Criteria for RUET ROBO RUN

Task : 
Each team has to build one autonomous bot which is able to go following the line
given in the arena.



Bot specification:
The bot must fit within 25cm * 25cm square. The power supply must be
dc(<=24V) installed in the bot. The bot must not do any harm to the arena or any
human being.



Arena Speciation:
As  specified in the figure (Black line on white background) .Run will start in the
start position and will end in end position as specified. In the path there are some
check points.



Rules for selecting winner:
Winner will be selected according to point earned. Earning the higher point will
get a higher rank. In the final round speed will be considered.
 

Fig1: Full Arena (Red mark text will not be present in original arena)

Fig2: Specification of dimensions of the arena 

Rules for points:
1.  Crossing every check point will be awarded with 3 points.
2.  Stopping at the end point will be awarded with 3 points.
3.  If the bot go outside the arena or stop or any other inconvenience occurs it
must take a restart.
4.  A team can take at most 5 restarts.
5.  A penalty of 1 point will be deducted from the score for every restart.
6.  While restarting the bot will be placed in the last check point it passed.
7.  Before restarting a team cannot do any major hardware change or any kind
of software change.


Rules for game play:
1.  One bot at a time will run in the arena.
2.  A team will have total 10 minutes to complete its run.
3.  Two rounds will be played among all team.
4.  A final round will be played between first, second and third according to
total point earned in the first two rounds.
5.  A team will be fully responsible for the safety of their bot.
6.  Judges have all the rights to take decision during the game play.

Rules for disqualification:
1.  A team will be disqualified if the bot does not fulfill the bot specification
criteria.
2.  A team will be disqualified if any attempt of cheating is made.
3. A team will be disqualified if any unfair behavior is seen.

Choice of Battery for Line Follower Robots

As normally line follower robot is small in size and need to accelerate quickly the choice of battery is very important . The size of the battery need to be small and the weight need to be very low. The power storage of the battery needs to be high.

Rechargable Battery :

 As the bot needs to run again and again choosing a rechargeable battery will be sensible. Two types of rechargeable battery can be used.

1. Lithium-ion battery
Mobile phone battery can be used. One mobile phone battery gives 3.7 v. Connecting them is series gives higher voltage and connecting them in paraller gives higher backup. The energy capacity is rated in mAh rating . Higher the mAh rating higher is the storage capacity and higher is the backup.

2.Lithium polymer battery:
Lithium-ion polymer batteries, polymer lithium ion or more commonly lithium polymer batteries (abbreviated Li-poly, Li-Pol, LiPo, LIP, PLI or LiP) are rechargeable (secondary cell) batteries. LiPo batteries are usually composed of several identical secondary cells in parallel to increase the discharge current capability, and are often available in series "packs" to increase the total available voltage.
Before using them just learn the safety precaution. They explode in high temperature. They need to be charged using controlled charger.

 



Non Rechargeable Battery :
If some one wishes to use non rechargeable battery then 9v Duracell batteries can be used.

My experience:

I used mobile phone batteries in series in my robot. They gave good backup, low weight and seize make it convenient and also good life time.

 

How to make a line follower robot

Here u will find some information but no details is given. For details just google. U will find may sites and blogs with details.


What is line follower Robot?

A line follower robot is a robot that runs following a line in an arena and may be do some other staffs . 



What do I need to make one?

You will need five things.
1. A circuit which includes a micro controller (brain of the bot).
2.Motors to run the bot.
3.Sensors to follow the line.
4.A Chassis to make a structure.
5.Battery as power supply.

How can I make the circuit?

You can create the circuit from the schematic you designed by using vero board and soldering or u can design a PCB  then print it and then solder. For designing PCB u can use Preteus or Eagle Cad.

What about the Microcontroller?

I use atmega32. It has 8 ADC channel which can be used. It has enough memory and pins  and easy to use. C language can be used to program it.


What kind of motor do I use?

U can use small DC geared motor. U can use L293d as motor driver IC. Speed control can be done by PWM. But the problem of u this type of motor is u can  not stop the bot suddenly due to inertia and accurate speed control is possible only is a limited range.
U can also use stepper motor. They will give very accurate movement. U can add external gear for higher torque. But beginner may find them difficult in handling . I found the awesome.
U can also use modified servo motor for continuous rotation. They are then variable speed geared dc motor. They very easy to control by PWM also no driver IC is not needed. May be very handy for beginners but a little bit costly.

How do I make sensors?

Reflection of LED light is higher in white surface and lower in black surface. This phenomena is used to identify the position of the bot in the arena. Both LDR and photo diode give higher resistance if incident light is lower and lower Resistance if incident light is higher. This feature is used to make sensors.For making sensors u can use LDR and LED pair . But for black and white surface IR emitter and IR photo diode will be the best. In the circuit u can use voltage divider arrangement take input using microcontroller adc pin. For faster response Comparator arrangement with opamp is good. A pot must be kept for calibrating in comparator.

How do I make Chassis?

Chassis can be made in many different ways. Make sure that weight is as low as possible and the body is rigid enough. For that u can use plastic board.

What will be the arrangement of wheel?

The easiest arrangement is two wheel with two motors in the backside and one free moving wheel in the front side. This will allow you differential movement. Just google "differential movement". You can collect wheels from old toy or can buy a new toy and take the wheels from there. For the free moving wheel u can use ball caster or can use rubber ball caster.



Which battery do I use?

You can use rechargeable Lippo battery. You can also use rechargeable Li-ion battery. Two or three mobile phone battery in series is a good choice but a bit expensive. Battery with higher Ah rating will give  more backup.

What will be the algorithm?

 Simply saying when the bot is drifting off the line to the left then turn right a little bit and vice versa. Many adjustment and modification is needed for faster and smooth run. Many different algorithm can be used. Just google and learn. PID is a famous one for a continuous and smooth line.


Some special tips:
1. Keep the weight as low as possible for lower moment of inertia.

2. Use some kind of shield for the sensors to keep it out of external light.

3. Use at least three sensor on each side of the line and another one a bit in distance on each side  for crossing checking that means total of eight sensors.

4.Use rechargeable batteries with enough backup capability.


Some links: (U will find plenty of them in internet )

Photos of some line follower

Bangladeshi Stores for Elcetonics and Robotics Spare Parts 

Choice of Motor for line follower

http://futuredreamersrobotics.blogspot.com/2013/02/making-line-follower-robot.html

http://futuredreamersrobotics.blogspot.com/2013/01/making-light-sensor.html

http://extremeelectronics.co.in/robotics/making-a-line-sensor-using-ir-receiver/

http://extremeelectronics.co.in/avr-tutorials/line-following-robot-using-avr-atmega8/

A Line Follower Robot

This is a line follower robot which follows a white line on a green background. We used LDR as sensor. ATMEGA 32 microcontroller as its brain. When it gets a black mark on the side of its path it takes the next turn on that side. The robot was prepare for GRC13 Bangladesh round.