RoboteQ AX2550/2850 user manual Analog Deadband Adjustment

Analog Deadband Adjustment

100K or higher potentiometer. Figure 66 shows how the output voltage varies at the vari- ous potentiometer positions, for three typical potentiometer values. Note that the effect is an exponentiation that will cause the motors to start moving slowly and accelerate faster as the potentiometer reaches either end.

This curve is actually preferable for most applications. It can be corrected or amplified by changing the controller’s exponentiation parameters (see “Command Control Curves” on page 42.

Voltage at Input

5V
		1K Pot
4V
3V
10K Pot		100K Pot
2V
1V
0V
Min	Center	Max

Potentiometer Position

FIGURE 66. Effect of the controller’s internal resistors on various potentiometers

Analog Deadband Adjustment

The controller may be configured so that some amount of potentiometer or joystick travel off its center position is required before the motors activate. The deadband parameter can be one of 8 values, ranging from 0 to 7, which translate into a deadband of 0% to 16%.

Even though the deadband will cause some of the potentiometer movement around the center position to be ignored, the controller will scale the remaining potentiometer move- ment to command the motors from 0 to 100%.

Note that the scaling will also cause the motors to reach 100% at sightly less than 100% of the potentiometer’s position. This is to ensure that 100% motor speed is achieved in all cir- cumstances. Table 22 below shows the effect of the different deadband parameter values. Changing the deadband parameter can be done using the controller’s switches (see “Con- figuring the Controller using the Switches” on page 153) or the Roborun utility on a PC (see “Loading, Changing Controller Parameters” on page 162).

AX2500/2850 Motor Controller User’s Manual 111