Sep 10, 2019There are multiple technologies that can manage the automation of door opening in industrial and warehouse environments, but each has its own benefits and shortcomings. Basic infrared or motion sensors identify when someone is near a door, prompting it to open, but they cannot discern who that person is. RFID, on the other hand, can uniquely identify a person or vehicle, but in some cases the read range can be difficult to tightly control.
A Texas retailer has solved its own logistical problem around managing automated roll-up doors in a heavily trafficked warehouse, using an RFID-based system from TagMaster North America and deployed by DH Pace Co. The solution employs battery-assisted passive (BAP) 2.45 GHz RFID technology to pinpoint a forklift's location within a few feet of an automated door, and to confirm whether that vehicle is authorized to enter before the door will open.
The company, which has asked to remain unnamed, stores and manages a large amount of temperature-sensitive products at its Texas warehouse. The facility has dozens of freezers and coolers in which the products are stored until they can be loaded onto a vehicle for delivery to stores. The firm has been challenged, however, with controlling when those doors are opened and closed. An IR-based sensor system caused the doors to open too often, even if a vehicle might not be entering the freezer or cooler, but simply remaining in the vicinity.
That created a safety hazard for the forklift drivers, says Ali Khaksar, TagMaster's president. They could, for isntance, be distracted from their work when doors were opening and closing around them, and they might take extra steps to ensure the doors didnt open inadvertently, which meant extra driving and potential accidents. The company deployed a sensor-based system to combat the issue. With the motion detection system in place, if the sensor detected motion, it would prompt the roll-up controller to open the door. "It wasn't working according to their expectation," Khaksar recalls.
The firm considered a passive RFID solution; however, too often, the tag-read range could be so long that the door opened even when the forklift wasn't immeditately in front of the door or trying to enter. The result would be the same problem: doors opening at inappriopriate times. That also could lead to excess energy costs, since the freezer's interior temperature would rise every time the door opened. Products stored near the freezer or cooler entrance could also experience a temperature rise that could affect the product's shelf life.
Tag Master began working with DH Pace and the retailer this past spring, Khaksar says. The first challenge was to reduce the read range of the forklift tags. "They wanted to read tags within 3 or 4 feet" of the door's reader at most, he explains. That is one of the benefits of TagMaster's BAP tags, Khaksar notes, adding, "With our microwave RFID system, it's very easy to define the read zone.
The company installed several dozen LR3Pro RFID readers, one above each door, to receive the RFID transmissions. The readers have logic built into them, with embedded controls to trigger the doors to open when authorized. ACTS ESSENTIAL software captures data and triggers the door operation, and can also send information to a back-end server.
The RFID team attached TagMaster S1240 BAP 2.45 GHz outdoor-use heavy-duty tags to the front of each forklift. Each tag has a unique ID number encoded to it, which beacons continuously. The tag's ID is linked to the forklift ID in the TagMaster software. In that way, warehouse management can access the software to update authorization rules for specific vehicles to enter through a given set of doors. The authorization could be changed regularly if required—for instance, on a daily basis for a certain driver's required access to a cooler door on one day, rather than another.
"With our solution, Forklift 1, 2, 3 or 4 can be authorized to access door 2, 3, or 4," Khaksar explains. In that way, the warehouse could ensure the right product was moved to the correct bay area. As each forklift comes within a few feet of the roll-up door, the reader captures the tag's transmission and determines whether that tag is authorized to enter. If it is, the door is prompted to roll open, after which it automatically closes following a preset length of time. The system thereby reduces the risk of injury for employees, while cutting the energy cost otherwise incurred keeping the coolers or freezers at optimal temperatures.
In addition, the company can use the software to capture data about the operational efficiency of its facility workers. The software can generate reports based on that access, helping management to understand the work taking place. For instance, the software stores data indicating how often each cooler or freezer was entered, and by which vehicles; an operator could be linked to specific vehicles to provide data about the personnel who entered.
The Linux-based software can be stored on a local server but is IP-based, allowing users to access data remotely as long as there is internet service, or via an Ethernet cable. The system was taken live about a year ago, Khaksar says. "The main ROI [return on investment] was preventing accidents and increasing safety," he states, but the company is also seeing a benefit in reduced energy cost. The firm may next opt to expand the deployment to other warehouses.
TagMaster provides intelligent access-control solutions in challenging environments. Its semi-passive tags are compliant with a proprietary air-interface protocol.
