Basic robot functions

This year, WildStang designed a robot that can do a variety of tasks. It can function in autonomous mode, hold 2 2X balls, grab a mobile goal, climb the platform, and hang from the horizontal bar.

Autonomous Mode

One of the important tasks was to be a mobile robot during the autonomous mode. Since we decided that our robot had to have control over the 2X balls during a match, one of the things our robot does during the autonomous mode is to take control of the 2X ball before the other robot does. So during the autonomous mode, the robot would drive to each 2X ball and keep it for later use. Another thing our robot had to do during the autonomous mode was to trigger the release of the small balls in the container above the player's station. The robot has to drive to the yellow ball and knock it off of the pedestal to trigger the balls to fall. WildStang felt, that for this year, if our robot can accomplish either of those two things during a match, then we had a good chance of winning.

Robot movement

WildStang built the robot's drive system this year based on the successes and challenges of last year's drive system. Our crab drive was very useful in that it turned in 90 degree angles, while facing in the same direction, and made our robot one of the most agile on the field, so we decided to keep them in the robot. The difference this year is that we replaced the rear two crab modules with "bupod" modules. In order to change which way the robot is facing, we needed to use something that would allow us to turn radially. The "bupod" (Biased UniPlanar OmniDirectional) modules, a.k.a. "omni-wheels," are mechanically less complex, and lower in weight than 4 crab modules with a skid plate for turning 90 degrees. They also would work well on this year's playing field surface. If we decided to do this, we will not only be able to move like last years robot, but we will also be able to turn radially quite well.

Drive Carriage System

This year, the field was made with different elevations, and unlike last year, there is no ramp to get onto the different elevations on the field. So we designed a system in which the robot's drive system is divided into two parts, and each one, the front and the back, can move up and down independently of each other. This means that the robot can move towards the elevated platform, lower both its drive carriages (thus raising the entire robot), then raise the front carriage, move forward, lift the other carriage, and without much effort, it would be on the platform. There is also a set of 4 sensors for each carriage, two outer and two inner, so that this movement may be done automatically. The driver only needs to move the robot forward and the drive carriages are raised and lowered automatically. Click here to download a video (also in video section) which demonstrates this system.

Robot Frame Structure

The robot this year is made mostly of formed aluminum sheet metal and aluminum extrusions and tubing. The robot is 35.5” X 29.5” X 57” This year the robot is tall because it needs to be able to access the top of the scoring bins, and also it needs to be able to reach the elevated bar on which it will hang. The robot has low ground clearance so it does not ride up on the small balls. It also has "outriggers" or "bumpers" on the front and back of the robot that are pnuematically activated for stability in climbing the platform.

Attachments

WildStang's robot has 3 main attachments. It has two arms on either side of the robot, one small arm and one big arm. The big arm is used to pick up the 2X ball from the floor, and has an "accumulator", which rotates to secure the 2X ball in the big arm. This arm can extend out to cap a stationary goal and fold back in. The small arm has the ability to pick up the 2X ball from the mobile goal, and transfer it to the other arm for capping. Its ends hold round pans, which help grip a 2X ball, or rotate against its surface to push it out of a goal. These two arms will help us keep control of the 2X balls. The 3rd main attachment is the winch. The winch has the ability to lift our robot above the ground using the elevated bar as an anchor.

Motors

• 2 Drill motors - 2 crab drives
• 1 globe motor - angular position of crab modules.
• 2 Chiaphuas - 2 "bupod" wheels.
• 1 seat motor - accumulator
• 2 fisher price motors - big arm (shoulder) and winch
• 2 window motors - left and right elbow of big arm
• 1 van door - small arm