Things to ask Houck

[PayneTrain]

*Will a 24V switch slower than a 12V powered motor via PWM

[hmartiro]

Maybe show him the regenerative motor controller and see if he thinks we'll be able to control motor position/speed from the Arduino?

http://www.basicmicro.com/RoboClaw-2x5A_p_47.html

[PayneTrain]

Off the top of his head he thought the lower current would switch faster because the two drivers of delay are the RC time current and the motor which acts as a big inductor. Since the RC times should be fixed, the Back EMF over the inductor is governed by V = L * dI/dt, thus if we have a smaller delta current then not as large of a back emf will build up, thus the change in motor state (from on to off for PWM) will not be as slow

[PayneTrain]

@hmartiro Sure I'll show him that in our next meeting, it looks like from ready the spec sheet on that controller that the Arduino would just give the motor controller a speed and the controller would use a PID routine to attain and maintain that speeed

[hmartiro]

What about position though? We need position control as well as speed

[hmartiro]

I think this is currently the biggest outstanding issue with our design/parts planning, so we should get this sorted out. We need to figure out how we can control the position of these motors.

@PayneTrain can you look into this when you get back, ask your ELE people maybe? We could try to control position by feeding the motor controller a speed and doing our own control inside the Arduino, but this seems like a bad idea. I would just like to feed a motor controller the desired speed and position and let it sort shit out, like what Hal said to do.

[PayneTrain]

K ill check this out Tue On Oct 14, 2012 4:25 PM, "Hayk Martirosyan" notifications@github.com wrote:

I think this is currently the biggest outstanding issue with our design/parts planning, so we should get this sorted out. We need to figure out how we can control the position of these motors.

@PayneTrain https://github.com/PayneTrain can you look into this when you get back, ask your ELE people maybe? We could try to control position by feeding the motor controller a speed and doing our own control inside the Arduino, but this seems like a bad idea. I would just like to feed a motor controller the desired speed and position and let it sort shit out, like what Hal said to do.

— Reply to this email directly or view it on GitHubhttps://github.com/hmartiro/project-thesis/issues/11#issuecomment-9426473.

[hmartiro]

More information about the 36/2 module controller from Maxon:

http://www.maxonmotorusa.com/medias/sys_master/8803613147166/360665_Hardware_Reference_En.pdf http://www.maxonmotorusa.com/medias/sys_master/8803612786718/EPOS2_Firmware_Specification_En.pdf http://www.maxonmotorusa.com/medias/sys_master/8803612819486/EPOS2_Communication_Guide_En.pdf

This thing comes with a software suite of its own for a computer and communicates with the board using an RS232 or USB 2.0 or CAN protocol. Could we communicate with it from the Arduino without needing the software suite, or would it be too complicated?

[hmartiro]

Based on this page of their various controllers, it seems to me we would be better off with the 390438

http://www.maxonmotorusa.com/medias/sys_master/8801023819806/12_309_310_311_312_EN.pdf

http://www.maxonmotorusa.com/medias/sys_master/8798033575966/EPOS2-24-2-Miniaturized-Positioning-Controller-No-Ifs-No-Buts.pdf?mime=application%2Fpdf&realname=EPOS2-24-2-Miniaturized-Positioning-Controller-No-Ifs-No-Buts.pdf

[hmartiro]

It'd be nice if we could get Houck on github to look at those two pages I just sent a message about, since they contain all the information