Can Can Challenge - the Challenge!

On 16th august 2011, Me, Jonathan and Daniel was full of tense, as we step up to the final testing. We ran into some mishaps, as shown in this video here.Luckily, we managed to fix some of these problems by changing the batteries in the robot and adjusting the program. We managed to get 22 cans in 2 minutes and got first! Though that was a very good effort, we still think hat the arm could be improved. For instance, maybe if we have an actual hand made of rubber, rather than 2 fingers, maybe the can will not slip off the hand occasionally. If possible, we could try to get better materials to use for the arm, so that the arm will not whip around occasionally.

Can Can Challenge - testing

Hooray, the arm worked! :D Not as we entirely expected it to work, but it worked never the less. We might have to change the program so that the arm goes behind the robot with the can.

Can Can challenge - programming

Johnathan has finished the set of commands for the robot to follow during the challenge. These set commands make the robot move forward, grab the can, and move back. When the button is pressed, the robot will move a certain distance for 1.5 seconds, and then the arm will rotate from the back of the robot towards the can, stop and then move again, grabbing the can, towards the back of the robot and the robot will move backwards towards the starting line, bringing the can with it.

Can Can challenge - base fabrication

Daniel and Tan You started fabricating the base of the arm. We took the base design in the ItoE notes and extended the length of it and stated making the base. We also fillet one end of the base for the arm to go through when the arm swing behind the robot.

Can Can challenge - Arm fabrication 2

With a new design of the arm, we went to fabricate it. It was then we found out that the workshop had wires, and can be used. The wires, though flimsy, are strong and light. So Jonathan suggested we use wires instead of sheet metal will holes punched through. So, our arm design has changed from sheet metal to 2 wires bundled together.

Can Can Challenge - Arm fabrication 1.5

We figured that one finger for the arm to grab the can wouldn't be enough, so we think that having to fingers, one near the top of the can and the other at the bottom, would be better for the arm to grab the can.

Can Can challenge - Arm fabrication

Jonathan has finished the autocad drawing of the arm. Me, Tan You, Didn't realize what is wrong with the drawing, but Daniel did. However, it was only when the drawing was printed then we realize that the arm was too big. So unfortunately, Jonathan had to do the arm all over again.

Can Can Challenge - Arm Design 3

We decided to use the rotating grabber arm for our robot. Simply because it is easier to program the robot to go back and forth rather than rotating and reversing at the same time.

Steps to how the robot will grab the can and brig it back.

1)The robot, at the starting line with the arm fully extended, will move till the arm is inline with the can.

2)The arm, attached to a servo motor, will rotate and grab the can.

3)The arm will rotate all the way to behind the robot while the robot goes backwards. towards the starting line. The robot arm will keep the can in place while the robot pushes the can back.

4)The moment the can goes past the starting line, we grab the can and the robot moves forward while the arm swigs back to the front.

5)steps 1-4 are repeated till the 2 mins is up.

Can Can challenge - Arm Design 2

We found out that when the arm is fully extended, a few centimeters will be able to reach over the other end of the line to grab the can when the robot is in-between the can line and the starting line. This led us to wonder if a fixed arm with a large hand attached to a rotating robot might be the quickest method to grab a many cans as we can. However, we discovered that the diameter of the can is just slightly too big that the robot have to go in a little further to grab the can. We thought of the robot moving in a diamond shape, but we couldn't guarantee that the robot will be in the same position all the time. So it was back the drawing board.

Can Can Challenge - Arm Design

Our Group today brainstormed on the various designs on what sort of arm can be used to grab the can from one end and transport it to the other end. Designs included the commonly used pincer, a rotating grabber arm, a fishing hook style arm, a crossbow style arm and a spatula style arm. A lot of ideas were thrown out of the window almost immediately because they were either to difficult to make, too impractical or it is obvious it wouldn't work. For example, the spatula arm wouldn't work as we cannot be sure whether the can will be flung back to the starting line and whether the can will even be flung in the first place. The fishing arm might work, but only if we are very precise with our programming, which probably won't happen. A crossbow arm is definitely out of the question, as it is very difficult to make. In the end, we had two left: the pincer and the rotating grabber arm, which are very simple to make and easy to program to grab the can.