Roller Stroller

By Sai Praneeth Singu, Ali Shokri & Chia Yen Wu

This project was done as part of material manipulation machine assignment for the ITECH programme.

Roller Stroller is a Mobile painting robot which fills the paint within the area designated autonomously and stays within the area.

Basics:

Arduino Uno

USB Cable

Motor Driver Shield L293D

AA Batteries (x 8)

Power bank

Sensors:

IR Sensors (x2)

Motor Related:

DC Motors 6V (x4)

MG 996R High torque Servo

Peristaltic Pump

Mechanics:

PETG Printed parts

M4 Bolts with nuts (2cm , 3cm & 4 cm) long 5 each

Material:

Plywood

Use the files given below for 3d printing the parts and assemble them as shown in the figure.

The roller act as a wheel. Two gears sit inside on the either side of each roller. Two DC motors sit on either side of the roller. Their shaft sits inside the gears. the motor mounts support the motors. The motor mount supports support the motor mount. Finally the frame connects both sides of the roller making it a front wheel assembly. Similarly, Rear wheel assembly is also printed with the same pieces.

The main Body consists of two plates made out of Plywood 6mm thick each. The front of the front piece & the rear of the back piece are connected to the both 3d printed frames. The other ends of the pieces are connected by means of a servo motor which is screwed to a column attached on back plate & is screwed to the front plate through its fan which rotates the plate.

The front plate is attached with two long thin L shaped plates for the IR Sensors to be attached. These IR sensors are used for edge detection & sudden changes in colour. A small wooden container with legs is attached on top of the front plate to fill in the paint. The Arduino Uno board & the motor shield is fixed on top of the front plate with a double sided tape. 4 AA batteries in series are used to power the dc motors and are placed on top of the column.

Each connection in the diagram is explained as following:

KY-032 IR Obstacle Sensor

   Right IR Sensor

       Out pin: connected to Motor Driver shield A1

       Vcc pin: connected to Motor Driver shield 5V

       Ground pin: connected to Motor Driver shield GND  

   Left IR Sensor

       Out pin: connected to Motor Driver shield A2

       Vcc pin: connected to Motor Driver shield 5V

       Ground pin: connected to Motor Driver shield GND

MG996R Servo Motor

     Signal pin: connected to Motor Driver shield Servo Terminal 1 (pin 10)

     Power pin: connected to Motor Driver shield 5V

     Ground pin: connected to Motor Driver shield GND

DC Motors

     DC Motor1: connected to Motor Driver shield M1

     DC Motor2: connected to Motor Driver shield M2

     DC Motor3: connected to Motor Driver shield M3

     DC Motor4: connected to Motor Driver shield M4

The logic behind the function is that if the left sensor detects an edge the servo steers a little to get it straight. but if both the ir sensors detect edges, the robot goes back a little and then steers to the right and also moves forward during the same time. Thereby the robot keeps moving within its confined area.

A Peristaltic pump has an inlet & outlet connected to a dc motor. It pumps liquid from one place to another. It's fixed onto the front plate. with one end of pipe in the container & the other attached to a splitter by means of which the paint falls directly onto the roller. Another 4 AA batteries in series are used to actuate the pump. The test is made on a black paper surrounded by white sheets. In the first run, it paints all the edges with a white paint while avoiding the white border & staying within the black sheet. In the next rounds, it also detects the white paint & moves to the inside area thereby painting all the area.

Your mobile Painting robot is ready to paint. Have fun.