The availability of more powerful information and communication technology (ICT) is not limited to high income countries. As I complete this article, I sit in a motel in rural southern Tanzania. It took me five flights since leaving Iowa to get here. Commercial flights to this city only started four months ago. Nevertheless, the moment I stepped off the plane I had access to cellphone service, data and internet.
The speed of data here is 3G as it sadly still is in parts of rural Iowa, U.S. 3G is too slow for autonomous vehicle technology, which requires a minimum of 4G and ideally 5G in order to take full advantage of the associated artificial intelligence. 5G is fifth-generation wireless that is expected to be 100 times faster than today’s 4G networks. It will enable and operationalize innovations such as driverless vehicles, drone-operated farming, robot-run factories, and remote surgery.
According to a recent Wall Street Journal article, by the end of this year China will have 150,000 wireless sites up and running compared to 10,000 in the United States. By end of 2020, China will have 100 million 5G users and enough network coverage to begin turbocharging its industries. 5G networks will exponentially increase the amount and speed of data that can be transmitted and exchanged between devices and cloud-based data collection, analysis and decision support. This is especially important when it comes to real-time analyzing of large data files associated with digital images which, for example, autonomous high-capacity, real-time grain grading systems would generate.
5G means any machine, controller, switch, sensor and camera could be monitored and activated remotely as instantly as if the decision was made locally (e.g., by a microprocessor or a person) but with the valued-added benefit of artificial intelligence accessing massive cloud-based databases and returning an optimized decision at an instant. This potential makes the advent of wireless monitoring and managing of stored grain quality in our industry a reality — and preparing for it now, a necessity — beyond anything we may have imagined in the past.
The first article in this series (March 2019) focused on ICT and autonomous vehicles and transportation. We made the point that grain receiving, sampling, grading, and subsequent transfer to wet holding, drying and storage will have to become faster and more autonomous to keep up with farmers and avoid losing their business to a competitor down the road who can. The second article (June 2019) discussed how automatic grain receiving, sampling, and grading will be able to accomplish that with better and faster measurement equipment such as NIR composition detectors, and with smarter equipment maintenance. This article focuses on real-time wireless monitoring and managing of stored grain quality. Future articles will focus on real-time tracking of inventory, lights out and hygienic operations, and digital services.
Wireless sensor safety concerns
During the past couple of years, several new companies have emerged as leaders in monitoring and managing stored grain conditions remotely with wireless sensors and networks of sensors. Wireless sensors that can be probed into the grain mass and monitor temperature and relative humidity (and convert those values to moisture content via the equilibrium moisture content relationship) from the grain surface can easily communicate with nearby antennas that pick up the signals, aggregate the data and send it into the cloud from where actionable alerts are sent back to operations managers.
However, the concern of having to probe such wireless sensors into the grain mass (and recover them) is the need to walk on the grain surface to do so. This can be dangerous and should not be practiced. Many companies have zero entry policies for the headspace of a bin, silo, tank and warehouse above a grain mass that is generally sloped at a grain-specific angle of repose. These policies prevent probing wireless sensors into a grain mass and renders the technology useless for its intended application.
Walking on the surface of an outside grain pile, whether tarped or not, also has its dangers and is therefore not advisable for probing in wireless sensors. To be practical, wireless sensors have to be placed into the grain mass while the grain flows into the storage structure.
Distribution in the grain mass
The key for wireless sensors to work in the grain mass is the ability to distribute them throughout the grain mass so they monitor grain conditions in at least as representative a manner or better than cable-based sensors. This requires the sensors to be equipped with miniature antennas that can establish communication with nearby sensors by penetrating through the rather dense grain mass, which is no small feat.
This capability, together with a small enough battery to power the antenna and on-board temperature and relative humidity sensors throughout the storage season, is actually the main breakthrough of what makes wireless sensing inside a grain mass an exciting possibility. Retrieving all sensors undamaged during unloading so that none of its parts or components become foreign material in grain without slowing down the unloading process at speeds of up to 50,000 bushels per hour (1,300 tonnes per hour) is another requirement wireless sensors must meet to be practical.
Placement of wireless sensors into a grain mass will challenge the current dominance of thermocouple-based temperature cables, which are limited to only measuring temperatures and newer generation digital cables that measure temperature and relative humidity of the interstitial air and calculate grain moisture content based on these values. Wireless sensors in grain stored in bins, silos and tanks will unlikely replace installed cables any time soon. However, storage structures such as warehouses, ground piles, railcars, barges, ship holds and even bags that cannot be monitored with cables would seem perfect applications for wireless sensors.
Our research group has been conducting trials with wireless sensors during the last two storage seasons. We have been able to place the sensors at the intended locations in the grain mass during loading. The sensors have been recording temperature and relative humidity values as accurately as cable-based digital sensors. Aeration fans could be turned on and off based on the reported grain conditions, and we successfully recovered 100% of all wireless sensors during unloading without impeding grain flow capacity.
As with any research and development effort, we have discovered a few shortcomings and several improvements that need to be addressed and incorporated before wireless sensing technology should be commercially deployed.
Other monitoring applications
Wireless sensors also will make it easier to measure CO2 in the grain mass or headspace above the grain surface, which has proven an effective early warning indicator of biological activity in stored grain caused by grain respiration, mold spores and insects. Wireless sensing of dew point temperature of the headspace air and the dry bulb temperature of the roof also will provide an easier means for determining condensation conditions and activating roof exhausters. This will prevent grain surface crusting with all of its negative consequences for grain quality such as plugging floor outlets during unloading, and entrapment or engulfment of people who should have absolutely no reason to enter a bin and try to fix a grain spoilage problem. Thus, wireless sensors have the additional potential benefit of making grain handling facilities a safer place to work.
Thanks to Internet-of-Things (IoT) technology, it is now possible to install inexpensive IoT switches on any existing motor throughout a facility and operate them from a smart phone. Our research group is experimenting this fall with such devices to operate drying and aeration fans from our smart phones either in manual on-off mode or with an App that can have the same sophisticated control schemes programmed in them as existing controllers costing thousands of dollars.
As wireless networking moves from 4G to 5G, this will become the norm throughout all of industry. The electric wires to energize motors will be the only “cables” needed to operate a grain facility in the near future. Think of the savings from not having to install conduit and control wiring from motor control centers (MCCs) to motors throughout your facility, and the smaller footprint future MCCs will have. This will be a similar revolution as when wall-mounted control boards with analog switch gear were replaced with microprocessor-controlled digital switch gear and computer screens.
Another wireless technology becoming available is three-dimensional moisture mapping of stored grain using technology similar to an MRI or CT scan. Scanning plates are installed along the inside wall of a round storage structure and penetrate horizontally into the grain mass (see illustration, page 50). The depth of the scan is a function of the signal strength from the sensors. The mapping data generated provides a granular view of moisture content approximately equivalent to a “bushel volume” (1.24 ft3 or 0.0351 m3) at all locations within the grain mass. An additional benefit of the system is its capability to also detect human, insect and spoilage activity because of differences in temperature similar to a thermal scan. Data from the system are uploaded to the cloud and actionable recommendations are provided to the operations manager on any device via a web-enabled interface. As all of the wireless monitoring platforms described in this article, this platform too allows for remotely and proactively monitoring and managing stored grain quality and quantity, automatically turning on and off aeration or in-bin drying fans, and receiving detailed inventory reports.
All systems also optimize fan operation based on the condition of the grain measured and local weather. Ideally, this will save energy and prevents the hidden cost of over-drying and the potential for spoilage.
Wireless sensors make business sense
Wireless technology for grain quality monitoring and management as well as other grain handling operations is evolving rapidly, especially as 5G networks are deployed globally. The grain handling industry will need to make the necessary investments to keep up with their customers — farmers and buyers alike — because they will embrace and utilize high-speed, real-time wireless technology that pushes large amounts of data into the cloud and expects information they can monetize in return thanks to decision support from artificial intelligence.