# Design of Autonomous Mobile Robot for Cleaning in the Environment with Obstacles
## 2 Mechanical Design and Electronics Parts
### Mobile Platform  
The robot has a four-wheel-drive platform, which gives the robot more power to carry the weight of its robotic arm and vacuum system. DC geared motors with encoders are used in the mobile platform. A low-level PID speed controller is implemented in Arduino Mega. Each wheel has a diameter of 10 cm. The total length of the mobile platform is 23.9 cm, and the width is 24.9 cm with wheels. The lead battery is used to power the electronics of the mobile platform.  
The upper body of the mobile platform is made up of three parts. These parts play a vital role in connecting the lower body part of the mobile platform with the vacuum system and robotic arm. The LIDAR holder provides the platform for the LIDAR sensor. The touch screen holder is also designed to hold a 7 inch touch screen connected to the top of the vacuum system. The height of the complete robot is 54.1 cm from the ground, a length of 54.1 cm when the robotic arm is fully enlarged, and 24.9 cm is the width of the platform with tires.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Joint Number** & **Servo Name** & **Quantity** & **Torque** \\ \hline Joint 1 & Tower Pro SG-5010 & 1 & 6.5 kg \(\times\) cm \\ Joint 2 & Feetech FS5115M & 2 & 15.5 kg \(\times\) cm \\ Joint 3 & Tower Pro SG-5010 & 1 & 6.5 kg \(\times\) cm \\ Joint 4 & Tower Pro SG-90-micro & 1 & 1.8 kg \(\times\) cm \\ \hline \hline \end{tabular}
\end{table}
Table 1: Details of servo motors.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**S.No** & **Component Name** & **Specification** \\ \hline
1 & ESC, skywalker & Input- 2-4 s Lipo, continous current 50 A \\
2 & Brushless motor, iFlight XING & 2750 KV, max current 50.03 A \\
3 & Lipo battery & 11.1v, 50C, 5000 mAh \\ \hline \hline \end{tabular}
\end{table}
Table 2: Details of electronics component for vacuum system.  
Figure 2: Cut sectional view of the vacuum system.  
Table 3 shows the components of the electronics part of the mobile platform. The robot in total has two batteries. A 6 V DC battery is used to power the motor drivers and low-level controllers, such as Arduino UNO and Arduino Mega, while a Lipo battery is used to power the servo motors of the robotic arm, vacuum system, and Raspberry Pi computer. The robot has three controllers. Raspberry Pi acts as the master controller connected through the serial link to Arduino Mega, which serves as the first slave controller. The Arduino Mega is also connected with Arduino Uno, using serial communication. As a result, Arduino Uno serves as the second slave controller, which controls the direction and speed of one motor. The other three motors are controlled with Arduino Mega, due to the limitations of the external interrupt pins. The L298n motor drivers control the motors' direction and speed. Each motor driver is capable of controlling two motors. Two wires from the microcontroller to the motor driver control the direction, and one wire controls the speed of the motor.  
\"Camera Tracer HD WEB008\" is the digital camera used for the vision system. The device captures HD-quality images with a resolution of 1280 \(\times\) 720 pixels. The lens has a wide-angle view of horizontal 100 degrees and can capture images with 30 frames per second. \"Hokuyo urg-04 lx-ug01\" is used as the LIDAR sensor.