Hierarchical-map Updating Approach for Simultaneous Localization and Mapping of Mobile Robots

For the tremendously increasing of system state in wild field, the computational complexities of mobile robot system should be taken into account. This paper proposes a hierarchical-map updating approach for simultaneous localization and mapping of robots. The basic idea of hierarchical-map is defining two kinds of maps during the recursive updating process, namely local map (upper map) and global map (lower map). The system states will be updated by the preset maps. The hierarchical-map updating process is just for the upper map and the lower map is updated after a certain running term. In the calculation, the state data of the upper map is far less than that of the lower map. It is validated by the experiments that, the approach is more optimal than others in computational complexities while ensuring the consistency estimate

Robot localization and path planning based on potential field for map building in static environments

In static environments, and regarding the landmarks also as obstacles in the given situation, this paper suggests a map building algorithm of simultaneous localization and path planning based on the potential field. The robot can locate its movement control discipline with the help of a potential field theory and by conducting simultaneous localization and mapping; besides, the following prediction and state estimation will be done based on predicted control law. With the method of path planning in the potential field, the minimum influential range of  space obstacles with repulsive potential can be adjusted, which is in adaptation to the landmarks and environments in which the landmarks are simultaneously regarded as obstacles. The experiments show that the suggested algorithm, through which the robot  can conduct simultaneous localization and mapping in the localized landmarks, is also at the same time used as an obstacle in environments. After analyzing relevant performance indicators, the suggested algorithm has been verified as consistent estimation

Robust Conditional Probability Constraint Matched Field Processing

192-200In order to improve the robustness of Adaptive Matched Field Processing (AMFP), a Conditional Probability Constraint Matched Field Processing (MFP-CPC) is proposed. The algorithm derives the posterior probability density of the source locations from Bayesian Criterion, then the main lobe of AMFP is protected and the side lobe is restricted by the posterior probability density, so MFP-CPC not only has the merit of high resolution as AMFP, but also improves the robustness. To evaluate the algorithm, the simulated and experimental data in an uncertain shallow ocean environment is used. The results show that in the uncertain ocean environment MFP-CPC is robust not only to the moored source, but also to the moving source. Meanwhile, the localization and tracking is consistent with the trajectory of the moving source

Direct observation of the intermediate in an ultrafast isomerization.

Using a combination of two-dimensional infrared (2D IR) and variable temperature Fourier transform infrared (FTIR) spectroscopies the rapid structural isomerization of a five-coordinate ruthenium complex is investigated. In methylene chloride, three exchanging isomers were observed: (1) square pyramidal equatorial, (1); (2) trigonal bipyramidal, (0); and (3) square pyramidal apical, (2). Exchange between 1 and 0 was found to be an endergonic process (ΔH = 0.84 (0.08) kcal mol-1, ΔS = 0.6 (0.4) eu) with an isomerization time constant of 4.3 (1.5) picoseconds (ps, 10-12 s). Exchange between 0 and 2 however was found to be exergonic (ΔH = -2.18 (0.06) kcal mol-1, ΔS = -5.3 (0.3) eu) and rate limiting with an isomerization time constant of 6.3 (1.6) ps. The trigonal bipyramidal complex was found to be an intermediate, with an activation barrier of 2.2 (0.2) kcal mol-1 and 2.4 (0.2) kcal mol-1 relative to the equatorial and apical square pyramidal isomers respectively. This study provides direct validation of the mechanism of Berry pseudorotation - the pairwise exchange of ligands in a five-coordinate complex - a process that was first described over fifty years ago. This study also clearly demonstrates that the rate of pseudorotation approaches the frequency of molecular vibrations

Revealing Hidden Vibration Polariton Interactions by 2D IR Spectroscopy

We report the first experimental two-dimensional infrared (2D IR) spectra of novel molecular photonic excitations - vibrational-polaritons. The application of advanced 2D IR spectroscopy onto novel vibrational-polariton challenges and advances our understanding in both fields. From spectroscopy aspect, 2D IR spectra of polaritons differ drastically from free uncoupled molecules; from vibrational-polariton aspects, 2D IR uniquely resolves hybrid light-matter polariton excitations and unexpected dark states in a state-selective manner and revealed hidden interactions between them. Moreover, 2D IR signals highlight the role of vibrational anharmonicities in generating non-linear signals. To further advance our knowledge on 2D IR of vibrational polaritons, we develop a new quantum-mechanical model incorporating the effects of both nuclear and electrical anharmonicities on vibrational-polaritons and their 2D IR signals. This work reveals polariton physics that is difficult or impossible to probe with traditional linear spectroscopy and lays the foundation for investigating new non-linear optics and chemistry of molecular vibrational-polaritons