Road Follower Truck ~ Studentsjoy

Wednesday, November 23, 2011

Road Follower Truck


Project code:- E59 Project Cost:- INR:- Rs. 7500/- USD:- 200$

Road Follower Truck

One of my friend working for B.H.E.L asked me once ,can you design a control circuit for the truck so that the truck can be operated without driver on the road.Thay had lot of trouble with the local union ,and some times drivers do not perform the way they are expected.
Their requirement was to convey a raw material from point a to point b in a circular fashion. Road reserved only for this purpose.

Road Follower Truck Block Diagram Road Follower Truck Block Diagram

One truck normally takes 150 trips in a day and they want to increase this frequency. There was lot of trouble with designing realtime due to somany factors,but I kept in mind when my student friend asked me to design for them,
I worked on the project and this is the presentation.This robo is self powered.
Heart of our robo is intel’most power family of microcontroller 8051,we are using U1 5v regulator ic, at89c2051microcontroller.ic U2, IC u3 is ld293 motor driver ic which drives two nos motors m1 and m2.
Road Follower Truck Representation Road Follower Truck Representation


Circuit operation:
We have fixed INFRA RED sensors on fore side on the robo. The principle of sensors is that black colour will normally observe the light where other colours will normally reflects the lights light source is fixed down ward D1 and D3 are infra red leds and D2 and D4 are photo diodes reflected light will fall on the photo numbers refer to the second channel). IR l.e.d. D1 has series resistor R11 limiting the current to 40mA. This is near the maximum for the l.e.d., producing a high level of illumination.
The radiation reflected back from the surface is detected by IR photodiode D2. This is reverse-biased so only a weak leakage current flows.The current passes through a high resistance (R9 plus preset
Potentiometer There are two sensors, each comprising an infra-red (IR) l.e.d. and an infrared pho todiode.
The l.e.d. is directed down onto the surface over which the vehicle is travelling. The photodiode receives the reflected radiation. The sensor gives a low logic output when the surface is black or dark- coloured, and a high output when the surface is white or light- coloured. The reason for using infra-red is to avoid interference from ambient light. No problems were found when operating in bright indoor daylight, or in low-level incandescent illumination.
The sensors are used to detect lines painted in black on a white background. Theoretically, it is possible to operate the sensors in the reverse direction, by chang ing the program so that they respond to white lines on a black background. This was the original intention, but an unexpect ed problem was encountered some black cardboard is not black, or at least, it is not black in infra-red light.Two different batches of black card were tried, purchased from the same stationers.
They both looked equally black to the eye; one did not reflect IR, but the other reflect- ed it very strongly. The robot was unable to detect a white strip on the reflecting black background. So it was decided to use white (or light-coloured) fluorescent or metallic card as the background and
paint the paths if the light is more the resistance of the ldr is normally low and transister remains in cutoff state on black road the transister q1 and q2 will reain in cutoff state and transister will go into on (conduction)state.if the robo falls out fron the black road area.
This low logic detection confirms that the robo is not on the black road if the robo is out of the black road this logic will become low and it indicates off-road. Depending upon the left or right sensor robo will move towards right or left direction in order to stay on road out put from both the sensors shoul be high when the robo is on the road.

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