Automatic velocity measurement system applied to elevator overspeed governors

All around the world, modern elevators transport safely and comfortably millions of passengers and freight each day. Since modern elevators emerged at the beginning of the 19th century, several advances have risen in this transportation system. Among them, safety conditions were significantly improved. Therefore, modern elevators must be equipped with safety protection systems to assure safety conditions and avoid accidents. An overspeed governor is one of the components of such a safety system. It acts as a stopping mechanism when the elevator car reaches an excessive velocity, known as tripping speed. When the tripping speed is reached, the overspeed governor is mechanically locked and halts the rope, thus stopping the elevator car. This paper describes the development of a new measuring system able to measure the trigger velocity of an overspeed governor with the help of a graphical interface available on a mobile electronic device (smartphone or tablet). Practical application: A new overspeed governor velocity measuring system uses a mobile electronic device for non-contact velocity measurement. This new process may replace the inaccurate measuring system currently employed by maintenance technicians, thus increasing its reliability. The main objective consists of rigorously testing the operation of overspeed governors. The developed system guarantees the automatic execution of the test under several anomalous operating situations, thus allowing the user to have real-time access to the test data obtained through a graphical interface available on a mobile electronic device.