digital differential analysis to control stepper motor?

Answer 1

I'm not sure what your exact question is.

Stepper motors are usually placed in feedback control loops to operate them. Feedback control loop systems may be analog or digital, but all are mathematically characterized by their system transfer function. Transfer functions almost always take the form of a differential equation (analog) or difference equation (digital) and it is always convenient to use Laplace transforms (analog) and Z-transforms (digital) to transform the differential into an algebraic for easier manipulation. Both LaPlace and Z transforms use complex math to represent differential equations.

So, when a stepper motor is used inside a control loop, differential analysis is used to determine how the motor will respond to currents on the windings, under load or no-load.

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