Micromouse Maze
Priamo Gregory
Micromouse is an event where small robotic mice compete to solve a 1616 maze. It began in the late 1970s.[1] Events are held worldwide, and are most popular in the UK, U.S., Japan, Singapore, India, South Korea and becoming popular in subcontinent countries such as Sri Lanka.
The maze is made up of a 1616 grid of cells, each 180 mm square with walls 50 mm high.[2] The mice are completely autonomous robots that must find their way from a predetermined starting position to the central area of the maze unaided. The mouse needs to keep track of where it is, discover walls as it explores, map out the maze and detect when it has reached the goal. Having reached the goal, the mouse will typically perform additional searches of the maze until it has found an optimal route from the start to the finish. Once the optimal route has been found, the mouse will traverse that route in the shortest achievable time.
A version of Micromouse called the Half-Size Micromouse was introduced at the 30th All Japan Micromouse Competition in 2009.[6][7] Instead of a 1616 maze, the Half-Size competition uses up to a 3232 maze. Cell and wall dimensions have been reduced by half,[8] providing a new challenge.
Mice used in competitions employ the fundamental elements of robot navigation, including mapping, planning, and localization. Additionally, they optimize their path through the maze using various search algorithms. Common search algorithms use variations of the Bellman flood-fill method,[9] Dijkstra's algorithm, A* search algorithm, among various graph traversal and tree traversal algorithms.
Mice can run at over three meters per second, depending on the maze design. Some of the best micromouse builders are Yusuke Kato,[10] Ng Beng Kiat[11] and Fumitaka Nakashima.[12] The current world record is 3.921 seconds[13] and is held by Ng Beng Kiat.
Performance in recent years has improved considerably. As of 2015, winning mice are likely to run with forward acceleration and braking well over 1g.[14] Cornering with centripetal acceleration as high as 2g is possible. Micromice are among the highest-performing autonomous robots.
Most recently, robots are being equipped with a fan to create a partial vacuum under the mouse while it is running.[15][16][17] The additional downforce available has made possible a huge improvement in performance. Compared to a non-fan mouse, the newer robots are likely to be able to achieve centripetal accelerations of 6g or more. Straight line accelerations can easily exceed 2.5g.
Worst case scenario is when there is only one way to get from one point toanother in the maze (i.e.: no loops) and the maze ending is just a 1x1 square(while training we may not need to always have a 2x2 ending).
If you have the facilities, you can make one from 12mm fibreboard. It is called MDF in the UK and probably nowhere else.
One of the benefits of MDF is that it leaves a very good surface which
will need little or no preparation for painting. Chipboard needs the edges
filling. You may be able to trust your timber merchant to slice a sheet
up into suitable strips.
Use a jig to cut the walls to length (168mm).
There should be no holes in the maze floor so the best way to join walls
to posts is with a tongue on the wall and a slot on the post. The post
will need fixing into a hole on the base. Since there should be a post
at every lattice point you will need to drill a lot of holes accurately
in the base. Use a jig for this as well.
How big should I make it?
As a competitor, you may not have access to a full size maze and you are
probably unlikely to have enough room for one anyway. Try building a couple
of sections that you can put together in different ways. I have seen at
least one mouse that could not cope with a full 15 cell run as it had
never run over a distance greater than a quarter of the maze. Many builders
manage an 88 practice maze. Even that will require about 5 foot square,
similar to the space taken up by a typical double bed. Similarly, your
searching algorithm had better not have any hidden bugs brought on by
not expecting a full-size maze.
Accuracy
Notice that the rules give some fairly specific guidance relating to tolerances
and imperfections in the maze. Try and ensure that you can cope with worse
than those given. While you are searching and travelling relatively slowly
this should not be too hard. The problems accumulate very quickly at speed.
Since the rules generally state that every lattice point must have at
least one wall attached to it, you can build a maze using 180mm walls
with a peg at one end with slot to make an integrated post. The other
end will just have a tongue. An alternative is to just put pins on the
lower edge of the walls and drill four holes at each lattice point.
The real bad news is that you are going to want to make 300-400 walls
for a full sized maze. A single 84 sheet of material may yield nearly
100 walls. If you can cut these carefully enough, paint the sheets first,
then cut them. This is a simple but tedious job. For my practice area,
I used planed softwood. This measured up at 12mm x 47mm. The loss of height
was no big deal because I use side-looking sensors. However, this material
is far from stable and my walls are now all curved in one or more directions.
I like to tell myself that, if my mouse can cope with these, it can cope
with anything. Of course, I also like to tell myself that I will win on
the lottery.
If you really want to get a feel for a competition run, make sure you
have some very bright lights to simulate the lighting conditions of the
competition. Oh, and try to have a number of autofocus cameras firing
IR at your mouse as well ?
Micro Mouse is a small robotic vehicle designed to navigate and solve a maze autonomously. The robot is programmed using microcontrollers like Arduino and equipped with sensors that help it detect and map its environment. The objective of the micro mouse competition is to find the shortest path from the starting point to the center of the maze.
The left-hand algorithm is a popular method used to navigate the maze. It involves keeping the left-hand side of the wall as a guide and always turning left at every intersection until reaching the center of the maze.
To program the micro mouse using Arduino, you will need to use a programming language like C++ and an Integrated Development Environment (IDE) like the Arduino IDE. You will also need to write a code that allows the robot to use the left-hand algorithm to navigate the maze.
Once the robot is programmed, it can be tested in a maze to see if it can navigate to the center using the left-hand algorithm. The robot's performance can be improved by tweaking its sensors, motors, and algorithms.
Overall, building and programming a micro mouse is a fun and challenging project that requires knowledge in electronics, programming, and robotics. With the right tools and techniques, anyone can build a micro mouse and compete in the micro mouse competition.
The team started to search for the best algorithm to be used, we found the flood fill algorithm that needs a localization technique. thus, we decided to use the left-hand algorithm for its simplicity as a soft start for solving the problem.
Coding the left-hand algorithm is an important step in building a micro mouse robot. The left-hand algorithm is a simple and effective method for navigating a maze, and it involves keeping the left-hand side of the wall as a guide and always turning left at every intersection until reaching the center of the maze.
As the problem specification file mention, the robot should suite a maze constructed form 16*16 cell, each cell of width 18 cm and with walls of 5cm high, in addition to more details specified in the problem document. For that, we created a 4*4 maze to help us adjust our robot and test it before the real evaluation.
After testing each component alone, we started to build the robot, we used 4 IR sensors, two for the front to detect the best angle and one for each side to detect side walls. we also used two ultrasonic sensors one on each side to help the robot adjust its location while running in the maze.
for the structure of the robot, we put the Arduino and the batteries on the top to provide the best balance in the robot weight, while the rest of the components are put down on the first layer so the sensors can sense the 5 cm walls.
The micromouse contest says there are 16 * 16 cells, but I wrote the code to handle pretty much any size of maze. The structure of the maze started as MazeWalls between every pair of adjacent MazeCells, and then I strategically removed just enough MazeWalls to make every cell reachable from every other cell. The code is long and well commented, so I invite you to read the micromouse maze generator code on github.
Essentially, you have a wooden maze made up of a 16 by 16 grid of cells. Mice must find their way from a predetermined starting position to the central area of the maze unaided. The mouse will need to keep track of where it is, discover walls as it explores, map out the maze and detect when it has reached the goal. As if that was not enough, the winner is the mouse that manages this the fastest.
Building a half-size micromouse may seem pretty hard but there have been a lot of helpful developments in small components lately that have arisen from smartphones and tiny drones. With care, it is possible to assemble remarkably compact and complex robots. This example has six motors and six wheels. The four corner wheels are for steering and the centre wheels are drivers.
The half size contest has very similar rules to the classic contest except that the goal can be any pre-defined block of cells in the maze. Searching can take a lot longer so the time limit is increased from 5 minutes for the classic contest to 10 minutes in the half-size contest. Here is the 2019 All Japan champion performing just the search.
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