Distance From Wire Settings - Toyota 7BPUE15 Service Manual

Toyota Orderpicker Model
The steer controller compares the strength of
four guidance signals (TL,TR, LL, RR) and
determines the truck's distance from wire
controller uses the DFW and HA to correct the
steering via the tractor steer manager.
The heading angle is the angle between the
direction the truck is pointed and the guide
wire. The steer controller calculates the angle
by comparing the TL, TR, LL and LR signals.
For example, if the TL and LR signals are
stronger than the TR and LL signals, the truck
is pointed to the right of the guide wire. This
calculation is compared to the configured
settings of HA slow and HA stop. If HA slow is
the heading angle is greater than 3", travel will
come to a controlled stop.
Distance from wire (DFW) is the distance the
centerline of the truck is from the guide wire.
The steer controller calculates this distance by
comparing the TL, TR, LL and LL. For example,
if the TL and LR are stronger than the TR and
LR signals, the left guidance coils are closer to
the guide wire than the right guidance coils.
The factory default settings for DFW slow is
1.6". If this distance is greater than 1.6'', travel
speed is limited. The factory default setting for
DFW stop is 3". If the distance is greater than
Service Manual
2005
March
The HA and DFW settings may be changed in
the Truck Configure Menu using Flashware
software. See "Options" on page 10-9.
When the steer controller calculates the HA and
DFW, it sends a steering correction request to
the steer/tractor manager via the CAN-bus
(BUS+, BUS-). The steer/tractor manager then
tells the steer power head which direction to
steer. This command causes the drive unit to
turn.
For example, if the steer controller calculates
that the truck is 1" to the right of the wire, it
tells the steer/tractor manager to turn the drive
unit and move the truck toward the left until all
4 guidance signals (TL,TR, LL, LR) are equal
distance from the wire.
While the drive unit is turning, the steer
feedback encoder reports the amount the drive
unit is turning. This encoder is mounted
directly on the steer motor's armature shaft and
rotates with the steer motor. As the encoder
turns, it sends two voltages, CHA and CHB, to
the steer/tractor manager. The steer/tractor
manager uses these voltages to track the drive
unit position, then sends the information to the
change state from approximately
volts and back a s the encoder rotates. The
resulting number of times the 2 channels
change state indicates how far the drive unit
has turned. When the required amount of
turning is sensed, the steer command is
removed.
The steer controller also verifies the direction
the drive unit is turning. CHA changing state
before CHB indicates one direction. CHB
changing state before CHA indicates the
opposite direction.
wire, once a steer request is carried out and the
truck moves forward, the sensors' relationship
feedback encoder, until the truck is both
parallel to and directly over the wire.
8.
Section Wire Guidance
Theory of Operation
5 volts to 0