.BLDC.Utilities.HallTimeSpan

Information

Evaluates the input signals from a HallSensor: a 180°-rectangle per phase (per pole pair) and determines electrical angular velocity w and electrical angle phi:

• w = angular velocity
• phi = angle = integral of w

The time span from one edge of the input signals to the next is measured, thus calculating the speed of rotation: 2*pi/(p*2*m)/(time - t0). Taking both rising and falling edges into account, p*2*m edges per revolution are observed. Note that the output is discrete w.r.t. to time, it is not differentiable. The algorithm depends on interrupts (which appear in Modelica as when-clauses). The direction of rotation has to be detected by a logic from the sequence of the Hall signals. Note that this algorithm depends on the accuracy of the representation of time, but usually gives better results than counting edges during a time gate.