Command control curves – RoboteQ Dual Channel Digital Motor Controller AX500 User Manual

Page 42

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General Operation

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AX500 Motor Controller User’s Manual

Version 1.9b. June 1, 2007

an equally large, or possibly larger, regeneration current surge. Always experiment
with the lowest acceleration value first and settle for the slowest acceptable value.

Command Control Curves

The AX500 can also be set to translate the joystick or RS232 motor commands so that the
motors respond differently whether or not the joystick is near the center or near the
extremes.

The controller can be configured to use one of 5 different curves independently set for
each channel.

The factory default curve is a “linear” straight line, meaning that after the joystick has
moved passed the deadband point, the motor’s speed will change proportionally to the joy-
stick position.

Two “exponential’ curves, a weak and a strong, are supported. Using these curves, and
after the joystick has moved past the deadband, the motor speed will first increase slowly,
increasing faster as the joystick moves near the extreme position. Exponential curves allow
better control at slow speed while maintaining the robot’s ability to run at maximum speed.

Two “logarithmic” curves, a weak and a strong, are supported. Using these curves, and
after the joystick has moved past the deadpoint, the motor speed will increase rapidly, and
then increase less rapidly as the joystick moves near the extreme position.

The graph below shows the details of these curves and their effect on the output power as
the joystick is moved from its center position to either extreme. The graph is for one joy-
stick only. The graph also shows the effect of the deadband setting.

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