RoboteQ AX2550/2850 Left / Right Tuning Adjustment, Exponentiation Parameter Value Selected Curve

Left / Right Tuning Adjustment

The AX2500/2850 is delivered with the “linear” curves selected for both joystick channels. To select different curves, you will need to change the values of “E” (channel 1) and “F” (channel 2) according to the table below. Refer to the chapter “Configuring the Controller using the Switches” on page 153, or “Using the Roborun Configuration Utility” on

page 159 for instructions on how to program parameters into the controller.

TABLE 9. Exponent selection table

Exponentiation Parameter Value	Selected Curve
E or F = 0	Linear (no exponentiation) - default value
E or F = 1	strong exponential
E or F = 2	normal exponential
E or F = 3	normal logarithmic
E or F = 4	strong logarithmic

Left / Right Tuning Adjustment

By design, DC motors will run more efficiently in one direction than the other. In most situ- ations this is not noticeable. In others, however, it can be an inconvenience. When operat- ing in open loop speed control, the AX2500/2850 can be configured to correct the speed in one direction versus the other by as much as 10%. Unlike the Joystick center trimming tab that is found on all R/C transmitters, and which is actually an offset correction, the Left/ Right Adjustment is a true multiplication factor as shown in Figure 17

% Forward

(Motor Output)

100

80

60

40

20

- 100 - 80 - 60 - 40 - 20

0 20

20

40

60

80

100

% Reverse

								% Forward
				0%				(Motor Output)
				-3%					100
				-5.25%						80
										60
										40
										20
				- 100	- 80	- 60	- 40	- 20
				% Command Input
40	60	80	100								20		40	60	80	100
									0
												20
												40
												60
				5.25%								80
				3%								100
	% Forward			0%					% Reverse

(Motor Output)

FIGURE 17. Left Right adjustment curves

The curves on the left show how a given forward direction command value will cause the motor to spin 3 or 5.25% slower than the same command value applied in the reverse direction. The curves on the right show how the same command applied to the forward

AX2500/2850 Motor Controller User’s Manual 43