Cross-Axis Feedforward

Optional Purchase Necessary: This feature is available only if you purchased the Dynamic Controls Toolbox option.

HARDWARE: This parameter does not apply when used with the GI4, the GL4, or the XL4s.

Cross-Axis Feedforward is a controller-level algorithm that minimizes off axis position errors by splitting the feedforward output generated by the feedforward gains between multiple motors on different axes. Use the parameters supplied to configure the algorithm.

The cross-axis feedforward algorithm works as follows:

Calculates the individual feedforward output for each axis by using the FeedforwardGainAff Parameter and FeedforwardGainVff Parameter.
Calculates the cross-axis feedforward output for each axis. This is done by multiplying the cross-axis feedforward gain parameters set on that axis (CrossAxisFeedforward00Gain through CrossAxisFeedforward05Gain) by the individual feedforward output of the selected axis (CrossAxisFeedforward00Axis through CrossAxisFeedforward05Axis).
Calculates the total feedforward output for each axis by summing the individual feedforward output and cross-axis feedforward output.

Pseudocode:

Compute IndividualFeedforwardOutput on each Axis by using FeedforwardGainAff and FeedforwardGainVff

For each Axis

    CrossAxisFeedforwardOutput[Axis] =
        (CrossAxisFeedforward00Gain · IndividualFeedforwardOutput[CrossAxisFeedforward00Axis]) +
        (CrossAxisFeedforward01Gain · IndividualFeedforwardOutput[CrossAxisFeedforward01Axis]) +
        (CrossAxisFeedforward02Gain · IndividualFeedforwardOutput[CrossAxisFeedforward02Axis]) +
        (CrossAxisFeedforward03Gain · IndividualFeedforwardOutput[CrossAxisFeedforward03Axis]) +
        (CrossAxisFeedforward04Gain · IndividualFeedforwardOutput[CrossAxisFeedforward04Axis]) +
        (CrossAxisFeedforward05Gain · IndividualFeedforwardOutput[CrossAxisFeedforward05Axis])
        
	TotalFeedforwardOutput[Axis] = IndividualFeedforwardOutput[Axis] + CrossAxisFeedforwardOutput[Axis]

End

To configure Cross-Axis Feedforward parameters in Automation1 Studio, open the Configure Workspace. In the Axes category, select the Optimization topic and find the Cross-Axis Feedforward module.