Advances in 2-D Sensing and Position Determination
THE DEMAND FOR POSITION SENSING IS GROWING, AND SENSOR MANUFACTURERS ARE ADDRESSING THIS MARKET DEMAND BY OFFERING AND INCREASING THE NUMBER OF SOLUTIONS.
Analog sensors have been available for decades. While this approach is well understood, and the necessary analog input cards are available for all PLC brands, analog data comes with its own sets of issues. The need to protect sensitive signals by employing shielded cable is just one of them.
With the introduction of industrial networks, sensors offering positional data were soon offered with direct connections to these networks. This is a sensible approach for costly, high-performance products, especially when the cost of the network connection is low compared to the sensing hardware itself. High-precision, long-range distance measurement devices (as seen in Figure 1) used in AS/RS positioning fall into this product category. Sensors with repeat accuracy of 1 mm or less allow high-bay storage with unparalleled density. While in the past it was necessary to construct oversized storage locations to make up for inaccuracies of the AS/RS movement, this is no longer necessary. Being able to reduce the size of a 1 meter storage location by just 2 cm allows 102 bays where previously only 100 bays could be implemented. Because this is now possible without increasing the floor space or building size, it represents a 2% net cost reduction of the facility.