Society of Robots - Robot Forum

Mechanics and Construction => Mechanics and Construction => Topic started by: mhanuel on October 20, 2008, 07:55:53 AM

Title: Differential Mobile Robot with 2 castor wheels examples
Post by: mhanuel on October 20, 2008, 07:55:53 AM: Hello to all,

Does anybody know of commercially available mobile robots that have the following configuration: Differential wheels with 2 caster. The casters wheels have a common axis that is parallel to the differential wheels axis.

I will appreciate any comments.

Thank you in advance.
Title: Re: Differential Mobile Robot with 2 castor wheels examples
Post by: ArcMan on October 20, 2008, 08:53:16 AM: A 2-caster configuration is useful for rough terrain, especially when the platform needs to stay as level as possible with the terrain. A well-designed robotic lawnmower comes to mind.

www.evatech.net (http://www.evatech.net)
Title: Re: Differential Mobile Robot with 2 castor wheels examples
Post by: mhanuel on October 20, 2008, 09:15:41 AM: Thank you ArcMan,

I need to study configurations like that, I ask for commercially available robots but I correct my question, in fact I need examples of any system (prototype, research, commercially).

Appreciated!
Title: Re: Differential Mobile Robot with 2 castor wheels examples
Post by: ArcMan on October 20, 2008, 12:25:08 PM: Well then...

You can check out my yard robot prototype in the Robot Videos section, which I posted recently.
It's differential drive with 2 swivel casters.

It just got done helping me in the yard this weekend by carrying around a leaf barrel. I carried the transmitter with me while mowing with the bagger. When the mower's bag filled up, I "called" the yard robot over and dumped the filled bag into the barrel on the robot. It turned a few heads from passersby when it seemingly started moving around the yard on its own.
Title: Re: Differential Mobile Robot with 2 castor wheels examples
Post by: pomprocker on October 20, 2008, 04:08:46 PM: Like mine??
(http://www.curiousinventor.com/assets/0000/0615/1014082006a.jpg)

See the link in my signature
Title: Re: Differential Mobile Robot with 2 castor wheels examples
Post by: mhanuel on October 20, 2008, 05:38:15 PM: Thank you pomprocker,

I saw your robot on other post on this forum,

I don't know how to model the Omni wheels. I have seem a similar configurations with rubber castor wheels.
What I need is to study the kinematic of this type of robots, and for that I must model the wheels, if you have modeled the wheels or have info about please let me know.

Appreciated,

Regards,
Title: Re: Differential Mobile Robot with 2 castor wheels examples
Post by: pomprocker on October 20, 2008, 07:49:29 PM: What do you mean by modeled the wheels? Like a 3D model with correct dimensions? Or some sort of mathematical model?
Title: Re: Differential Mobile Robot with 2 castor wheels examples
Post by: mhanuel on October 20, 2008, 08:56:05 PM: Quote
Or some sort of mathematical model?

Yes, the mathematical model.
So far, I am taking a course that is focused on robot modeling. Our first topic was wheeled robots. We have to find a way to model the robot in order to apply kinematics. Then we should move to the dynamic of the robot.
We have seen several types of wheels. We have considered that the wheels are non deformable, move on a horizontal plane and it's assume that the contact between the wheel and the ground is reduced to a single point of the plane.

I really don't know how to deal with that omni wheels, so I will try first the rubber wheels with all the idealization explained above.
But the configuration of your robot it's interesting.

Thank you,
Regards,
Title: Re: Differential Mobile Robot with 2 castor wheels examples
Post by: castors wheels on November 23, 2009, 01:02:14 AM: Hi...mhanuel.I hope we could help you in this regard. You can enough information from the link provided in y signature. We are the best producers in casters and I hope we could fulfill your purpose.