.BLDC.Utilities.EncoderTimeAndCount

Information

Evaluates the input signals from an IncrementalEncoder:

• 0-track y[1] = 1 pulse per revolution with a length of 2*pi/(4*pRev)
• A-track y[2] = pRev pulses per revolution
• B-track y[3] = pRev pulses per revolution, displaced by 2*pi/(4*pRev)

and determines mechanical angular velocity w and mechanical angle phi:

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

During the samplePeriod all rising and falling edges of A-track and B-track are counted. The direction of rotation has to be detected by a logic from the values of A-track and B-track. From the time span between first and last edge within the samplePeriod and the count of edges, the angular velocity can be calculated: w=(count - 1)*2*pi(4*pRev)/(t_last - t_first). 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).