Authors: Ms. Achal A. Koyale, Ms. Shravani S. Golegaonkar, Ms. Maithili V. Mangalagiri
Abstract: In modern public and commercial environments, frequent physical contact with door handles increases hygiene risks and creates accessibility challenges for elderly and physically challenged individuals. To overcome these limitations, this paper presents the design and implementation of a contactless automatic door opening and closing system using ultrasonic distance sensing and microcontroller-based control logic. The proposed system employs an HC-SR04 ultrasonic sensor to continuously monitor the presence of approaching objects. When the detected distance falls below a predefined threshold, a servo motor is actuated to control the opening and closing of the door. A delay-based safety control algorithm is implemented to prevent unintended door closure and to ensure smooth and reliable operation. The system is developed using low-cost and easily available hardware components, making it suitable for small-scale and public applications such as hospitals, offices, shopping malls, and public washrooms. Experimental results demonstrate accurate object detection within a range of 2 cm to 80 cm, stable door operation, and minimal response delay. The proposed system provides an efficient, economical, and scalable solution for contactless door automation and can be further enhanced through IoT integration and advanced sensing technologies.
