Patent ID: 8869945

Claim:
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.