Anti-piggybacking: sensor system for security door to detect two individuals in one compartment

• US 5,201,906 A
• Filed: 09/09/1991
• Issued: 04/13/1993
• Est. Priority Date: 10/11/1989
• Status: Expired due to Term

• Current Assignee: Tomsed Corporation (Kareni BV)
• Original Assignee: Milan Schwarz
• Inventors: Mayer, Robert, Schwarz, Milan
• Primary Examiner(s): Cuomo, Peter M.
• Assistant Examiner(s): Boucher, D.
• Application Number:
  US07/756,451
• Time in Patent Office: 582 Days
• Field of Search: 367/93, 340/552, 340/541, 340/545, 49/26, 49/31, 49/42, 109/8
• US Class Current: 109/8
• CPC Class Codes: E05F 15/608 for revolving wings
• CPC Class Codes: E05G 5/003 Entrance control E05G5/02 takes precedence
• CPC Class Codes: E05Y 2900/132 Doors
• CPC Class Codes: G01S 15/04 Systems determining presence of a target
• CPC Class Codes: G01S 15/87 Combinations of sonar systems
• CPC Class Codes: G07C 9/22 in combination with an identity check of the pass holder
• CPC Class Codes: G08B 13/1636 using pulse-type detection circuits

Abstract

A control system for a revolving door includes an ultrasonic sensor having multiple sensor heads. The door has a housing and multiple movable compartments formed by door wings. The sensors emit energy waves into the housing in bursts, then receive echoes from any objects, including people, in the compartments. The sensors are activated when the door is activated by an authorized user. A controller stores a binary "echo" or "no echo" signal in memory in response to an emitted energy wave. The system determines a maximum height of an object or person in a compartment, then measures the total amount of time that it detects something above a selected percentage of the maximum height. When this time reaches a predetermined amount, the system interprets that as "piggybacking" (two individuals in one compartment). The system also interprets signals that go above, drop below, and then rise above the selected percentage again as piggybacking.

Claims

1. A control system for a security door having a housing with a first portal, a second portal, and movable door member, forming at least one compartment, for normally blocking passage between the first and second portals, the control system comprising:

means for identifying an authorized user;

means for moving the door member to move a compartment containing the authorized user from the first portal to the second portal;

means for tracking movement of the door member and the compartment containing the authorized user from the first portal to the second portal;

sensing means disposed in the housing for emitting energy waves into the housing between the first and second portals, and for detecting echoing of the energy waves due to any objects or users in the housing; and

a controller connected to the means for moving, the means for identifying, the sensing means, and the means for tracking for driving the means for moving in response to identification of an authorized user, said controller including means for detecting successive heights in response to echoes detected b the sensing means and means for determining that there is a second user in the compartment containing the authorized user on the basis of the successive detected heights.

2. The system of claim 1, wherein the means for detecting and determining comprises means for comparing the successive detected heights to a predetermined percentage of a maximum detected height, and for indicating that a second user has been detected when a minimum number of the detected heights exceed the predetermined percentage of the maximum height.

3. The system of claim 1, wherein the means for detecting and determining comprises means for comparing the successive detected heights to a predetermined percentage of a maximum detected height, and for indicating that a second user has been detected when the detected heights form a pattern where they exceed the predetermined percentage of the maximum height, then fall below the predetermined percentage of the maximum height, then once again rise above the predetermined percentage of the maximum height.

4. The system of claim 2, wherein the controller further comprises means for determining a height of an object or user detected by the sensor means for successive positions of the door means, means for comparing further compares successive detected heights to a predetermined percentage of a maximum detected height, and indicates that a second user has been detected when the detected heights form a pattern where they exceed the predetermined percentage of the maximum height, then fall below the predetermined percentage of the maximum height, then once again rise above the predetermined percentage of the maximum height.

5. The system of claim 1, wherein the security door is a revolving door and the movable door member forms a plurality of movable compartments.

6. The system of claim 1, wherein the controller performs security measures in response to a determination that there is a second user in the compartment containing the authorized user, the security measures comprising at least one of stopping the door member and reversing the door means until the compartment containing the authorized user returns to the first portal.

7. The system of claim 1, wherein the controller determines that there is a second user when the echoes detected by the sensing means form a predetermined pattern.

8. A method for controlling a security door having a housing with a first portal, a second portal, and a movable door member, forming at least one compartment, for normally blocking passage between the first and second portals, the method comprising the steps of:

identifying an authorized user;

moving the movable door member to move a compartment containing the authorized user from the first portal to the second portal in response to identification of an authorized user;

tracking the amount of movement of the movable door member containing the authorized user from the first portal to the second portal;

emitting bursts of energy waves from a sensor into the housing between the first and second portals, and detecting echoes of the energy waves with the sensor due to any objects or users in the housing; and

successively determining a height of an object or user in the authorized compartment in response to echoes detected by the sensing means and the amount of movement of the movable door member and determining that there is a second user in the compartment containing the authorized user on the basis of the successively detected heights.

9. The method of claim 8, wherein the step of determining further comprises a step of comparing the successive detected heights to a predetermined percentage of a maximum detected height, and determining that there is a second user in the compartment containing the authorized user when a minimum number of successive detected heights exceeds the predetermined percentage of the maximum height.

10. The method of claim 8, wherein the step of determining comprises a step of comparing the successive detected heights to a predetermined percentage of a maximum detected height, and indicating that a second user has been detected when the detected heights form a pattern where they exceed the predetermined percentage of the maximum height, then fall below the predetermined percentage of the maximum height, then once again rise above the predetermined percentage of the maximum height.

11. The method of claim 9, wherein the step of determining further comprises a step of comparing the successive detected heights to a predetermined percentage of a maximum detected height, and indicating that a second user has been detected when the detected heights form a pattern where they exceed the predetermined percentage of the maximum height, then fall below the predetermined percentage of the maximum height, then once again rise above the predetermined percentage of the maximum height.

12. The method of claim 8, wherein the security door is a revolving door and the movable door member forms a plurality of compartments, and the step of moving comprises revolving the door member to move the plurality of compartments.

13. The method of claim 8, wherein the step of determining comprises determining that there is a second user when the echoes detected by the sensing means form a predetermined pattern.

14. The method of claim 8, further comprising a step of performing security measures in response to determining that there is a second user, the security measures comprising at least one of stopping the door member and reversing the door member until the compartment containing the authorized user and second user returns to the first portal.