Section 8. Theory of Operation
Model 5200 High-Level Orderpicker
Wire Guidance System
Wire Guidance System
While the lift truck is in guide mode, driving off the guide wire or losing its signal sounds the alarm (horn) and stops the lift truck.
Functional Overview When the auto/manual switch (S61) is set to auto, the lift truck is placed in seeking mode. The following conditions are present in seeking mode: •
Horn chirps at approximately 20 chirps per second
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The steer LED representing the closest position of the drive unit flashes continuously
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Max. travel speed, tractor-first = 2 mph (3.2 km/hour)
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Max. travel speed, forks-first = 1 mph (1.6 km/hour)
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Steering control resides with the operator
As the lift truck approaches the guide wire, the near wire coils sense the wire. When the guide wire is between the near wire coils of one of the sensors, the lift truck enters the acquire mode. The following conditions are present during the acquire mode:
Wire guidance stops and steering reverts to the operator when the auto/manual switch is flipped to manual.
System Description A guide wire embedded in the floor has an AC (alternating current) magnetic field around it. This magnetic field is directly proportional to the amplitude of the current supplied from the line driver. Refer to PDSS-0051, Raymond Wire Guidance, for information on warehouse-installed equipment. As the lift truck drives near a guide wire, a voltage is induced into the coils due to the AC current in the guide wire. As the coils get closer to the guide wire, the voltage increases. As the coils get farther from the guide wire, the voltage decreases. This voltage is amplified at the card in each sensor assembly and sent to the Filter Card. The lift truck is equipped with two wire guidance sensors:
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Horn stops chirping
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All 5 steer LEDs flash signaling the lift truck senses the guide wire
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Tractor sensor, installed under the front bumper, ahead of the drive unit
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Steering control shifts from the operator to the Guidance Manager
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Load sensor, installed between the baselegs.
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Lift truck automatically steers on the wire
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Max. travel speed, tractor-first = 2 mph (3.2 km/hour)
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Max. travel speed, forks-first = 1 mph (1.6 km/hour)
After the lift truck straightens so the guide wire is between and parallel to the near wire coils of both the tractor and load sensors, the lift truck changes to guide mode. The following conditions are present during guide mode: •
All 5 steer LEDs stay lit continuously
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The Guidance Manager controls steering
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Lift truck can travel at full speed
8-14
The tractor and load sensors are identical. Each has 4 guidance coils. The 2 outside coils guide the lift truck and the 2 inside coils generate the near wire signal. Three signals are sent from each sensor card to the Filter Card. See the table below.
Tractor Sensor Signals
Load Sensor Signals
Tractor Left (TL)
Load Left (LL)
Tractor Right (TR)
Load Right (LR)
Tractor Near Wire (TNW)
Load Near Wire (LNW)
Publication Number: 1043922B, Revised: 2 Sept 2015
