scholarly journals Learning-based Robust Motion Planning With Guaranteed Stability: A Contraction Theory Approach

2021 ◽  
Vol 6 (4) ◽  
pp. 6164-6171
Author(s):  
Hiroyasu Tsukamoto ◽  
Soon-Jo Chung
Author(s):  
M. M. Rayguru ◽  
I. N. Kar

Various practical applications use filtered backstepping technique, which follows the same procedure as backstepping design but uses high gain filters to circumvent the analytical computation of derivatives. As a result, there exists a time-scale separation between the system dynamics and the fast filter dynamics. This paper proposes a new contraction theory-based technique to design a high gain disturbance observer-based filtered backstepping controller and to quantify the convergence bounds in terms of design parameters. The quantification of the bounds explicitly shows the dependency of the closed-loop performance on various parameters, which in turn provide more ways to tune the performance apart from reducing the magnitude of filter parameter. Unlike the existing results, the proposed approach relaxes the conservative restriction, required on the filter parameter to achieve a satisfactory closed loop performance. The efficacy of the proposed method is verified through simulation examples.


2009 ◽  
Vol 54 (4) ◽  
pp. 816-820 ◽  
Author(s):  
Quang-Cuong Pham ◽  
N. Tabareau ◽  
J.-J. Slotine

Author(s):  
Xudong Weng ◽  
O.F. Sankey ◽  
Peter Rez

Single electron band structure techniques have been applied successfully to the interpretation of the near edge structures of metals and other materials. Among various band theories, the linear combination of atomic orbital (LCAO) method is especially simple and interpretable. The commonly used empirical LCAO method is mainly an interpolation method, where the energies and wave functions of atomic orbitals are adjusted in order to fit experimental or more accurately determined electron states. To achieve better accuracy, the size of calculation has to be expanded, for example, to include excited states and more-distant-neighboring atoms. This tends to sacrifice the simplicity and interpretability of the method.In this paper. we adopt an ab initio scheme which incorporates the conceptual advantage of the LCAO method with the accuracy of ab initio pseudopotential calculations. The so called pscudo-atomic-orbitals (PAO's), computed from a free atom within the local-density approximation and the pseudopotential approximation, are used as the basis of expansion, replacing the usually very large set of plane waves in the conventional pseudopotential method. These PAO's however, do not consist of a rigorously complete set of orthonormal states.


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