Ramp Climbing - Curtis 1244 User Manual

Curtis 1244 Manual,
Rev. E

Ramp Climbing

➇
The vehicle response to increased gradients such as loading ramps can be tuned
via the Field Map parameter. Decreasing the Field Map parameter allows faster
vehicle speeds while climbing ramps, but it will also have the effect of reducing
the ability of the controller to generate torque in the vehicle's mid range speeds.
step 1. If faster vehicle speed is desired when climbing ramps, decrease
the Field Map parameter value until the desired ramp climbing
speed is attained. It should be noted that if the motor's torque
capability is exceeded under the conditions of load and ramp
gradient, vehicle speed will be limited by the motor's capability
and the desired vehicle speed may not be attainable. The system
will find a compromise point at which sufficient motor torque is
generated to climb the ramp at an acceptable speed. If the Field
Map parameter value is reduced to 0% and the desired speed
is still not attained, the system is being limited by the motor's
torque capability under these operating conditions. Caution
should be used in reducing the Field Map parameter since at low
Field Map values it is possible that the motor could be operated
outside its safe commutation region.
step 2. If the drive system cannot produce sufficient torque for a fully
loaded vehicle to climb the desired ramp, try increasing the Field
Map, Field Max, and/or Drive Current Limit parameters. The
impact of increasing these parameter values on other driving
characteristics must be evaluated. Increasing the Field Max will
provide more field current, and increasing the Drive Current Limit
will provide more armature current. If the Field Max is set at the
manufacturer's specified limit and the Drive Current Limit is set
at the rated maximum, then vehicle speed up the ramp is limited
by the motor or the vehicle's gearing and cannot be increased
by tuning the controller. note: To determine if the controller's
armature current is at its set value during ramp climbing, read
the "Arm Current" in the programmer's Test Menu.
6 — VEHICLE PERFORMANCE ADJUSTMENT
65