10,866 research outputs found
Architectural Considerations for a Self-Configuring Routing Scheme for Spontaneous Networks
Decoupling the permanent identifier of a node from the node's
topology-dependent address is a promising approach toward completely scalable
self-organizing networks. A group of proposals that have adopted such an
approach use the same structure to: address nodes, perform routing, and
implement location service. In this way, the consistency of the routing
protocol relies on the coherent sharing of the addressing space among all nodes
in the network. Such proposals use a logical tree-like structure where routes
in this space correspond to routes in the physical level. The advantage of
tree-like spaces is that it allows for simple address assignment and
management. Nevertheless, it has low route selection flexibility, which results
in low routing performance and poor resilience to failures. In this paper, we
propose to increase the number of paths using incomplete hypercubes. The design
of more complex structures, like multi-dimensional Cartesian spaces, improves
the resilience and routing performance due to the flexibility in route
selection. We present a framework for using hypercubes to implement indirect
routing. This framework allows to give a solution adapted to the dynamics of
the network, providing a proactive and reactive routing protocols, our major
contributions. We show that, contrary to traditional approaches, our proposal
supports more dynamic networks and is more robust to node failures
On the Throughput-Delay Trade-off in Georouting Networks
We study the scaling properties of a georouting scheme in a wireless
multi-hop network of mobile nodes. Our aim is to increase the network
capacity quasi linearly with while keeping the average delay bounded. In
our model, mobile nodes move according to an i.i.d. random walk with velocity
and transmit packets to randomly chosen destinations. The average packet
delivery delay of our scheme is of order and it achieves the network
capacity of order . This shows a practical
throughput-delay trade-off, in particular when compared with the seminal result
of Gupta and Kumar which shows network capacity of order and
negligible delay and the groundbreaking result of Grossglausser and Tse which
achieves network capacity of order but with an average delay of order
. We confirm the generality of our analytical results using
simulations under various interference models.Comment: This work has been submitted to IEEE INFOCOM 201
Position control of an industrial robot using an optical measurement system for machining purposes
A series of mechanical properties and disturbances limit the accuracy achievable in robotic applications. External control of the end effector position is commonly known as being an appropriate mean to increase accuracy. This paper presents an approach for position control of industrial robots using the pass-through between an industrial CNC and servomotors. A CNC-controlled robot is used together with an external optical measurement system to close the feedback loop of robot end effector and robot controller in order to improve robot accuracy. For short cycle times and implementation reasons a PLC is used for signal processing and control implementation. The relevance of the approach is outlined in experiments. The robot behaviour in free space motion and in machining application is analysed with the optical measurement system and a CMM
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