RoboteQ AX2850 - Manual (Page 85)

AX2550 Motor Controller User’s Manual 85
Mode Description
SECTION 8
Closed Loop
Position Mode
This section describes the AX2550 Position mode, how to wire the motor and position sen-
sor assembly and how to tune and operate the controller in this mode.
Mode Description
In this mode, the axle of a geared-down motor is coupled to a position sensor that is used
to compare the angular position of the axle versus a desired position. The controller will
move the motor so that it reaches this position.
This unique feature makes it possible to build ultra-high torque “jumbo servos” that can be
used to drive steering columns, robotic arms, life-size models and other heavy loads.
The AX2550 incorporates a full-featured Proportional, Integral, Differential (PID) control
algorithm for quick and stable positioning.
Selecting the Position Mode
The position mode is selected by changing the Motor Control parameter in the controller to
either
• A Open Loop Speed, B Position
• A Closed Loop Speed, B Position
• A and B Position
Note that in the first two modes, only the second motor will operate in the Position mode.
Changing the parameter is best done using the Roborun Utility. See “Loading, Changing
Controller Parameters” on page 181.
For safety reasons and to prevent this mode from being accidentally selected, Position
modes CANNOT be selected by configuring the controller using the built-in switches and
display.