RoboteQ AX2550/2850 user manual Closed Loop Speed Control, Close Loop Position Control

Selecting the Motor Control Modes

Controller

FIGURE 13. Effect of commands to motors examples in mixed mode

Closed Loop Speed Control

In this mode, illustrated in Figure 15, an analog tachometer or an optical encoder (AX2850 only) is used to measure the actual motor speed. If the speed changes because of changes in load, the controller automatically compensates the power output. This mode is preferred in precision motor control and autonomous robotic applications. Details on how to wire the tachometer can be found in “Connecting Tachometer to Analog Inputs” on page 58.

Closed Loop Speed control operation is described in “Closed Loop Speed Mode” on page 123.

Tachometer or

Optical Encoder (AX2850 & AX3500 only)

Speed Feedback

FIGURE 14. Motor with tachometer or Encoder for Closed Loop Speed operation

Close Loop Position Control

In this mode, illustrated in Figure 15, the axle of a geared down motor is coupled to a potentiometer that is used to compare the angular position of the axle versus a desired position. This AX2500/2850 feature makes it possible to build ultra-high torque “jumbo ser- vos” that can be used to drive steering columns, robotic arms, life-size models and other heavy loads. Details on how to wire the position sensing potentiometers and operating in this mode can be found in “Closed Loop Position Mode” on page 115.

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