Re: Motor Analysis

In lugnet.robotics, Andrew Meyer wrote:
> The FLL team that I mentor has several hundred motors, both the new and the old
> ones. This wealth of motors got me thinking "Well, out of that size a sample,
> there's gotta be two that are perfectly matched, and some that are close. I
> should analyze all of them..." So, I built a simple little test mount to run
> them in. It has a rotation sensor connected to the motor by the double bevel
> gears, using the friction cross-over pins to simulate a load. That...was the
> easy part. The part that I thought would be easy (the code) isn't. What I tried
> to do is run the motor at power levels 1-5 forward, while recording the sensor
> data as data points. Then, I run the motor in reverse, power levels 1-5, while
> datalogging the rotation sensor data. This process is repeated three times. What
> I wanted all of that to do is calculate the loaded RPM of the motor at each
> power level, as a useful and fair method of motor comparison. It doesn't. The
> problems I think I ran into:
> *integer math
> *no absolute value function
> *unfamiliarity with Robolab's Investigator section
>
> Is what I'm trying to do a reasonable thing to want to do with an RCX and some
> free time? Is it possible? Has anyone else ever done things like this before?
>
> Any and all help will be much appreciated, and I can email code if you let me
> know. Also can post pictures of rig if needed.
>

Did you check here;

http://www.philohome.com/motors/motorcomp.htm

Philippe has done a lot of work which might be of use.

JB