DESIGN AND IMPLEMENTATION OF DISTANCE MEASUREMENT MODULE, FEEDBACK SUBSYSTEM, AND USER INTERFACE SUBSYSTEM IN ADAPTIVE GUIDING CANES FOR THE VISUALLY IMPAIRED

• Main Author: Kusuma Wardhana, Fadhil
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/87706
• Institution: Institut Teknologi Bandung

The adaptive guiding cane is a navigation aid designed to enhance the independence and mobility of visually impaired individuals. In this final project, the author developed and implemented a distance measurement module, a feedback subsystem, and a user interface subsystem for the adaptive guiding cane system. Each component was designed to work synergistically, providing accurate, intuitive, and accessible information tailored to the navigation needs of visually impaired users. The distance measurement module utilizes the HY-SRF05 ultrasonic sensor as its primary component, which operates by measuring the travel time of sound waves emitted by the transmitter to an object and back to the receiver. This module can detect distances within the critical range of 72 to 216 cm with an average error of 1.37%. At the minimum distance of 72 cm, the measurement error is as low as 0.77%, while at the maximum range of 216 cm, the error remains low at 1.22%. The distance data collected is processed by the Raspberry Pi Zero 2W, which serves as the main microcontroller. The reliability of this sensor ensures the module operates stably across various environmental conditions. The feedback subsystem is designed to notify users of the presence of objects or obstacles around them. Feedback is provided through two primary methods: audio and vibration. Audio feedback is delivered via wireless earphones connected to the Raspberry Pi Zero 2W via Bluetooth. This system produces beep sounds with increasing frequency as the detected object gets closer, mimicking a parking sensor system. It is designed to operate within a safe sound intensity range of 65–80 dB, ensuring user comfort while protecting their hearing from excessive noise exposure. On the other hand, vibration feedback is generated using a vibration module, with intensity controlled by a Pulse Width Modulation (PWM) signal. The vibration intensity dynamically increases as the detected object comes closer, providing tactile information that is easy for users to interpret. The combination of these two methods offers flexibility, enabling users to choose feedback types based on their preferences and environmental conditions, such as in noisy environments or situations requiring heightened sensitivity. The user interface subsystem aims to provide ease and convenience in operating the system for visually impaired users. This system employs four push buttons designed to manage the primary functions of the device, such as turning the device on and off, selecting feedback modes, and activating or deactivating object detection. These buttons are connected to the GPIO pins of the Raspberry Pi and are programmed with a debouncing feature to ensure accurate input detection, avoiding unintended multiple activations. The physical placement of iv the buttons is ergonomically designed to facilitate ease of operation, even without visual guidance. The implementation process involved the integration of the distance measurement module, the feedback subsystem, and the user interface subsystem into a single, efficiently connected system. System testing was conducted to evaluate the performance of each subsystem and the overall system under real-world conditions. The results showed that the distance measurement module achieved high accuracy across the critical range. The feedback subsystem effectively provided audio and vibration notifications corresponding to object distances. Additionally, the user interface subsystem demonstrated quick and reliable responses to user inputs, supporting intuitive and effective navigation. With the results achieved, this adaptive guiding cane is expected to be an innovative and practical solution for visually impaired individuals. The system not only enhances user mobility and independence but also opens opportunities for further technological advancements and development.