Electricity: motive power systems – Motor-reversing – Periodic- or intermittent-reversing
Reexamination Certificate
1999-02-08
2001-07-03
Martin, David S. (Department: 2837)
Electricity: motive power systems
Motor-reversing
Periodic- or intermittent-reversing
C318S468000, C318S480000, C049S025000, C049S026000, C049S031000
Reexamination Certificate
active
06255791
ABSTRACT:
FIELD AND BACKGROUND OF THE INVENTION
The present invention relates to an ultra sonic method and apparatus for automatically controlling the opening and closing of moving doors, particularly sliding doors.
Automatic door control systems are gaining wide-spread use in order to control traffic into or out of enclosed spaces which are heated or cooled by airconditioning systems. Such door control systems not only must detect and respond to objects moving towards the closed doors, but must also provide protection against injury by a closing or opening door, and further, should minimize the time the door is in the open condition in order to minimize wastage of the energy used for airconditioning the enclosed space.
OBJECTS AND BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide an ultrasonic method and apparatus for automatically controlling the opening and closing of doors having advantages in the above respects.
According to one aspect of the present invention, there is provided a method of automatically controlling the opening and closing of a door movable over a floor, and a drive for driving the door to its open and closed positions, comprising the following operations: (a) ultrasonically monitoring a predetermined approach area located in front of the door for the entry of an object into the approach area and the movement of the object towards the closed door; (b) ultrasonically monitoring a first predetermined lateral area laterally outwardly of the outer end of the closed door, and a second predetermined lateral area inwards of the inner end of the door for the presence of an object in the opening-door and closing-door protect areas; and (c) controlling the drive in response to the monitoring operations.
According to further features in the described preferred embodiment, monitoring the predetermined approach area is performed by a first group of ultrasonic transceivers spaced along the door and directed at an acute angle towards the floor; whereas monitoring the protect area is performed by a second group of ultrasonic transceivers spaced along the door and directed substantially perpendicularly towards the floor.
According to another aspect of the present invention, there is provided a method of automatically controlling the opening and closing of a door movable over a floor, and a drive for driving the door to its open and closed positions, comprising, ultrasonically monitoring a predetermined approach area located in front of the door by: (i) dividing the predetermined approach area into a plurality of strips; (ii) dividing each strip into a plurality of cells, to thereby define a matrix of cells; (iii) detecting the presence of an object in any of the matrix of cells; (iv) detecting the center of gravity of all the cells in which an object is detected; (v) monitoring the movement of the detected center of gravity with respect to the door; and (vi) controlling the drive to open the door when the detected center of gravity is determined to be moving towards, and at a predetermined speed towards or within a predetermined distance from, the closed door.
As will be described more particularly below, such a method may be implemented by an expansible modular construction by providing an ultrasonic head for each strip of the approach area and by processing the output of each head in a separate channel. Also, the novel method avoids the need to discriminate between different sensors (e.g., by frequency or time discrimination), and also the need to distinguish between many objects in the approach area. Such a method also distinguishes cross-traffic (traffic moving substantially parallel to the doors) which should not open the doors, from approaching traffic which should open the doors.
The invention also provides apparatus for automatically controlling the opening and closing of doors in accordance with the above method.
Further features and advantages of the invention will be apparent from the description below.
REFERENCES:
patent: 4706227 (1987-11-01), DuVall et al.
patent: 4866881 (1989-09-01), Morrow et al.
patent: 4894952 (1990-01-01), Trett et al.
patent: 4914859 (1990-04-01), Gionet et al.
patent: 5428278 (1995-06-01), Bollengier et al.
patent: 5996281 (1999-12-01), Takano et al.
Barish Benjamin J.
Janus Development LTD
Martin David S.
Sheinbein Sol
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