Supplemental elevator safety system

A method for ensuring safety in an elevator system, the method comprising:

• setting a first speed limit;
• measuring a speed of an elevator car;
• entering a first operating mode when the measured speed is greater than the first speed limit, wherein the first operating mode comprises:
• setting a limit value for a rate of deceleration;
• calculating elapsed time since entering the first operating mode;
• measuring the rate of deceleration;
• and
• applying a brake if the measured rate of deceleration is below the limit value for the rate of deceleration;
• determining if the elevator car is within a door zone when the measured speed is less than the first speed limit;
• entering a second operating mode when the elevator car is not within a door zone and entering a third operating mode when the elevator car is within a door zone,
• wherein the second operating mode comprises:
• comparing the speed of the elevator car to a second speed limit;
• and
• applying the brake if the speed of the elevator car exceeds the second speed limit;
• and
• wherein the third operating mode comprises:
• comparing the speed of the elevator car to a third speed limit;
• setting a first and second limit value for a distance of the elevator car to a door zone;
• comparing a distance of the elevator car to a door zone to the first and second limit value for a distance of the elevator car to a door zone;
• and
• applying the brake if the speed of the elevator car exceeds the third speed limit or if a position of the elevator car is between the first and second limit value for a distance of the elevator car to a door zone.