Term Project on Design Lab on Vibration and Dynamic Systems
Recognized for exceptional performance, ranked 1st in term project presentation (received A+)
Key skills: Arduino / UART communcation / obstacle evasion / 3D printing / 3D modeling
Abstract
At the time of the project, societal awareness regarding sanitization was heightened due to the ongoing Covid-19 pandemic. In response to this trend, I envisioned designing an autonomous hand sanitizing robot. This robot is programmed to navigate randomly around a building, adept at avoiding obstacles in its path. Upon detecting a hand near its sanitizer dispenser, the robot halts and dispenses hand sanitizer. This innovation serves as a proactive measure to promote public hygiene, providing a convenient and touchless sanitization solution for individuals within the building. By aligning with the prevailing emphasis on hygiene, this robot aids in managing public health in a user-friendly and automated manner.
Robot Hardware
The robot hardware consists of sanitizer pressor and mobile robot base. First, the sanitizer pressor consists of a stepper motor connected to a rack and pinion, which vertically presses the sanitizer. The Infrared distance sensor placed in front of the pressor sense the human hand. Next, mobile robot base first wanders around the building, by controlling the DC gear motors. It includes the sonar sensor, and conveys two Arduino Uno boards and batteries.
Fig 1. Robot hardware overview
Software Design
The setup involves two Arduino boards, each situated at the back of the robot base, designated to control distinct hardware elements of the robot; one is responsible for managing the sanitizer dispenser mechanism, while the other oversees the mobile robot base operations. Given the necessity for coordinated movement and operation between the sanitizer dispensing and the mobile base, these two Arduino boards communicate with each other using UART (Universal Asynchronous Receiver/Transmitter) communication protocol. This arrangement ensures synchronized functioning between the mobile base and the sanitizer dispensing actions, allowing for effective and seamless operation as the robot navigates through the building and dispenses sanitizer when needed.
Obstacle Evasion
The mobile robot base is programmed to roam randomly within the building. During its wanderings, it utilizes a sonar sensor to detect any obstacles that could potentially collide with it. If the sensor's readings indicate a distance of less than 130mm to an obstacle, the robot halts its movement. It then remains stationary until the distance value alters, indicating a clear path. Upon sensing a change in distance, the robot randomly selects a new direction, either left or right, and resumes its movement. This obstacle avoidance mechanism ensures the robot's safe navigation through the building, minimizing the risk of collisions while it performs its sanitization duties.
Sanitization
The design incorporates an infrared distance sensor on the front of the sanitizer dispenser mechanism. When this sensor detects an object—such as a hand—within its sensing range, it triggers the robot to halt its movement. Following this, the robot activates the stepper motor, which in turn operates the mechanism to press down on the sanitizer dispenser, releasing hand sanitizer onto the detected hand. This setup ensures that the robot not only provides a mobile sanitization solution but also operates in a touchless and automated manner, contributing to enhanced hygiene practices within the building.
Combined Movement
Equipped with an obstacle evasion algorithm and a sanitization algorithm, the robot is proficiently programmed to carry out its designated tasks. As it randomly roams around the building, the obstacle evasion algorithm ensures that it navigates safely by detecting potential collisions and taking necessary actions to avoid them. On the other hand, the sanitization algorithm triggers the dispensing of hand sanitizer whenever a hand is detected near the dispenser mechanism. These integrated algorithms enable the robot to contribute to the maintenance of hygiene within the building, by providing accessible sanitization while also ensuring safe and autonomous navigation through its environment.
