Coin Sorter

This was our final project. The objective was to design and construct a coin sorter. Here are the requirements and restrictions.

1. This new device should be capable of holding and automatically sorting 100 US coins in less than 2 minutes.

2. The energy source of the device can be very flexible and may include gravity, coil springs, small DC motors with battery, wound springs, or similar devices, as well as manual cranking. A combination of some or all of these items can also be used as the power source.

3.The device should be small in size (should fit in a 15’x15’x15’ box), portable, easy to operate, easy to manufacture in mass quantities, and safe.

4. The total budget given to your design team for the prototype is less than or equal to $15.

We used a system of four boxes and used gravity and hand cranking as our power sources. Here are a few pictures of our design.








Our design worked very well. We only missed 2 coins which gave us 98% accuracy and we did it in 34 seconds, the fastest out of any other group.

Automated Guided Vehicles

Our fourth project was to build and program an automated guided vehicle. Here are the requirements and restrictions:

1. Design a Lego Robot to safely transport, without damage, 2 ping-pong balls and a golf-ball from the top of a platform to a box separated by a given distance d.

2. The outside dimensions of the flat platform are L30xW10 cm and it is constructed from 1/4² grade plywood. The balls initially rest in three 1cm. diameter holes that are 5 cm apart on the platform. The outside dimensions of the disposal box where the ping-pong balls need to be transported into are approximately L35xW18xH18 cm.

4. The Lego Robot must fit within the 20x20x20 cm box.

5. The design objective is to pick up and deliver the balls within the shortest amount of time. Your robot should follow a 2 cm wide black line on the white laminate floor going from the center of the platform to the center of the disposal box. The line will NOT be a straight and will contain 4 T-junctions, two leading to wrong direction and two leading back to finishing platform. Your robot should not get confused about the line while navigating over these junctions. In addition, there will be two extra challenges. First one is a semi-cylindrical bump with L20xW10xH5 cm dimensions located somewhere along the path, and your robot must navigate over it. The second one is a wooden block with L35xw18xH18 cm dimensions located somewhere along the path, and your robot needs to navigate around it. The exact location of these obstacles will not be given until the project demonstration time.

6. Initially, your robot should not be in contact with the pig-pong and golf balls, you can start at any position on or around the flat finishing platform.

7. Once the robot is positioned and in place in front of the platform, a start signal will be given and the robot must deliver the balls from the platform to the box within 3 minutes. The transport time will be measured from the start signal to when the last ball is dropped to the box. Once the robot is started, no external communication, interaction, or influence of any kind is allowed - the robot must be completely autonomous.

8. The projects will be ranked according to their travel time (shortest time will take the first place). The performance scores will be assigned will be proportional to travel time. In addition, below penalty scores will be assessed if you fail one of the objectives.
- Failing to deliver a ping-pong ball, 15 pts each
- Failing to deliver the golf-ball, 20 pts
- Failing to go over the bump, 10 pt
- Failing to navigate around the obstacle, 15 pts.

This project was very difficult. It challenged us to the max. Again our first objective was to design a robot that could pick up two ping pong balls and a golf ball all at once. Our robot could have easily gone across the bump. It had a motion sensor in place to detect an obstacle, but we did not know how to distinguish from the box and an obstacle so we decided to develop two different programs to avoid the obstacle altogether.





Here is Brandon Hahn fixing our robot in frustration after it broke apart while adding more pieces to it.



While programming our robot we came across many problems. We had a tough time mounting our motor to pick up the balls but finally we found away to do so. Our next task was to get it to follow the black lines. This was very tricky. We tried using the program from the cd program but for some reason it would not work with our robot. So we were unable to get our robot to follow the black line. Here is our final robot.



After we built our robot and knew that we were unable to follow the black line, we set out to obtain the most points possible. We were going to go straight to the delivery box and deliver all three boxes. There lied a problem though, our motors were not callibrated correctly and our robot could not even make a straight line. So we abandoned that idea and did the best we could.

We ended up being able to pick up all three balls and follow the black line for a little bit but this project ended up being more than we could handle.

Sumo Wrestling Lego Robot

Our third project was to build a robot out of Legos that could push or manuever another robot of the same standards our of a sumo wrestling circle. Here are the requirements and restrictions:

1. The robots must fit within 8×8” square in the starting position, but may expand automatically to any size once the contest begins.

2. The height of the robot is unlimited.

3. The robots must weigh no more than 4.0 lb. You are not allowed to use anything other than the standard kit issued to you in terms of main components (Yellow RCX Lego Brick, 3 motors, 2 touch sensors, 2 light sensors, 1 rotational sensor). However, there are no restrictions in terms of small Lego pieces as long as they are components from Lego MindStorm set.

4. Gluing, taping, wrapping with rubber band, or similar fastening methods are strictly forbidden!

5. Autonomous robots must contain all the necessary intelligence within its structure. No interference may be provided from outside the ring. Robots may be turned on by hand at the beginning of the match, and then must be left to their own devices. No touching, adjusting, repairing, reorienting, etc. of the robots will be allowed once the start button is pressed.

Our first main goal was to develop a robot that could withstand a big hit. We figured that the programming would be the easy part and that constucting a stable robot would be the most difficult part. We were quite wrong. We began programming and it was much more difficult than expected. Finally we created a program that told the robot to go straight until it hit a black line and then go in reverse until it hit another black line. Then it would turn at an angle while going straight again. In doing this our robot would cover then entire circle.

After programming our robot to maneuver around the circle, we decided to develop somewhat of a weapon. We built the black rotating device in hopes it would remove someones wires or lock onto someone's robot and break some pieces off. In reality this last minute addition saved our robot from being defeated in early. It locked on to another robot and just spun in circles.

Here is our final robot which ended up finishing in the final four with 5 teams left.








In competiton, our robot mainly lacked power. We should have made our robot a little slower in order to add some torque and power which may have enabled us to push robots out of the circle a little easier.

Project 2 Results

Our bridge was very sturdy but we missed calculated the dryness of the glue and how long it would take to dry. That factor led to our downfall. We figured the glue was not as dry as it could have been. It held the minimum weight and quite a bit of weight after that but eventually it gave into the pressure.