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Cool Project: Room Explorer Bot with Mapping Functions

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ROBOTC user, Sigtrygg (forum name), recently shared a project on the ROBOTC forums that they have been working on called the NXT Room Explorer Bot with Mapping Functions. Check out the YouTube video of the robot in action …
 


Sigtrygg description and breakdown of the bot …
 

The robot is based upon a standard REM-Bot but in addition equipped with a HiTechnic gyro, HiTechnic compass sensor and an omni-wheel. First the robot moves about 360° to calibrate the compass using the gyro (thank you to Xander Soldaat for code!). Then the robot moves its sonar-head to the right, to the left and in front position to get the distances according to its position. After doing this it turns around to the wall with the minimum distance and drives in front of it until sonar sensor detected a minimum sensor distance, e.g. 20cm. Then the robot turns parallel to the wall, moves his sonar-head to the right detecting the distance to the wall and drives counter clockwise parallel to the wall balancing distance. A mapping-task records the compass and odometry data every second and calculate the polar coordinates to cartesian coordinates (x,y). The coordinates are written as “map.txt”-file. So you can use Excel or an other program to draw the path which the robot had moved. In addition to that you can follow the path at the NXT-LCD-screen. I had to choose a scale for it, so you have to suit the scale to your room size. If the robots touch sensor has detected an obstacle the robot moves back and turn left for 90 degrees and continuous his explorer-duty always running counter clockwise with wall to the right. How to expect the end of path doesn’t suit exactly to the beginning because of inaccuracies of compass and odometry measures.

CIMG3122

Construction of the robot. The upper sensor is the compass sensor.

CIMG3125

Construction of the robot. The upper sensor is the compass sensor.

Screenshot

Screenshot of Excel data-sheet

LCD Screenshot

LCD Screenshot

To read more about this project, check out the ROBOTC Forum post here!

Written by Cara Friez

July 18th, 2014 at 8:00 am

Cool Project: Monster Ball Sorting Factory

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OLYMPUS DIGITAL CAMERA

 

Ray McNamara is relatively new to ROBOTC, having only really started to seriously use it within the past year, but already he’s come up with some interesting projects that caught our eye. The “Monster Ball Sorting Factory”, which he shared with us on the forum, is definitely a cool project we had to share.
 


 

The Factory is a cooperation between two robots Ray’s designed. One is an NXT Forklift truck, which uses a special non-standard part: a pair of Omni Wheels in the back to replace the standard single rotating wheel, which makes the Forklift’s turns a lot more reliable.

The other is a long, conveyor belt and claw arm robot that sorts balls piled onto a conveyor belt based on their color. It then puts them into containers, which the Forklift periodically takes and places in a slot so that the robot can dump it into a bigger bin. This robot is a combination of an earlier project, the “Bin Emptying Machine,” that takes the balls out of their container with a rail mounted crane that does the sorting.

We asked Ray about the project and his motivation for doing it and he replied:

“My Monster Sorter is still a work in progress, much to my wife’s annoyance due to the amount of real-estate it has been taking up in the lounge room since early December 2012.  I hope to have it all running on a single NXT (excluding the Forklift), by means of 2x Mindsensors Motor Multiplexers and 1x Mindsensors Sensor Multiplexer. If my calculations are right, the single NXT Brick will control 8x Motors and 10x Sensors.

My motivation was the challenge to learn how far I take the standard Colour Sorter model. It really started back in 2010, when I convinced Rotacaster Australia‘s GM to turn his industrial rollers into Omni-wheels for my LEGO Models and robots. After almost exhausting the possibilities of Holonomic Platforms, I looked into other uses for the Rotacaster Wheels, resulting in my Forklift Truck.

Once I had my Forklift Truck, I needed to put it to work. The Ball Sorting Factory was what evolved over a few days. Since then I have been fine tuning the hardware and the ROBOTC code used to control it. In the process, I have also been Beta Testing some Mindsensors Sensors and Multiplexers with it.

I always try to include a detailed description, photos, video, code and CAD files for my robots when they are published to my blog. Although it takes a lot of time to put my blog posts together, I feel it is worth it. I get a lot questions and praise from many people who use my resources. I especially enjoy helping out students with their queries.”

To download the code to this project, click here – ROBOTC Code for Factory and ROBOTC Code for Forklift.

Thanks to Ray for taking the time to respond to our questions! Visit Ray’s website at www.rjmcnamara.com to see more projects, pictures, codes, videos, and much more.

Do you have a cool project or video you want to share with us? If so, send us an email at socialmedia@robotc.net.

Written by Cara Friez

July 31st, 2013 at 3:55 pm