This paper presents the results of a software system which integrates geographical information systems (GIS), object oriented simulation (OOS), and multi-sensor fusion algorithms. This system allows the Navy to evalua...
详细信息
ISBN:
(纸本)1565553195
This paper presents the results of a software system which integrates geographical information systems (GIS), object oriented simulation (OOS), and multi-sensor fusion algorithms. This system allows the Navy to evaluate the performance of different multi-sensor configurations in order to identify enemy ships, friendly ships, or other entities present in the ocean. ArcGIS provides geographical information such as seabed composition, bathymetry, and proximity to the coast. The simulation system developed on AnyLogic takes the GIS data as input, and performs simulations to evaluate the impact of the geographical conditions on the ability of the sensors to identify entities in the ocean.
Matching laser range scans observed at different points in time is a crucial component of many robotics tasks, including mobile robot localization and mapping. While existing techniques such as the Iterative Closest P...
ISBN:
(纸本)9780262524841
Matching laser range scans observed at different points in time is a crucial component of many robotics tasks, including mobile robot localization and mapping. While existing techniques such as the Iterative Closest Point (ICP) algorithm perform well under many circumstances, they often fail when the initial estimate of the offset between scans is highly uncertain. This paper presents a novel approach to 2D laser scan matching. CRF-Matching generates a Condition Random Field (CRF) to reason about the joint association between the measurements of the two scans. The approach is able to consider arbitrary shape and appearance features in order to match laser scans. The model parameters are learned from labeled training data. Inference is performed efficiently using loopy belief propagation. Experiments using data collected by a car navigating through urban environments show that CRF-Matching is able to reliably and efficiently match laser scans even when no a priori knowledge about their offset is given. They additionally demonstrate that our approach can seamlessly integrate camera information, thereby further improving performance.
We propose models that focus on the improvement of flexibility in manufacturing supply networks by enabling a tighter information coupling between the various planning levels without tampering with the autonomy of ent...
We propose models that focus on the improvement of flexibility in manufacturing supply networks by enabling a tighter information coupling between the various planning levels without tampering with the autonomy of enterprises which are geographically distributed. The problem is approached from the perspective of social network planning using a community of agents. These agents have unique properties which they exhibit at different planning levels. Characterization of agents in the models is discussed.
The field of Unmanned Aerial Vehicles (UAV) has gained great significance in the R&D activities of several institutions, and numerous realizations have been constructed. controlling the movement of a UAV is one of...
详细信息
ISBN:
(纸本)9789633130117
The field of Unmanned Aerial Vehicles (UAV) has gained great significance in the R&D activities of several institutions, and numerous realizations have been constructed. controlling the movement of a UAV is one of the most significant tasks in the hierarchical control system that should be realized in order to successfully manage UAVs in several missions. Precise control of the movement requires accurate mathematical models of the aircraft that correspond to the several control schemes that are intended to apply, including linearised, LPV, and nonlinear ones. The source of mathematical models includes the physical model constructed on the basis of the Newtonian equations and the rules of aerodynamics, as well as the use of empirical observations, measurements. The methodology of system identification offers the tools that can be used to manage this field. The systems and control Laboratory of the computer and Automation Research Institute in cooperation with University of Minnesota and Budapest University of Technology and Economics has built - as a part of a more general framework established to solve complex UAV control problems - small UAVs, equipped with on-board sensors and embedded computer with the purpose of obtaining an adequate test platform for the aircraft experiments. Based on on-board measurements acquired during the flight tests performed with the UAVs, the opportunity has been given to test several system identification approaches corresponding to the control tasks to be solved. This paper gives an outline of the system identification and modelling methods that have successfully been applied, and also analyzes the problems encountered in the data-acquisition - signal processing - computing chain.
Wireless mesh networks (WMNs) receive much research interests because of their reliability, scalability and low cost. Obtaining high-throughput for multicast applications (e.g. video streaming broadcast) in WMNs is ch...
详细信息
ISBN:
(纸本)8996076112
Wireless mesh networks (WMNs) receive much research interests because of their reliability, scalability and low cost. Obtaining high-throughput for multicast applications (e.g. video streaming broadcast) in WMNs is challenging due to the interference and the change of channel quality. Cross-layer design and network coding are approaches which have been recently received considerable attention for high-throughput problem in wireless networks. In this paper, we propose an approach namely CLNC (Cross-Layer Network Coding) which is a combination of the above approaches to improve throughput in multicast wireless mesh networks. Our simulation results show that when the number of receivers is high CLNC's throughput is higher at least 30% than that of known methods such as AODV, DSDV and DSR and higher than that of MAODV. Moreover, PDR (Packet Delivery Ration) of CLNC is higher than that of MAODV and DSDV.
A new adaptive quasi-sliding mode control algorithm is developed for a class of nonlinear discrete-time systems, which is especially useful for nonlinear systems with vaguely known dynamics. This design is model-free,...
详细信息
A new adaptive quasi-sliding mode control algorithm is developed for a class of nonlinear discrete-time systems, which is especially useful for nonlinear systems with vaguely known dynamics. This design is model-free, and is based directly on pseudo-partial-derivatives derived on-line from the input and output information of the system using an improved recursive projection type of identification algorithm. The theoretical analysis and simulation results show that the adaptive quasi-sliding mode control system is stable and convergent.
The paper investigates several pole placement methods in the linear case and suggests a new pole placement method by means of fuzzy linear equations. The linear methods concern the constant real part poles, the poles ...
详细信息
A multi-marker automaton is a finite automaton which keeps marks as pebbles in the finite control, and cannot rewrite any input symbols but can make marks on its input with the restriction that only a bounded number o...
详细信息
As the number of components in cluster-based systems increases, costand power consumption also increase. One way to reduce both problems is usingsmaller networks with adequate congestion management mechanisms. Recents...
详细信息
ISBN:
(纸本)9783540898931
As the number of components in cluster-based systems increases, costand power consumption also increase. One way to reduce both problems is usingsmaller networks with adequate congestion management mechanisms. Recentsuccessful proposals (RECN) eliminate the negative effects of congestion,the Head-of-Line (HOL) blocking, leaving congestion harmless. RECN relies onsource-based networks architectures, where the entire route is placed at packetheaders before injection. Unfortunately, distributed table-based routing is alsocommon in cluster-based networks, being InfiniBand the most prominent *** propose a novel congestion management technique for distributed tablebasedrouting. The mechanism relies on additional congestion information locatedat routing tables. With this information HOL blocking is minimized bysmartly using switch queues. Detailed memory organization and the way congestioninformation is updated/propagated is described. Preliminary results indicatethat with modest resource requirements maximum network performance is keptregardless of congestion.
Construction parts consisting of two-layer composite materials made of carbon fiber reinforced plastic (CFRP) laminates and TiAl6V4 still need to be machined, whereby drill holes are frequently manufactured. Special a...
详细信息
ISBN:
(纸本)0872638618
Construction parts consisting of two-layer composite materials made of carbon fiber reinforced plastic (CFRP) laminates and TiAl6V4 still need to be machined, whereby drill holes are frequently manufactured. Special attention has to be paid to the machining quality, which implies dimensional accuracy as well as a defect-free peripheral zone. Machining defects often occur as a consequence of excessive mechanical and thermal loads, which are often caused by wrong process conditions or by the wrong choice of machining process itself. With respect to widely used state-of-the-art machine tools providing high performance and equipped with potent control unit, for the comparatively large drill hole, circular milling gains interest as an alternative to the drilling operation (Weinert et al. 2005). Here, the circular milling process is compared to the drilling process focusing on the hole making of 6 mm diameter to two-layer composite material consisting of CFRP (carbon fiber reinforced plastic) laminates and TiAl6V4. The investigations were focused mainly on the influence of hole making process on the bore hole quality. The hole diameter, the surface roughness and the roundness are compared and evaluated between circular milling process and drilling one, and also the two processes followed by reaming. Moreover, the thrust forces during the two processes were measured and the transition between the thrust force and tool wear are considered.
暂无评论