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Imagine that you decide to go to the beach on a sunny day, to relax your mind and recharge your energy. Sounds awesome! Unfortunately, as you arrive to the beach, you will be shocked by the tremendous amount of garbage thrown in the sand. Bottles and cans of all sizes are thrown here and there by apathetic people.
Beach pollution is a very serious issue as we go to the beach to enjoy the environment and not to sit on bottles and cans. It harms and pollutes the environment, animals and humans.
Our team was inspired to tackle this problem and to make an automatic robot in the form of a car, that gathers or picks small cans, bottles, pebbles or any small shape pollutants to collect them and later easily be sorted out to the bin.

The beach cleaner is a type of an autonomous RC car. The user can turn it on by pressing on the green button in the back of the car, or off by pressing on the red button.

The car has two DC motors connected to the front wheels, and the rear wheels are free to rotate on the shaft. We calculated the Torque and RPM according to our needs which has been shared in the picture mentioning calculations.

As soon as the green button is pressed, the motors start running and the car moves forward. The flowchart of car’s track is sketched in the image attached.

The first thing to think about is, How to detect garbage? So, this was done using a flex sensor. When the sensor touches the garbage, and due to the forward motion of the car, it will bend indicating that there is garbage (with some delay). At this moment, the car stops, realizing it has found a garbage, it goes back 1 meter and then releases the shovel using a servo motor and moves 1.5 meter distance to make sure that the garbage is on the shovel. Then, the shovel makes 140 degrees rotation about its axis to put the garbage in the garbage collector and then it goes back to its initial position.

Now, suppose the garbage is big. How big? Greater than 10 cm (length of flex sensor). So, now, we consider anything greater than 10 cm height from surface, and obstacle. Great! Now, we use an ultra sonic sensor to detect an obstacle greater than 10 cm height.

For the case of an obstacle , the sensor detects and the car stops. It will now wait for 10 seconds to make sure its not a moving obstacle. Firstly, in the case of a moving obstacle, the car just holds for 10 seconds and then resumes back to normal working. Secondly, in the case of static obstacle then it will now stop and then turn left and then right, right and the again back to left to go back to the normal linear track. Now in order to understand the width of the obstacle so as to turn right and right formation, we added another ultra sonic sensor placed on the right side of the car. This made sure that we don’t bump into obstacles.

Turning left and right on electric motors is easy. We don’t need any mechanisms such as Ackerman steering method to turn the wheels. We turn right by making the right wheel go forward for 4 seconds and left wheel locked and vice versa for turning right. This method however comes with certain limitations.”

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