Kind: captions
Language: en
this tiny robot Mouse can finish this
maze in just six seconds
every year around the world people
compete in the oldest robotics rooms the
goal is simple get to the end of the
maze as fast as possible personal you
came second
lost by 20 milliseconds but competition
has grown fierce
when somebody saw my design they said
you're crazy
why is there so much tension what's
riding around
Anna Anna
[Applause]
this video is sponsored by onshape
in 1952 mathematician Claude Shannon
constructed an electronic mouse named
Theseus that could solve a maze the
trick to making the mouse intelligent
was hidden in a computer built into the
maze itself made of telephone relay
switches the mouse was just a magnet on
Wheels essentially following an
electromagnet controlled by the position
of the relay switches it is now
exploring the maze using a rather
involved strategy of trial and error as
he finds the correct path to register
the information in its memory later I
can put him down in any part of the maze
that he's already explored and he'll be
able to go directly to the goal without
making a single false turn Theseus is
often referred to as one of the first
examples of machine learning a director
at Google recently said that it inspired
the whole field of AI
25 years later editors at The Institute
of electrical and electronics Engineers
or IEEE caught wind of a contest for
electronic mice or lemaus electronique
as they had heard they were ecstatic
were these the successors to Theseus but
something had been Lost in Translation
these mice were just batteries and cases
not robots capable of intelligent
Behavior but the misunderstanding stuck
with them and they wondered why couldn't
we hold that competition ourselves
in 1977 the announcement for ieee's
amazing micromouse maze contest
attracted over 6 000 entrants but the
number of successful competitors
dwindled rapidly eventually just 15
entrants reached the finals in 1979.
but by this point the contest had
garnered enough public interest to be
broadcast Nationwide on the evening news
and just like the rumor that inspired
the competition micromouse began to
spread across the world
[Music]
thank you
[Music]
[Applause]
guys
[Music]
even people in the top two or three you
can see them trying to set their mice up
and they can barely find the buttons to
press because it's absolutely
nerve-wracking
[Music]
well it doesn't matter what it was it
could be horse racing it could be Motor
Racing it could be Mouse racing
if you have a shred of competitiveness
in you you want to win right
just like a real Mouse a micromouse has
to be fully autonomous no internet
connection no GPS or remote control and
no nudging it to help it get unstuck it
has to fit all its Computing Motors
sensors and power supply in a frame no
longer or wider than 25 centimeters
there isn't a limit on the height of the
mouse but the rules don't allow climbing
flight or any forms of combustion so
rocket propulsion for example is out of
the equation
[Applause]
[Music]
the maze itself is a square about three
meters on each side subdivided by walls
into corridors only 18 centimeters
across and in 2009 the half size micro
Mouse category was introduced with mice
smaller than 12 and a half centimeters
per side and paths just nine centimeters
across the final layout of the maze is
only revealed at the start of each
competition after which competitors are
not allowed to change the code in their
mice
foreign
the big three competitions all Japan
Taiwan and USA's Apec usually limit the
time mice get in the Maze to 7 or 10
minutes and mice are only allowed five
runs from the start to the goal so if
you spend a lot of time searching that's
a penalty makes sense
so the strategy for most micro mice is
to spend their first run carefully
learning the Maze and looking for the
best path to the goal while not wasting
too much time then they use their
remaining tries to Sprint down that path
for the fastest run time possible
solving a maze may sound simple enough
though it's important to remember that
with only a few infrared sensors for
eyes the view from inside the maze is a
lot less clear than what we see from
above still you can solve a maze with
your eyes closed if you just put one
hand along one wall you will eventually
reach the end of most common mazes and
that's exactly what some initial
micromose competitors realize too and
after a simple wall following Mouse took
home gold in the first Finals the goal
of the maze was moved away from the
edges and freestanding walls were added
which would leave a simple wall
following Mouse searching forever
your next Instinct might be to run
through the maze taking note of every
fork in the road whenever you reach a
dead end or a loop you can go back to
the last intersection and try a
different path if your last left turn
got you nowhere you'd come back to that
intersection and go right instead you
can think of this strategy as the one a
headstrong Mouse might use running as
deep into the maze as it can and turning
back only when it can't go any further
this search strategy known as depth
first search will eventually get the
mouse to the goal the problem is it
might not be the shortest route because
the mouse only turns back when it needs
to so it may have missed a shortcut that
it never tried
The Sibling to this search algorithm
breath first search would find the
shortest path with this strategy the
Mouse runs down one branch of an
intersection until it reaches the next
one then it goes back to check the path
it skipped before moving on to the next
layer of intersections so the mouse
checks every option it reaches but all
that backtracking means that it's
re-running paths dozens of times at this
point even searching the whole maze
often takes less time
so why not just do that a meticulous
Mouse could search all 256 cells of the
maze testing every turn and corner to
ensure it has definitely found the
shortest path but searching so
thoroughly isn't necessary either
instead the most popular micromouse
strategy is different from all of these
techniques it's a search algorithm known
as flood fill
this Mouse's plan is to make optimistic
Journeys through the maze so optimistic
in fact that on their first journey
their map of the maze doesn't have any
walls at all they simply draw the
shortest path to the goal and go
when their optimistic plan inevitably
hits a wall that wasn't on their map
they simply mark it down and update
their new shortest path to the goal
running updating running updating always
beelining for the goal under the hood of
the algorithm what the micro Mouse is
marking on their map is the distance
from every Square in the Maze to the
goal to travel optimistically the mouse
follows the trail of decreasing numbers
down to zero whenever they hit a wall
they update the numbers on their map to
reflect the new shortest distance to the
goal this strategy of following the
numerical path of least resistance gives
the flood fill algorithm its name the
process resembles flooding the maze with
water and updating values based on the
flow
once the mouse reaches the goal it can
smooth out the path it took and get a
solution to the maze however it may look
back and imagine an even shorter
Uncharted path it could have taken the
mouse might not be satisfied that it's
found the shortest path just yet while
this algorithm isn't guaranteed to find
the best path on first pass it takes
advantage of the fact that micromise
need to return to the start to begin
their next run so if the mouse treats
its return as a New Journey it can use
the return trip to search the maze as
well
between these two attempts both
optimized to find the shortest path from
start to finish it's extremely likely
that the mouse will Discover it and the
mouse will have done it efficiently
often leaving irrelevant areas of the
maze entirely untouched flood fill
offers both an intelligent and practical
way for micromise to find the shortest
path through the maze
once there was a clear strategy to find
the shortest path and once the
microcontrollers and sensors required to
implement it became common some people
believed micromouse had run its course
as a paper published in IEEE put it at
the end of the 1980s the micromous
contest had outlived itself the problem
was solved and did not provide any new
challenges
[Music]
in the 2017 all Japan micromouse
competition both the bronze and silver
placing Mice found the shortest path to
the goal and once they did they were
able to zip along it as quick as 7.4
seconds
but mazakazu utsunami is winning Mouse
red comet did something entirely
different this is the shortest path to
the goal the one that everyone took this
is the path that red comet took it's a
full five and a half meters longer
that's because micromise aren't actually
searching for the shortest path they're
searching for the fastest path and red
comet's search algorithm figured out
that this path had fewer turns to slow
it down so even though the path was
longer it could end up being faster so
it took that risk
it won by a 131 milliseconds
differing routes at competition are now
more common than not and even just
getting to the goal remains difficult
whether due to a mysterious algorithm or
a quirk of the physical maze
[Music]
micromise don't always behave as you'd
expect
[Music]
Ed
micromouse is far from solved because
it's not just a software problem or a
hardware problem it's both it's a
robotics problem red comet didn't win
because it had a better search algorithm
or because it had faster motors its
cleverness came from how the brains and
body of the mouse interacted together it
turns out zombie the maze is not the
problem right it never was the problem
right but it's actually about navigation
and it's about going fast every year the
robots get smaller and faster lighter
there is still plenty plenty of
innovation left and there's a small
group of devotees in Japan busy building
quarter-sized micromass which would sit
on a quarter
[Music]
nearly 50 years on micromouse is bigger
than ever foreign
s have appeared solved at first glance
before the high jump was an Olympic
sport since 1896 with competitors
refining their jumps using variations
like the scissor the western roll and
the straddle over the decades with
diminishing returns but once foam
padding became standard in competition
dick Fosbury rewrote the sport in 1968
by becoming the first Olympian to jump
over the pole backwards now almost every
high jumper does what's known as The
Fosbury Flop
if micromouse had indeed stopped in the
1980s the competition would have missed
its own Fosbury flops two innovations
that completely changed how micromice
ran after all a lot can change in a
sport where competitors can solder on
any upgrade they can imagine
the first Fosbury Flop was one of the
earliest Innovations in micromass and
had nothing to do with technology it was
simply a way of thinking outside the box
or rather cutting through the box every
Mouse used to turn Corners like this
but everything changed with the mouse
Mighty three so Mighty Mouse 3
implemented diagonals for the first time
and that turned out to be a much better
idea than we really thought and because
it's cool you know maze designers often
put diagonals into the maze now so uh
you know you could end up with a maze
where it never comes up but most of the
time it's actually a benefit
in order to pull off diagonals the
chassis of the mouse had to be reduced
to less than 11 centimeters wide or just
five centimeters for half size
micromouse the sensors and software of
the mouse had to change too when you're
running between parallel walls all you
have to do is maintain an equal distance
between your left and right infrared
readings but a diagonal requires an
entirely new algorithm one that
essentially guides the mouse as if it
had blinders on normally if you're going
along the side of a wall or something
like that you know most of the time you
can see the wall all the time and so
that helps you to guide yourself and you
know when you're getting off but in the
diagonal situation you just see these
walls coming at you and if you Veer even
a tiny bit off course snagging a corner
is a lot less forgiving than sliding
against a wall diagonals are still one
of the biggest sources of crashes in
competition today
but in exchange a jagged path of turns
transforms into one narrow straight away
[Applause]
these days nearly every competitive
micromouse is designed to take this risk
diagonals opened up room for even more
ideas around the same time mice were
applying similar strategies to Turning
instead of stopping and pivoting through
two right turns a mouse could sweep
around in a single U-turn motion and
once the possibility of diagonals were
added the total number of possible turns
opened up exponentially
the maze was no longer just a grid of
square hallways with so many more
options to weigh figuring out the best
path became more complex than ever but
the payoff was dramatic what was once a
series of stops and starts could now be
a single fluid snaking motion how
micromice imagined and moved through the
maze had changed completely
available technology was getting
upgrades over the years as well tall and
unwieldy arms that were used to find
walls were replaced by a smaller array
of infrared sensors on board the mouse
precise stepper Motors were traded in
for continuous DC motors and encoders
the DC motors give you more power for
less size and weight and so we were
interested in doing that so then you
have to have a Servo you have to
actually have feedback on the motor to
make it do the right thing gyroscopes
added an extra sense of orientation
it's like a compass absolutely you have
this thing with you they came about
because of mobile phones really so the
technology provides people with things
which weren't there before all of the
Turning is done based off the gyro
rather than counting pulses off the
wheels because it's much more reliable
but even with all the mechanical
upgrades the biggest physical issue for
micromise went unaddressed for decades
one thing you'll see almost every
competitor holding is a roll of tape
once you know to look for it you'll see
it everywhere this tape isn't for
repairs or reattaching Fallen Parts it's
to gather specks of dust off the wheels
in between rounds at the speed and
precision these robots are operating
that tiny change in friction is enough
to ruin a run
foreign
if you want to turn while driving fast
you need centripetal force to accelerate
you into the turn and the faster you're
moving the more Force you need to keep
you on the track
the only centripetal force for a car
turning on flat ground is friction which
is determined by two things the road
pushing up the weight of the car or the
normal force multiplied by the static
coefficient of friction which is the
friction of the interface between the
tire and road surface this is why race
tracks have banked turns the Steep
angles help cars turn with less friction
because part of the normal force itself
now points in to contribute to the
centripetal force required if the bank
turn is steep enough cars can actually
make the turn without any friction at
all the inward component of the normal
force alone is enough to provide the
centripetal force required to stay on
track
micromise are no different and they
don't have Bank turns to help as they
got faster and faster by the early 2000s
their limiting factor was no longer
speed but control of that speed they had
to set their center of gravity low and
slow down during turns to avoid slipping
into a wall or flipping over
but unlike race cars there wasn't
anything in the rules to stop micromouse
competitors from solving this problem by
engineering an entirely new mechanism
micromous second Fosbury Flop was almost
considered a gimmick when the mouse
mocomo 08 first used it in competition
you might be staring at the video to try
to see it but you won't instead it's
something you'll hear
[Music]
that isn't the mouse revving its engines
it's spinning up a propeller and while
flying over the walls is against the
rules there's nothing in the rules
against a mouse vacuuming itself to the
ground to prevent slipping David was the
first person I saw put a fan on a mouse
but he used a ducted fan and I think he
was really looking at kind of reaction
force you know blowing the thing down he
had a skirt around but it was not
terribly effective yeah forgiving the
idea is to let this little air in as
possible and like your vacuum cleaner
when you block your vacuum cleaner right
the motor unloads and speeds up and so
the current drops but if you let too
much air in the current's very high and
these are just quadcopter Motors and
they draw a lot of colors at the scale
of micromouse a vacuum fan often just
built from handheld drone Parts is
enough to generate a downward Force five
times the mouse's weight
wow okay
that's impressive so how much does the
car actually weigh about 130 grams and
if you listen I don't know if you'll get
it on your microphone but
oh yeah I'm here the Lotus slow down it
loads up with that much friction
micromise today can turn Corners with a
centripetal acceleration approaching 6
G's that's the same as F1 cars
once nearly everyone equipped fans the
added control allowed Builders to push
the speed limit on micromise when it's
allowed to it will out accelerate a
Tesla Roadster but not for very fun
and they can zip along at up to seven
meters per second faster than most
people can run
[Applause]
every one of the features now standard
on the modern micromouse was once an
experiment and the next Fosbury Flop
might not be far off the first
four-wheeled micro Mouse to win the
all-japan competition did so in 1988 but
it would take another 22 years of the
winning Mouse growing and losing
appendages before four-wheeled mice
became the norm with micromice still
experimenting in six and eight wheel
designs omnidirectional movement and
even computer vision who knows what the
next paradigm shift will be your time on
the maze actually begins only when you
leave the start Square so he's not
for any of this time
but if you want to get started with
micro Mouse you don't need to worry
about wheel count or vacuum fans or even
diagonals it is to my mind the perfect
combination of all the major disciplines
that you need for Robotics and
engineering and programming embedded
systems all wrapped up in one accessible
bundle that you can do in your living
room and you don't need a laboratory to
run it
you come along because you're curious
and then you think I could do that that
doesn't look so hard and then you're
doomed really if it sucks you in it uh
it turns into quite the journey
at its core micro Mouse is just about a
mouse trying to solve a maze though
nearly 50 years later it's a simple
problem that's a good reminder there is
no such thing as a simple problem
[Music]
is
[Music]
if you want to build your own micro
Mouse you'll likely need to design Parts
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thank onshape for sponsoring this video
and I want to thank you for watching