are designed based on the properties of the system. Simulation results of the response of the manipulator to the shaped inputs are presented in the time and frequency domains. Performances of the shapers are examined in terms of level of vibration reduction, time response specifications and robustness to parameters uncertainty. The effects of derivative order of the input shaper on the performance of the system are investigated. Finally, a comparative assessment of the impact amplitude polarities of the input shapers on the system performance is presented and discussed.

Output Based Input Shaping for Optimal Control of Single Link Flexible Manipulator

“…Since it is slender and long, rotary inertia effect and transverse shear are neglected. Elastic behavior of the system was modeled based on these assumptions using Bernoulli-Euler beam theory [3,25]. Thus for an angular displacement θ(t) and a slight elastic deflection u(x,t), the total displacement can be given as…”

Hybrid Input Shaping and Feedback Control Schemes of a Flexible Robot Manipulator

“…In this work, the previous SNA input shaper (Mohamed et al, 2006) has been modified by locating the negative amplitudes at the centre between each positive impulse sequences with even number of total impulses. This will result the shaper duration to one-fourth of the vibration period of an undamped system as shown in Fig.…”

“…A significant number of negative shapers for vibration control have also been proposed. These include negative unity-magnitude (UM) shaper, specifiednegative-amplitude (SNA) shaper, negative zero-vibration (ZV) shaper, negative zero-vibration-derivative (ZVD) shaper, negative zero-vibration-derivative-derivative (ZVDD) shaper and time-optimal negative shaper (Mohamed et al, 2006;Rappole et al, 1993).…”

Vibration Suppression of a 3-DOF Parallel Manipulator Based on Hybrid Negative Impulses Multi-Mode Input Shaping

“…However, the lightweight linkages increase vibration and make the motion trajectory of manipulators inaccurate [3][4]. The input shapers can overcome the disadvantage.…”