Overhead Crane Position Measurement Posted in: AR1000 Laser Distance Sensor – Tags: Civil Engineering, Metal and Steel Production, Position Measurement

Bridge Cranes Integrate Laser Distance Sensors at Steel Mills

Steel mills producing large coils of sheet stock store their inventory on the floors of huge warehouses.  The large, heavy coils are picked and placed using overhead cranes, often referred to as bridge cranes.  These cranes ride the length of the building along two parallel rails. A hoist moves on the trolley and lowers a hook or other mechanical grabber to move objects. Operators control the crane’s movement via an overhead control cabin or by remote-control from the manufacturing floor.

Modern factories automate the pick and place of their inventory in 3D space by equipping their overhead cranes with multiple laser distance sensors to provide crane position measurement. This automates the gross movements of the crane and minimizes the time to locate and move a particular piece of inventory.

A common application is in steel mills, where building lengths often exceed 250 meters. In a common scenario, the AccuRange 3000 distance measurement sensor measures the position of the crane’s trolley along these longest stretches. Working with its companion product, the side-to-side positions and the hoist’s vertical positions are accurately monitored by AccuRange 1000 laser distance sensors and provide anti-collision assurances. The AR1000 can measure up to 30 meters on natural targets and up to 150 meters with a retroreflective target with an accuracy of ± 3 mm.

These models are well-suited for tough industrial environments and interface directly with system PLC’s using analog and serial outputs. Today’s mills retrofit manual-control cranes with automation systems employing laser positioning sensors for their crane position measurement.

Acuity manufactures and sells the AccuRange™ brand of laser rangefinders, which use time-of-flight measurement principles to detect a target’s position or displacement. The device models offer a variety of ranges, accuracies and speeds to suit a variety of industrial automation projects.