JDERobot

Some time ago I made some tests on dlopened modules, trying to find some simple autoloading mechanisms. The usual way we were using dlopen was followed by a dlsym calls collection. This way you can get functions defined inside the module. But this forces the application to know the searched symbols names.

An easy way to avoid this is letting the module to register itself, providing some registering mechanism, on loading time. So the only requirement is some kind of constructor called inmediatelly after dlopen call. gcc function atributes in C and variable initialization through functions in C++ are really easy ways to get this pourpouse.

More info can be found here.

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In this talk José María Cañas will present the foundations of projective geometry for dealing with images:
(a) 2D projective geometry, points, lines, homogeneous coordinates.
(b) Image formation: from 3D reality to 2D images, projection matrix, 3D translations and rotations
(c) I will talk about Progeo, a C library used in many JDE applications to relate 2D image pixels with 3D space
(d) Camera calibration, different types of cameras.

Date: 2009/03/06, 17h
Place: Robotics Lab (room 117), Departamental-II, URJC, Móstoles

You can see or download full recorded speech on .avi video here

I’ve finished my Final Year Project, entitled “Visualizador 3D interactivo para laboratorios de análisis de marcha”. Our objectives were to develop a 3D interactive tool that could help the doctor in the treatments and analysis of patients with walking pathologies.

Concretely, I have programmed a 3D visualizer that shows skeleton figures with the movement captured previously on the real patient. My application reads the file with the position of the patient’s joints and it draw the moving skeleton on a virtual environment with this data.

I have made the application more ergonomic and interactive: there are Play/Pause buttons, a speed dial, a progress bar and some camera controls by the only use of the mouse. this way, the managing is more intuitive and ergonomic.

Finally, the application allows to show some graphics with the temporal evolution of the positions or primary rotation angles of any joint. You can select the choised joint by the upper menu or simply clicking in the joint inside the virtual world.

In this video, you can see the Skeleton Visualizer in all his brilliance:

Last Thursday, I defended my project with great success. I obtained a 10. Thanks to all.

Link for more information:
http://jde.gsyc.es/index.php/Dmuelas_skeleton_visualizer

Dr. Marta Marrón from Universidad de Alcalá will present us the algorithms developed on her PhD thesis to visually track several objects using particle filters. The visual 3D tracking of several objects at the same time has many applications in robotics and computer vision. The main advantage of her MultiTargetTracking (MTT) particle filters is that they are truly multimodal, overcoming the only-one-target feature of the classic particle filters. The algorithm she proposes clusters the particle set in different groups according to the several relevant objects in the scene and tracks them with such multimodal single particle population.

Date: 2009/02/16, 17h
Place: Conference Room, Departamental-II, URJC, Móstoles

Yesterday we went to the URJC (Alcorcón) in order to see the motion capture system installed there; and a house prepared to track a person who lives inside the building.


Vicon systems have been doing exactly to track and analyze movement. So, in this hospital they use it to examine the development of patients who have some anomaly on gait. Furthermore, because of Vicon systems is so complex to use it, they have another motion capture system called “Step 32″.




On the other hand, we went to a special house installed there too. In this house, we can be tracked throughout daily life. And then, they get statistical graphics for knowing how we move inside home.

Some days ago Dr. Humberto Martínez, from Universidad de Murcia, gave us a talk about his experience in the TeamChaos team. TeamChaos team has competed at the RoboCup in the last years, first in the Sony Legged League with Aibos and now in the Standard Platform League, with the Nao humanoid. RoboCup is a very demanding environment for robotics, as long as it is very dynamic, competitive and the onboard computers have limited computing power.

He described the architecture of the software controlling the robot, named ThinkingCap, some locomotion issues and perception algorithms. Locomotion has increased its complexity from the four legged Aibos to current biped humanoids. Speed and stability are now to key topics. Perception is mainly based in vision and must be very efficient in order to allow responsive behaviors.

You can download the slides used in this talk. And you can see or download full recorded speech on .mpg video here

About two weeks ago, we recorded Pioneer robot wandering over this department hall. The goal is quite simple: the robot must go from one side to another one. It uses a scanning laser in order to avoid dynamic (e.g. people) and static obstacles (e.g. doors, walls).

Experiments show that algorithm is extremely efficient. We tested the system on a real environment, and it was able to wander around obstacles and people who are walking over there.

In the next video you can see running JDE 4.3 with usb camera in pico-itx.

Today we’ve watched the “Revolution OS”, a 2001 documentary. It traces the history of GNU, Linux, and the open source and free software movements. It features several interviews with prominent hackers and entrepreneurs (and hackers-cum-entrepreneurs), including Richard Stallman, Michael Tiemann, Linus Torvalds, Larry Augustin, Eric S. Raymond, Bruce Perens, Frank Hecker and Brian Behlendorf.

The film begins in medias res with an IPO, and then sets the historical stage by showing the beginnings of software development back in the day when software was shared on paper tape for the price of the paper itself. It then segues to Bill Gates’s Open Letter to Hobbyists in which he asks Computer Hobbyists to not share, but to buy software. Richard Stallman then explains how and why he left the MIT Lab for Artificial Intelligence in order to devote his life to the development of free software, as well as how he started with the GNU project. Linus Torvalds is interviewed on his development of the Linux kernel as well as on the GNU/Linux naming controversy and Linux’s further evolution, including its commercialization. Richard Stallman remarks on some of the ideological aspects of open source vis-á-vis Communism and capitalism and well as on several aspects of the development of GNU/Linux. Michael Tiemann (interviewed in a desert) tells how he met Stallman and got an early version of Stallman’s GCC and founded Cygnus Solutions. Larry Augustin tells how he combined the resulting GNU software and a normal PC to create a UNIX-like Workstation which cost one third the price of a workstation by Sun Microsystems even though it was three times as powerful. His narrative includes his early dealings with venture capitalists, the eventual capitalization and commodification of Linux for his own company, VA Linux, and ends with its IPO.

You can see it on: http://video.google.es/videoplay?docid=7707585592627775409 (this video is available under the terms of the GNU Free Documentation License )

Pico-Itx

This board is 100% compatible with linux (debian, ubuntu). We have managed to install Debian Sid in this board without problems. Moreover we have installed the new version of JDE (4.3) by means of debian packages and everything has worked well.

In the next screenshot you can see a jde execution in pico-itx motherboard:

running jde4.3 in picoitx

We have a mini-itx mother-board and touch tft 7″ too. We will describe the experiences with this gadgets in the nexts weeks.