Industrial wireless sensor networks can facilitate the deployment of a wide range of novel industrial applications, including mobile applications that connect mobile robots, vehicles, goods and workers to industrial networks. Current industrial wireless sensor standards have been mainly designed for static deployments, and their performance significantly degrades when introducing mobile devices. One of the major reasons for such degradation is the neighbor discovery process. This paper presents and evaluates two novel neighbor discovery protocols that improve the capability of mobile devices to remain connected to the industrial wireless sensor networks as they move. The proposed protocols exploit topology information and the nature of devices (static or mobile) to reliably and rapidly discover neighbor devices. This is achieved in some cases at the expense of increasing the number of radio resources utilized and the energy consumed in the discovery process. The proposed solutions have been designed and evaluated considering the WirelessHART standard given its widespread industrial adoption. However, they can also be adapted for the ISA100.11a and IEEE 802.15.4e standards.

Industrial wireless sensor networks can help improve the efficiency, reconfigurability and flexibility of future factories, and facilitate the introduction of new applications. Industrial applications are generally characterized with strict reliability and latency requirements. The capacity to meet such requirements is highly dependent on an efficient utilization of communication links. Such efficient utilization will become even more critical as the number of deployed sensors and traffic in factories increase. In this context, this paper presents a novel link scheduling scheme for industrial wireless sensor networks that uses shared links among nodes that are part of the same path or multi-hop route. The transmission of a message along a route acts as a virtual token to identify which node should use the shared links at each point in time. This study demonstrates that the proposed link scheduling scheme can significantly improve the reliability, latency and efficiency of industrial wireless sensor networks. The proposed link scheduling scheme is here applied to industrial wireless sensor networks, but it can be used in other centralized TDMA-based multi-hop wireless networks.

ResumenEl uso de redes inalámbricas industriales supondrá una mejora de la productividad, la flexibilidad y la eficiencia de las fábricas del futuro debido a su alto potencial para facilitar el despliegue de nuevas aplicaciones. Algunas de las aplicaciones permitirán la incorporación de nodos móviles para su monitorización y control, tales como vehículos autónomos, robots móviles, e incluso trabajadores. Los estrictos requisitos de las aplicaciones industriales, unidos a la posibilidad de desplegar dispositivos móviles, requieren el diseño de algoritmos de asignación de recursos que coordinen las transmisiones de los diferentes nodos de la red para transportar de forma fiable y eficiente la información entre origen y destino. En este contexto, este artículo presenta y evalúa un nuevo algoritmo de asignación de recursos radio que emplea enlaces compartidos entre los nodos que forman una misma ruta para mejorar el rendimiento de las comunicaciones extremo a extremo. Los resultados obtenidos demuestran el potencial del algoritmo propuesto frente a algoritmos existentes, tanto en redes con nodos estáticos como en redes que incluyan nodos móviles. Palabras ClaveRedes inalámbricas industriales, redes multisalto, asignación de recursos radio, movilidad.

Wireless industrial communications are expected to represent an essential component of the Factories of the Future. Current industrial wireless standards have been designed for networks with fixed devices, while future systems might require the mobility of certain devices within a factory. The neighbour discovery mechanism is an important feature of wireless standards for facilitating the mobility of devices. WirelessHART includes a contention-based neighbour discovery mechanism that is not particularly suited for efficiently discovering mobile devices. In this context, this paper proposes a new protocol, called Listen Advertise Network Neighbour Discovery (LAN-ND) that improves the neighbours' detection probability of WirelessHART, and reduces the average time needed to detect new neighbour devices.

This paper presents a practical implementation of a photovoltaic I-V curves and maximum power point estimation algorithm (IVMPPE). The IVMPPE estimates the I-V curve and sets the operation of the solar panels at a voltage that extracts the maximum available power without tracking. The operation is based on solving the parameters of the solar array equivalent electrical model, in real time, only with the measurements of six voltage and current coordinates near the operating point. Moreover, the strategy for selecting the measured points and the discard procedures for incorrect estimated curves are also detailed. To validate the IVMPPE, it has been tested under different operating conditions, and its accuracy has been compared with the classical perturb and observe (P&O) technique. The distinguishing feature of the IVMPPE is that complete I-V model is obtained, not only the MPP, enlarging the capabilities to other fields, e.g., real-time monitoring and prediction.

Wireless communication technologies will represent an essential technological component of the Factories of the Future in order to facilitate the real-time monitoring of the industrial processes, as well as the working conditions and the workers' health and safety. To this aim, wireless sensor networking technologies are being evolved to overcome the industrial challenging propagation environments and guarantee the strict QoS requirements characterizing industrial applications. However, a major future demand for wireless industrial systems could be the capability to support mobility. In this context, this paper analyzes the impact of mobility on the performance of industrial wireless communication systems based on a centralized management like the WirelessHART standard.