In this research work, an Automatic sliding door System using an infrared sensor was developed. It uses a sensor, a control unit & drive unit to open and close doors at the entrance of a public building. The primary aim of this research work is to learn in details about how the automatic door system works and to understand the concepts involved. The secondary aim is to fabricate a simple circuit model to show how the system works. The main activities involved in this work are the research done on how the automatic door works, sketching a detailed circuit & then fabricating a simple model.

Sliding door is a type of door which opens horizontally by sliding, whereby the door is either mounted on or suspended from a track. Types of sliding doors include pocket doors, Arcadia doors, and bypass doors. Sliding doors are commonly shower doors, glass doors, screen doors, wardrobe and the system can also be done and implemented in the building of school, hall, auditorium, banks, shopping malls, various departmental buildings and they can be extremely useful in a wide variety of environments. Automation is the art of making processes or machines self-acting or self-moving, it also pertains to the technique of making a device, machine, process or procedure more fully automatic, it is a self-controlling or self-moving processes. Automation in the electrical, electronics and computing world has grown rapidly of which it dates back to 1940 when the first electronics computing machine was developed. This has aided humans as it basically reduces/eliminates human intervention, of which automatic sliding door also makes the list of automation in the electro-computing world. An automatic door is an automated movable barrier installed at the entrance of a room, building or space to control and restrict access or provide privacy. Also an automatic door indicates a door that opens on its own as a moving object approaches it. It is an electro-mechanical door that has undergone the process of automation. The reason for making the sliding door automatic is to allow pedestrians to gain easy entrance in and out without having anyone to keep opening and closing the sliding door.

Automatic doors are doors which open automatically when approached by someone, rather than needing to be opened manually with a door handle or bar. Automatic doors are powered open and closed, a door fitted with a spring to close it is not an automatic door. Automatic door is the application of advanced sensor technology, computer programmable control through the PLC and AC variable speed control system PLC control electromechanical actuators to open and close a door automatic door system. Automatic doors originated in the 20th century, 30 to 40 years, which was mainly used for military warehouse, an important plant for the fire, bullet-proof and easy to open the door. Designs for automatic doors vary. Some slide open, while others consist of panels which fold when people enter or exit, and others swing in or out like conventional doors. The doors are equipped with a motion sensor which can detect people when they approach, and the sensitivity of the sensor can be adjusted as needed. For people in wheelchairs and other disabled individuals, automatic doors are an immense boon, since conventional doors can be very hard to work with. It may be impossible to open a conventional door while seated in a wheelchair or navigating with crutches, for example, and for people with disabilities in their hands and arms, conventional doors can present a real obstacle. Automatic doors ensure disabled access into public facilities. These doors require electricity to operate, with electricity driving the motor which opens the doors. Many automatic doors have a manual override so that in the event of a power failure or a mechanical problem, the doors can still be opened. The doors are also designed to be sensitive to obstacles in the doorway, so that they will not close on someone or something which happens to be in the middle of the path of the doors. These safety measures ensure that automatic doors are safe in a variety of situations.

There are three methods by which an automatic door is activated. 1. A sensor detects traffic is approaching. Sensors for automatic doors are generally:

• A pressure sensor - e.g., a floor mat which reacts to the pressure of someone standing on it.
• infra-red curtain or beam which shines invisible light onto sensors; if someone or something blocks the beam the door will be open.
• A motion sensor which uses low-power microwave radar for the same purpose.
• An electronic sensor (e.g. based on infra red or radio waves) can be triggered by something that someone carries, or is installed inside a vehicle. These are popular for garage doors.
•  A switch is operated manually, perhaps after security checks. This can be a push button switch or a swipe card.
•  The user pushes, or pulls the door, once the door detects the movement it completes the open and close cycle. These are also known as power-assisted doors.

In addition to activation sensors, automatic doors are generally fitted with safety sensors. These are usually an infra-red curtain or beam, but can be a pressure mat fitted on the swing side of the door. The purpose of the safety sensor is to prevent the door from opening or slow its speed if an object is detected in its path whilst opening and to prevent the door closing or reactivate it if an object is detected in its path.

There are different types of automatic doors these days.

Automatic swinging door.
1. Automatic telescopic door.
2. Revolving automatic door.
3. Automatic parking barrier.
4. Automatic balanced door.