1,254 research outputs found
Modelling and Synchronisation of Delayed Packet-Coupled Oscillators in Industrial Wireless Sensor Networks
In this paper, a Packet-Coupled Oscillators (PkCOs) synchronisation protocol
is proposed for time-sensitive Wireless Sensor Networks (WSNs) based on
Pulse-Coupled Oscillators (PCO) in mathematical biology. The effects of delays
on synchronisation performance are studied through mathematical modelling and
analysis of packet exchange and processing delays. The delay compensation
strategy (i.e., feedforward control) is utilised to cancel delays effectively.
A simple scheduling function is provided with PkCOs to allocate the packet
transmission event to a specified time slot, by configuring reference input of
the system to a non-zero value, in order to minimise the possibility of packet
collision in synchronised wireless networks. The rigorous theoretical proofs
are provided to validate the convergence and stability of the proposed
synchronisation scheme. Finally, the simulations and experiments examine the
effectiveness of PkCOs with delay compensation and scheduling strategies. The
experimental results also show that the proposed PkCOs algorithm can achieve
synchronisation with the precision of ( tick)
Lightweight Synchronization Algorithm with Self-Calibration for Industrial LORA Sensor Networks
Wireless sensor and actuator networks are gaining momentum in the era of
Industrial Internet of Things IIoT. The usage of the close-loop data from
sensors in the manufacturing chain is extending the common monitoring scenario
of the Wireless Sensors Networks WSN where data were just logged. In this paper
we present an accurate timing synchronization for TDMA implemented on the state
of art IoT radio, such as LoRa, that is a good solution in industrial
environments for its high robustness. Experimental results show how it is
possible to modulate the drift correction and keep the synchronization error
within the requirements
Verification and Performance Analysis of Time Base Coded Data Protocol
The recent improvements in implantable medical devices combined with advanced wireless sensor networks are set to revolutionize the health-care industry by providing real-time, low-cost health monitoring for the patients. A new-field called Implantable Wireless Body Sensor Networks (IWBSN) has become a hot research topic because of its energy constraints and complex design. The main components of IWBSN are the base-station and implantable sensor nodes. The most important challenge is designing the sensor nodes which has to stay inside the body for long time. A novel protocol called ``Time-Based Coded Data" (TBCD) was formed in an attempt to reduce the energy consumption in the sensor nodes. While validating TBCD protocol clock drift and wireless body channel were not considered. Clock drift causes the sensor nodes to go out of synchronisation in an inconsiderable period of time. The human tissues provides a high path loss to the wireless channel.
This thesis proposes an error compensation method for both delay and clock drift. This helps the base-station and sensor nodes to stay synchronised for a longer period of time. The thesis also proposes a verification framework work which focusses on providing realistic situations to validate ultra low power IWBSNs. This framework enables to prove the functionality of TBCD protocol with delay and drift calculation and enables to find the optimum transmit power, sensitivity of the transceiver for TBCD protocol to work efficiently for an optimal distance between sensor nodes and the base-station. In addition, it has been proved that the life time of the battery of sensor nodes using TBCD protocol is greater when compared to the state-of-art protocols
Modelling and Synchronisation of Delayed Packet-Coupled Oscillators in Industrial Wireless Sensor Networks
In this paper, a Packet-Coupled Oscillators (PkCOs) synchronisation protocol is proposed for time-sensitive Wireless Sensor Networks (WSNs) based on Pulse-Coupled Oscillators (PCO) in mathematical biology. The effects of delays on synchronisation performance are studied through mathematical modelling and analysis of packet exchange and processing delays. The delay compensation strategy (i.e., feedforward control) is utilised to cancel delays effectively. A simple scheduling function is provided with PkCOs to allocate the packet transmission event to a specified time slot, by configuring reference input of the system to a non-zero value, in order to minimise the possibility of packet collision in synchronised wireless networks. The rigorous theoretical proofs are provided to validate the convergence and stability of the proposed synchronisation scheme. Finally, the simulations and experiments examine the effectiveness of PkCOs with delay compensation and scheduling strategies. The experimental results also show that the proposed PkCOs algorithm can achieve synchronisation with the precision of 26.3µs (1 tick)
Multi-view data capture for dynamic object reconstruction using handheld augmented reality mobiles
We propose a system to capture nearly-synchronous frame streams from multiple
and moving handheld mobiles that is suitable for dynamic object 3D
reconstruction. Each mobile executes Simultaneous Localisation and Mapping
on-board to estimate its pose, and uses a wireless communication channel to
send or receive synchronisation triggers. Our system can harvest frames and
mobile poses in real time using a decentralised triggering strategy and a
data-relay architecture that can be deployed either at the Edge or in the
Cloud. We show the effectiveness of our system by employing it for 3D skeleton
and volumetric reconstructions. Our triggering strategy achieves equal
performance to that of an NTP-based synchronisation approach, but offers higher
flexibility, as it can be adjusted online based on application needs. We
created a challenging new dataset, namely 4DM, that involves six handheld
augmented reality mobiles recording an actor performing sports actions
outdoors. We validate our system on 4DM, analyse its strengths and limitations,
and compare its modules with alternative ones.Comment: Accepted in Journal of Real-Time Image Processin
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