The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 04, 2000
Filed:
Jan. 22, 1999
Steven D Coste, Berlin, CT (US);
Sally D Mahoney, Forestville, CT (US);
Otis Elevator, Farmington, CT (US);
Abstract
A normal terminal stopping device (NTSD) using terminal zone position checkpoint detection with a binary coding method to identify a checkpoint within a terminal zone, and a digital shaft encoder mounted on the shaft of the hoist motor to determine a car position relative to a target stopping point. A microprocessor-based controller is used to compare a velocity command signal to a velocity limit reference. If the velocity command exceeds the velocity limit, the NTSD functions will take over to cause the elevator car to decelerate at the NTSD rate. In particular, the velocity limit reference is computed according to lead compensation and curve shaping techniques to attain better drive tracking characteristics of the motion controller. Binary coded checkpoints are used to eliminate error introduced in a car position derived from a motor shaft digital encoder. The normal terminal stopping device and method according to the present invention is less sensitive to the vane spacing as compared to the conventional NTSD designs.