Scheduling

  • Typically the wire guidance is scheduled after the rack has been installed and bolted in place.
  • The aisles to be wire guided, along with 15ft beyond end of racking, should be free and clear of any obstructions.
  • The facility should have adequate lighting and ambient temperature, (minimum of 50 degrees).
  • There must be a water tap on site with sufficient volume and pressure.
  • There must be a location at the site for the pouring off of the cutting and cleaning water. If that is not feasible, other arrangements will need to be made with Trueline.

Floor Specification

  • A lift truck can operate on practically any floor, although floor related problems can affect the truck performance.

  • Poor floor surfaces can consist of:
    • Excessive floor cracks
    • Slab heaving
    • General high/low unevenness

Basic Wiring Requirements

  • Typically installation of the wire is located down the center of each aisle to be guided and extends a minimum of 15 feet beyond both ends of the racking when possible.
  • The wire starts at the line driver and goes down the center of each aisle requiring guidance and terminated back at the line driver.
  • This installation creates a continuous loop of wire for the signal to run through.
  • Two guide wires located in the same aisle must be a min. of 30-36” apart based on truck manufacturer.
  • A guidance system will always have an even number of lines installed to create a closed continuous loop.

Wire Guidance – VNA Applications

Wire Guidance is based on the fact that a wire conductor through which a signal is flowing, will create an electromagnetic field around itself. The field is strongest at the conductor and it’s magnitude decreases as it radiates out. A line driver dispatches the signal to the wire installed in the floor. The electromagnetic field is the generated around the wire (conductor). A guide antenna located on the underside of the vehicle contains two coils positioned to be an either side of the embedded wire. The electromagnetic field passes through the coils and induces an electric voltage across the coil ends. The voltage can be detected across the termination of the coil and is proportional to the strength of the field. The difference in electric voltage between the two coils will, after amplification, send a signal to the steering motor of the lift truck.

Wire Installation

Advantages:

  • Additional floor clearance without guide rollers – beneficial on uneven floors
  • Larger systems tend to be more cost effective with wire guidance – NO additional bottom rack level to compensate for the floor guide rails
  • NO mechanical stress on vehicle or floor structures (rails)
  • Floor level storage without rail interference or structural compensation (raise floor level or install lower rack shelf level)
  • Increased flexibility to change the layout – wire can stay in the floor simply cut new path disconnect area or aisle not to be used
  • Reduced overall system installation times
  • Adaptable to full automation

Planning

  • A blueprint of the proposed rack installation should be provided to best determine the layout of the wire guidance system.
  • Blueprints can be faxed or e-mailed, preferably in Autocad.
  • A blueprint will help determine:
    • The amount of linear feet to be installed.
    • The location of line driver.
    • The total number of aisles to be guided.