Patent 10549954 was granted and assigned to Otis Elevator Company on February, 2020 by the United States Patent and Trademark Office.
According to an aspect, an elevator system includes an elevator car 14 to travel in a hoistway 11 and a linear propulsion system 20 to impart force to the elevator car. The linear propulsion system includes a secondary portion 18 mounted to the elevator car and a primary portion 16 mounted in the hoistway. The primary portion includes a plurality of motor segments 26. The elevator system also includes a load sensor 52 operable to detect an elevator load on a brake. The elevator system further includes a control system 46 operable to apply an electrical current to at least one of the motor segments that overlaps the secondary portion, determine a measurement of the elevator load, and vary an electrical angle estimate while the brake is engaged and thrust is applied.