Thread: Discussion ESC Response Testing
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Old Nov 30, 2010, 03:42 AM
obor is offline
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France
Joined Nov 2003
287 Posts
Hi kapteinkuk,
Very interesting work indeed.
ESC response time is key to ensure good stability of all those multicopters, and commercial ESC are so different in their behavior.

So, I decided also to put together some simple hardware + software in order to measure as best as possible ESC response time, and to compare them at various PWM rate and reflashed or not.

My measurement are based on : PWM pulse size sent to ESC, RPM motor.
Any variation in the throttle duty sent to the ESC, should result in a variation of the RPM on the motor.

I used an arduino with a magnetic RPM probe connected to it. The arduino measures the RPM, and controls the PWM pulse sent to the ESC. PWM frequency signal can be set anywhere between 50 and 450Hz.
Currently, it is doing PWM to ESC, later i may do also I2C to compare with I2C ESC like mikrokopters ones.

Currently, my settings for RPM measurements are the following:
- 6 magnets on the motor
- measurements are done every 25msec

I have started to test with the following pulses:
1400-1600-1200-1800-1300-1700 (usec), means throttle variations between 40-60-20-80-30-70 (%). The change rate of these duty can be configured anywhere between 4msec to > 1sec.
Those Throttle variations intend to be as close as possible to what really happens on motors of an Multikopter.

I'll publish some pictures of the hardware, and results are I get them (if ok to publish it here).

Any comment about the way measurements are done is welcome of course.
Olivier
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