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
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
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.
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
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
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
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
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
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