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View Full Version : [Project] Mantis - Two Tonne Turbo Diesel Hexapod Walking Machine



mdenton
03-28-2013, 06:29 PM
So it may have taken me much longer than I anticipated.. 3.5 years, but here it is.. finally!

More information and images can be found here:

www.facebook.com/mantisrobot
(http://www.facebook.com/mantisrobot)
www.mantisrobot.com (http://www.mantisrobot.com)

*EDIT* People who are interested in the build process and test footage etc, there is plenty of this on the Facebook page above, alos I have just opened up the blog that I kept during the design and build, which is really just a build diary:

http://mantisrobot.blogspot.com (http://mantisrobot.blogspot.com)

If you like what I've done with this project, please help promote it the usual way.. Like/Tweet/Share/Forward etc :)


http://www.youtube.com/watch?v=1h9Mw-s9mzI

Gertlex
03-28-2013, 07:25 PM
Well damn. That is some niiice work. Congrats to your team on a job well done. Will there be more footage of it on uneven terrain?

jwatte
03-28-2013, 11:10 PM
I'm in awe!

I looked at mantisrobot.com but apparently it's a parked domain?

Gertlex
03-29-2013, 12:22 AM
I'm in awe!

I looked at mantisrobot.com but apparently it's a parked domain?
You need the www. for whatever reason.

mdenton
03-29-2013, 05:59 AM
Yeah I'll try fix the mantisrobot.com, the www. does work though.

Small team on this one, which is why it took me so long :) Just me and one other mechanical engineer worked on the desing and initial build for a year, with lots of the big fabrication outsourced. Then I had another guy help out with the Operator Interface software on the WinCE touch panel you see during power up, the rest has been on my own.

There is already a bunch of footage and images on the facebook page (http://www.facebook.com/mantisrobot).

Currently the only sensors are in the feet, so it is walking blind, hence needing an operator to guide it. I have plans to add non-contact sensors to the legs to detect obstacles, but need to get some feedback on this first to see if I can get funding to take things further.

Th232
03-29-2013, 07:23 AM
More and more giant hexapods on the scene... I like it!

How hard is it to operate at this stage?

mdenton
03-30-2013, 06:35 AM
More and more giant hexapods on the scene... I like it!

How hard is it to operate at this stage?

Easy to operate, power up and power down need a little concentration, but once you know what your doing... :)

jwatte
03-30-2013, 02:34 PM
Could you share the trade-off why you chose hydraulics instead of generator + electric motors?

tician
03-30-2013, 04:29 PM
Could you share the trade-off why you chose hydraulics instead of generator + electric motors?
When is the last time you saw a purely electrically actuated (de-)construction vehicle other than a crane? Electric motors work really well in enclosed industrial facilities, but not so much outdoors (lots moving parts that are sensitive to humidity and debris that have to be well sealed against intrusion). Hydraulics just tend to be more resilient (built in damping), and cheaper and easier to build and maintain in that sort of environment. Also... (http://youtu.be/VBMUvAUPTGM?t=8m13s)

jwatte
03-30-2013, 11:52 PM
When is the last time you saw a purely electrically actuated (de-)construction vehicle other than a crane?

I was thinking the Lego Power Builder ride, but you're right: that's indoors!

I drive an electric car, and I have a friend who's designed a hybrid diesel-electric drivetrain that uses a diesel turbine to generate electricity to drive delivery trucks, so clearly the electric motor thing *can* be made to work in a rugged environment.

tician
03-31-2013, 12:34 AM
I drive an electric car, and I have a friend who's designed a hybrid diesel-electric drivetrain that uses a diesel turbine to generate electricity to drive delivery trucks, so clearly the electric motor thing *can* be made to work in a rugged environment.
Are the motors directly connected to (contained within) the wheels, or are they tucked away in the engine compartment and connected through a large-ish transmission? A lot of modern locomotives are diesel-electric, but that is still not quite multiple compact actuated joints in a off-road/construction environment.

I am apparently rather argumentative today. Sorry.


Also, not sure how I managed to not say this earlier: friggin' awesome bot.

mdenton
03-31-2013, 04:57 AM
So there are pros and cons of hydraulics v electric actuators, too many to go into here, and most of which have been pointed out, however, one of the biggest things for us was simoly that hydraulics are much cheaper than an equivalent power electric actuator. Although an electric version would have been nice and clean to work on, not to mention simpler to control:)

Hydraulics are generally much mor resilient though in outdoor environments.

jwatte
03-31-2013, 02:00 PM
Thanks for the discussion, that's actually the kind of pro/con I was looking for!

mdenton
04-02-2013, 12:14 PM
Hi,

For those who are looking for more technical information I have just opened up the blog I kept during the design build process. This was more of a build diary than blog, it can be seen here: http://mantisrobot.blogspot.com

Xevel
04-02-2013, 07:10 PM
Thanks Matt!

I love to see the process of building such a gigantic and awesome project, thank you thank you thank you!

mdenton
04-05-2013, 06:07 AM
I've been asked for more technical information, particularly by Rick Lehrbaum for this Linuxgizmos (http://linuxgizmos.com/mantis-hexapod-robot-embedded-linux-computer/) article:


So here is the Mantis Hexapod control system architecture / overview:


https://fbcdn-sphotos-d-a.akamaihd.net/hphotos-ak-ash3/60644_564054796949385_231968584_n.jpg


Also this may be of interest, this is part of the H&S document for Bestival 2012, showing the working envelope and operational guide lines:


https://fbcdn-sphotos-g-a.akamaihd.net/hphotos-ak-prn1/35004_564055903615941_227362235_n.png


When the machine is powered up, the following applies:


RED: (No Go Area)
When the machine is powered up, under no circumstances should any personnel enter the Red area. Only when the machine is powered off or in a low power state can trained personnel enter this area.


ORANGE: (Leg Operational Area)
During normal walking operation the legs should stay within the orange area, but can be over-ridden under manual control by the operator to reach within the yellow area.


YELLOW: (Leg Reach Area)
The yellow area is the personnel clearance distance during operation. This represents a 3000mm radius from the leg coxa/hip joint that places personnel outside the maximum reach of a leg.


When the machine is powered off, all areas are safe, however, if the machine is supported above the ground by its own legs and without any prop stands, NO personnel should go underneath the body!

mdenton
04-09-2013, 11:09 AM
Here is another video shot in 2012 during field tests. Includes footage at the end of how I transport the Mantis.


http://youtu.be/1sRlFQLwg3w

jwatte
04-09-2013, 01:10 PM
Where in California can you find that much grass that's not already paved over with tract housing!?
:-)

mdenton
05-17-2013, 04:37 PM
Here is a video shot almost one year ago, the first outdoor tests. Raw footage.


http://youtu.be/fRmT0eWSXv4

hwan we
05-17-2013, 05:24 PM
Excellent Hexapod Walking Machine:o

Fast walking speed video ~~
I want to see :robotsurprised:

mdenton
06-23-2013, 05:31 PM
Some stills and aerial footage from Elmia Wood 2013


http://youtu.be/Fbubqzh7GDI

jwatte
06-23-2013, 10:52 PM
I thought you were in SoCal -- how did you get to Denmark?

Edit: After doing some sleuthing, I learn that you're actually in southern England. Must have been that film & TV effects vibe that threw me off.
Ferry or chunnel? :-)

mdenton
06-24-2013, 08:49 AM
Took the ferry from Harwich to Esbjerg Denmark, great road trip through Copenhagen up to Jonkoping!