RoboteQ AX2850 Closed Loop Position Mode, Mode Description, Selecting the Position Mode

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.

AX2550 Motor Controller User’s Manual 85