This project is done by a team of five. I will be talking about my main part in this project.
- Reorientation/Separation Design
The main challenges of the project includes separation of the tangled up hinges and reorientation of this hinges so that they can be outputed in a steady stream line of same orientation for robots to pick up.
Initially, I came up with a “pick up” system where the hinges would drop along a ramp as shown below in order to be reoriented. A conveyor belt will be running below the dropping point to carry the reoriented hinge to destination:
The success rate was below 50% because the hinges would fall out of the track so this method was not ideal. HOWEVER, this testing lead me to discover a pattern of falling of the hinges – when hinges fall from height, it “always” lands with three orientations – face up (desired final position), tent (shown below), and face down (orthogonal position to face up ) .This is because of the center of gravity of the part due to its geometry. With this discovery, went ahead and tested my theory in simulation (and physically by actually dropping it over 200 times). See animation below:
This discovery set the tone of the following designs my team and I did. We eventually realized that gravity not only could help us achieve initial position sorting, but also acts as “de-tangling” force. Therefore we designed two “dropping waterfall” with conveyor belts of varying speeds to separate and roughly sort hinge position. Final result can be seen below (pardon the poor quality, initial part and the noise in the background..)
- Motor Driven Roller (MDR) + Arduino
I installed IR sensors at the end of each conveyor belt. The algorithm basically goes like this: once the “separation” conveyor belt (2nd) sensed a whole belt-full of hinges, the 1st feeding conveyor belt stops. 2nd belt then start to feed into the “initial reorientation” (3rd) conveyor belt for position sorting. Once the 2nd belt clears up, 1st belt will restart and this whole process keeps going.
** To request more information about the whole system, please contact me for more details.