Line follower first prototype.
earlier this month i attended robotic2012 in Birmingham to watch the UK micro-mouse competition. After building a micro-mouse last year for a project it was really interesting to speak to some of the best in the country. whilst there we also got to see some of the other competitions they were running such as drag and robot tracer.
Robot tracer is an event where a robot has to follow a white line on a black surface around a course, you usually get up to 5 runs to set a best time. the robot who completes the course in the quickest time wins. many of the robots that entered this year seamed relatively slow and many were made from “off the shelf” robots, some even used stepper motors to drive the wheels. having built many simple line followers it seamed like it would be relatively easy to build a small line follower that could easily outrun the slower bots.
so what sets this competition apart from previous line followers i have built?
the interesting thing about robot tracer is that the course is made up of straight sections and curves of set radius. on the track there is a marker at the beginning and end of every curve or straight section as well as markers for the begging and end of the circuit. this means that if you can read the markers you could easily learn the course on your first run and then adjust speeds for your other runs (faster on straights and slower on tighter curves). most of the robots that entered this years competition were not able to read these markers and did not learn the course, limiting top speed.
i have decided to try and build a line follower to enter next years competition. i intend on building a small, light robot capable of learning the course. this will require the robot to have some sort of encoders to record position as well as accurate control of wheel speeds.
after doing some research i have purchased some small pololu gear-motors for the robot as well as an atmega 328 based microcontroler with a motor driver. at the moment this has been mounted to a breadboard for easy prototyping and is running off a spare 7.4v battery from my micro-mouse (far to big). i am currently using tires from some Solarbotics RW2i wheels however i have printed my own hubs for these, along with a prototype chassis to hold everything together. this is only a rough design and i intend to make it allot smaller eventually however this will make testing ideas very easy.
plan now is to work out some sort of control for the robot (either Bluetooth or small RF transmitter) and also work out how i can add encoders to the motors.