“I have seen several interesting projects of robots that paint or manufacture PCBs, etc,” explained Julio on his blog. “I was looking for something different.”
His daughter is a big fan of air hockey, so he decided to use his love for robotics to construct an ‘Air Hockey Robot’. To get started Julio decided to use basic RepRap 3D printer parts such as the NEMA17 Stepper Motors, Arduino Mega microcontroller boards, RAMPS, belts, bearings, rods, and printed pieces.
“The main advantage of using these parts, is that they are cheap and easily available,” said Julio.
Not only was the robot portion of the Air Hockey Robot build entirely by Julio, but also the entire air hockey table – using old PC fans to create the stream of air.
The robot has 2 motors running the Y-axis, and 1 running the X-axis. The software that runs the robot was created from scratch by Julio, after he determined that the Marlin software, which typically runs RepRap printers just wouldn’t get the job done. For the electronic eye that is located on air hockey paddle, Julio went with the PS3 EYE Cam, using OpenCV libraries for capturing, filtering, thresholding, and segmentation. The camera on the paddle detects a specifically colored puck, and sends it to the computer via serial port.
The computer systems detects the direction of where the puck is moving, using 2 consecutive frames from the camera, to determine the overall trajectory of the puck. The computer (as programmed by Julio) will then decide what type of move to make. Does it defend the goal, defend and attack, or just straight out attack?
So how good is this robot? Currently it could easily beat a child, but Julio said that an adult with some previous air hockey experience can still win. However, with a few small improvements to the code, he is sure that it could become extremely difficult to beat.
While the project seems very complicated, Julio is pretty insistent that it is not. He is not completely done with this project, as he still has a few additions that he would like to make.
“Currently the robot is not able to detect goals but we could improve this in future,” he explained. “In the future the robot can self-calibrating the camera using predefined movement at the beginning – to avoid the camera calibration.”
Julio is even considering building a dual robot table, where people put their robots up against someone else’s.
Discuss this robot, as well as the technical aspects that go into developing something like this at: https://3dprintboard.com/showthread.php?1685-Man-Creates-an-air-hockey-robot-using-3d-printer-parts
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