Quote:
Originally Posted by Ether
I don't know is this is possible without completely breaking the Jag's comm protocol, but a flexible way to implement that would be updated Jag firmware which supports a second input command to the Jag (in addition to the setpoint) so that the user could use a lookup table or nonlinear equation or other arbitrary processing (based perhaps on open-loop experimental measurements) to create that "feedforward" command.
Until and unless the Jag firmware changes, moving the controller completely out of the Jag allows this flexibility, as some have suggested on other threads. An example is attached.
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At this rate, I would be happy with a linear feed forward, where:
Output = Kff * setpoint + Kp * error + Ki * integral + Kd * derivative
All this would require is the ability to pass another constant (Kff) along to the Jag.
Even if the linear response isn't perfect, the PID loop will likely be responsive enough to make up the difference.
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