Disturbance observer based sliding mode control of nonlinear mismatched uncertain systems

• Published in: Communications in nonlinear science & numerical simulation Vol. 26; no. 1-3; pp. 98 - 107
• Main Authors: Ginoya, Divyesh, Shendge, P.D., Phadke, S.B.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2015
• Subjects: Computer simulation; Derivatives; Disturbance observer; Disturbance observers; Estimates; Mathematical models; Mismatched uncertain systems; Multiple-surface sliding control; Nonlinear system; Nonlinearity; Sliding mode control; Strategy; Uncertainty; Disturbance observer; Mismatched uncertain systems; Multiple-surface sliding control; Nonlinear system
• ISSN: 1007-5704; 1878-7274
• DOI: 10.1016/j.cnsns.2015.02.008

•A disturbance observer based control is proposed for nonlinear mismatched uncertain systems.•The issue of ‘explosion of terms’ in multiple surface sliding mode control is tackled.•Comparison of the proposed scheme with four other well-known methods using a benchmark example.•Experimental validation on a flexible joint manipulator. This paper presents a new design of multiple-surface sliding mode control for a class of nonlinear uncertain systems with mismatched uncertainties and disturbances. In the method of multiple-surface sliding mode control, it is required to compensate for the derivatives of the virtual inputs which gives rise to the so-called problem of ‘explosion of terms’. In this paper a disturbance observer based multiple-surface sliding mode control is proposed to estimate the uncertainties as well as the derivative of the virtual inputs to overcome this problem. The practical stability of the overall system is proved. The effectiveness of the proposed control strategy is illustrated via simulation of a benchmark problem and comparison with other control strategies. The proposed scheme is validated by implementing it on a serial flexible joint manipulator in the laboratory.