A system for detecting and processing over-acceleration and over-speed conditions, the system comprising: a speed detector configured to monitor a speed of an elevator system mass; an acceleration detector configured to monitor an acceleration of the elevator system mass; and a controller electrically connected to the speed detector and the acceleration detector, the controller configured to: receive a sensed speed of the elevator system mass from the speed detector; receive a sensed acceleration of the elevator system mass from the acceleration detector; calculate a filtered speed of the elevator system mass as a function of the sensed speed and the sensed acceleration; and compare the filtered speed to a threshold speed to determine if the elevator system mass has reached an over-speed condition; and characterised in that the controller is configured to: multiply a speed error by a gain to determine a proportional speed error; integrate the speed error and multiply the integrated speed error by the gain to determine an integrated proportional speed error; sum the proportional speed error, the integrated proportional speed error, and the measured acceleration to determine a filtered acceleration; and integrate the filtered acceleration to determine the filtered speed. a speed detector configured to monitor a speed of an elevator system mass; an acceleration detector configured to monitor an acceleration of the elevator system mass; and a controller electrically connected to the speed detector and the acceleration detector, the controller configured to: receive a sensed speed of the elevator system mass from the speed detector; receive a sensed acceleration of the elevator system mass from the acceleration detector; calculate a filtered speed of the elevator system mass as a function of the sensed speed and the sensed acceleration; and compare the filtered speed to a threshold speed to determine if the elevator system mass has reached an over-speed condition; and characterised in that the controller is configured to: multiply a speed error by a gain to determine a proportional speed error; integrate the speed error and multiply the integrated speed error by the gain to determine an integrated proportional speed error; sum the proportional speed error, the integrated proportional speed error, and the measured acceleration to determine a filtered acceleration; and integrate the filtered acceleration to determine the filtered speed. receive a sensed speed of the elevator system mass from the speed detector; receive a sensed acceleration of the elevator system mass from the acceleration detector; calculate a filtered speed of the elevator system mass as a function of the sensed speed and the sensed acceleration; and compare the filtered speed to a threshold speed to determine if the elevator system mass has reached an over-speed condition; and characterised in that the controller is configured to: multiply a speed error by a gain to determine a proportional speed error; integrate the speed error and multiply the integrated speed error by the gain to determine an integrated proportional speed error; sum the proportional speed error, the integrated proportional speed error, and the measured acceleration to determine a filtered acceleration; and integrate the filtered acceleration to determine the filtered speed. multiply a speed error by a gain to determine a proportional speed error; integrate the speed error and multiply the integrated speed error by the gain to determine an integrated proportional speed error; sum the proportional speed error, the integrated proportional speed error, and the measured acceleration to determine a filtered acceleration; and integrate the filtered acceleration to determine the filtered speed.