Notice of Violation of IEEE Publication Principles: Hybrid Time-Optimal Predictive Control for Mechanical Systems with Backlash Nonlinearity

Notice of Violation of IEEE Publication Principles

"Hybrid Time-Optimal Predictive Control for Mechanical Systems with Backlash Nonlinearity"
by Dong Lingxun, Dou Lihua, Feng Heping
in the Proceeding of the 2008 IEEE/ASME International Conference on Mechatronics and Embedded Systems and Applications, 12-15 October 2008

After careful and considered review of the content and authorship of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE's Publication Principles.

This paper contains significant portions of original text from the papers cited below. The original text was copied without attribution (including appropriate references to the original authors and/or paper titles) and without permission.

Due to the nature of this violation, reasonable effort should be made to remove all past references to this paper, and future references should be made to the following article:

"Hybrid Theory-Based Time-Optimal Control of an Electronic Throttle,"
by Mario Vasak, Mato Baotic, Ivan Petrovic, and Nedjeljko Peric
in IEEE Transactions on Electronics, Vol 54, No 3, June 2007, pp. 1483-1494

"Controlling Mechanical Systems with Backlash-A Survey"
by M. Nordin and P.-O. Gutman
in Automatica Volume 38, Issue 10, October 2002, pp. 1633-1649

"A Hybrid Approach to Modeling, Control and State Estimation of Mechanical Systems with Backlash"
by Ph. Rostalski, Th. Besselmann, M. Baric, Femke von Belzen, M. Morari
in International Journal of Control, vol. 80, no. 11, pp. 1729-1740


The mechanical system with backlash nonlinearity is distinguished between a "backlash mode" and a "contact mode". The inherent switch between the two operating modes makes the system a prime example of hybrid system. In this paper, a piecewise affine (PWA) model of the mechanical system with backlash nonlinearity is built. A constrained time-optimal predictive control problem based on the hybrid PWA model is formulated for solving the optimal control problem of mechanical system with backlash nonlinearity. The proposed constrained time-optimal predictive control strategy consists of two parts, that is, control invariant set computation and constrained time-optimal control law computation. For the purpose of reducing computation of online implementation, the control law is precomputed offline for the range of model states and references by combining dynamic programming strategy with the reachability analysis for the PWA model. In the simulation of tracking the reference speed, it is demonstrated that the constrained time-optimal predictive control approach has better tracking control effect and less computation time compared with the constrained finite time optimal control approach. The resulting control law achieves that for any reference the tracking error remains within a small bounded set, furthermore, the online implementation becomes simpler by the offline computation in the former step, thereby reducing computation burden and being implemented on low-cost hardware for systems with small sampling time.