A capsule system driven by a harmonic force applied to its inner mass is considered in this study. Four various friction models are employed to describe motion of the capsule in different environments taking into account Coulomb friction, viscous damping, Stribeck effect, pre-sliding, and frictional memory. The non-linear dynamics analysis has been conducted to identify the optimal amplitude and frequency of the applied force in order to achieve the motion in the required direction and to maximize its speed. In addition, a position feedback control method suitable for dealing with chaos control and coexisting attractors is applied for enhancing the desirable forward and backward capsule motion. The evolution of basins of attraction under control gain variation is presented and it is shown that the basin of the desired attractors could be significantly enlarged by slight adjustment of the control gain improving the probability of reaching such an attractor. Crown Copyright (C) 2014 Published by Elsevier Ltd. All rights reserved.
Bibliographical noteDate of Acceptance: 08/10/2014
Dr Yang Liu would like to acknowledge the financial support for the Research Project of State Key Laboratory of Mechanical System and Vibration (MSV201401) by Shanghai Jiao Tong University and the Small Research Grant (31841) by the Carnegie Trust for the Universities of Scotland.
- motion control
- position feedback control