Elevator safety monitoring system, elevator system, elevator drive unit, and method for operating an elevator

An elevator safety monitoring system comprising:

• an elevator car absolute position and speed feedback device;
• a safety monitor connected to the absolute position and speed feedback device;
• a safety device fixed into and relative to an elevator shaft;
• and
• a safety zone extending inside an elevator shaft, the safety zone being delimited by means of the safety device,
• wherein the safety zone is associated with an allowable maximum speed of an elevator car, wherein the allowable maximum speed is lower than a rated speed of the elevator car outside the safety zone,
• wherein the safety device is configured to change between an activated state and a non-activated state, in an activated state the safety device is arranged to extend to a section of the elevator shaft in which the elevator car is allowed to be moved during normal operation of the elevator and to obstruct movement of the elevator car into the safety zone, thereby establishing a safety space into the safety zone, and in a non-activated state the safety device is arranged to allows movement of the elevator car into the safety zone, and
• wherein the safety monitor is configured to determine a slowdown failure of the elevator car approaching the safety zone, and, upon the determination of the slowdown failure, command an actuator to decelerate the elevator car to the allowable maximum speed.