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Old 11-19-2014, 03:30 PM   #1334 (permalink)
e*clipse
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Quote:
Originally Posted by freebeard View Post
Which thread is that? I get so confused. This thread is AC FOC, which I originally encountered as described as Polyphase DC.

e*clipse -- I'm looking at resolvers and sensorless control, and thinking 'why not both?'. Per motor; for redundancy. Then another microcontroller could be a hypervisor. The Space Shuttle used triple redundancy with a 4th computer for oversight.


Regarding using resolvers and sensorless control - I think it's a good idea. If the sensor output of both the resolver and the current sensors are used for the primary motor controller's anyway, then the sensors' information in its raw form could be sent to another computer as well. Both computers would need to be synchronized so the data matches.

An issue would be how to deal with decision hierarchy. It would be interesting to see how the space shuttle deals with 4 levels of this. I guess I would still want an "E-stop" button and an "Override" button.

For a while I was working on a different throttle; it used a hall-effect sensor that put out a PWM waveform that was proportional to its rotary position. If there was a non-PWM signal (high or low) the microcontroller would put out an error signal. It was a good way to ensure an "all ok" signal. Perhaps something like this could be used for between-computer communication for critical information, rather than analog 5V signals or serial bus communication.
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