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  • Bertrand 5:16 pm on December 18, 2009 Permalink | Reply
    Tags: , Robotics   

    Magnetic Clevis 

    Since 2 years, i’m playing around with natural permanent magnet. I’m really surprise that nobody is using this natural force as it should. There is a lot of new way to explore.

    Here is a little concept of of magnetic articulation driven by 3 or 4 little electric engines.  The main goal is to let natural magnets hold the biggest part of the weight and use a very little energy to drive it.  It could be use as a stepper engine except that the angle could be setup very precisely. The strength of the joint could be modify without adding extra electric energy. Also the velocity factor could be very interesting. There is no mechanical contact between the 2 heaviest parts so no sound, no heat and no usury. Only the driven part: the electric motors, the driving screws and the spherical bearing will!

    As i saw in many industrial manufacturer since few years, the electromagnetic bearing are now very in use. (ex: SKF)

    Here is a very simple concept of natural magnet bearing:

    Magnetic Bearing Basic

    This is an aluminium shaft with box magnet all around at 45 degrees. On each sides, i put a ring magnet in the repulsive side.  Of course, it’s a schema, so i let the rings floating in space to keep the pictures readable. So more the ring are closer from each other, more there is pressure over the whole shaft.

    After that, my question was how to made this turn.  As i was studying chopper’s swashplate few years ago, i fund a way to adapt this mechanical method to my concept. Simply by creating a disharmony between the rotor’s box magnets strength like this:

    So by tilting a little the rings in symmetry over it, this will give a direction to the shaft. Now the question is how to make the rings turn in symmetry without using a lot of energy? For this i setup a set of 3 driving screws to hold the rings magnet with spherical bearing. The 2 shaft’s strokes are set in an opposite stepping, that way, when i turn the shaft there are getting closer each other, or farest in opposite rotation.

    Magnetic Clevis from Lempereur Bertrand on Vimeo.

    Here a little schema of the Final concept:

    This is with 3 shaft but it could work also with 4.

    If you want to experiment some stuff with magnets:

    http://www.supermagnete.fr/eng/

    http://www.hkcm.de/

    For industrial stuff:

    http://shop.hpceurope.com/an/home_catalogue.asp

    Constant Velocity Joint

     
  • jyonkov 7:40 pm on October 9, 2009 Permalink | Reply
    Tags: , , , , , Robotics,   

    NLP and Ontologies 

    For a while now I’ve been thinking about using knowledge representation – Ontologies as a base for creating a modular Natural Language Processing system focused on extracting structured data from unstructured. For example we can create/use Ontologies (models) that describe “simple” concepts like: Address, Time, Task, Expense, Transaction etc… and use them to “match” information from a text stream. The reason i’m writing this is because i think that there is a common ground for collaboration… I know Stefan is interested in RDF/OWL,  the company that Neven is involved is in a very near domain and finally i was playing with Google Wave which i think is a good platform for creating intelligent bots that will be very easy to distribute if they turn out to be useful :)

    Here are some references:
    http://wordnet.princeton.edu/
    http://protege.stanford.edu/
    http://jena.sourceforge.net/
    http://www.openrdf.org/
    http://code.google.com/apis/wave/guide.html

     
    • Daniel Radev 9:20 am on October 10, 2009 Permalink | Reply

      Although I’m currently not even in near domain (kernel level C driver development is not even close by any means) it is very interesting to me and would gladly participate…

      • jyonkov 10:48 am on October 10, 2009 Permalink | Reply

        Awesome, I’ll try to start with some examples “soon” :)

    • Nikolay 8:41 pm on October 10, 2009 Permalink | Reply

      I want to add a few NLP projects that I personally find interesting: openNLP, which is in Java, and NLTK, which is in Python.

      • jyonkov 6:10 am on October 11, 2009 Permalink | Reply

        Thanks Nikolay, I browsed around the links you provided and stumbled on Apache UIMA, a graduated IBM Research project which has recently been approved as an OASIS Standard. I think that it could be used as a framework in which we can plug our NLP modules when they mature.

        • Nikolay 4:10 am on October 13, 2009 Permalink | Reply

          It seems pretty good, but why it’s still in the incubator… since 2006?

    • Nikolay 6:16 pm on October 14, 2009 Permalink | Reply

      Here’s one project that uses Apache UIMA – SEASR. It has interesting stuff such as sentiment analysis.

    • Neven Boyanov 10:11 pm on October 14, 2009 Permalink | Reply

      This is very interesting topic indeed.

      Knowledge representation is just one part of the process. It is relatively simple task to represent knowledge in a digital form no mater how complex structures or algorithms you should use or how much processor power and memory you will need. But the task does not end with the representation of this knowledge, you need to do something with it.

      One of the obstacles that existed before was the enormous quantities of information that need to gathered first and then process them, but now with Google and all other web-spiders and similar, collecting the information is feasible.

      By the way, Google machine translation is mostly based on what they find on the web and they think one is translation of the other. It’s a version of the statistical machine translation. Others use other sources for parallel corpora such as books, legal documents, etc.

      I will do a parallel here, like the hypothetical best compression algorithm is very similar to a random generator – in its behavior and the result that it produces, in a similar way the perfect machine translation engine is very similar to the best knowledge representation and processing system. It should be in fact a representation of the entire human knowledge with the ability to derive new representations of it in form of one human language or another.

      I like the idea of presenting a program by what it does. The computer language and the computer behavior pair are not very different from humans’ language and respectively their behavior. One day we will be creating programs just by example given to the some kind of knowledge processor that will convert it to a machine code based on what we expect that program to do, just by giving verbal examples.

      I forgot to mention that there was a worldwide recognized NLP conference in Bulgaria, in September, that I was invited to attend but couldn’t for reasons beyond my control, organized by the Bulgarian Academy of Science. The lecturers were mostly from EU and few from US.

      Also, don’t take seriously what I’m saying here about NLP, I’m not proficient enough in that area. :P

      • Svetoslav Vencislavov Pavlov 12:36 am on October 27, 2009 Permalink | Reply

        Hello ! I’m not sure what an ontology is.I’m not a Linguist. Let’s say “ontology” is the grammar way of building a sentence(in English). As I have a simple Language processor( Phrase generator ) , we are able to connect a pattern :) /logical or even derived relational database with different “ontologies”/patterns to Phrase generator. And we are not talking about Natural language processing, and for Virtual Natural Language Processor :)
        “ontology” may become every grammatic rule.
        As you can connect one Application to different databases, you are able to create a pure Logical database based on Artifficial Intelligence with predicats connected to the Application with recurent conections(not database) based on Neural networks Theory. And so, this Application becomes a BOT to communicate with :)

        the beginning( reference ) :
        http://www.languagetool.org/ ( be a patient and smart )
        http://extensions.services.openoffice.org/node/2297

  • Daniel Radev 8:26 pm on September 21, 2009 Permalink | Reply
    Tags: Robotics,   

    Swarm Robotics 

    Here is an article plus a lot of videos about Swarm Robotics

     
    • Nikolay 10:42 pm on September 22, 2009 Permalink | Reply

      That’s the future, I think, which includes nanobots used especially in medicine.

  • Neven Boyanov 2:11 pm on September 21, 2009 Permalink | Reply
    Tags: Robotics,   

    About robots and what other people are doing 

    I have list of websites about robots and robotics that are very interesting. I did this research some years ago when I had more free time to surf the net, but I will probably get back to the subject of robots and robotics soon.

    I am personally most interested in micro-robots which are considered those that are in size less that 1 cubic inch. The Ants from MIT (http://groups.csail.mit.edu/lbr/ants/) is very good example.

    The Swiss EPFL institute had done great deal of research and work in that area. Not all the pages are currently active, but they have archives of most of their projects. Here are some links:

    Here: http://nanolab.me.cmu.edu/projects/waterrunner/ – a project from Carnegie Mellon University – Water Runner Robot.

    Of course Linux has its share in the business too: http://www.linuxfordevices.com/c/a/News/Open-source-robotic-simulation-packages/ – “Open source robot simulation software simplifies the creation of physical …”. IBM are in the business too – http://www.ibm.com/developerworks/linux/library/l-robotools/.

    For  “iFanatics” there is that silly walking  iPhone robot (http://robots.net/article/2670.html) create by Japanese eningeer Kazu Terasaki.

    If you want to start practice here you can find some gear:

    … and some tutorials:

    Other links that you may fond interesting:

    Open source robot simulation software simplifies the creation of physical Linux-based robots, according to an overview article at IBM’s DeveloperWorks site. Simulators such as ODE, Simbad, TeamBots, KControl, Gazebo, and Carmen can help test ideas before putting them into hardware, writes author M.
     
    • jyonkov 9:43 am on September 23, 2009 Permalink | Reply

      This is awesome… it took me 1 days to review all the info here but i stumbled on very interesting things… now i’m trying to choose a modeling environment… I think Matlab has good value because of academics (for example http://mindstorms.lfb.rwth-aachen.de/index.php/en/publications ) but i’ll try some of the open source projects too.

  • nkolev 8:14 pm on September 17, 2009 Permalink | Reply
    Tags: Fail, Robotics   

    And now, the most ridiculous robotics project I’ve ever seen: Deep Green, featured today on TechCrunch.

     
  • nkolev 7:17 pm on September 17, 2009 Permalink | Reply
    Tags: , Robotics   

    Here’s an interesting robotics project: iCub, the Toddler Robot. Go check it out!

     
    • jyonkov 5:42 am on September 18, 2009 Permalink | Reply

      This video makes you think about how kids learn, a specially if you have kids ;) I personally think that reproducing human behavior can be quite difficult taking in consideration the billions of years of evolution. But from experience, I think that it can be useful to cheat a bit and model behavior with mathematical models that we know are not the ones human brain uses… For example while working at MASA Group I’ve created a model (weighted graph) that represented a map and simple behavior principles and applied a simple A* shortest path algorithm that eventually preformed better in terms of motion planning than some PHD cognitive research projects and while writing this I’ve realized that my work has a name now: behavior pathfinding. The thing that can be quite exiting is to find a simple way to determine position in space for example using ultrasound and triangulation and implement simple robot that use “behavior pathfinding” to navigate it-self around. A free way to model and test this positioning system can be http://www.scilab.org/

  • jyonkov 11:40 pm on September 11, 2009 Permalink | Reply
    Tags: Robotics   

    Lets make robots 

    I’ve recently stumbled on a site about making robots http://letsmakerobots.com/. There some good videos and a lot of info about parts. I like the PING))) Ultrasonic Sensor for detecting obstacles and distance. For me the ultimate goal would be to make a robot that knows its position and orientation in my apartment and can create a map in its memory that can be used to navigate itself without bumping in any obstacles. To do this i may have to use a more sophisticated board than http://arduino.cc/.  My first step is to position 3 sound sources with different frequencies in my apartment and record the combined signal,  calculate the position of the mic based on the speed of sound using Matlab etc… Easy setup difficult calculations ;)

     
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