A smart city is a city which functions in a sustainable and intelligent way, by integrating all its infrastructures and services into a cohesive whole and using intelligent devices for monitoring and control, to ensure sustainability and efficiency. From smart design of buildings which capture rain water for later use, to intelligent control systems, which can monitor infrastructures autonomously, the possible improvements enabled by sensing technologies are immense. Ubiquitous sensing poses numerous challenges, which are of a technological or social nature.
The Sensing Evolution
Sensors are a crucial component of any intelligent control system. A process is improved based on its environment and for a control system to be aware of its environment, it is typically fitted with an array of sensors, from which it collects the required data. It then uses the appropriate variables to characterize its environment to adjust its operations accordingly.
The availability of a multitude of different sensors and continuously evolving technology enable applications that were infeasible in the past due to high costs and limited availability. Technology advances not only drive the innovation behind sensors, they also enable sufficient processing power for small-scale devices to which these sensors can be interfaced to at a relatively low cost. From the perspective of the requirements for smart cities, wide availability of these technologies translates to a large number of opportunities in terms of sensing.
Smart Sensors for Smart Cities
Within the context of the smart city, meters to determine gas, electricity and water consumption have traditionally been mechanical. However, smart metering implies a new generation of technologies. Electricity meter readings have evolved from the manual procedure of reading the mechanical meter, to automatic meter reading which were deployed to reduce costs and improve the accuracy of meter readings.
The ever increasing number of smartphones opens up a totally new sensing scenario. Smartphones are fitted with a variety of sensors such as GPS, gyroscopes, accelerometers and compasses, enabling a variety of crowd sourcing applications, which will eventually be augmented by the Internet of Things (IoT). In particular, collaborative data collection is a popular crowd sourcing application.
Enabling Technologies for smart cities
Some technical issues regarding communication between sensor nodes still have to be resolved. In the context of the Internet of Things (IoT), the communication between sensors nodes has to be wireless, as the cabling costs for millions of sensors is impractical and extremely expensive. Low power communication standards, suitable for an extremely large number of devices and their heterogeneity, are necessary. In particular, depending on location and necessary coverage, there are a number of different networks in smart cities.
Energy Harvesting- energy efficient solutions for sophisticated power management
Wireless sensor networks are characterized by severe resource constraints, one of which is the reliance on battery life. With the deployment of sensor nodes in very large numbers in smart cities, it is infeasible to replace or recharge batteries in these devices. Creating energy efficient solutions from protocol design to sophisticated power management schemes are efficient and necessary methods, but not sufficient. A popular way of supplementing power includes solar panels, but sunlight is not always available and it is not the most cost effective solution. The harvesting of energy from alternative sources in the environment is actively being researched and developed. Examples of these energy sources include thermal, light (solar), wind, mechanical (vibration) and many others. However, efficient ways of capturing this energy are vital, as the energy from these sources is usually available in extremely small quantities.
Hence, ways to scavenge energy from the environment to prolong the nodes’ lifetimes and improve market adoption are essential. Sources are typically from light, heat and sources of kinetic energy such as vibrations, etc. Of course, this technology can also be applied to drive any other low-energy device.
Methods of energy harvesting, in the context of smart cities include:
Wind energy: Small scale turbine rotation is converted to electrical energy. Such turbines can be located in open places where wind is easily accessible. For instance, nodes used for structural health monitoring, deployed in bridges and similar structures, can readily use this kind of harvesting. Other methods involve the use of piezo-electric materials or vibrating membranes
RF energy: An antenna receives RF signals and an RF-DC converter module converts the RF signals to DC voltages. With multiple antennae emitting signals, this type of harvesting is worth exploring
Electric field: Electric and magnetic fields around power lines, for instance, can be exploited for energy scavenging, as shown in sensors deployed in the near proximity of these overhead lines can exploit these electric or magnetic fields.
Vibrations and movement: Kinetic energy, from vibrations for instance, can be harvested in many different locations. For instance, at utility’s facilities, nodes deployed for condition monitoring can exploit vibrations for energy scavenging. Vibration is probably the most efficient energy sources for scavenging, as well as HVAC ducts in office buildings.
At Anglo African, our automation solutions are based on intelligent installation system that meets the highest requirements for applications in modern building control. KNX technology (http://www.knx.org) is accepted as the world’s first open standard for the control of all types of intelligent buildings – industrial, commercial or residential. Our solutions are for new and existing buildings and is extendible/adaptable to new needs.
Are you looking to improve the efficiency of your business . Learn how Anglo African team can help you to implement an automation strategy for your enterprise needs. The Anglo African team is fully committed to helping you in achieving your new vision to drive operations to the fullest potential. For specific queries, get in touch with Navin by calling on: 2331636 or via e-mail at navin.mautbar@infosystems.mu
