Let's Make Robots!

RC Car managed by Java leJOS NXJ

Drive with an autonomous systems using ultrasonic sensors and GPS
CIMG0045.JPG30.44 KB

This project tries to manage any RC Car which you can purchase in your city using a NXT brick and a Lattebox NXTe.

I am finishing a preliminar GPS navigation solution for leJOS project, but I have a problem to understand some value, azimuth.
In my tests I had some problems to understand the azimuth value which is returned by the method AzimuthTo in a Coordinates Object. AzimuthTo return an angle which is referenced with North pole.

In my tests I use a GPS point as goal:

Goal: 40.445049309324573,-3.4673066139221191

I give you a GPS point which is located on the street where I did my tests:

Current: 40.445049309324573,-3.4673066139221191

If you make a line bettween the both points, the line is on the street but azimuth give a value 144º so if the robot change the course to angle 144, so the robot would leave the street. I don't understand how to use the value 144. Is it neccessary to make any trigonomical calculation to find the solution?

I have made a doc about the problem and some questions:

I made some videos about the system:

Do you have an alternative calculus to make the azimuth calculus?
Do you undertand my problem?

Today I begun to test my first GPS Navigator. Besides I have to improve the system which manage the steering maybe using PID or another technique...


If you take a look the prototype, I have uploaded some pics in my Flirck account:


This year I will use a new RC Car chassis, Maverick Strada model which I replaced some pieces, for example the speed controller. With this model, the place where is located NXT brick is more stable.

I have released a new gallery about this model:

NXTe allows me to control RC Servos and DC Motors easily. Currently I can go forward and backward. leJOS project has worked so hard to improve garbaje collector, to manage with NXT's CPU complex Java Programs.

I have released a new RC Controller. I am working on this tasks:

  1. Integrate GPS Subsystem
  2. Integrate Google Earth Support
  3. Improve autonomous subsystem
  4. Develop GPS Navigation
  5. Research Kalman Filter to make sensor fusion

I have published a map where you can see the place where I am doing the tests. I need a large area to test algorithms.


Further information here: http://www.juanantonio.info/jab_cms.php?id=228

Note: In my website, in the previous URL, it is possible to download a paper about the project.


Juan Antonio Breña Moral

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i love it  ;)    seems to be very fast and powerfull!!! 

what will the GPS system do? 


GPS System will be used to:

Extract GPS Data to use them with new leJOS GPS Navigator.

Besides I am testing JSR-179, javax.microedition.location API to calculate distances and azimuth.

Test it with the new example which I created: http://lejos.svn.sourceforge.net/viewvc/lejos/trunk/examples/DistanceTest/DistanceTest.java?revision=1770&view=markup

Tonight I created a new document in my website about the progress with GPS Navigator: http://www.juanantonio.info/jab_cms.php?id=238

In relation to the chassis, yes it is so much powerfull. I reduce the DC Motor speed, because I need to test my algorithms and it runs so fast! :D Imagine if I lost my robot because he runs more than "Correcaminos"

Juan Antonio Breña Moral

very very interesting!!!

keep up the good work!!!   ;)

GPS system? that's really interesting! make sure to keep us updated!


ah, could you also add some detailed information about the way it works? it sounds nice. (the robot i mean not the gps)

Hi friend, in the website, I published a paper about the project. do you need more informacion? say me and I will help you.






Juan Antonio Breña Moral