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21.
Fusion of probabilistic A* algorithm and fuzzy inference system for robotic path planning 总被引:1,自引:0,他引:1
Robotic Path planning is one of the most studied problems in the field of robotics. The problem has been solved using numerous
statistical, soft computing and other approaches. In this paper we solve the problem of robotic path planning using a combination
of A* algorithm and Fuzzy Inference. The A* algorithm does the higher level planning by working on a lower detail map. The
algorithm finds the shortest path at the same time generating the result in a finite time. The A* algorithm is used on a probability
based map. The lower level planning is done by the Fuzzy Inference System (FIS). The FIS works on the detailed graph where
the occurrence of obstacles is precisely known. The FIS generates smoother paths catering to the non-holonomic constraints.
The results of A* algorithm serve as a guide for FIS planner. The FIS system was initially generated using heuristic rules.
Once this model was ready, the fuzzy parameters were optimized using a Genetic Algorithm. Three sample problems were created
and the quality of solutions generated by FIS was used as the fitness function of the GA. The GA tried to optimize the distance
from the closest obstacle, total path length and the sharpest turn at any time in the journey of the robot. The resulting
FIS was easily able to plan the path of the robot. We tested the algorithm on various complex and simple paths. All paths
generated were optimal in terms of path length and smoothness. The robot was easily able to escape a variety of obstacles
and reach the goal in an optimal manner. 相似文献
22.
Supraglacial debris (SGD) cover on mountain glaciers is known to greatly influence various glacier processes and alter their response to climate change. In this study, vital glacier parameters of five glaciers with varying debris coverage (about 7–26%), located in Zanskar basin, Ladakh Himalaya, were monitored using Landsat imagery (from 1977 to 2013) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) global digital elevation model (GDEM). Results reveal how varying amounts of SGD induce categorically distinct responses on glaciers, sharing same geographical settings. The clean glaciers (CG) in the area were found to have higher retreat rates (about 8–19 m year?1), comparable areal shrinkage (about 13–15%), higher accumulation area ratios (AARs) (>0.5), rapid increase in SGD (about 1.6–3.0-fold), and association with increasing numbers of peri- and proglacial lakes (2–8 per glacier). The debris-covered glaciers (DCG) showed minimal frontal changes (about 2–5 m year?1), higher areal shrinkage (about 14–21%), low AARs (<0.5), slow SGD changes (about ≤1.2-fold), and association with increasing numbers of peri- and supraglacial lakes (SGLs) (2–39 per glacier). Moreover, while changes in SGD had a strong negative correlation with changes in glacier area, retreat rates, and AAR, they were positively related with increase in area of SGLs. 相似文献
23.
Satish Shukla Dhananjay Gopal Antonio-Francisco Roldán-López-de-Hierro 《国际通用系统杂志》2016,45(7-8):815-829
Very recently, in order to unify the notions of fuzzy metric space and metric-like space, Shukla and Abbas introduced the concept of fuzzy metric-like space and proved some fixed-point results in this setting. In this article, we modify the notion of Cauchy sequence and completeness to generalize their results. Thus, we extend their theorems to a more general framework, which is also appropriate to generalize some recent, well-known results in this line of research. Furthermore, several examples are presented to illustrate the significance of our results. 相似文献
24.
Syed Suhaib Deepak Mathaikutty Sandeep Shukla 《Electronic Notes in Theoretical Computer Science》2008,200(1):33
In Kahn process network (KPN), the processes (nodes) communicate by unbounded unidirectional FIFO channels (arcs), with the property of non-blocking writes and blocking reads on the channels. KPN provides a semantic model of computation, where a computation can be expressed as a set of asynchronously communicating processes. However, the unbounded FIFO based asynchrony is not realizable in practice and hence requires refinement in real hardware. In this work, we start with KPN as the model of computation for GALS, and discuss how different GALS architectures can be realized. We borrow some ideas from existing dataflow architectures for our GALS designs. 相似文献
25.
The electrical conductivity, σ, and thermoelectric power, S, of copper chromite (CuCr2O4) are reported in the temperature range 295 to 815 K. A break (T B) in the slope of the plot of log σ against T ?1 was observed around 556 K. Apart from this break, the curves are linear, and their slopes correspond to activation energies of 0.60 eV (T B<556 K) and 1.22 eV (T B>556 K). A break (T′ B) in the slope of the -S against T ?1 plot was also observed round 556 K. Apart from the break at this temperature, the S against T ?1 curves are linear. At T′ B>556, S can be expressed by the relation $$S = - \left[ {\left( {\frac{{0.65 eV}}{{{\text{2}}eT}}} \right) + (0.42) mV K^{ - {\text{1}}} } \right]$$ The mechanism involved in the electrical transport is the hopping of holes from Cr4+ centres to neighbouring Cr3+ ions. The typical hopping mobility of the holes is of the order of 106 m2 V?1 sec?1. The mobility activation energy of the holes in CuCr2O4 decreases with temperature due to the smoothing of the potential barriers between Cr4+ and Cr3+ sites. 相似文献
26.
Thermopower data of
S in both of itsα- andβ-phases are reported and the results are compared with the data on
Se.
Communication No. 129 from the Solid State and Structural Chemistry Unit. 相似文献
27.
A Brewster polarizer in this study is any dielectric plane reflecting surface reflecting light at or near the Brewster angle of incidence. In this paper, we consider an interesting phenomenon observed when we use an extended source of light or a cone of light with its axis incident on the plane surface at the Brewster angle. The resulting reflected light is viewed (a) through an ordinary sheet polarizer and (b) after reflection from another Brewster polarizer. The extinction pattern of light by such a system is in the form of an elongated black shadow in (a) and a nearly circular shadow in (b), respectively. These shadows are explained on the basis and use of the familiar Fresnel equations at a plane interface between two dielectric media. Photographs of the shadows are also presented. 相似文献
28.
Performing manipulation tasks interactively in real environments requires a high degree of accuracy and stability. At the same time, when one cannot assume a fully deterministic and static environment, one must endow the robot with the ability to react rapidly to sudden changes in the environment. These considerations make the task of reach and grasp difficult to deal with. We follow a Programming by Demonstration (PbD) approach to the problem and take inspiration from the way humans adapt their reach and grasp motions when perturbed. This is in sharp contrast to previous work in PbD that uses unperturbed motions for training the system and then applies perturbation solely during the testing phase. In this work, we record the kinematics of arm and fingers of human subjects during unperturbed and perturbed reach and grasp motions. In the perturbed demonstrations, the target’s location is changed suddenly after the onset of the motion. Data show a strong coupling between the hand transport and finger motions. We hypothesize that this coupling enables the subject to seamlessly and rapidly adapt the finger motion in coordination with the hand posture. To endow our robot with this competence, we develop a coupled dynamical system based controller, whereby two dynamical systems driving the hand and finger motions are coupled. This offers a compact encoding for reach-to-grasp motions that ensures fast adaptation with zero latency for re-planning. We show in simulation and on the real iCub robot that this coupling ensures smooth and “human-like” motions. We demonstrate the performance of our model under spatial, temporal and grasp type perturbations which show that reaching the target with coordinated hand–arm motion is necessary for the success of the task. 相似文献
29.
Shukla R Banerjee P Sharma SK Das R Deb P Prabaharan T Das B Adhikary B Verma R Shyam A 《The Review of scientific instruments》2011,82(10):106103
The experimental results of an air-core pulse transformer are presented, which is very compact (<10 Kg in weight) and is primed by a capacitor bank that is fabricated in such a way that the capacitor bank with its switch takes the shape of single-turn rectangular shaped primary of the transformer. A high voltage capacitor assembly (pulse-forming-line capacitor, PFL) of 5.1 nF is connected with the secondary of transformer. The transformer output voltage is 160 kV in its second peak appearing in less than 2 μS from the beginning of the capacitor discharge. The primary capacitor bank can be charged up to a maximum of 18 kV, with the voltage delivery of 360 kV in similar capacitive loads. 相似文献
30.