Curtis 1243
GEN
2 Manual
62
5 — VEHICLE PERFORMANCE ADJUSTMENT
(ii) Set the Field Map Start parameter slightly higher than the
observed armature current value.
(iii) Load the vehicle and drive it on flat ground with full throttle
applied. Further adjustments to the vehicle
’
s loaded speed can
now be made by varying the Field Map parameter. Increasing the
Field Map value will decrease the vehicle
’
s loaded speed, and
decreasing the Field Map value will increase the vehicle
’
s loaded
speed.
CAUTION:
If the Field Map Start parameter is set too high, the motor
’
s
safe commutation region may be exceeded. If this is the case, reduce the
Field Map Start parameter to a safe value. Then, adjust the Field Map
parameter as needed to reach the desired loaded top speed. Reducing the
Field Map value will help bring the loaded speed closer to the unloaded
speed. However, care must still be taken because it is possible for too low
Field Map values
—
like too high Field Map Start values
—
to result in
exceeding the motor
’
s safe commutation region.
FINE TUNING
Four additional vehicle performance characteristics can be adjusted:
5
Response to Reduced Throttle
6
Response to Increased Throttle
7
Smoothness of Direction Transitions
8
Ramp Climbing.
These characteristics are related to the
“
feel
”
of the vehicle and will be different
for various applications. The
fi
ne tuning adjustments are especially noticeable
in precision maneuvering, which is typically Mode 1. Careful tuning of the M1
Accel Rate, M1 Decel Rate, M1 Restraint, M1 Braking Rate, and M1 Braking
Current Limit parameters will ensure the most comfortable possible vehicle
response at low speeds.
5
Response to Reduced Throttle
The way the vehicle behaves when the throttle is reduced or completely released
can be adjusted to suit your application, using the Decel Rate and Restraint
parameters. Refer to the description of these parameters in Section 3 before
beginning this procedure.
STEP
1. Set the Decel Rate based on the desired time for the vehicle to
stop upon release of throttle when traveling at full speed with full
load. If the vehicle brakes too abruptly when the throttle is
released, increase the Decel Rate.