Penalty Functions for Handling Large Deviation of Quadrature States in NMPC
Journal article, 2017

Nonlinear Model Predictive Control for mechanical applications is often used to perform the tracking of time-varying reference trajectories, and is typically implemented using quadratic penalty functions. Controllers for mechanical systems, however, are often required to handle large deviations from the reference trajectory. In such cases, it has been observed that NMPC schemes based on quadratic penalties can have undesirably aggressive behaviours. Heuristics can be developed to tackle these issues, but they require intricate and non-systematic tuning procedures. This paper proposes an NMPC scheme based on a specific class of penalty functions to handle large deviations of quadrature states from their reference, offering an intuitive and easy-to-tune alternative. The behaviour of the proposed NMPC scheme is analysed, and the conditions for its nominal stability are established. The control scheme is illustrated on a simulated quadcopter.

nonlinear model predictive control

mechanical systems

Huber penalty function

large deviation from the reference

Author

Sébastien Gros

Chalmers, Signals and Systems, Systems and control, Automatic Control

Mario Zanon

Chalmers, Signals and Systems, Systems and control, Mechatronics

IEEE Transactions on Automatic Control

0018-9286 (ISSN)

Vol. 62 8 3848-3860

Subject Categories

Robotics

DOI

10.1109/tac.2017.2649043

More information

Created

10/7/2017