The FIRST® LEGO® League (FLL®) Challenge has 2 parts: the Robot Game and the Project. In the Robot Game, the kids build and program an autonomous LEGO® MINDSTORMS® robot to score points by performing mission tasks. These missions will be inspired by the Challenge theme, so you will see many concepts that may get your team thinking about this year’s topic.
Missions require the robot to navigate, and to capture, transport, activate, or deliver objects precisely on a printed mat on a special table. The robot has 21⁄2 minutes to complete as many mission tasks as possible.
The team and robot must follow a set of rules, which you will be able to download from the FLL website. For example: if team members touch the robot while it’s working, it must be stopped and carried to Base. At tournaments, a referee oversees the action to ensure that everyone is following the rules.
At tournaments, 2 half-tables are attached back to back to form a full competition table, so your team will participate opposite a team on the other side. You are not competing against that team. Rather, both teams will try to earn their own highest score. The robots are isolated from each other by table border walls, but there is always at least 1 mission that causes interaction between robots on adjacent tables.
Robot Game Preparation Before your team can start building and programming a robot, you will need to set up your materials and make sure you have all the Robot Game information. The information described below will be available in early fall when the Challenge is released. You will need a LEGO SPIKE PRIME set, or MINDSTORMS EV3 set and a Field Setup Kit to participate in the Robot Game. That is not all you need though! Before your team begins working on their robot, you should:
Download and print the Challenge document from the page of FLL Challenge & Resource. It contains the Project and 3 sections about the Robot Game: Field Setup, Missions, and Rules.
Build your FLL table. The FLL table holds the robot’s playing field. You have the option to build a complete table or only the top and borders. Simple but large, the table does require basic carpentry skills for construction. Instructions for building the table are in the Field Setup document as well as on the FLL website (Table building instructions)
Build your mission models. The mission models are the official objects the robot interacts with as part of the game. The instructions for building the mission models can be found on the page of FLL Challenge & Resource. You are freeto build these as soon as you receive your Field Setup Kit. Mission model construction takes a single person 3 to 6 hours, depending on experience. Many teams build the mission models together during their early season meetings.
Set up your field. You now have the table, the mat to put on it, and the models to put on that. The last thing to find is the bag of tan sheets of Dual Lock fastening material that came in the Field Setup Kit box. This material is used to secure some of the models to the mat. You are now ready to follow the FLL Challenge & Resourceto complete the setup of the playing field. Follow these instructions closely to be sure the field you practice on is identical to those found at tournaments.
Read the Missions. The Missions section (part of the Challenge document) describes what the mission models represent and how your team can earn points on the field in Robot Performance. The Missions section describes the condition that will earn you points – it is up to your team to decide how to make those conditions happen. For example, if you can earn 4 points for a mission model touching the mat, your team might design a robot that can knock it over onto the mat, place it on the mat gently, roll it onto the mat, etc. If the Missions and Rules do not forbid an idea, then it is allowed. Like the Rules (below), the Missions need to be read carefully and repeatedly throughout the season. A small detail that doesn’t mean anything to you in week 1 may turn out to be a big deal in week 4!
Read the Rules. The Rules section gives exact definitions for terms related to the game and to tournament play. They keep things fair and fun, and keep matches running smoothly. They also tell specifically how a match must be conducted, and place constraints on the robot’s parts, the team’s action, the robot’s action, and the scoring. You and any team member dealing with the robot are HIGHLY advised to read the Rules carefully and REPEATEDLY. Rules that may seem confusing or not applicable at the beginning of the season will mean more and more as you gain experience.
Robot Game Execution Once you have prepared by completing the steps above, your team is ready to begin working on a robot.
Strategize, build, and program your robot, and Have FUN!Plan, build, and program; test, repair, and reassess; repeat! Good coaching requires restraint here. As tempting as it is, don’t build the attachment or make the decision. Ask questions to get the team thinking so they can find the answers themselves.
Check the Robot Game Updates forcritical new information.The Robot GameUpdates are a running list of official responsesto missing, unclear, or incorrect informationabout the Robot Game. Updates postedhere SUPERSEDE text from the Challengedocument. There are also answers tofrequently asked questions, and official calls on whether or not certain strategies are allowed. Refer to the Robot Game Updates often and carefully. Find the Robot Game Updates on FLL Challenge & Resource.
Repeat the steps above until your objectives are met. Whether your goal is to complete 5 missions or to complete all of them, the process always involves many cycles of thinking, trying, failing, improving, and succeeding.
Prepare for a Tournament When your team attends a tournament, your robot will compete in 2 different areas: Robot Performance and Robot Design.
Robot Performance Unlike other areas of FLL, teams receive a numerical score during Robot Performance matches. The Robot Performance Award recognizes a team that scores the most points in the Robot Game. Your team’s score will be determined by the number of points the robot scores during scheduled matches.
Each match is separate and only the highest score will count. You do want to have a robot that can perform well consistently, but your team should not be discouraged if you have 1 bad match.
Robot Design During the tournament day, Robot Design judges will interview and observe your team. Some events require formal Robot Design presentations, while at other events the judges may simply ask your team questions. Either way, it is a good idea for your team to prepare a basic introduction to the robot in case the judges ask.
There may also be a competition table with mission models in the judging area. Your team should be prepared to demonstrate their solution to at least one of the missions and talk about their strategy. Review the information about your tournament carefully and contact the tournament organizer if you have any questions about what your team should expect.
If your team chooses to print a section of programming to leave with the judges, make sure they choose a section that is easy to follow but highlights some difficult problem they overcame. Print the programs in icon form (not text) to make them easier for the judges to review. When the judges choose teams to receive awards, this information will remind them about your team’s robot.
Learn more about how your team’s Robot Design elements will be judged by reviewing the awards and rubrics. Notice that among other criteria the rubrics encourage teams to:
Consider the importance of structural integrity and efficiency.
Find the right balance of robot speed, strength, and accuracy.
Use code that is modular, streamlined, and understandable by others.
Not rely on driver intervention to help the robot navigate.
Robot Design Executive Summary (RDES) To help the Robot Design Judges quickly and consistently learn about your robot and the design process used, we are requiring a short presentation. An “executive summary” is often used by engineers to briefly outline the key elements of a product or project. In other words, the purpose of the RDES is to give the Robot Design Judges an outline of your robot and all that it can do. The RDES is intended to help your team consider in advance the most important information to share with the Judges. What you chose to share will enable the Judges to effectively evaluate your team and provide more helpful feedback. Your team is free to determine how much time you invest, but realistically it should only take a few hours to develop and practice the RDES. The RDES is NOT intended to be as extensive or time consuming as your Project. Your team will present your RDES at the beginning of your Robot Design judging session. The entire presentation, including the trial run, should not take any longer than four (4) minutes. Following your Robot Design presentation the Judges will pose questions for your team to answer. You are not required to provide a written version of the RDES to leave with the Judges. Basic Outline: The RDES should include the following elements: Robot Facts, Design Details, and a short Trial Run.
Robot Facts: Share with the Judges a little bit about your robot, such as the number and type of sensors, drivetrain details, number of parts, and the number of attachments. The Judges would also like to know what programming language you used, the number of programs and the amount of memory used by each program, and your most consistently completed mission. Design Details:
Fun: Describe the most fun or interesting part of robot design as well as the most challenging parts. If your robot has a name, who chose the name and why. If your team has a fun story about your robot please feel free to share.
Strategy: Explain your team’s strategy and reasoning for choosing and accomplishing missions. Talk a little bit about how successful your robot was in completing the missions that you chose. Judges may like to hear about your favorite mission and why it is your favorite.
Design Process: Describe how your team designed your robot and what process you used to make improvements to your design over time. Briefly share how different team members contributed to the design and how you incorporated all the ideas.
Mechanical Design: Explain to the Judges your robot’s basic structure, how you make sure your robot is durable and how you made it easy to repair or add/remove attachments. Explain to the Judges how the robot moves (drivetrain), and what attachments and mechanisms it uses to operate or complete missions.
Programming: Describe how you programmed your robot to ensure consistent results. Explain how you organized and documented your programs, as well as, mention if your programs use sensors to know (and ensure) the location of the robot on the field.
Innovation: Describe any features of your robot design that you feel are special, different or especially clever.
Trial Run: Demonstrate the operation of your robot for the Judges performing the mission(s) of your choice. Please do not do an entire robot round; time will be needed for Judges to ask questions of your team.
Official Mindstorms EV3 Resources & Software Guide to FLL Programming Options – New this year! “You can use any software that allows the Robot to move autonomously – meaning it moves on its own. No form of remote control is allowed.” This guide is not from FIRST or LEGO, but it is a handy overview of some of the programming languages available from long-time, trusted FLL mentors. Please note that the robot must still move autonomously, venues will not have Wi-Fi access for teams, and the only programming language support provided by FIRST in Michigan and at events will be in the EV3-G (default from LEGO) language.
COACH RESOURCES FOR MINDSTORMS EV3
There are many LEGO MINDSTORMS EV3 materials available online. These have been evaluated to be useful for FLL coaches and teachers (and free!):
Build a basic robot and learn to program motor blocks and four sensors. Course starts with an excellent introduction to the pieces of the EV3. One comprehensive course to get a coach up to speed from no previous knowledge. Videos total 100 minutes.
Full curriculum for teaching robotics through the EV3, pulling together other outside resources.
COACH RESOURCES FOR SPIKE PRIME
STUDENT RESOURCES FOR MINDSTORMS EV3
STUDENT RESOURCES FOR SPIKE PRIME
9 Robot Game Tips
From FLL Engineer Scott Evans, NH, U.S.
Read the Challenge document carefully and repeatedly!!! Assign a “Documents Expert” or 2 on your team. True, lots of things these days are designed not to need directions, and many times even if something says “Read these directions before starting,” you can figure it out yourself, but... Be warned: The FLL Robot Game is not one of those things. Experience shows that teams who don’t read the documents repeatedly operate in a fog all season and learn things the hard way at tournaments. On the other hand, teams who know the details save lots of confusion and time, have fewer questions, higher success, and more fun.
Set manageable goals. When you’re first confronted with the Missions and they seem overwhelming, agree as a team on the 3 (or 1?) you think are the easiest, and pretend they are the whole Robot Game. Master those missions so your robot gets them every time. Congratulate yourselves. Now... if you did 3, you could probably do 4, right? Is there maybe 1 more you figure you can do? Master that 1 without affecting the others, and continue this process until you really do have a feeling for what’s possible.
Make your robot’s navigation depend on features of the field whenever possible. While it’s true that a robot can be programmed to do a lot using only odometry (counting how many times its motors have turned) and/or timing (counting how many seconds its motors have run), variability in friction and battery strength can throw these methods off track. Instead, learn to complement these methods with techniques and sensors that interact with the field (light, color, touch, and ultrasound). For example, a robot programmed to drive forward 3 rotations and then turn for 2 seconds might go to the right spot and make a 90o turn when you program it, but later, when started from a different place, maybe with low battery strength, it will definitely end up in a different spot on a different angle. But if you program it to drive until it sees a line, then you make it back up against the wall after the turn, it will always end up on the correct spot, at 90o.
Don’t try to program more than 1 step at a time. Every mission strategy will be a sequence of steps. The robot has to get to a place and do a task, then get to the next place and do the next task, etc. Make sure it can get to and do each task consistently before trying to program for the next. If you program several actions and test them all at once, you’ll find yourself fighting confusion, backtracking, and repeating your work.
Build things strong enough that the robot can be knocked over in any direction and not break. Make the robot as compact as you can, because large parts make the robot unstable, tough to drive in narrow areas, and act like levers in their own destruction. Make “redundant” (extra) reinforcements when possible. Use gray (loose) pins instead of black (friction) pins when possible – believe it or not, they are LESS likely to separate.
While building, keep access to essential features in mind. It seems like a bother, but it’s wise to keep all cables attached to your EV3 or NXT brick (the “brain” of your robot) while building. If you don’t, you’re likely to end up re-doing things when you discover cables don’t reach or they interfere with attachments. Also, constantly confirm that you can see the display, access the buttons, and get the batteries out without too much hassle.
Build a shroud around your optical (color and light) sensors. A change in ambient (surrounding) light can mess up your optical (color and light) sensor programs. While it is possible to calibrate them, it is even better to avoid the need. Try to build your optical sensors into the center of the robot’s shadow, or make a light shield around them.
For consistency in turning, build sliders/casters as close to the drive wheels as you can without giving away stability. The farther away their contact with the mat is from the drive wheels, the harder the robot will be to turn. To understand this concept, pick up a broom and sweep the floor next to your feet. Now try to sweep a spot far away from your feet.
Don’t try to work for much more than 90 minutes at a time, and be sure to call it a day if you’ve spent more than 30 minutes frustrated and stuck. Your brain will actually work on the problem overnight, and while you’re doing other things. When you come back to the problem, very often you’ll figure it out quickly.