Let's Make Robots!

Hudson, the butler bot.

After a few more tests it seems 4lbs is the limit for the motors on him... one of them isn't spinning as fast as the other now. I've checked the motor and made sure there weren't any binds anywhere. I'm waiting till I have the money for a new control board, its still Arduino based but allows me to use AX-12 servos, which I can plumb into ROS from what I've read.
Thanks to christmas and Birthdays I now have 5 of these AX-12's but have no way to control them haha.


I got the Drive motors and wheels mounted last night, the battery controller circuit and motor controller all mounted, and all the wires have been put through. As a test I used the 5v regulated power and the Signal and power leads for the motor controller to hook it up to an RC reciever, so I could hook it all up and test the drive system. The videos I have attached show off the drive system, going over Large Tile, Medium tile and carpet... I had to help the transition for carpet a little bit, it high centered while moving over. I probably need to drop down the casters just a little more.
Let me know what you think!


I have added on the Distance sensors on front, also reconfigured the Arm a bit. I then have spent the last few days soldering together a breaker box, essentially that connects both batteries together and outputs all the votages I need. I have the 11.1v LiPo going in one side, and the 7.4v liPo going in the other, outputs vary, a kinect power adapter output, 1 11.1v output for the motor controller, a 7.4v output for the Servos, and a 5v output for the Logic for the Servo Controller. Oh and I added Tension springs to the arm so my servos don't die lol. Now all I need to do is get the drive system in place, which I found out I don't have the apropriate hubs for the wheels :\ so i will have to to wait to get those in before it is moving... I have though about jerry rigging the the hubs to work.. or gettings the bigger wheels that I do have hubs for but I haven't decided which yet.
















Due to over heating computer issues, this is now the third time I will be attempting to write this :\
Hudson, is a butler robot, I'm designing him to initially grab snacks and be asked to go get various items.

Here is his Specs:
-Arduino microcontroller serial connected to a Lynxmotion SSC32 servo controller
-A robotic arm, brackets and base are all parts from Lynxmotion, servos are kind of a hodge podge of different types.
-2 IR sensors, both for wall and stair sensing(so he doesn't take a fumble :P )
-A ultrasonic range sensor for long distance sensing.
-Microsoft Kinect, for 3d vision sensing
-Motors for the drive system are, 12v Geared motors, stall torque is 231.5 oz-in, 152 rpm
-The Brains, HP Mini 1000 netbook, running Ubuntu and ROS from Willow Garage

So yeah my robot so far. Let me know what you think. I'm open to suggestions.

Thanks for viewing.

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how do you or going to charge the batteries with out taking them out or turning off butler bot

very nice 

I've been thinking about that lately... I'm working on right now a new Chasis for Hudson, and I'm going to be splitting up his internals into smaller components. When I'm done with the Chasis he should be around 4ft tall with a base of around 15inch round base.

The battery pack so far is 2 separate 5000mah lipos, one at 14.8v and the other at 11.1v. The newer battery pack will align his spine, and I'm trying to figure out how to build together a battery management system thats similar to what you'd see in EV(electric vehicles). He will have a lot more powere, I'm just not sure how or what type of batteries I'll be using.

I have plans for both hobby grade and my own specialized battery pack and management system, I'll still be using Lipos. The power control module(thats what I'm calling it :P ) should have a dock like feature once i'm done.

I could've sworn I came up with a simaler design for a butler robot a month ago! well, looks pretty good so far, anyway :)

Sorry, I posted this in december, and was working on it 3 months before.


I would mention that with a pair of contact points perpendicular to each other, you will always have a problem with high centering over obstructions. I believe that is a major reason two wheelers with a single caster are common.

Yeah I found this out the hard way when transitioning between the carpet and tile...

I'm going to be rebuilding his base as soon as I get the funds. I have a design I'm leaning towards now thats a bit more stylish.
Thanks for the tips though.

oooh, kinect, i wonder, do you need to buy the whole xbox for the kinect? i don't want to have 2 xboxes! :D

Nope you can buy them separately from the Xbox

I got mine refurbished from Game Stop.


Very cool robot! Are you planning to do any slam? or vision processing, this is going to be a very interesting robot when your done!

Yes, I'm going be using SLAM as my main state machine, and the openni_kinect will be used for video processing and hopefully if I can build it object recognition.