WIRELESS SENSORS
ENERGY HARVESTING FOR SENSORS Gathering data from wireless sensors is critical in the Industrial Internet of Things (IIoT) era. Various energy harvesting methods can provide power. Chris Vavra reports.
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well-planned Industrial Internet of Things (IIoT) infrastructure can allow a small team of workers to do the work of dozens more by leveraging data from thousands of devices on the plant floor. This might seem daunting, but Will Zell, CEO and co-founder of Nikola Labs, sees this as the convergence of data and technology advances. Now, more than ever, workers have the ability to get a greater picture thanks to sensors attached to the devices on the plant floor. “These sensors can provide data each day and see a picture that is being painted of what is and isn’t working in the plant,” Zell said in his presentation. ‘Wired versus Wireless for IIoT Solutions: The Pros, Cons, and Key Considerations,’ at Fabtech 2019 in McCormick Place in Chicago. “By leveraging sensor-based technology, you create a multitude of value.” This is critical because unplanned downtime is costing manufacturers hundreds of billions of dollars each year. While companies are moving from reactive maintenance to preventive maintenance, Zell said the cultural shift can really take hold with the IIoT and improve automation and plant safety. Some fear automation might be replacing workers on the manufacturing floor. Zell sees it differently. “The real challenge is how you change a maintenance team by installing sensors that can help the team without replacing them. Make them feel proactive. If this is executed well, a small team can leverage thousands of machines to do the work of dozens of humans,” he said.
Wired versus wireless Sensors, regardless of type, are designed to provide information, including how
UK2
April 2020
motors and drives operate. The most common challenge is the sensors have to be retrofitted onto the device because very few are installed with built-in technology. The equipment involved may be 20- to 30-years old. Wired industrial Through energy harvesting IIoT can deliver maintenance-free wireless sensors have sensors through sources such as vibration, RF and light energy. continuous Image courtesy of Chris Vavra. power and data reliability. Users don’t have to worry energy requirement than a pressure or about transmitted information getting temperature sensor. Zell believes that lost. The upfront costs for a wired sensor properly managing harvested energy, are high, and the sensors may be located sensing and data communication is key in areas difficult to access. to achieving a maintenance-free wireless Wireless sensors have emerged through sensor. He said: “Sensor platforms that the IIoT and are easier and cheaper have energy harvesting that can deliver to install compared to wired sensors. data to IIoT systems.” Wireless sensors have more limited data Zell provided an example of RF capture and require batteries. Battery life wireless powering from a sensor over has increased, but batteries do need to distance via RF signals transmitted from a be replaced. For a large facility, that could transponder. From there, an RF harvesting cause all kinds of problems for the plant chip receives the signal to regulated dc team because thousands of sensors may power. need to be brought back up to speed. According to Zell, delivering IIoT at scale can be achieved with wireless Wireless powering energy harvesting. While there is a The problem can be alleviated through place for wired sensors, particularly ambient energy harvesting and radio for applications that cannot afford frequency (RF) wireless power delivery. downtime, the overall benefits of energy With energy harvesting, Zell said, the IIoT harvesting will provide more reliable can deliver maintenance-free wireless data at faster speeds at lower costs for sensors using vibration, RF and light manufacturers. plus-circle energy. How much energy depends on the data payload and sensor type. An Chris Vavra is associate editor, Control ultrasound or video has a much different Engineering, CFE Media and Technology.
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