RoboCup Challenge: Assessment

RoboCup Challenge: Assessment

1. Analyse problem

   • Context
     • SpaceX - human colony on Mars
     • Autonomous robots - data collection, support colonisation effort
     • Path to follow, but some obstacles
       • Move obstacles off path or navigate around
     • Optional light and sound display once completed
     • 4 weeks, no delays
   • Analysis
     • Need to use line follow code, immovable object code and movable object code
     • Must navigate from one green point to the other
     • Need to be able to identify objects and decide how to handle them to continue on path
     • "As quickly as possible": might have to decrease accuracy to achieve speed
     • "A pathway for the robots to follow": only one line to follow, until criss-cross intersection
       • Note: movable and immovable boxes don't change position on map

2. Ideas

   • Follow the path
     • Intersections
       • Use the green boxes to turn right whenever detected, then resume line follow. This is so the robot doesn't change direction if it misses the line
     • Corners
       • Rotate one wheel forward to turn until black line is spotted
         • May be too far away from line and keep spinning and not see anything, or accidentally spin too far and see black line and travel in opposite direction
         • Easiest to turn corners, but only one way depending on spin direction
         • SAMPLE CODE
       • Rotate one wheel forward and one back at same time
         • More distinctive turn, possibly more accurate
         • SAMPLE CODE
         • Could accidentally move to wrong side of line due to excessive turning and then go in wrong direction
     • Black line
       • Swerving line-follow
         • Start on right side, turn left till see black, turn right again until see floor
           • Need to identify PSI values for black line and floor
           • Turn one motor (wheel) at a time to move forward progressively, or could rotate one wheel forward and the other back at same to for more defined turn
           • However, may not deal with intersections or corners well if the robot misses the line and flips directions
           • Possibly most efficient and fastest method, achieving criteria
         • SAMPLE CODE
       • Move forward on black line
         • Start with robot on black line, if it sees black, move forward until it doesn't see black, then rotate both directions until sees black again
           • Need to identify PSI values for black line and floor
           • For rotational black line check, would turn only one wheel to sweep and not jump over black line by accident. For moving forward, just rotate both wheels
           • Most accurate method, but really slow, higher chance of accomplishing intersections and corners, though could get stuck on really tight corners trying to find the black line
         • SAMPLE CODE
   • Avoid obstacles
     • Movable
       • Move forward into block and keep going until it moves
         • Might be inefficient if it doesn't get out of the way
       • Detect movable block (if it's the large one) and turn out to the side push it out of path the continue line following
     • Immovable
       • Reverse backwards, turn slightly and aim for box again to see if it misses, used ultrasonic sensor to navigate around box
         • Could only half clear the box, miss and get stuck. Besides, ultrasonic sensor is on the front and won't be able to detect box on side
       • Reverse backwards, turn, move forward, and navigate around block using precise measurements
         • If the box measurements change, the code doesn'work

3. Robot Sensors

   • Ultrasonic
     • Determines robot's distance away from obstacle
     • Senses closest distance reading, gives value in centimetres. Used in navigating around spaces.
       • The sensor sends out a frequency wave that's above human hearing. The wave is reflected back when it hits the target. The distance is measured by time between emission and reception.
   • Colour/light
     • Determines colour values by sensing reflection of light
     • Determines PCT, which can be used to change robot actions. Used in line-follow.
       • A PCT value in terms of EV3 robotics and programming means percent (%), as in value out of 100. To obtain a PCT value, the sensor emits light from a transmitter and detects the value of the light that is reflected back at the receiver.
   • Touch
     • Determines whether the robot has hit an obstacle or not. Used in obstacle moving.
     • The button on the sensor is either depressed, giving a value of 1, or not depressed, giving a value of 0. These values can be used as variables to adapt code
       • The touch sensor works like an electrical switch. When there's contact, it opens the circuit and allows electrical current flow.

4. Available Resources

   • eLearn
     • Information about robot and assessment
       • Learn how to make algorithms, flowcharts and pseudocode
       • Learn how to code and build robots
   • Microsoft Tools
     • Microsoft Word
       • Writing assessment and analysing data
   • EV3
     • Programming software
       • Used to code robot to complete challenge
     • Website
       • Used to find correct robot build and learn how to use software

5. Non-functional requirements

   • Things that aren't necessary to completing the code, like aesthetics
     • Self-determine criteria: celebratory dance
       • Visual and sound: light and screen display with robot turning and moving in dance

6. Functional Requirements

   • Robot travels around map
     • Use specific functions to decide how to move around
       • Line-follow
       • Right turn
       • Left turn
   • Robot is able to determine best solution for obstacles and complete solution
     • Movable
       • Push box out of the way and resume path
     • Immovable
       • Run into box then navigate around it

7. Constraints/limitations

   • The map
     • The map route doesn't change
       • Can't make an easier way to reach boxes and follow the line
   • Robot build
     • The colour sensor is permanently on one side of robot
       • May be inefficient to constantly have to change line-follow code, given the direction the robot turns to reach line
   • Time
     • 3 hours maximum of coding time per week
       • Have to only use class time, due to lack of resources, can't work on robot code from home

8. Prescribed Criteria

   • This is the criteria listed in the task sheet
     • Follow the path
       • Use colour sensors to navigate around the map: forward, left and right
     • Detect and navigate around immovable objects
       • Determine what an immovable object is using touch and ultrasonic sensors, then work out how to move around them and resume on the path
     • Detect and clear the movable objects from the path
       • Determine the movable object with touch and ultrasonic sensors then work out how to move around them and push them off the path efficient before resuming line-follow code

9. Self-determined criteria

   • Celebratory Dance once the robot has finished moving the movable box
     • Visual
       • Robot display a face on screen, arm motor move up and down, spin in circles, rotate each wheel forward and back twice
     • Sound
       • play a tune using sound blocks, have the robot play one of the pre-created audio tracks

Imagens e arquivos do mapa