Thread: Discussion ESC Response Testing
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Old Dec 02, 2010, 10:14 AM
Peter Seddon is offline
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Would an inner current loop not be the best may of maximising the performance and allow the smoothing to be eliminated completely? It would ensure that the motor accelerated at a rate limited only by current and inertia of the motor/propellor. It would add to the complexity and would probably have to be complemented by an outer speed or voltage loop. Such a scheme could be applied to either pwm or i2c ESC's. The deceleration performance is always going to be inferior unless you further add to the complexity by going to a full 4quadrant control, which might give the battery a hard time as you could be trying to dump back some nasty spikey currents.

Peter


Quote:
Originally Posted by obor View Post
I agree also. This is an interesting test. It is worth to try it with my test machine , sending i2c controls instead of PWM. Now what controls should be applied, to best represent a Kopter behavior:

- 10%-100%
- 40%-60%
- 50%-70%
?


Yes. And it makes sense to do it for downward first, as ESC response time is slow when going down. And I wonder if an ESC with Brake set, would behave correctly with that downward curve...


I assume you are talking about FC + BL-CTRL with "current" feedbacked by the I2C. With PPM, there is no way to feedback current.


I see your points. But, in that case the refresh rate of the FC must be much higher than the refresh rate of the ESC itself. And also, motor rotation is not that quick, at full speed it takes 4msec for one full rotation.
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