Using energy harvesting, radio technologies to power wireless sensors

A 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, the 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 vs. 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 maintenance team without replacing them. Make them feel proactive. We feel if this is executed well, a small team can leverage thousands of machines to do the work of dozens of humans,” he said.

Wired vs. wireless sensors

Sensors, regardless of type, are designed to provide the plant team with information, including about how motors and drives operate. The most common challenge is the sensors have to be retrofitted onto the device because very few are actually installed with built-in technology. It’s not uncommon for the equipment involved to be 20 to 30 years old.

Pros for wired industrial sensors include continuous power and data and reliability. Users don’t have to worry about transmitted information getting lost. However, the cons loom quite large. The upfront costs for a wired sensor are very high and the sensors are often connected in places that are difficult to access and reach.

Wireless sensors, which have emerged through the IIoT, are easy to install and are much cheaper to install compared to wired sensors. The problem with wireless sensors, apart from limited data capture, is they require batteries.

In the short-term, that might not be a problem because the batteries last a long time. However, there will come a time when the batteries do need to be replaced for all the sensors. If this is a large facility, the problem could cause all kinds of problems for the plant team because there could be thousands of sensors that need to be brought back up to speed.

Wireless powering

The problem can be alleviated through ambient energy harvesting and radio frequency (RF) wireless power delivery. Through energy harvesting, Zell said, the IIoT can deliver maintenance-free wireless sensors through sources such as vibration, RF and light energy.

How much energy is required depends on the data payload and the type of sensors. An ultrasound or video has a much different energy requirement than a pressure or temperature sensor.

Zell said properly managing harvested energy, sensing, and data communication is key to achieving a maintenance-free wireless sensor.

“Sensor platforms that have energy harvesting that can deliver data to IIoT systems,” Zell said.

Zell provided an example of RF wireless powering from a sensor over distance via RF signals transmitted from a transponder. From there, an RF harvesting chip receives the signal to regulated dc power.

Delivering IIoT at scale can be achieved, Zell said, with wireless energy harvesting. While there is a place for wired sensors, particularly for applications that cannot afford downtime, the overall benefits of energy harvesting will provide more reliable data at faster speeds at lower costs for manufacturers.

Chris Vavra is associate editor, Control Engineering, CFE Media and Technology, cvavra@cfemedia.com.

MORE ANSWERS

Keywords: wireless sensors, energy harvesting

The Industrial Internet of Things (IIoT) can help manufacturers improve data efficiency on the plant floor.

Wireless sensors are cheaper than wired sensors for gathering data, but they rely on batteries.

Energy harvesting can help manufacturers bypass the battery problem by gathering energy from many different sources.

Consider this

What applications would benefit most from energy harvesting for wireless sensors on your plant floor?

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