Lack of an accurate and low-cost method to reconstruct indoor maps is the main reason behind the current sporadic availability of digital building floor plans. The conventional approach using professional equipment is...
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Lack of an accurate and low-cost method to reconstruct indoor maps is the main reason behind the current sporadic availability of digital building floor plans. The conventional approach using professional equipment is very costly and only available in the most popular areas. In this paper, we propose and demonstrate CrowdMap, a crowd sourcing system utilizing sensor-rich video data from mobile users for indoor floor plan reconstruction with low-cost. The key idea of CrowdMap is to first jointly leverage crowd sourced sensory and video data to track user movements, then use the inferred user motion traces and context of the image to produce an accurate floor plan. In particular, we exploit the sequential relationship between each consecutive frame abstracted from the video to improve system performance. Our experiments in three college buildings show that CrowdMap achieves a precision of hallway shape around 88%, a recall around 93% and a F-measure around 90%. In addition, we achieve on average 9.8% room area error and on average 6.5% room aspect ratio error. The evaluation result demonstrates a significant improvement of accuracy compared with other crowd sourcing floor plan reconstruction systems.
Wireless technologies have been successfully applied in the process industry since the creation of the firstinternational standard IEC62591 WirelessHART. Applications started in areas where wireless sensors provide r...
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ISBN:
(纸本)9781479989386
Wireless technologies have been successfully applied in the process industry since the creation of the firstinternational standard IEC62591 WirelessHART. Applications started in areas where wireless sensors provide rich process information to the automation systems. Although real and demonstrated control applications are advertised, wireless-for-control is still in the initial stage and faces a lot of challenges. In particular, feedback latency and battery longevity, which are also problems for wireless-for-sensing, are even more critical when wireless actuators are applied. There are additional challenges in using wireless actuators because they actively affect the process. This paper lays the foundation for control using a wireless actuator. It demonstrates how traditional control methodologies can be modified to effectively work with general wireless communication. The innovations are tested with simulations and experimentations, both on commercial distributed control systems.
Wireless charging has provided a convenient alternative to renew sensors' energy in wireless sensor networks. Due to physical limitations, previous works have only considered recharging a single node at a time, wh...
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Wireless charging has provided a convenient alternative to renew sensors' energy in wireless sensor networks. Due to physical limitations, previous works have only considered recharging a single node at a time, which has limited efficiency and scalability. Recent advance on multi-hop wireless charging is gaining momentum to provide fundamental support to address this problem. However, existing single-node charging designs do not consider and cannot take advantage of such opportunities. In this paper, we propose a new framework to enable multi-hop wireless charging using resonant repeaters. first, we present a realistic model that accounts for detailed physical factors to calculate charging efficiencies. Second, to achieve balance between energy efficiency and data latency, we propose a hybrid data gathering strategy that combines static and mobile data gathering to overcome their respective drawbacks and provide theoretical analysis. Then we formulate multi-hop recharge schedule into a bi-objective NP-hard optimization problem. We propose a two-step approximation algorithm that first finds the minimum charging cost and then calculates the charging vehicles' moving costs with bounded approximation ratios. Finally, upon discovering more room to reduce the total system cost, we develop a post-optimization algorithm that iteratively adds more stopping locations for charging vehicles to further improve the results. Our extensive simulations show that the proposed algorithms can handle dynamic energy demands effectively, and can cover at least three times of nodes and reduce service interruption time by an order of magnitude compared to the single-node charging scheme.
Wireless-based device-free human sensing has raised increasing research interest and stimulated a range of novel location-based services and human-computer interaction applications for recreation, asset security and e...
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Wireless-based device-free human sensing has raised increasing research interest and stimulated a range of novel location-based services and human-computer interaction applications for recreation, asset security and elderly care. A primary functionality of these applications is to first detect the presence of humans before extracting higher-level contexts such as physical coordinates, body gestures, or even daily activities. In the presence of dense multipath propagation, however, it is non-trivial to even reliably identify the presence of humans. The multipath effect can invalidate simplified propagation models and distort received signal signatures, thus deteriorating detection rates and shrinking detection range. In this paper, we characterize the impact of human presence on wireless signals via ray-bouncing models, and propose a measurable metric on commodity WiFi infrastructure as a proxy for detection sensitivity. To achieve higher detection rate and wider sensing coverage in multipath-dense indoor scenarios, we design a lightweight sub carrier and path configuration scheme harnessing frequency diversity and spatial diversity. We prototype our scheme with standard WiFi devices. Evaluations conducted in two typical office environments demonstrate a detection rate of 92.0% with a false positive of 4.5%, and almost 1x gain in detection range given a minimal detection rate of 90%.
The proceedings contain 55 papers. The topics discussed include: low-power listening goes multi-channel;PhyTraces: simulating new RF environments with physical layer traces;a novel wake-up receiver with addressing cap...
ISBN:
(纸本)9781479946198
The proceedings contain 55 papers. The topics discussed include: low-power listening goes multi-channel;PhyTraces: simulating new RF environments with physical layer traces;a novel wake-up receiver with addressing capability for wireless sensor nodes;symmetric coherent link degree, adaptive throughput-transmission power for wireless sensor networks;indoor occupant positioning system using active RFID deployment and particle filters;harnessing non-uniform transmit power levels for improved sequence based localization;FlashTrack: a fast, in-network tracking system for sensor networks;crowd-sensing with polarized sources;a dual-sensor enabled indoor localization system with Crowdsensing spot survey;on decentralized in-network aggregation in real-world scenarios with crowd mobility;and the information funnel: exploiting named data for information-maximizing data collection.
The following topics are dealt with: mobility, data collection, and network lifetime maximization; camera and multimedia networks; mobile applications and security; routing, MAC, and wireless interference; network dep...
The following topics are dealt with: mobility, data collection, and network lifetime maximization; camera and multimedia networks; mobile applications and security; routing, MAC, and wireless interference; network deployment and topology optimization; estimation and detection; and load balancing.
This paper presents a methodology of distributed control system design for autonomous cooperative control of intelligent mobile robots. Following the natural concept of control architecture evolution, a bottom-up appr...
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ISBN:
(纸本)9781479959556
This paper presents a methodology of distributed control system design for autonomous cooperative control of intelligent mobile robots. Following the natural concept of control architecture evolution, a bottom-up approach for control system design is presented. first, microcomputer based intelligent device modules, such as multiple infrared range finding sensor modules, and odometry and locomotor control modules, are constructed as a device manager layer on a distributed multi-microcontroller network based hardware structure to detect walls and obstacles and to move around the surroundings of a two-wheeled mobile robot. Then functional control modules, such as landmark and obstacle recognition and localization, robot motion control are implemented based on the device layer. Environment features such as lines and corners are estimated using a set of range sensors and a vision sensor. Next, some intelligent behavior modules, such as wall following, obstacle rounding, and target seeking, and environment mapping are implemented as cooperative activities based on the functional control modules. Upon these hierarchical activity modules, a non-centralized control approach is applied to implement the autonomous coordination of concurrent activities among behavior modules for the high-level tasks such as sensory navigation in unknown environments. The system integration and implementation issues are discussed for the proposed approach.
We investigate increased efficiency by integrating smart metering systems, such as those used for electricity, gas, and water services. Since gas and water meters are not connected to power lines, they are generally b...
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We investigate increased efficiency by integrating smart metering systems, such as those used for electricity, gas, and water services. Since gas and water meters are not connected to power lines, they are generally battery powered. Wireless multihop communications protocols used by these systems must therefore use little power in order to prolong operational life, in contrast to wired meters with supplied power that have little necessity for power-saving. We propose a wireless multihop communications protocol that enables integration of gas and water meters by devising a communications method for smart electric metering systems.
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