Sensor-based exploration for planar two-identical-link robots

Author(s):  
Ming-Lei Shao ◽  
Rui-Jun Yan ◽  
Jing Wu ◽  
Ji-Yeong Lee ◽  
Chang-Soo Han ◽  
...  

We present a new roadmap based on a generalized Voronoi graph for two-identical-link mobile robots to explore an unknown planar environment. It is called the L2-generalized Voronoi graph and is defined in terms of workspace distance measurements using only sensor-provided information, with the robot having the maximum distance from obstacles, and is therefore optimum in a point of view for exploration and obstacle avoidance. The configuration of the robot possesses four degrees of freedom, and hence the roadmap is one-dimensional in an unknown configuration space [Formula: see text]. The L2-generalized Voronoi graph is not always connected, and so is connected with an additional structure called the L2R-edge, where the robot is tangent to a GVD structure with the same orientation for the two links. This roadmap is termed L2 hierarchical generalized Voronoi graph. The L2 hierarchical generalized Voronoi graph includes two structures: the L2 hierarchical generalized Voronoi graph and the L2R edge. Although the condition of two identical links looks somewhat constraining, the L2 hierarchical generalized Voronoi graph is still worth pursuing because the case is very common in the engineering environment.

2003 ◽  
Vol 17 (5) ◽  
pp. 385-401 ◽  
Author(s):  
Keiji Nagatani ◽  
Yosuke Iwai ◽  
Yutaka Tanaka

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Robert J. Hinde

We examine the interaction between an open-shell chlorine atom and a para-H2 molecule in the region of configuration space that corresponds to a weakly bound Cl–para-H2 van der Waals dimer. By constructing and diagonalizing the Hamiltonian matrix that represents the coupled Cl atom electronic and H2 rotational degrees of freedom, we obtain one-dimensional energy curves for the Cl–para-H2 system in this region of configuration space. We find that the dimer exhibits fairly strong electronic-rotational coupling when the Cl–H2 distance R is close to ; however, this coupling does not modify substantially the positions and depths of the van der Waals wells in the dimer’s curves. An approximation in which the para-H2 fragment is treated in the strict limit thus appears to yield an accurate representation of those states of the weakly bound Cl–para-H2 dimer that correlate with H2 in the limit.


1998 ◽  
Vol 37 (04/05) ◽  
pp. 518-526 ◽  
Author(s):  
D. Sauquet ◽  
M.-C. Jaulent ◽  
E. Zapletal ◽  
M. Lavril ◽  
P. Degoulet

AbstractRapid development of community health information networks raises the issue of semantic interoperability between distributed and heterogeneous systems. Indeed, operational health information systems originate from heterogeneous teams of independent developers and have to cooperate in order to exchange data and services. A good cooperation is based on a good understanding of the messages exchanged between the systems. The main issue of semantic interoperability is to ensure that the exchange is not only possible but also meaningful. The main objective of this paper is to analyze semantic interoperability from a software engineering point of view. It describes the principles for the design of a semantic mediator (SM) in the framework of a distributed object manager (DOM). The mediator is itself a component that should allow the exchange of messages independently of languages and platforms. The functional architecture of such a SM is detailed. These principles have been partly applied in the context of the HEllOS object-oriented software engineering environment. The resulting service components are presented with their current state of achievement.


2015 ◽  
Vol 22 (04) ◽  
pp. 1550021 ◽  
Author(s):  
Fabio Benatti ◽  
Laure Gouba

When dealing with the classical limit of two quantum mechanical oscillators on a noncommutative configuration space, the limits corresponding to the removal of configuration-space noncommutativity and position-momentum noncommutativity do not commute. We address this behaviour from the point of view of the phase-space localisation properties of the Wigner functions of coherent states under the two limits.


Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4156
Author(s):  
Luís B. P. Nascimento ◽  
Dennis Barrios-Aranibar ◽  
Vitor G. Santos ◽  
Diego S. Pereira ◽  
William C. Ribeiro ◽  
...  

The planning of safe paths is an important issue for autonomous robot systems. The Probabilistic Foam method (PFM) is a planner that guarantees safe paths bounded by a sequence of structures called bubbles that provides safe regions. This method performs the planning by covering the free configuration space with bubbles, an approach analogous to a breadth-first search. To improve the propagation process and keep the safety, we present three algorithms based on Probabilistic Foam: Goal-biased Probabilistic Foam (GBPF), Radius-biased Probabilistic Foam (RBPF), and Heuristic-guided Probabilistic Foam (HPF); the last two are proposed in this work. The variant GBPF is fast, HPF finds short paths, and RBPF finds high-clearance paths. Some simulations were performed using four different maps to analyze the behavior and performance of the methods. Besides, the safety was analyzed considering the new propagation strategies.


Author(s):  
Mathias Fink

Time-reversal invariance can be exploited in wave physics to control wave propagation in complex media. Because time and space play a similar role in wave propagation, time-reversed waves can be obtained by manipulating spatial boundaries or by manipulating time boundaries. The two dual approaches will be discussed in this paper. The first approach uses ‘time-reversal mirrors’ with a wave manipulation along a spatial boundary sampled by a finite number of antennas. Related to this method, the role of the spatio-temporal degrees of freedom of the wavefield will be emphasized. In a second approach, waves are manipulated from a time boundary and we show that ‘instantaneous time mirrors’, mimicking the Loschmidt point of view, simultaneously acting in the entire space at once can also radiate time-reversed waves.


Author(s):  
Dong Liu

Solvothermal reaction between Cd(NO3)2, 1,4-phenylenediacetate (1,4-PDA) and 1,3-bis(pyridin-4-yl)propane (bpp) afforded the title complex, [Cd(C10H8O4)(C13H14N2)]n. Adjacent carboxylate-bridged CdIIions are related by an inversion centre. The 1,4-PDA ligands adopt acisconformation and connect the CdIIions to form a one-dimensional chain extending along thecaxis. These chains are in turn linked into a two-dimensional network through bpp bridges. The bpp ligands adopt ananti–gaucheconformation. From a topological point of view, each bpp ligand and each pair of 1,4-PDA ligands can be considered as linkers, while the dinuclear CdIIunit can be regarded as a 6-connecting node. Thus, the structure can be simplified to a two-dimensional 6-connected network.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 846
Author(s):  
Liang Zhao ◽  
Yu Bao ◽  
Yu Zhang ◽  
Ruidong Ye ◽  
Aijuan Zhang

When the displacement of an object is evaluated using sensor data, its movement back to the starting point can be used to correct the measurement error of the sensor. In medicine, the movements of chest compressions also involve a reciprocating movement back to the starting point. The traditional method of evaluating the effects of chest compression depth (CCD) is to use an acceleration sensor or gyroscope to obtain chest compression movement data; from these data, the displacement value can be calculated and the CCD effect evaluated. However, this evaluation procedure suffers from sensor errors and environmental interference, limiting its applicability. Our objective is to reduce the auxiliary computing devices employed for CCD effectiveness evaluation and improve the accuracy of the evaluation results. To this end, we propose a one-dimensional convolutional neural network (1D-CNN) classification method. First, we use the chest compression evaluation criterion to classify the pre-collected sensor signal data, from which the proposed 1D-CNN model learns classification features. After training, the model is used to classify and evaluate sensor signal data instead of distance measurements; this effectively avoids the influence of pressure occlusion and electromagnetic waves. We collect and label 937 valid CCD results from an emergency care simulator. In addition, the proposed 1D-CNN structure is experimentally evaluated and compared against other CNN models and support vector machines. The results show that after sufficient training, the proposed 1D-CNN model can recognize the CCD results with an accuracy rate of more than 95%. The execution time suggests that the model balances accuracy and hardware requirements and can be embedded in portable devices.


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