My aim is to produce a line follower robot with a bump sensor Essay

My aim is to produce a line follower robot with a bump sensor which can reverse if it goes off course. Research: Line follower robots are most commonly produced to take part in competitions. The purpose of the line follower robot is to follow a line. The robot will only follow a line that is black against a white background or a white line against a black background. This is so that the sensors can distinguish a clear difference in light and so the robot can trace and follow the line. From my research I have decided to use infrared LED emitters (phototransistors). They are fairly cheap but work relatively well. To research into the project I was going to make I looked on the internet to find other examples of the line follower robots. I found many different variations and concentrated on the components used. I looked into books and gathered information on how to assemble the circuit on the breadboard and researched on how the components work. I have researched on the type of amplifiers I could use for the line follower. I will use an amplifier to increase the current as I am using low voltage. I looked on the Maplins website (www.maplins.co.uk) and decided to use the LM386 because it is suitable for low voltage applications and it is relatively cheap. Specification: * The robot has to be able to follow straight lines, curves and turn around corners * It has to follow a black line that is against a white background * It must work using one 9V battery * The robot must be able to reverse from any obstacle it hits * It should be able to function on its own (No help needed to guide it) * It should be small and light, easy to move and pick up if veered off course. * Should indicate what direction it will turn Generation of possible solutions: I could use 2 light dependant resistors to detect the difference in light reflected from the line. It would react quite slowly I could use two phototransistors which emit infrared beams onto the line. When less light is detected on the phototransistors there is less resistance thus allowing the motors to move. Sub-system development: My circuit had two designs combined. First is the line follower, which detects light and moves according to the line, and the other part is a bump sensor which when it stumbles across an obstacle it reverses, this is ... ...llowed the light. I also used an ammeter to check the current passing through the circuit. This confirmed that my circuit was working correctly. When I covered the phototransistors the there was around 0.4 A passing through. However, when I applied light onto the phototransistors (using an ordinary LED) I noticed that the reading on the ammeter was 8.6 A. this proves my theory that covering the phototransistors, it increases the resistance. Evaluation: My circuit works well and follows my specification. The motors move forward when light is placed and it and slow down when no light is present on the phototransistors. * Robot has the ability to move in s straight line, around curves and turn corners. * With the photo transistors it can follow a black line against a white background. * It works using a 9V battery * It has a relay which reverses the direction of the motors turning so it can move away from obstacles * It doesn’t require anyone to move it or guide it using a remote control. * It is light and easy to move so when it goes of course I am able to put it back on the line * Has two LEDs which indicate what direction it is turning