Search results for "LESS"
showing 10 items of 2452 documents
Robustness Analysis of an Extended Kalman Filter for Sensorless Control of Induction Motors
2010
This paper deals with robustness analysis of Extended Kalman Filters (EKFs) for sensorless motion control of induction motors. Analysis is carried out by means of simulation experiments considering a conventional EKF, in which system and measurement noise covariance matrices are constant, and an adaptive EKF in which the system noise covariance matrix is updated on-line using a PID-type algorithm driven by the stator current estimation errors.
Improving the efficiency of a standard compliant wireless battery charger
2012
In this paper, a wireless charger for portable electronics devices is presented. A power transmitter, also known as the magnetic pad, and a power receiver are magnetically coupled. A receiver architecture which improves the power conversion efficiency is proposed. All advantages brought by the proposed architecture are discussed and standard constraints are presented as well. The receiver is fully standard-compliant. A wireless station for mobile application is designed and tested. Simulation and experimental results are compared. As shown by experimental results, thanks to the proposed architecture the power conversion efficiency of the receiver section is really close to a unit value. Pow…
Industrial applications of wireless networks: a bridge crane distributed control system based on bluetooth
2005
This paper shows the possibility to use Bluetooth for wireless short range communication in an industrial environment. In this line a distributed control system based on Bluetooth has been proposed for a bridge crane system. Its configuration is mainly based on the use of distributed nodes connected by means of Bluetooth. Traditionally many types of devices have been delivered as mechanical devices and more or less all or the intelligence and control has been added. Nowadays there is a growing trend towards a higher level of built-in intelligence in the devices, constituting the intelligent nodes. This type of systems allows the implementation of highly flexible control systems capable of a…
Integration and application of emerging RF systems formed by wireless sensor networks: exhaustive experiment to their implantation in different envir…
2007
This paper shows the possibility to use Bluetooth for wireless short range communication in an industrial environment. Traditionally many types of devices have been delivered as mechanical devices and more or less all or the intelligence and control has been added. Nowadays there is a growing trend towards a higher level of built-in intelligence in the devices, constituting the intelligent nodes. This type of systems allows the implementation of highly flexible control systems capable of adapting themselves to different situations. With the introduction of RF systems, another dimension is aggregated, the possibility to wirelessly connect to the devices. The technology makes it possible to e…
Low-Cost Alternatives for Urban Noise Nuisance Monitoring Using Wireless Sensor Networks
2015
Noise pollution caused by vehicular traffic is a common problem in urban environments that has been shown to affect people's health and children's cognition. In the last decade, several studies have been conducted to assess this noise, by measuring the equivalent noise pressure level (called L eq ) to acquire an accurate sound map using wireless networks with acoustic sensors. However, even with similar values of L eq , people can feel the noise differently according to its frequency characteristics. Thus, indexes, which can express people's feelings by subjective measures, are required. In this paper, we analyze the suitability of using the psychoacoustic metrics given by the Zwicker's mod…
Analysis of proposals to reduce SAR levels from GSM terminals
2002
Is wireless communication dangerous? In recent years some scientists and lay people have expressed alarm at the possible harm mobile phones could cause to the user's health, even cancer. Handset terminals must meet standard limits based in SAR measurements. In this paper we present several proposals to minimize SAR values computed over a numerical user's head model using absorbent materials and new generation antennas.
Cyber Security for Wireless Semantic (SCADA/DCS) Systems
2016
International audience; Supervisory Control and Data Acquisition and Distributed Control Systems named (SCADA/DCS) have played a key role in the design of modern power smart applications, particularly in the automatic management of real time energetic platforms. In this work, we present a semantic cyber security vulnerabilities add to classic one, with the use of semantic embedded application in smart devices in semantic wireless (SCADA/DCS) systems, focusing on the semantic attacks. In this work, we present a new security semantic wireless protocol as a secure communication support for these modern semantic wireless systems named (ZIGBEE/SOAP/SECURITY), obtained by the combination between …
Velocity sensorless control of uncertain load using RKF tuned with an evolutionary algorithm and mu-analysis
2010
Abstract In case of a velocity control scheme for a load directly driven by an actuator, large variations of its parameters are problematic due to possible instability and large variations of the final performances. This performances are then decreasing if a sensorless control is implemented due to cost, reliability or application constraints. This paper proposes solutions to quickly and accurately tune an observer with a lower computer time consumption and lower conception time. A previous calculated state feedback is used as base for a Kalman filter with special noise matrices. An evolutionary algorithm optimizes the observers degrees of freedom all over the variations. The mu-analysis th…
Decentralized Synchronization for Zigbee wireless sensor networks in Multi-Hop Topology
2010
Abstract The most effective solution for energy saving in low-rate wireless sensor networks is maintaining each node in a doze state as long as possible. In order to guarantee network connectivity, the intervals at which the network sensors are turned on and off have to be coordinated. We analyze the Zigbee MAC performance in sensor networks deployed in multi-hop topologies. For this networks, critical inefficiencies can arise due to transmissions performed by hidden nodes. We evaluate the impact of different synchronization schemes on the network performance, both in terms of network capacity and in terms of energy consumption. We show how the synchronization function can be opportunistica…
A unified radio control architecture for prototyping adaptive wireless protocols
2016
Experimental optimization of wireless protocols and validation of novel solutions is often problematic, due to limited configuration space present in commercial wireless interfaces as well as complexity of monolithic driver implementation on SDR-based experimentation platforms. To overcome these limitations a novel software architecture is proposed, called WiSHFUL, devised to allow: i) maximal exploitation of radio functionalities available in current radio chips, and ii) clean separation between the logic for optimizing the radio protocols (i.e. radio control) and the definition of these protocols.