Designing the Robot The first step in this multi-week project was to design the robot and make the critical initial decisions that would govern the implementation period. These decisions dealt with things as abstract as the strategy used to get robots to cooperate, to issues as specific as gear and wheel choices. Many of these ideas would have to ultimately be changed later on, but it was important to concretize as much as possible from the beginning to accomodate for the tight schedule.

Tools The tools our teams employed were made up of a combination of purchased hardware (such as solenoids and relays), lego bulding blocks provided by USC, and the "brain" of the robots known as the handyboards. The legos provided relative sturdiness and great flexibility in designing the robotcs and proved to be sufficient for most of the structural requirements. However,we also used incompatible pieces such as omni-directional wheels which proved to be difficult to accomodate for in the overall lego architecture.

In Depth: The Handyboard As stated before, the handyboard constituded the CPU, or brain, of the robots. Each team was allowed to use two, one for each robot on the team. Handyboards are brogrammed in C and allow for a good deal of programming flexibility (as opposed to more primitive alternative such as PBasic employed by the Basic Stamp). On of the key benefits of the Handyboard is its ability to run multithreaded programs and thus allowed the students to employ parallelism in their Behavior-Based, Reactive, and Hybrid architectures. This point alone proved to be a key issue during the testing process. However, the handyboard also posed several limitations that helped students prepare for real world obstacles. The main one of these was power consumption. Students were expected to be able to manage their power and be able to use it wisely throughout the competition.

Implementation Once planning had been completing the implementation period could begin. Students soon found that the majority of their time would not be spent creating their designs, but instead tweaking them and debugging them. On of the most important issues in this competition proved to be performance tuning: adjusting for light conditions, changing coefficients in feedback controls, etc. The main algorithms employed may have been similar accross the board, but it was the best tweaked robots that did the best, for a single number could make the difference between brilliant performance and complete failure. Our particular team chose a bahavior-based model to implement the strategy into our robot. As stated earlier, the handy board was prime for this as it allowed for multithreading which is essential for true parallelism. This means that our different "behaviors" could run simutlaneously, as opposed to forcing the design into a linear structure. This allowed us to remove much of the code bloat and focus on the true outline of our design, instead of worrying about particular coding issues. Below is our goalie code, which serves as a good example of this. As you can see, there is not much code, but it works astoundingly well, and is incredibly easy to read. By going to the main function you can see early on that there are two main behaviors: moving left and right, and following the ball if it is seen. Both of these feed into the central "actuators" behavior which aggregates what the different behaviors want to do into one specific signal to the wheels and other components. With just this, both behaviors cooperate very well and both do their job very well. Also, this allowed us to centralize the power consumption code. If you look closely, you will see that the same ball follwoing behavior also makes sure that the kicker only activates when the ball is within range, assuring we don't waste power when there is nothing to do.

Team Spotlight

Team Awesome utilized inventive arangements of available technology to make the most capable robot on the field this year. However, due to a series of unfortunate events during matches that made their mechanisms malfunction, they were beaten 4-6 by Pistols at Dawn in the Semi-Final round.

By Patricia Choa and Colby Drake