Comments on: Sphere bots get some new skills http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/ Fresh hacks every day Fri, 10 Feb 2012 14:02:57 +0000 hourly 1 http://wordpress.com/ By: none http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-104157 Mon, 26 Oct 2009 23:34:35 +0000 http://hackaday.com/?p=17334#comment-104157 i made a sphere bot.. it had a hamster ball with a hamster inside. it rolled away and never came back :(

]]> By: Greg http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-102521 Tue, 20 Oct 2009 03:35:17 +0000 http://hackaday.com/?p=17334#comment-102521

theres more videos by gyroscopes.org that demonstrate some pretty cool gyroscopic precession.

]]> By: Dan Cardin http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101981 Sun, 18 Oct 2009 03:05:48 +0000 http://hackaday.com/?p=17334#comment-101981 Well, thats nifty then, since it seems to defy gravity.

]]> By: Madmaxx http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101938 Sat, 17 Oct 2009 23:16:32 +0000 http://hackaday.com/?p=17334#comment-101938 @ Dan Cardin

the stick with the ball has a gyro in the ball. when the gyro is spinning, it keeps itself positioned in relation to its original position and resists changes in yaw thereafter. once the gyro stops, the whole assembly falls.

]]> By: Mic http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101828 Sat, 17 Oct 2009 02:52:55 +0000 http://hackaday.com/?p=17334#comment-101828 Greg you’re absolutely right. What I meant to convey was the idea of compensation. You would obviously need a more complicated and specialized system, but my proposed concept has merit. Something designed to measure and compensate for g forces. I mean you’re right it is more complex, but you still need a computer to measure forces and to compensate for the ones that mess up your control inputs. That’s what I tried to say, but, a segway is a lame example as you have said =P Awesome creation, serious props man.

]]> By: Dan Cardin http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101816 Sat, 17 Oct 2009 00:55:01 +0000 http://hackaday.com/?p=17334#comment-101816 @Greg: how is it that the gyro you have on the table is staying up? Is the lighting in the video obscuring something that I should be seeing or is it just a metal stick with the spinning ball parts on the end…and standing up on its own?

]]> By: Andrew http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101736 Fri, 16 Oct 2009 17:04:03 +0000 http://hackaday.com/?p=17334#comment-101736 This is ingenious. Nice work!

]]> By: Greg http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101723 Fri, 16 Oct 2009 16:29:44 +0000 http://hackaday.com/?p=17334#comment-101723 @Mic: The control system for this robot is significantly more complex than for the segway. I’m building a custom system with an IMU and encoders on all the parts. I’m also developing the dynamic equations of motion mathematically, which are all delightfully non-linear. After that I’ll be able to write the software to cancel out all the wacky movements.

]]> By: Greg http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101718 Fri, 16 Oct 2009 16:24:24 +0000 http://hackaday.com/?p=17334#comment-101718 @Jonathan: The gyros are actively driven to rotate left/right to generate the precession torque. So they are in fact used like CMGs.

The reason you can’t just use CMGs is because you can only store so much momentum. By conservation of angular momentum, you can only generate a certain amount of torque*time before your CMG system is ‘depleted’.

Steering is accomplished using the pendulum, but can be supplemented by the CMGs as well (in a slightly different/more complicated configuration).

]]> By: Greg http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101712 Fri, 16 Oct 2009 16:08:58 +0000 http://hackaday.com/?p=17334#comment-101712 @Gizer20: Yes the robot still shifts center of mass for normal motion. The stored momentum gives the pendulum more than just gravity to push against to create torque. It uses both at the same time.

The shell is actually a polycarbonate gumball machine globe.

]]> By: Mic http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101690 Fri, 16 Oct 2009 14:05:50 +0000 http://hackaday.com/?p=17334#comment-101690 Hack a segway and use its guidance system to buffer out all the wacky movements to give better control?

]]> By: Jonathan http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101671 Fri, 16 Oct 2009 09:13:06 +0000 http://hackaday.com/?p=17334#comment-101671 @Greg: indeed, hydraulics rock :)

So I suppose (also from the pictures) there are two gyros spinning in the horizontal plane, I think you are only using them as a angular momentum storage, and then simply driving the ball against this momentum-heavy pendulum. (since attempting to tilt them will cause them to react by tilting left to right in opposite directions, which they cannot)

But how about simply attaching the gyros to the inside of the sphere on left to right gimbals, without using a pendulum, and then tilting them?
This should create forward torque I think, and would sound more like a CMG to me, no?
Not sure about turning though…

]]> By: Gizer20 http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101670 Fri, 16 Oct 2009 09:10:42 +0000 http://hackaday.com/?p=17334#comment-101670 So your robot still changing the gravity center to move arround, but when is stuck in a hole or something similar you use the gyroscope to create extra torque and get out from there no?

By the way, awesome robot where do you get the sphere?

]]> By: _matt http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101668 Fri, 16 Oct 2009 09:07:31 +0000 http://hackaday.com/?p=17334#comment-101668 Two words:

AWESOME

]]> By: sunny185 http://hackaday.com/2009/10/15/sphere-bots-get-some-new-skills/comment-page-1/#comment-101662 Fri, 16 Oct 2009 08:43:14 +0000 http://hackaday.com/?p=17334#comment-101662 Nice idea)

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