As the use of elevators has grown and their performance has been improved to provide safer, more dependable, and more efficient travel for passengers in multi-story buildings, so too have elevator controls been improved. The operation of the modern-day elevator is very complex, involving strict safety requirements. As a part of an elevator's equipment, the controls must accommodate several types of passenger requirements: VIP service (firefighters and medical personnel), restricted access, non-stop service, and peak demand needs. Elevator controls also need to feature modes of operation for fire response and maintenance.
The basic operation of an elevator involves moving between floors in the hoist-way, stopping at floors, and opening and closing the doors at each floor, allowing passengers to enter and exit safely. An elevator car typically has a single door with a door operator, a drive that can accelerate and decelerate the car in the hoist-way, and an emergency stop brake for safety purposes. Early elevators required manual operators to control the car's speed and stop it at individual floors. To improve efficiency, hall buttons and car button controllers were incorporated as part of the system to manage input from passengers. The car lantern controllers and car position indicator provide feedback to the passengers after their requests have been made. All inputs by passengers are received and processed at the elevator’s controller panel, located in the machine or equipment room. The elevator controller is a sophisticated monitoring and control system that optimizes performance by scheduling and dispatching elevator cars efficiently to requested destinations.
Traditional elevator control programs are not able to provide the most efficient methods of maintaining high transportation capacity. Newer elevator control systems use what the elevator industry refers to as 'artificial intelligence' to predict passenger demand. These systems group occupants by destination for faster service. Passengers enter their desired floor into a keypad near the hoist-way entrance, and are then assigned to a specific elevator car based on similar destinations. The system automatically assesses elevator positions and assigns a car that will deliver passengers to their desired floor. This reduces wait times and repeated stops, and also reduces crowds in lobbies and cars. A computerized traffic program analyzes elevator use, predicts peak periods, and then directs cars in anticipation of heavy demand. The system also continually calculates traffic patterns in order to analyze usage and keeps track of capacity by monitoring the weight inside each car.
Passenger elevators on an accessible route must meet the requirements of the ADA Accessibility Guidelines (ADAAG) for Buildings and Facilities. Location and types of control devices for passenger input are defined by ADAAG. All elevator functions are required to be accessible.
Typical Elevator Controls
- Hall Buttons: located in elevator lobbies and corridors. Must be centered 42" above the floor. These call buttons will give a visual signal when a request is placed and again when the request has been completed.
- Hall Lanterns: provide visual and audible signals at each hoist-way entrance. Signaling of the hall lantern indicates which elevator has answered a passenger request and the direction the elevator is traveling. These fixtures must be mounted so that their center-line is at least 72" above the floor.
- Hall Position Indicators: located above the hoist-way entrance frame. Indicates the position of the car and can also indicate the direction of travel.
Within the elevator car, and usually part of the car panel, is the car operating panel, which can include the direction and position indicator, floor buttons, emergency buttons, and other secured switches.