Main Page
|
Course Admin
|
Course Resources
|
Rules & Regulations
|
Team Profiles
|
Photo Gallery
|
Contact Info
 
  You are here: RoboFlag Main Page > Rules & Regulations


  Contest Rules

The following list of rules and regulations is intended to ensure that all robots compete on a level playing field (haha), and that the robots are compliant enough to play with each other. All robots that compete in the final competition must observe the rules and regulations or be subject to scoring penalties and/or disqualification.

In all matters of interpreting these rules before and during the contest and in any issues not covered by these rules, the decisions of the official project coordinator (William Sitch) will be final. These rules were based on previous competitions coordinated by Prof. John Knight and the Trinity College Fire Fighting competition.

The RoboFlag rules and regulations - which will be dynamic for a while to allow competitors to point out loopholes (point them out to me!) - were last updated on Oct. 23, 2001 and are as follows:

  1. Contest Objective
  2. The Playing Field (Arena)
  3. Ambient Lighting
  4. Robot Operation
  5. Robot Size, Weight & Materials
  6. Sensors
  7. Electricity
  8. Cables
  9. Robot Identification and Marking
  10. Infrared Robot Beacons and Detectors
  11. Flags, Visible Flag Beacons, and Detectors
  12. Grabber Specifications
  13. Legal Contact Guidelines
  14. RF Communication Guidelines
  15. Running Order
  16. Scoring
  17. Types of Games
  18. Penalties
  19. Safety
  20. Interpreting the Rules
  21. Updated Rules and Regulations
  22. Location and Dates



1. Contest Objective

The objective of each team is to build one autonomous mobile robot that can play a game of capture the flag. The robot must be able to identify both flags, detect other robots, communicate with friendly robots, move the flag, detect arena zones, and exhibit aggressive movement algorithms. All robots must adhere to the rules and regulations laid out in this document.

The game of capture the flag is meant to foster an environment of challenging competition. The game will promote situations that require a complex set of strategies to complete, including complex navigation, beacon detection, object manipulation and a fair bit of aggression. The final goal of the project is to merge the six teams into three groups (with two robots per group), requiring cooperation and communication between a pair of robots.

Note that the main thrust of the course is to develop a single robot that will compete with another robot (from the other team in your group) against a pair of robots from a different group. You will be judged on how well your robot can play the game.



2. The Playing Field (Arena)

There is no official floor plan for the RoboFlag event - robots will play in an arena that can be customized for each game. At the request of the competitors, robots will be allowed to wander around before the match begins in order to map the arena. A 5-minute time limit will be placed on the mapping attempt.

The arena will be rectangular in shape and will measure approximately 16'x8'. 12" high matte black (non-reflective) walls will be used throughout the arena. Any seams in the arena floor will not be taped over, so robots must be able to handle both a height and width discontinuity of up to 1/8". All attempts will be made to ensure the floor is flat, even, and clean. 1/4" dowel holes, used to anchor the floating wall segments, will be present in the floor material.

NOTE: The arena walls are matte black in order to reduce the reflection from the robot's IR beacons (used to broadcast the presence of each robot). This coating does reduce the intensity of most reflections, but IR navigation beacons have been confirmed to work without problems.

The floor of the arena will be a sheet of pressure-treated plywood, without laminate. The floors will probably be coated with the same matte black material used for the walls, except for the two 1'x8' zones at either end of the arena. These zones will be painted with the two different zone colours. The arena will be aligned with the 12' length running in a magnetic North-South (or East-West, to be determined later) direction.

NOTE: There's a question/answer about the different arena floor colours (and detection options) available in the FAQ. Info on a reflectance sensor, IR emitter/detector pairs, etc.

All passageways and corners will be at least 2' (24") wide. There will be no moving parts within the arena. The arena may not be orthogonal, although the walls and obstacles will be planar (no curved surfaces). There will be no "dead ends" in the arena, so robots can always be approached from more than one direction. NOTE: There's a FAQ question and a clarification about dead ends.

The insertion points will remain the same for each game and will be assigned within the two separate arena zones. Robots attempting to map the arena before a game will be allowed to start mapping from the assigned insertion point. Starting positions will not be within line-of-sight of each other.

The robots will be positioned with their "back" to the wall in their own zone, pointing their "front" towards the other team's zone. Robot placement within the zone is decided by the course coordinator or competition judges.

A preliminary location for the final contest is the Architecture Pit. An example of a possible floor plan is shown below.




3. Ambient Lighting

The ambient lighting in the contest arena will obviously be difficult to predict until the location of the competition area has been determined. Competitors will be given time on the contest day to make ambient light level readings, if necessary, to calibrate their robots. The room will be lit with standard overhead fluorescent lights.

Robots should be able to adapt rapidly to different lighting conditions, as there may be lights associated with video cameras (IR and visible light), flash bulbs (high intensity visible light), or other auxiliary incandescent or natural light.



4. Robot Operation

Once turned on, the robots must be self-controlled without any human intervention, that is, these are to be autonomous robots that operate without any remote control. No power or signal tether lines will be allowed.

You won't be allowed to give your robot ANY special instruction (except for what type of game it's currently going to play). You should download the code for the type of game, move the robot into the arena, and press "START". That's it.

The robots can bump into or touch the walls of the arena as they move about, but they are not allowed to significantly mark or damage the walls in doing so. The robots cannot leave anything behind as they travel through the arena and cannot make any marks on the floor of the arena that aid in navigation.

Robots are not allowed to split into multiple robots, drop traps or snares, or otherwise affect the competition arena or other robots in an indirect manner. Robots ARE allowed to come into contact with other robots, but only within the following legal contact guidelines.

Apart from direct (legal) pushing and shoving, robots must not interfere with each other in any way and therefore your robot must not:

  • Use any active weapons (cutters, drills, flippers, etc)
  • Come into contact with another robot outside the legal contact heights
  • Emulate another robot's beacon, or emulate a flag beacon
  • Use any form of electromagnetic radiation to hinder another robot
  • Flood radio channels in order to disrupt communications
  • Alter its own beacon in order to avoid being detected



5. Robot Size, Weight & Materials

The maximum size of each robot is 12" by 12" by 12" (30.5cm x 30.5cm x 30.5cm). Robots are not allowed to look over the walls of the arena, and must never extend themselves beyond 12" in any direction. All robots will be carefully measured and larger robots will be disqualified. If the competitors wish to add a flag, hat, or other purely decorative, non-functional items to their robot, they may exceed the height limitation. The item must have absolutely no effect on the operation of the robot and not interfere with the legal contact heights.

NOTE: There are a number of different heights that you should take into consideration while designing your robot. These heights are:

  • The flag beacon height specification (here)
  • The flag grab bar height specification (here)
  • The legal contact height specification (here)

If the robot has sensors or feelers, they will be counted as part of the robot and must not exceed the 12" width or height limitation. If grabbing devices are mounted on movable platforms, they will be counted as part of the robot and must not extend past the 10" width or 12" height maximum for the robot. The grabber must not extend past a 1" buffer zone inside the maximum width of the robot, as described here.

NOTE: Your robot must be the widest at the legal contact heights. This means that no part of your robot can extend past your bumper for pushing and shoving. This is to ensure that parts of two robots cannot become tangled or ensnared.

There are no restrictions on the weight of the robot.

There are no restrictions on the type of materials used in the construction of the robot, except in regards to safety and that the robot must be designed and constructed by the competitors and cannot consist of a commercially available product or kit. Robots cannot be based around the modification of a commercially available product or kit. Robots CAN use commercially available products or kits if they are used as construction material. ie: don't use the Acme Robot Kit, but feel free to use some Lego or Meccano.

Carleton University will be providing equipment to the teams. Any parts which are surplus to the Universities other needs, or which can be legitimately borrowed from the labs or workshops, may be used. Some items will be available on a first-come first-served basis. Do not assume that you will be reimbursed for ANY costs you incur during the course of the project.



6. Sensors

There are no restrictions on the type of sensors that can be used as long as they do not violate any of the other rules and regulations. Specifically, they must not interfere with other robots. Using an aggressive sonar sensor may confuse other robots using sonar ranging. Use of sonar sensors will be strongly discouraged due to the small size of the arena and the possible confusion of having multiple sonar-using robots playing the same game.

Competitors are not allowed to place any markers, beacons or reflectors on or around the arena. Robots are not allowed to use navigation cues external to the arena. Robots must conform to the IR beacon specifications, however.

While many film and video cameras use infrared light as part of their automatic focusing system, all attempts will be made for cameras to use manual focusing and natural lighting in order to limit the exposure to external IR and intense light sources. Competitors should arrange to have an adjustable ambient level for sensor use.



7. Electricity

Robots must run from self-contained batteries. The batteries must not leak toxic chemicals if tipped over. Unsealed lead-acid batteries used in cars and motorcycles are not allowed.



8. Cables

There shall be no external power, control cables, or hoses attached to the robots.



9. Robot Identification and Marking

Each robot will have a "robot ID" number, which is unique for each robot and doesn't change. Your robot will be identified with this number and you will be called to participate in games based on this number. This number will be the data bits you send in your infrared robot beacon.

Your robot must be clearly marked with the "robot ID" number. This 1-digit marking must consist of a black number on a white background, with the character occupying a 1" by 1" space. The marking must be visible from above the robot.

The robot identification numbers will be assigned by the project coordinator.

Each robot must also transmit in one of the four timing schemes outlined in the infrared robot beacon section. The timing scheme used will change for each game, so you MUST have a hardware switch that changes your timing.



10. Infrared Robot Beacons and Detectors

Each robot must have a fully compliant beacon, centrally mounted at the highest point of the robot. The beacon must not be obstructed. The beacon meets the design requirements below:

  • supports multiple robots working in different teams
  • uses modulated infrared (940nm) light for line-of-sight operation
  • must be compatible with commercially available encoder/decoders
  • must be detectable from 12'+ with standard high-power LEDs
  • must not interfere with other sensors

Timing
Consecutively, each beacon must:

  • emit 213ms of modulated infrared light
    • comprised of seven HT12A encoded words
      (produced by giving data to the encoder for ~198ms)
    • consisting of 940nm light modulated at ~38.0kHz
    • emitted 360-degrees around the robot
      (minimum of 50% beam power in any direction)
    • must be detectable at 12+ feet with a standard device (50+mA/LED)
  • looks for infrared light from another robot
      (for N blocks of 213ms each, N is assigned by course coordinator)
  • emit 213ms of modulated infrared light (as spec'd above)
  • looks for infrared light from another robot
      (for 6-N blocks of 213ms each)
  • repeat the process
This process is further detailed
here. An example of the timing is shown below.

This can be shown in a chart form as follows:


The coloured blocks indicate when the particular robot is transmitting and the white blocks indicate when the robot is 'looking' for other transmitters.

The above chart shows each robot transmitting from 0 to 213ms, then 'looking' for an amount of time before transmitting another 213ms pulse. This allows us to have four robots in the same area that will ALWAYS detect each other within 1.7s.

NOTE: The IR beacon design proposed above is quite sensitive to fluorescent lights and the infrared signal they produce. You will probably need to shield your detectors from the overhead lights.



11. Flags, Visible Flag Beacons, and Detectors

The flag is a critical component of the capture the flag games, it's the object that must be found and retrieved. As such, the specifications for the flag are important in regards to the design of the robots. Two flags will be used in the final competition, identical except for the frequency of the beacon.

Each flag will:

  • be mobile in all directions, with a minimum amount of rolling resistance
  • have a cylindrical metal body, approximately 4-5" wide
  • feature a beacon, visible from 360-degrees, as described below
  • have a circular metal (conductive) grab bar, approximately 8-9" wide
    • electrically isolated from the body of the flag

In order to simplify flag detection, each flag will have a unique beacon that robots must be able to detect. This beacon will be placed at the top of each flag and will emit a constant flash of visible light. Note that the rate of oscillation will be a constant 50% duty cycle, and the medium of communication will be visible red/orange light.

The flag beacon will use a bright red/orange light (with a wavelength of approximately 635nm) from ultra-bright LEDs. LEDs from 615-640nm have the highest millicandela ratings, making them brighter and easier to detect than other colours. LEDs also have a very quick turn-on and turn-off time, and will oscillate very accurately at the beacon frequencies. The flag beacons will flash at 20.01Hz and 29.80Hz, essentially 20 and 30Hz, with a 50% duty cycle.

An excellent detector is a photodiode with built-in amplifier, tuned to the correct wavelength of the LEDs. This photodiode needs to be fairly resistant to higher frequency infrared (from the robot beacon, the IR distance sensors, etc), sensitive to a flashing point source, and insensitive to the ambient light.

The Burr-Brown (a division of Texas Instruments) OPT101P is an excellent selection. The datasheet is here. This device is available from DigiKey as part number OPT101P-ND. Further information on the flag beacon, and detail regarding the detection process, is further detailed here.

The flag will have a number of specified heights associated with it, these are listed (and shown) below:

  • the metal body will completely cover the legal contact height
  • the grab bar will be at a height of 7"
  • the beacon will be at a height of 9" (and is centrally mounted)


In order to facilitate a grab detection sensor, the grab ring will be electrically conductive and isolated from the body of the flag. This will allow a robot to perform a continuity test between two electrodes on a grabber design. Because more than one robot can grab the flag at a time, and in order to reduce the possibility of damage, robots can only use a 5V potential drop during any possible continuity test. It's advised that you fuse any electrical connections that may come into contact with the flag grab bars.



12. Grabber Specifications

Under no circumstance should a grabber be used to interfere with another robot. This rule is ensured by restricting the range of motion of the grabber to within 1" of the boundary created by the contact zone bumper.

This will allow the grabber to successfully engage the grab ring around the flag, (because it extends 2" from the body of the flag) but will not allow grabber contact with the arena or other robots. The 1" buffer between the grabber and the edge of the robot must be at the maximum grabber extension.

This is illustrated below:


NOTE: Your robot must be the widest at the legal contact heights. This means that no part of your robot can extend past your bumper for pushing and shoving. This is to ensure that parts of two robots cannot become tangled or ensnared.

In order to facilitate a grab detection sensor, the grab ring will be electrically conductive and isolated from the body of the flag. This will allow a robot to perform a continuity test between two electrodes on a grabber design. Because more than one robot can grab the flag at a time, and in order to reduce the possibility of damage, robots can only use a 5V potential drop during any possible continuity test. It's advised that you fuse any electrical connections that may come into contact with the flag grab bars.



13. Legal Contact Guidelines

The legal contact guidelines are a strict set of regulations to facilitate a small amount of bumping and pushing between robots. Note that these guidelines are restrictive, and that there are penalties for robots that do not adhere to these regulations. Please consult the project organizer for more information or clarification on any of these guidelines.

Robots may engage in low-speed pushing and bumping while attempting to achieve a game goal (like grabbing or moving the opponent's flag). Robots must not engage in contact while not in the presence of a flag. Specifically, this means that your robot must be designed for a primary goal other than pushing around other robots.

The legal contact guidelines are as follows:

  • Robots may only engage in low-speed pushing and bumping
    • ie: no pulling or spinning is allowed
  • All contact must be made within the legal contact height
    • from 2" to 4" above the arena floor, detailed below
  • All contact must be made with a smooth surface
    • ie: no spikes, snares or sharp edges
    • rubber tires and wheels may be allowed (ask!)
  • No active weapons may be used during the contact
    • ie: no drilling, punching, cutting, sawing, etc.

As part of the guidelines, robots can only contact each other at certain heights. This specification will allow robots to push and shove, but not need to be covered in armour. Any contact outside the legal contact heights will be heavily penalized.

The legal contact heights are from 2" above the arena floor, to 4" above the arena floor. All contact between robots MUST be made within this 2" height restriction.

NOTE: Your robot must be the widest at the legal contact heights. This means that no part of your robot can extend past your bumper for pushing and shoving. This is to ensure that parts of two robots cannot become tangled or ensnared.



14. RF Communication Guidelines

As part of their game strategy, robots may decide to communicate with each other using MING 300MHz serial-input AM Transmitters and Receivers. These parts are available from DigiKey, part numbers TX-99V3-ND and RE-99V3-ND, respectively. The transmitter and receiver will communicate with the MING encoder/decoder motherboards, DigiKey part numbers RE-01-ND and TX-01-ND, respectively. Information regarding these devices is available from Ming Microsystems. Note that you will need a 9-12V source for the RE-01 and TX-01 motherboards.

Use of the AM transmitters must be regulated to ensure that a fair game is conducted. Robots that are not playing must NOT transmit on the shared 300MHz band and competitors are warned that electronic warfare will result in disqualification. You should design a radio transmission "off" switch to avoid accidentally transmitting when not involved in a game. (This is the ~TE line I discuss below)

The encoder and decoder motherboards use an 8-bit address (set by a dip-switch) to deliver 4-bits of latched data. Each robot should select an individual 8-bit address and robots should pre-program their transmitters with their team-mates addresses.

What this means is that the robot's encoder motherboard (connected to the HandyBoard and the transmitter to send the data) will be fixed with the address of the robot's teammate. The decoder motherboard (connected to the receiver and the HandyBoard to receive the data) will have a unique address that the teammate is transmitting to.

You will need to somehow get the active-low enable signal onto the TX motherboard ~TE line. Check it out in the Holtek 12E datasheet. Because the transmitter would otherwise be transmitting all the time, we need to turn it on and off when transmitting to avoid flooding the communication channel. The line is a NOT transmit enable, so when ~TE is low, the device will transmit, and when ~TE is high, the device will not transmit.

NOTE: Because the transmit and receive addresses on the RF boards will be fixed, you will only require a few data lines to transmit information between your robots. Assuming a 2-bit connection is required, allowing for four (4) different signals between cooperating robots, your robot would require the following I/O lines:

  • 1 digital output line connected to TX motherboard ~TE line
  • 2 digital output lines connected to TX motherboard data lines
  • 2 digital input lines connected to RX motherboard data lines
  • 1 digital input line connected to RX motherboard "data received" line
So this means you will need 3 digital output lines and 3 digital input lines to communicate. It may be possible to use fewer I/O lines, but with greater design complexity.

The communications protocol and specifications are designed to allow for games with more than two robots where teams would like to work on advanced strategies.



15. Running Order

Each team will compete consecutively in the competition. While teams are encouraged to attempt minor software and/or hardware tweaks to enhance their score, it is important to note that the arena will be changed for each round. Teams will be allowed to interact with an official arena one day before the competition.



16. Scoring

Due to the complexity of the final events, a detailed scoring method has not yet been decided. There are a number of penalties that will be observed in the final score.

The scoring is as follows:

  • 10% Aesthetics
  • 30% Technical (difficulty of design/construction)
  • 60% Performance (competition score from the games)
    • 40% Solo Performance (score from the Team Game)
    • 60% Group Performance (score from the Group Game)
17. Types of Games

The game of "capture the flag" is a schoolyard game that's played out with a number of variations. The RoboFlag competition will feature a simple version of the game as follows:

  • Robots start at different ends of an arena, in their own "zones"
  • Each "zone" has a flag associated with it, the flags are different
  • Robots must not move flags found in their own zone (penalty)
  • Robots must find the other zone, identify the flag, and move the flag back to their own zone
  • The first robot(s) to move the opponent's flag into their zone wins the game
    • Some games require 80% of team A's robots, plus 80% of team B's flag, to be present in team A's arena zone for the game to be complete and for team A to win

Several different types of games, all based around the capture the flag idea, will be played during the final competition. Only two game types will be judged for points, however, due to the complexity of judging a multi-robot game. The games are as follows:

  • Capture the Flag - Team Game (40% of competition score)
    • Two robots play capture the flag against each other
    • "capture the flag" is the simple game explained above
    • Scoring is based on the quality of the game, minus any penalties
    • Three separate games will be played in three different arenas
  • Capture the Flag - Group Game (60% of competition score)
    • Four robots play capture the flag against each other (2 vs. 2)
    • "capture the flag" is the game explained above, but with two robots working together against two other robots
    • For the game to end, both robots and the opponents flag must be in the robot's zone
    • Scoring is based on the quality of the game, minus any penalties
    • Three separate games will be played in three different arenas
  • Capture the Flag - Solo (not scored)
    • One robot plays capture the flag with no opponents
    • Only one robot and one flag are present in the arena
    • There is no scoring for these games, just bragging rights
  • Capture the Flag - Multi (not scored)
    • All robots play capture the flag
    • Only one flag is present in the arena
    • There is no scoring for these games, just bragging rights



18. Penalties

The goal of the project is to design and build one autonomous mobile robot that can play a game of capture the flag. While there are several actions that are not completely illegal, they do have penalties associated with them. These penalties are usually a small price to pay for a robot that can successfully capture the flag.

The penalties are as follows:

  • Moving Your Own Flag
  • High-velocity or Excessive Robot Contact
    • If a judge identifies a robot was primarily responsible for a high-velocity collision, or is excessive in the amount of contact with another robot, a penalty will be assessed against the offending team. This penalty will discourage teams from building robots that will attempt to win by physically damaging the other robots.
    • A high-velocity collision is defined as a collision that would cause the judge to wince
    • Excessive contact would be a strategy which involves pursuing and attacking another robot
    • The penalty will be severe for the instigating robot (approx. 30% of the game points)
    • There will be no penalty for the other robot (& hopefully nothing is broken)
    • The instigating robot may be removed from the competition
  • Unwarranted Robot Contact
    • If a robot initiates significant contact with another robot while not in the presence of either flag, a penalty will be assessed against the offending robot. This penalty intends to discourage random acts of robotic violence.
    • Significant (or non-incidental) contact includes intentional ramming or bumping
    • The penalty will be minor for the instigating robot (approx. 10% of the game points)
    • There will be no penalty for the other robot
  • Illegal Robot Contact
    • If a robot initiates contact with another robot that is outside the legal contact height, or features the use of a sharp edge or an active weapon, a penalty will be assessed against the offending robot and the offender may be disqualified. This penalty will discourage illegal acts of robotic violence.
    • The penalty will be severe for the instigating robot (approx. 50% of the game points)
    • There will be no penalty for the other robot
  • Damaging the Arena
    • If a judge rules that a robot was responsible for wanton damage and destruction and that the arena was solidly made, a penalty will be assessed against the team.
    • The penalty will be moderate (approx. 15% of the game points)



19. Safety

Contest judges or the project coordinator may stop any robot at any time if they feel that it is performing, or is about to perform, any action that is dangerous or hazardous to people, equipment, or other robots. No robot is allowed to use any flammable, combustible, corrosive or radioactive process. Robots must not be programmed to hurt, maim, or kill innocent bystanders or project supervisors.



20. Interpreting the Rules

In all matters of interpreting these rules before and during the contest - and in any issues not covered by these rules - the decisions of the official project coordinator (William Sitch) will be final.



21. Updated Rules or Regulations

All registered competitors will be kept updated regarding any rule changes and/or modifications prior to the contest. Updates will be immediately posted to the webpage.



22. Location and Dates

The contest will be held from 3-5PM in the Bell Theatre, Minto Centre, at Carleton University in Ottawa, Ontario, Canada on March 13, 2002. There will be time available before March 13th for competitors to test their robots in the official arenas.


 
 
Main Page
|
Course Admin
|
Course Resources
|
Rules & Regulations
|
Team Profiles
|
Photo Gallery
|
Contact Info