Oct 22, 2014Deere-Hitachi Construction Machinery Corp. is employing AeroScout Industrial Wi-Fi radio frequency identification tags to track the assembly of construction machinery at its facility in Kernersville, N.C. The solution, provided by Kubica Corp., a Michigan systems engineering company previously known as Prime Technologies, identifies when each excavator passes through a specific zone on its way to the next assembly station, thereby increasing efficiency and providing visibility into the firm's work-in-progress (WIP). Cisco provided its Cisco Mobility Services Engine, an appliance that triangulates each tag's position. Prime Technologies had provided a similar solution to John Deere's Seeding Group in 2011 (see John Deere Planter Factory Gains Efficiency).
The excavation-machinery assembly plant is the result of a 1988 joint venture between John Deere and Hitachi, and both brands of excavators are made onsite. As part of that partnership, the two companies take turns managing the facility during alternating three-year periods.
Last year, the Deere-Hitachi enterprise began discussions with AeroScout Industrial regarding a real-time location system (RTLS) solution that could provide greater visibility into where each excavator is located during assembly, in real time, as well as collecting historical data for efficiency upgrades. AeroScout, which offers battery-powered RFID tags that transmit unique identifiers to Wi-Fi nodes, recommended Kubica for the system integration and installation. At the time, recalls Dennis Kubica, Kubica Corp.'s CEO, Deere-Hitachi was expanding the assembly operations and required a system that would enable it to track WIP and amend operations as needed to improve efficiency.
Deere-Hitachi's workers were tasked with manually updating information from the assembly floor, in order to create a record of how quickly a product moved through each station, as well as when it was removed from the assembly line for some other service, such as fixing a detected flaw. However, the company wanted to take that responsibility out of the hands of employees, and create a more automated solution that would collect the data in real time. (Deere-Hitachi has declined to comment for this story.)
The company indicated to Kubica that it wanted an active RFID tag that could be applied to each individual excavator, but that could also be reused, thereby saving the cost of tag replacement.
Kubica designed a solution that includes a magnetic holder for AeroScout's battery-powered T2 tag, so that it could be attached temporarily to an excavator's chassis prior to assembly. The firm also installed AeroScout battery-powered EX-2000b exciters at 40 choke points through which excavators passed between assembly stations, as well as additional Cisco Wi-Fi nodes to increase location granularity when tag transmissions are received. The collected information is managed by the Cisco Mobility Services Engine, which uses tag data received by the Wi-Fi nodes to triangulate a tag's location. The Mobility Services Engine then forwards that data to AeroScout's MobileView software, which interprets the location data and feeds it to Deere-Hitachi's own management system via Kubica-provided middleware. The solution was taken live at the end of 2013.
At the start of the assembly process, workers place an excavator chassis on a cart, where it remains until it is ready for shipment to a customer. A staff member then attaches an AeroScout tag to the chassis, and scans the bar-coded ID number printed on the tag's front. That ID is then sent to the MobileView system, which links it to the new excavator's serial number. As the tagged machine is moved from one assembly station to the next, it passes through a series of choke points. Each choke point's exciter transmits a 125 kHz low-frequency (LF) signal encoded with a unique ID. The excavator's T2 tag receives that ID number, prompting it to transmit its own ID, as well as that of the exciter. The MobileView software then updates that excavator's location.
If the excavator is taken off the assembly line—for example, to have another service provided, or to correct a flaw—the Wi-Fi nodes will continue to receive tag transmissions. What's more, the nodes will allow the system to identify the machine's general location, if not its exact position within the facility.
Once its assembly is completed, the excavator passes through an inspection station, where its tag is interrogated for a final time before it is removed. The excavator is then prepared for shipment to a customer.
With the technology in place, Deere-Hitachi knows exactly which excavator is in which part of the assembly process. It also knows when a particular excavator's assembly has been completed, or if one has been removed from the line (for additional servicing, for instance).
Moreover, the system enables management to identify the times at which delays occur, and in which choke zone. This information indicates any processes for which efficiency could be improved.