micromouse

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WHAT IS MICROMOUSE ? : 

WHAT IS MICROMOUSE ? A Micro Mouse is an autonomous electro-mechanical robot, typically consisting of three main subsystems: The drive system An array of sensors, and The control system. Its purpose is to find its way and goal point through ANY type of maze - in the shortest amount of time. It integrates several different disciplines of engineering, ranging from electrical to mechanical to computer science

MAZE : 

MAZE The standard maze is made up of a 16 by 16 grid of cells. Each cell has 180mm square in length and 50mm high. Now days somewhere 32 by 32 grid are also uses. In India IIT-B organizing international micro mouse event and using 16X16 standard maze.

REQUIREMENTS : 

REQUIREMENTS MICROCONTROLLER :-89C52 ICS:-L298N, MC44603 & LM324. MOTOR:- STEPPER/DC SENSOR PCB BATTERY CHASSIS WHEELS WIRES SOFTWARE BURNER MAXIM DS2423 4kbit 1-WIRE RAM WITH COUNTER.

MICROMOUSE- BRAIN : 

MICROMOUSE- BRAIN ATMEL 89C52 - cheap and easy to use. - 8KB of PEROM and 256X8-bit of internal RAM. - 64KB of external memory support. - Three 16-bit timerss/counter. - Eight interrupt source. - It supports SPI program downloading.

IMPORTANT ICS : 

IMPORTANT ICS MOTOR DRIVER - IC L298 can be used as the motor driver for the stepper motors because of its high current capabilities - Pin 1 and 15 are used to control motor. - Pin 2,3,13 and 14 are output pin. - Pin 5,7,10 and 12 are used for different input - Pin 4 are used for supply and 8 for ground.

Slide 7: 

PWM CONTROLLER - MC44603 used as pwm controller. - This device has the unique ability of automatically changing operating modes. - It control pwm unbiased effect in micromouse. - PWM controlling provides smooth drives for stepper motor. - This device also give a safety towards burning of any circuit item. - It does not allow unusual voltage supplies.

SENSOR : 

SENSOR IR SENSOR - Sensors are the most critical of all the systems. The accuracy of the micro mouse relies on the quality of sensors. - Four pairs of sensor are required. - Each sensor block is comprised of an infrared emitter, the Vishay TSAL6100 device and phototransistor, Vishay BPV11F - The sensors work on the basis of reflection. - An infrared led is turned on, emitting light in the infrared spectrum, and a reading is made with an adjacent photo transistor and corresponding ADC unit.

CIRCUIT DESCRIPTION OF SENSOR : 

CIRCUIT DESCRIPTION OF SENSOR The phototransistor’s collector is connected to an analog-to digital converter input on the microcontroller. The infrared LED is directly controlled by an output port on microcontroller.

ERROR & P-CONTROL : 

ERROR & P-CONTROL As there is chances of wheel slip at the time of micromouse movement. Chances of error:- 1):-If left looking sensor output is less than the output of right looking sensor . 2):- Or right looking sensor output is less than the output of left looking sensor. To get rid of this problem we use the p-control method. P control stands for proportional . In this we used the feedback concept to control the execution efficiently. In this system sensor data is used as feedback.

ERROR ANALYSIS : 

ERROR ANALYSIS If wall is on both side err=left adc - right adc if err is positive. - mouse is near to left wall and as correction has to move on right side. If wall is only left side err=left adc – reff value if err is positive. - mouse is near left wall and as correction it has to move towards right. If wall is only right side err=right adc – reff value if err is positive - mouse is near right wall and as correction it has to move towards left.

P-CONTROL IMPLEMENTATION : 

P-CONTROL IMPLEMENTATION err_d= err – err_past Adj= err*kp + err*kd kp is proportional controller constant kd id derivative controller constant. The value of Adj is used to either speed up or speed down one of the wheel.

CHASSIS AND WHEELS : 

CHASSIS AND WHEELS The chassis needs to hold two motors, a castor , circuit and the power supply. It can be made using aluminum sheets. The robustness and flexibility of the robot depends on the chassis. The wheels are a crucial part of the robot as they must be very precise in their size for the straight motion of the robot

POWER SUPPLY : 

POWER SUPPLY Micro mouse need a 12V battery as our power supply. Ni-Cd batteries can be used for this purpose because of their better performance. The batteries should be as light as possible to maintain better move for micromouse.

IMPORTANT FACT OF MICROMOUSE : 

IMPORTANT FACT OF MICROMOUSE HOW TO SOLVE 16X16 MAZE?? - Maze can be solve in three simple steps. 1):- First need to explore the whole maze. 2):- After exploring we need to find traversed distance of each block by micromouse. 3):- Final step is to find the shortest distance of center and than give final move to reach goal in shortest time, which depend on coding style and hardware efficiency. Broadly used algorithm for the maze solution is flood-fill algo.

MAZE EXPLORATION : 

MAZE EXPLORATION We define a recursive function :- explore(). Than we used mark() which saved visited block as visited with the help another function maze_entry(). mark[mmc_x][mmx_y]=1……… maze_entry(mmc_x,mmc_y,mmc_dir,front_open) As explore called recursively ,upon termination of this call micromouse will return to the previous square. if(front_open&& unmarked(mmc_y,mmc_x,old_dir)) { go_to(old_dir); * go 1 forward* explore(); * call recursive* go_to(old_dir+2); *go 1 back* } We defined direction as left, right , front so we need three recursive call. After exploring whole maze micromouse will return to starting square

DISTANCE CALCULATION : 

DISTANCE CALCULATION AIM TO FIND MINIMUM DISTANCE OF EACH MAZE SQUARE FROM STARTING PONT:- - For this approach we used FLOOD-FILL algorithm. - According this algo we defined 2D array map int type. - Array used for recording the distance. - we used -1 to mark each unreachable square and [0,0] for starting square. map[i][j]= -1; / initialize/ nmap[i][j]=0; / copy back after each iteration/ …………………………. map[0][0]=0; nmap[0][0]=0; change=1; while(change); /while used to map , entry change/ { change=0 for(i=0;i<mazesize;i++) for(j=0;j<mazesize;j++) / if condition used to take care of maze borders/ { if (map[i][j]== -1) { if(i>0) if(wall[i][j][0]&&map[i-1][j]!= -1) / if value!= -1 than new distance computed and enterd in {namp[i][j]=map[i-1][j]=1} distance array namp/ ……………………………..

THANK YOU : 

THANK YOU

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ALGORITHM IMPLEMENTATION AND MAZE MAPPING BY:- HEETESH KUMAR SINGH