Problem: How to collect inventory movement data from forklift trucks.
Solution: Choose one of the following:
- Give the driver a pencil and clipboard.
- Equip the driver with a handheld bar code scanner and apply bar code labels to inventory goods.
- Equip the forklift with an RFID reader and apply RFID tags to inventory goods.
For many decades, choice #1 was the only way to do business. Bar coding came along in the 1960s and 1970s, and today choice #3 is popular, but it is expensive and complicated -- just ask those who are trying to apply it to their operations.
Now another choice is available. Skan-Free™ automated data collection from Sky-Trax provides real-time, accurate data collection without handheld scanners, RFID tags, or pencils and clipboards.
The system uses an optical sensor called an Optical Label Reader, or OLR, which is affixed to the front of a forklift, typically mounted behind the backrest. It consists of a very small camera, an optical system, and an internal computer. Like a handheld bar code scanner, it reads a bar code symbol printed on the load label. As a load is being acquired or deposited, the OLR searches its field of view for the bar code symbol, and reads the bar code quickly and accurately to identify the item. Item ID is transmitted to an onboard mobile computer called the Sky-Box, which processes or stores the data and transmits the information wirelessly back to an inventory control system, or WMS. For applications where mobile computers are already on board the vehicles, the OLR can transmit data via industry-standard communications protocols.
If a load is missing its label, or a label has been obscured or damaged, a second optical sensor -- the Pallet Detector™ -- provides confirmation that a load is or is not on board.
OLR read rates have been shown in field trials to be much better than RFID read rates, providing a crucial improvement in data accuracy. The OLR can read labels over a range of several feet, whereas RFID scanners typically need close proximity. Unlike RFID, OLR is unaffected by building structure, load contents, or radio interference. Lighting is self-contained and controlled by OLR internal software. The system works in factories, warehouses, and distribution centers.
The secret sauce to this technology is the type of bar code imprinted on the label, and the capabilities of the OLR optics and software to find and read the symbol. Matrix or “two-dimensional” bar codes are relatively new, but are solving long-standing problems of label readability. Skan-Free utilizes matrix symbologies, adding one more dimension of opportunity; label placement and orientation are no longer critical (see photo). While linear bar codes can also be read by OLR, the improved readability of 2D codes will remain the Skan-Free system preference.
System Benefits
Skan-Free implementations eliminate the need for drivers to interact with a WMS through a truck-mounted terminal. Dismounting the truck to scan a label is no longer necessary, and field trials have shown a substantial improvement in productivity and safety, thanks to this benefit.
The OLR can provide live video to the driver to assist in acquiring the load -- a benefit long sought, especially in high-reach facilities where top storage positions are at nosebleed altitude.
Lift truck drivers no longer need to use bar code scanners, clipboards, or data entry terminals to collect tracking information. Skan-Free “smart” trucks ensure data collection is complete, accurate, and available in real-time. Over-tasked drivers do not miss, skip, or create erroneous or after-the-fact data entry. Immediate productivity gains are achieved by removing data collection tasks from the driver. And because the driver is no longer disengaging the truck to find and scan labels, operations are safer.
Significantly, physical operations and WMS software work better together because inventory data is complete and accurate. Time formerly spent searching for lost inventory, correcting data errors, and manually inputting data is virtually eliminated. By eliminating “lost” inventory, which was often due to erroneous or absent transaction data, shipping accuracy is improved, production plans run smoothly, inventory visibility increases, and operational reports are trustworthy.
