Modified slowdown and braking of an elevator car

A method of controlling the operation of an elevator system of the kind comprising an elevator car and drive means, said drive means including a motor the speed of which varies according to the torque loading on it, brake means for halting the car and a component the angular velocity of which varies in proportion to said speed, said method being effective to bring the car to a halt at a floor level and comprising the steps of:

• producing by sensor means a first signal indicative of the angular velocity of said component,
• producing a reference signal,
• comparing the first signal with the reference signal to derive a difference signal indicative of the weight carried by the car, and
• controlling the operation of said drive means in response to said difference signal to compensate for weight carried by the car during the halting of the car at said floor level;
• said step of controlling comprises the step of actuating said brake means for a period which varies in response to said difference signal.

A method for controlling the operation of an elevator system of the kind comprising an elevator car, drive means, and control means, said drive means including a motor operable at a plurality of nominal speeds and the actual speed of which varies from said nominal speeds according to the torque loading on the motor, brake means for stopping the car;

• said control means issuing a first control signal at a predetermined time for changing said motor nominal speed to a slower nominal speed and issuing a second control signal at a later predetermined time for actuating said brake means, said first and said second control signals being issued at times when said car is travelling at a substantially constant speed;
• said method comprising the steps of:
• producing in response to said first and said second control signals respective first and second difference signals, said first and second difference signal being produced by comparison of a reference signal with respective first and second sensor signals, each of which is indicative of the angular velocity of the motor at a time in close proximity to the time of issue of said first and said second control signals, respectively,
• changing the nominal speed of said motor from a fast to a slower speed at a time an interval after the production of said first control signal, said interval being variable as a function of said first difference signal, and
• actuating said brake means at a time an interval after the issue of said second control signal said interval varying in response to said second difference signal.