45,618 research outputs found
Design of a multiple bloom filter for distributed navigation routing
Unmanned navigation of vehicles and mobile robots can be greatly simplified by providing environmental intelligence with dispersed wireless sensors. The wireless sensors can work as active landmarks for vehicle localization and routing. However, wireless sensors are often resource scarce and require a resource-saving design. In this paper, a multiple Bloom-filter scheme is proposed to compress a global routing table for a wireless sensor. It is used as a lookup table for routing a vehicle to any destination but requires significantly less memory space and search effort. An error-expectation-based design for a multiple Bloom filter is proposed as an improvement to the conventional false-positive-rate-based design. The new design is shown to provide an equal relative error expectation for all branched paths, which ensures a better network load balance and uses less memory space. The scheme is implemented in a project for wheelchair navigation using wireless camera motes. © 2013 IEEE
Security of GPS/INS based On-road Location Tracking Systems
Location information is critical to a wide-variety of navigation and tracking
applications. Today, GPS is the de-facto outdoor localization system but has
been shown to be vulnerable to signal spoofing attacks. Inertial Navigation
Systems (INS) are emerging as a popular complementary system, especially in
road transportation systems as they enable improved navigation and tracking as
well as offer resilience to wireless signals spoofing, and jamming attacks. In
this paper, we evaluate the security guarantees of INS-aided GPS tracking and
navigation for road transportation systems. We consider an adversary required
to travel from a source location to a destination, and monitored by a INS-aided
GPS system. The goal of the adversary is to travel to alternate locations
without being detected. We developed and evaluated algorithms that achieve such
goal, providing the adversary significant latitude. Our algorithms build a
graph model for a given road network and enable us to derive potential
destinations an attacker can reach without raising alarms even with the
INS-aided GPS tracking and navigation system. The algorithms render the
gyroscope and accelerometer sensors useless as they generate road trajectories
indistinguishable from plausible paths (both in terms of turn angles and roads
curvature). We also designed, built, and demonstrated that the magnetometer can
be actively spoofed using a combination of carefully controlled coils. We
implemented and evaluated the impact of the attack using both real-world and
simulated driving traces in more than 10 cities located around the world. Our
evaluations show that it is possible for an attacker to reach destinations that
are as far as 30 km away from the true destination without being detected. We
also show that it is possible for the adversary to reach almost 60-80% of
possible points within the target region in some cities
Symbiotic Navigation in Multi-Robot Systems with Remote Obstacle Knowledge Sharing
Large scale operational areas often require multiple service robots for coverage and task parallelism. In such scenarios, each robot keeps its individual map of the environment and serves specific areas of the map at different times. We propose a knowledge sharing mechanism for multiple robots in which one robot can inform other robots about the changes in map, like path blockage, or new static obstacles, encountered at specific areas of the map. This symbiotic information sharing allows the robots to update remote areas of the map without having to explicitly navigate those areas, and plan efficient paths. A node representation of paths is presented for seamless sharing of blocked path information. The transience of obstacles is modeled to track obstacles which might have been removed. A lazy information update scheme is presented in which only relevant information affecting the current task is updated for efficiency. The advantages of the proposed method for path planning are discussed against traditional method with experimental results in both simulation and real environments
Smart Signs: Showing the way in Smart Surroundings
This paper presents a context-aware guidance and messaging
system for large buildings and surrounding venues. Smart Signs are
a new type of electronic door- and way-sign based on wireless sensor networks.
Smart Signs present in-situ personalized guidance and messages,
are ubiquitous, and easy to understand. They combine the easiness of
use of traditional static signs with the flexibility and reactiveness of navigation
systems. The Smart Signs system uses context information such
as user’s mobility limitations, the weather, and possible emergency situations
to improve guidance and messaging.
Minimal infrastructure requirements and a simple deployment tool make
it feasible to easily deploy a Smart Signs system on demand.
An important design issue of the Smart Signs system is privacy: the
system secures communication links, does not track users, allow almost
complete anonymous use, and prevent the system to be used as a tool
for spying on users
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