The reason I didn’t want to include the remote control stuff is to remove that bit of complexity and also at the time of build all I had for a disposable remote was a really crappy push button forward/back left/right remote… Honestly I would recommend that you get a remote that has variable sticks and then you just read it into analog pins on the arduino and then for forward and back just incorporate the reading into the vAngle calculations… For left and right just remember that whatever you remove from say the left side motor torque you add the same amount to the right side motor torque…
Kas, a friend of mine designed an Arduino compatible board that mates with the VNH2SP30 motor driver, he gives away boards if you pay the shipment. Take a look here: http://www.billporter.info/?p=286
If you mean the small thing that on most pictures is on the right of the motor controller, that is a switching voltage regulator for the electronics (5v) so no power is wasted through heat (from 12V…). It’s from Dimension Engineering. You can replace it with a regular 7805, but have a heat radiator mounted on it.
About the motors, I watched a few balancing robot videos on youtube and one of them was clicking really annoying. I hope it’s not gonna be the case with the pololu motors…
How are the wheels? I’ve been “balancing” between buying a pair or cutting them on my cnc.
kas, Madsci tells me that Lynxmotion motors he used before he bought the Pololu motors for more speed have less backlash. He took a short video to show me how much is the backlash on the Pololu motors, by holding the encoder axle and wiggling the wheel on the motor. I think it’s way bigger than I thought, and his wheels are smaller diameter than the wheels I plan on using.
Backslash is as shown on your video I don’t know what is acceptable, but less backlash is definitly better for this type of application I like the Pololu’s for their native built in encoders I will let you know the outcome (it may take some weeks)
For a Zero backlash solution, please refer to my post dated July 28th
I am not a math person. So I’m trying to figure out what should be the max speed of the robot to be able to straighten itself from almost a flat position, perhaps 10 degrees or so from horizontal (say the robot has some arms that lift the top at that angle, than drive forward at max speed to lift the top and then start balancing). Would 10 meters per second lift 1 kg weight (the weight being mostly at the top of the robot)?
Looking at the AX-12 servos, they are a bit slow I think (51 RPM), but we’ll know for sure when we know the max speed needed. Another option would be the RX-24F servos (very expensive!!!), that have 127 RPM, so with a 10" wheel diameter they can get a max speed of 10 MPS. 10" wheels with inflatable tires we can get from baby strollers.
Thanks for the links! I knew about the supermodified, but the other servo links are cool too.
I think I’ll use what I have for now and try out how it works. I want to re-design my MiniEric robot so I can make it balance, if I will not succeed I’ll just add back the caster ball. I’ll design in AutoCAD and cut the parts from 1/4 inch acrylic I bought years ago, keep the Faulhaber motors but remove the 90 degrees gearing to get rid of the backlash. After I manage to make it balance, I’ll just add more stuff to it. Perhaps I should keep the current one as it is and build a new version, as the motors are on sale at the Electronic Goldmine… I figured I’ll save on cash for the big robot or some other stuff like a GPS… (not balancing related…).
So, keep me posted with your progress, as I will do with mine!
I am really glad to see you were able to get it balancing so well… And the design looks good and solid… Kind of a great feeling when they finally stand on their own eh!.. hehehehe
