Wire Guidance

Summary

Wire Guidance - Wire guidance is used to improve the accuracy of the movement of an MHE in a VNA.

Technical Information

This automated VNA storage setup uses wires installed into the concrete floor to guide the MHE. MHE vehicles are equipped with a pair of sensors that detect the wire; one on each longitudinal end on the bottom of the truck, which are connected to a control system that locks the steering in place once entering the aisle. The sensors detect a low frequency signal emitted from the wire embedded in the floor.

This method of guidance in the VNA is an efficient one as it:

Eliminates excessive damage to the MHE, from not having to bank into rails at the beginning of each aisle etc.
Eliminates the bottom racking beam, which is needed in rail guidance, so pallets can be stored on the floor
Lower long term maintenance cost.
Increases efficiency as the stored products can be moved in a safer and more accurate way.
Wire guidance improves space efficiency so two MHE could potentially be in the aisle at the same time using both sides of the racking (if aisle is wide enough).

The VNA guidance system chosen must be incorporated in part of the concrete slab design, as the embedded wires will affect the underlying reinforcement. There is a relatively small chance that saw cuts for the wire installation can induce cracks in the slab.