UBBots 2013 contest

Last Sunday (10.03.2013) our BarRD attended the UBBots 2013 competition for which he has been preparing all this time.

We are very pleased to announce that our work has been greatly rewarded by the following sponsors: Bitdefender, Fortech, iSDC, SDL and Yardi.

We would also like to thank our professor, Mr. Mihai Oltean, who has been offering us constant help and guidance.

Thank you for your support, for appreciating the complexity of our project and for the awesome prizes! :)

Cristina and Teodora

BarRD - inside view

Testing: approach table -> rotate -> detect bottle -> grab it

Progress:

• grab the bottle and lift it a little
• move forward and rotates to detect the glass (use the front camera)
• move around the glass until it is in the desired spot (use the front camera)
• lift the bottle and pour liquid into the first glass
• lift a little bit more and pour liquid into the second glass
• descend and then let go of the bottle

Below is a video that shows how the robot approaches the table by respecting a certain distance, rotates around it and stops when it encounters the bottle within the center of the image.After front facing the bottle it goes forward until the bottle is detected, rotates until it is in the center of the image, and grabs it.

Testing: approach table -> rotate -> detect bottle

Lately, we've made a few adjustments to our design, i.e., we added a side camera and changed the capture angle for the front camera (it is now way above the gripper).

As for the implementation, we switched to colour detection for the bottle due to various reasons.

Progress:

• rotate around the table and scan the table for the bottle
•  set the bottle to the centre of the image and prepare the robot's position for when approaching the bottle (use the side camera)
•  get close to the bottle and center it. This is crucial to grabbing the bottle with the gripper (use the front camera)

Below is a video that shows how the robot approaches the table by respecting a certain distance, rotates around it and stops when it encounters the bottle within the centre of the image. It then turns around, backs off, and drives back, this time front facing the bottle. The reason for doing so is that otherwise, the robot might hit the bottle with its gripper.

 Side note: a more complex video is on its way... In the meantime, enjoy the more artistic side of BarRD:

Image processing: table and bottle detection

Lately we've stepped into the computer vision area and worked on the image processing part of the project. The OpenCV library was used.

There are four main tasks that need image processing in real time:

  1. Table detection

      This is the first detection. The robot will localize the table from a distance and get close to it. 

  2. Bottle detection (1)

     The first bottle detection is done while rotating around the table, in order to localize the bottle's position. 

  3. Bottle detection (2) 

      The second detection is done while standing in front of the bottle. This is done mainly because of precision reasons.  

  4. Cup detection

     The last processing is done with the purpose of localizing the cup in which the liquid will be poured.

All of the above mentioned processing steps are done based on template matching, with various improvements within the algorithm.

What have we been up to?

      Up until now we've implemented steps 1 and 3, i.e., the table and bottle (2) detections.

      We have also worked on "centering" the captured image provided that we need this when the robot approaches the previously detected object.

     Apart from this, a LEGO ultrasonic sensor has been installed, which brought improvements to the grabbing of the bottle.

Testing: grab -> lift -> pour

A couple of hours of programming later and we were ready to run a test for grabbing the bottle, lifting it up, pouring liquid and bringing it back to its initial position.

For this, we used:

1.  a Lego motor that controls the gripper (grab)
2.  a Lego motor that lifts up/descends the arm
3.  a Lego motor that rotates the arm (pour)

and 2 Lego touch sensors:

1. to set the home position of the arm for the rotation
2. to signal that the bottle has been grabbed

Below, you can find a demo that illustrates the above mentioned steps:

Side note: for now, the pouring process is in "simulation mode" only :)

More stability, please

While testing the robot's movements, such as plain straight drive, rotations, brakes and arm lifting, we noticed that the robot had the tendency to balance back and forth.

As a solution to this instability problem, we attached a metallic piece to the backside of the iRobot device:

This turned out to be a tremendous help!