In this project, teams of two robots each will compete in an Egg Hunt tournament.
Batteries Computer Etiquette Design Notebooks Egg Hunt Robot Testing Egg Hunt Team Strategies Group Structure and Dynamics Laboratory Etiquette "Secret" Strategies
Case Study in Real-World Project Management--The Apollo Space Program
Case Studies in Real-World Debugging--John Glenn, Test Pilot
The Egg Hunt will occur in an octagonal arena with "nests" at either end (Figure 1). (This is the arena we have been using in Olin 803.) The walls of the arena will be 12 inches high and painted flat black. The floor of the arena will be grey indoor-outdoor carpet, laid down over the carpeting already at the contest site. Each nest will be 3 feet wide by 2 feet deep and will be painted flat white. The nests have their own flat white floors to distinguish them from the arena carpeting. Across the entrance to each nest will be a metal strip (also painted flat white) that will be high enough to prevent eggs from rolling out of the nest on their own, but which should not impede the free passage of robots. At the back of each nest will be a polarized incandescent light. The light in one nest will be vertically-polarized and the other will be horizontally-polarized. You will be supplied with polarizing filters for the light sensors on your robot. You will find it necessary to utilize a robust scheme that is as insensitive as possible to changes in the ambient light. At the beginning of each round, each team will be assigned a polarization direction (and therefore a home nest). Thus, you should design your robot so that it can easily be switched from a horizontally-polarized to a vertically-polarized home nest and vice versa.
The arena will contain 40 pastel-colored eggs and 10 flat-black eggs randomly scattered throughout. These colors are chosen to simplify detection using the available light sensors. The object of the competition is for each team to gather as many pastel eggs as possible in its nest, while avoiding gathering black eggs. The winner of a round is the team with the higher score. In scoring, pastel eggs are worth +1 point, while black eggs are worth -4 points. The ratio of pastel/black eggs and their respective point values are deliberately chosen such that a completely random egg collection strategy results in a zero score. That is, if you gather all 50 eggs, your score is 40 + (-4 x 10) = 0.
Robots will work in teams of two. We will choose the teams to create what we deem is the best balance. Since your team will be scored on the final contents of its home nest only, many different strategies are possible. The simplest possibility is for both robots on a team to try to gather as many pastel eggs as possible. However, various specializations are also possible. For example, one robot can try to gather eggs for the home nest while the other tries to steal eggs from the opponent's nest. Another possibility is for one robot to guard the home nest while the other robot forages for eggs. Or one robot can try to prevent a robot on the other team from gathering eggs (but be sure not to mistake your teammate for an opponent!). Recall our policy that you are financially responsible for any damage you cause to the controller boards or LEGOs before you consider too aggressive a strategy! In addition, since black eggs actually deduct points, it might be worthwhile to attempt to deposit them in the opponent's nest. There are also many different strategies for transporting eggs, from carrying them one at a time in a simple manipulator to carrying a set of them in an internal storage area to "shooting" them toward the nest from a distance.
"Cloned" robots are forbidden. Each group must design, build, and debug its own unique robot. Teams are expressly prohibited to build two identical robots, whether the design is recycled from an existing mid-semester robot or is novel. While cloning a good robot design improves Egg Hunt performance, past experience has shown that this strategy is destructive to group dynamics. The group whose robot wasn't the basis for the clone design have nothing to do but build; they have no intellectual investment in the design. Design notebooks from such groups have been quite poor. Since your course grade depends largely upon your design notebook and not at all upon your team's Egg Hunt performance, we have thought it best to forbid cloning, and thus keep every group fully motivated and involved.
Each round will last for 10 minutes. At the start of each hunt, each team of robots will be placed side by side in front of its home nest. You should detect stalled motors and respond accordingly, because you will not be allowed to touch your robot once a round has begun. We reserve the right to free stuck robots as we deem necessary to keep the contest interesting and to avoid damage to the ($300) controller boards. Of course, we will not interfere with any strategy whereby one robot is actively preventing another from making progress, as long as there is no immediate danger to the controller boards.
In the event of a tie, a 3-minute sudden death playoff will be held. All robots will be reset to their starting positions. The first team to get a pastel-colored egg into its home nest, or a black egg into its opponent's nest, will win. If there is no winner after 3 minutes, a coin toss will decide the round, with a representative of the team with nest A making the call of heads or tails.
Regularly-scheduled extra sessions will be offered by the staff. Times and dates will be announced as these become available. Check your E-mail and the course webpage for the latest updates. You are encouraged to take advantage of as many of them as your schedules permit. Remember, however, that the extra sessions are simply that, extra. They are not intended as a substitute for work during regular class sessions. Last-minute pleas for extra time by groups with poor attendance at regular class sessions will be met with no sympathy whatsoever.
Teams will be assigned at the first class after the Mid-Semester Break. You and your teammates have the next two class periods to work out your team strategies and overall robot designs. By the end of the second class, this process should be complete. We will meet with each team (in private) to discuss your plans, and examine your design notebooks (which must contain a record of your team's design discussions).
To provide some structure to this meeting, every team must prepare a written document describing the proposal. Here's the format:
Imagine that you have to present a research proposal to a granting agency. You must have some Specific Aims (what your team strategy is, what each robot's strategy is, how you're going to detect eggs and nests, etc.). You must have some Preliminary Results (derived from the previous course exercises) which demonstrate that what you're proposing is feasible (e.g., working prototypes of egg discriminators, polarized light sensors, geartrains, and any novel or special mechanical apparatus). You must have a reasonable Timetable of prioritized tasks that must be accomplished. This should be summarized in a brief, neat document which we can look at while you're selling us on your design. Your design notebooks must document your thought processes. We must be convinced that what you are proposing is doable in order for us to approve it.
If we do not approve a team's proposal (due to over-grandiosity, impracticality, or lack of progress), we reserve the right to make such suggestions and changes as we see fit, in order to give the team a reasonable chance of fielding competitive robots. We do not expect to be placed in this situation.
The Project Proposal is not a contract, and can be changed as circumstances warrant. However, you are expected to refer back to it regularly and comment upon its advantages or emergent shortcomings, if any. A significant part of your second-half design notebook should be devoted to issues arising from the Project Proposal. (See the Rubric Matrix Grading Policy document for details.) The Project Proposal should be used as a planning tool, not a write-and-throw-away exercise.
By the time of the first Final Robot Testing session, we expect that every robot will be complete and in competition-ready form. These sessions are intended as dress rehearsals under actual contest conditions. The object is to run round after round of mock competitions involving 4 robots, in order to get out the final bugs and kinks. Rigorous field testing of completed designs is the only way to insure successful robots at the Egg Hunt. Members of groups which do not field credible, functional, contest-ready robots on the first Final Robot Testing session will have the Group Dynamics component of their final course grades lowered by one letter grade. We're serious about field testing.
By default, individual robots are the sole property of the individual groups responsible for them. Appropriate consent must be obtained from the owners before any changes are made to code or mechanical design. Within a group, this means that the three group members must agree upon the changes to be made (or at least authorize someone to make changes, whatever they may be, as necessary). Within an Egg Hunt team, this means that the robot of one group cannot be touched by members of the other group without the first group's expressed and explicit consent. If one group is floundering (from the other group's perspective), they have the right to flounder, even to fail spectacularly at the Egg Hunt; the other group cannot directly interfere without consent. Failure to obtain necessary consent for modifications (within a group or team) will lower a student's grade (whatever it would have been otherwise) by one full letter grade.
In addition, graduate students are required to write a major paper describing the design and performance of their group's contest robot (the robot that the student actually worked on himself/herself). This paper comprises 30% of the graduate student grade. Detailed requirements for this paper are presented in a separate document. Both the paper and graduate design notebooks are due at the on the Final Due Date.
As a guide for both students and staff, we here make explicit some possible sticky points about what is allowed for LEGO constructions. Violations render the transgressor subject to disqualification and forfeiture if discovered during the Egg Hunt. The instructors are the final arbiters of whether or not something is allowable.
Extra sensors (lever switches, pushbutton switches, photoresistors, phototransistors, breakbeam sensors) and lamps, in addition to those in the standard kit, can be handed out for use on an as-available basis. For many items, there is a small extra stock already assembled, as well as a larger unassembled stock which can be assembled by request. The staff reserve the right to limit quantities if requests are deemed unreasonable.
No extra LEGO parts will be dispensed, even if there is a large stock supply. Don't even ask.
It is permissible for teammates to share components among themselves (e.g., to build one really big robot, leaving one really little robot). The consenting parties are responsible for the resulting inventory headaches at the end of the semester :-)
Tape is forbidden for structural purposes, except for the mounting of sensors which do not have a pre-fab LEGO element. Permitted examples: lamps, LEDs, phototransistors, photoresistors, breakbeam sensors, and non-standard switches; also, for mounting non-LEGO sensor shielding materials. Devious attempts to use sensor tape as illegal structural support will be condemned without mercy. Tape cannot be used to build nets, snares, flypaper, or obstacles to block the opponents' nest beacon.
String is subject to the same prohibitions as tape. String may be used in pulley arrangements (e.g., to pull open a gate or door).
Hot glue, Super Glue, epoxy, etc., are subject to the same prohibitions as tape and string.
The following materials can be freely provided for sensor shielding: white and black cardboard, black electrical tape, white paper, and aluminum foil.
Any debris purposefully dumped into the arena must be composed entirely of LEGOs; it may not include tape, string, glue, cardboard, aluminum foil, etc.
No batteries or motors in addition to those provided in your LEGO kit may be used, even if you want to buy enough for everyone.
The grey LEGO battery pack (4.5 V) may be used to power lamps and motors; appropriate adapter cables can be assembled upon request. The second motor battery pack included in each kit cannot be used in this manner. The grey LEGO battery pack may be switched on manually at the start of a round, but cannot be touched subsequently. If you wish to control its switching on and off, you will have to build appropriate LEGO mechanisms and use the computer board to control them.
No use of lubricants (oil, grease, Vaseline, WD40) is permitted.
Black LEGO rubber bands can be used in any way you like (including structural support). Breakage will not be viewed charitably, however. No non-LEGO rubber bands are permitted.
LEGO and non-LEGO mascots, signs, flags, and other ornaments are permitted, so long as they are not being used in devious attempts to circumvent the above rules.
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