De Ruyter & De Witt
For our fourth year competing in the FIRST Robotics Competition, we were able to build 2 of the same robots, thanks to our partners. We named the robots "De Ruyter" & "De Witt". De Ruyter is named after a Dutch Admiral "Michiel de Ruyter". Who lived in the same period as Rembrandt van Rijn and because this year's game is FIRST STRONGHOLD. It fits very well with our robot. De Witt was a good friend of Michiel de Ruyter, so it is was fitting to name the second robot after him. With the "De Ruyter", we went for the FIRST time in our history to 2 regionals. New York City Regional in New York was our FIRST regional. After that, we went to the New York Tech Valley Regional in Troy. With the "De Ruyter", we won the Creativity Award sponsored by Xerox at the New York City Regional and the Imagery Award in honor of Jack Kamen at the New York Tech Valley Regional. We were very grateful for getting these awards. This year we hadn't qualified ourselves for the FIRST Championship 2016 in St. Louis.
For our robots De Ruyter & De Witt we chose to build a high robot and not go for the low bar defense. Our focus was to build a robot for shooting boulders into the high goal of the towers. Next to that, we want to be able to defeat as many defenses. Also, we want to make the vision part more important. So, we want to make the robot aim and shoot autonomously.
To be able to get a boulder into the high goal we had chosen to build a shooter. To be as flexible as possible we made a shooter that can move 180 degrees horizontal and 25 degrees vertical for accurate aiming with vision. With absolute encoders which track the angle of the shooter and vision, we could easily make the shooter move to the perfect position to shoot into the tower. Through a flywheel that gives speed to the boulder, we can shoot the boulders into the high goal. During the competitions, we found out that getting your vision accurate is very difficult because of the lights the regionals use to light up the field.
Also this year we wanted to create some kind of modular electro box. Because of the design of our robot, we decided to build an electroplate and a rotating plate for easy access to the 3 Talon SRX and 9 Victor SP motor controllers. Furthermore, we place the RoboRIO with a Navx board on the electroplate. The Navx board we use for determining the position of the robot was very important during autonomous. Also, we used pneumatics for controlling the intake arm and shifting the shifter gearboxes.
To get the builder into the shooter we needed a transport system. We used elastic bands for transporting boulders from the intake arm into the shooter. With the help of end switches, we can detect when a boulder is inside the robot and store the boulder in the transport system till the robot is in position and ready to shoot. On the sides of the transport system, we place our air tanks so that we didn't need a compressor on the robot.
After the success with sheet metal drivetrain in 2015, we once again design and build our own custom drivetrain. This time we chose to use 6 pneumatic wheels on the drivetrain for easy defense clearing and stability. We powered them with 2 dual CIM ball-shifter gearboxes for efficient driving. Thanks to the ball-shifter gearbox we could easily switch so we could get more torque or more speed. Further, we used 2 encoders of 256 steps on each side for location tracking during autonomous. After the season and the many events around the world, we noticed that the bottom plate of the drivetrain was very damaged by all the defenses. So, we learned that with this kind of game you have to make sure that the bottom of the drivetrain is strong enough to endure the obstacles of the game.
To take the boulders inside the robot we used the same elastic bands as we also use in the transport system. We used the intake arm also to help with breaching the defenses. So, we used a lower bar for the cheval de frise and lifting boulders. We placed 2 wheels on the sides of the intake arm for lifting the portcullis. With pneumatics, we lift the intake arm and protect it from bumping against other robots.