Our First Semester Project- A Humanoid Greeting Robot

Our first semester project was a simple humanoid robot; under the supervision of Prof. Dr. Sajal Kumar Das Sir, Department Of Mechatronics Engineering, RUET. This paper presents the highlights of the design of this robot and experimental results.

Objectives:

The initial aim of the project was to make a small structure that resembles to human body. The design was for functional purposes, such as interacting with human tools and environments. When a moving object would come close to the structure, it's eyes would be ablaze, would welcome verbally and shake hands.

How It Works:

The robot has a head designed to replicate human facial features such as eyes and mouth. It also has two arms, two legs and a main body. The whole structure was made of plastic wood. Two LEDs were used as eyes, a voice module along with a speaker were used to deliver the welcome words and a servo motor to control the movable arm.

After making the structural body by plastic wood.

Painting the body.

We have used a PIR sensor (Passive Infrared Sensor) to detect the presence of any moving object, connected to the LEDs. The PIR sensor itself has two slots in it, each slot is made of a special material that is sensitive to IR. The lens used here is not really doing much and so we see that the two slots can 'see' out past some distance (basically the sensitivity of the sensor). When the sensor is idle, both slots detect the same amount of IR, the ambient amount radiated from the room or walls or outdoors. When a warm body like a human or animal passes by, it first intercepts one half of the PIR sensor, which causes a positive differential change between the two halves. When the warm body leaves the sensing area, the LEDs blow up.

We also used a voice module ISD1820; which offers single-chip voice recording and playback capability. After detecting human presence, a speaker connected to the ISD1820 delivers the greeting words such as "Welcome to the department of Mechatronics Engineering".

In the robotic arm, we have used a servo motor, which is controlled by sending an electrical pulse with variable width or pulse width modulation(PWM). The motor can usually turn 90° in either direction for a total of 180° movement. Here, the motor's neutral position is a little parallel to the main body of the robot. When PWM is sent to the motor, it turns 90° upwards and the arm gets prepared to handshake with the visitors. The servo was controlled by Arduino.

TEAM MEMBERS:

The whole project was done successfully after overcoming some challenges; with a lot of contributions of the 30 team members, the students of Department of Mechatronics Engineering, 16 series, RUET. Everyone was supportive of the project. The members are:
MD. Abul Kashem Niloy, Erphan Ahmmad Bhuiyan, Shahriar Jahan Sakib, FIZ Suhrid, Roknuzzaman, Riaz Khan, MD. Hafizur Rahman, Abdullah Al Noman, Jalal Uddin, MD. Shihab Uddin, Nabila Afrin, Mushfiq Alam, Tansu Sila Haque, Shahid Ahmed Hasib, Iffat Fahmida, Seikh MD. Naimul Islam Nayeem, Jaki Muzahid, MD. Rejaul Karim Reja, MD. Alam Nashrah Khan, Yeahia Sarker, MD. Zahid Hasan, Nurul Amin Asif, Anika Shama, MD. Zahid Hossain, MD. Maeenul Azad Akhand, Shorif Ul Islam, Mehtar Jahin Tatha, Wasif Ahmed, MD. Ruhul Amin and Swarnali Deb Bristi.