Aircraft security system

• US 5,063,371 A
• Filed: 12/22/1989
• Issued: 11/05/1991
• Est. Priority Date: 09/29/1986
• Status: Expired due to Term

• Current Assignee: Fenwal Safety Systems Incorporated
• Original Assignee: Guardian Acquisition Corp.
• Inventors: Gudaitis, Algird M., Oyer, Michael W.
• Primary Examiner(s): Crosland, Donnie L.
• Assistant Examiner(s): SWARTHOUT, BRENT
• Application Number:
  US07/455,246
• Time in Patent Office: 683 Days
• Field of Search: 340/505, 340/506, 340/511, 340/517, 340/518, 340/524, 340/541, 340/552, 340/555, 340/525, 340/825.07, 340/825.15, 340/825.16, 340/825.52, 340/825.54 , 340/945, 340/825.06, 340/310 A, 340/507, 375/107, 364/424.01, 364/550
• US Class Current: 340/541
• CPC Class Codes: G08B 26/002 only replying the state of the sensor

Abstract

An aircraft security system includes a central control unit, several remotely located cluster controllers and a plurality of intrusion sensors associated with and controlled by each cluster controller. A two-wire bus carries power from the central control unit for operating each of the cluster controllers and the sensors, and carries data signals in both directions between the central control unit and the cluster controllers. The two-wire bus reduces weight and installation costs. The system includes an initial calibration mode wherein sensor type information and sensor parameters are sent from the central control unit to each cluster controller. The signal strength from each sensor is then measured and stored in the central control unit. During later operation, the sensor signal strengths are measured and compared with the initial values. If a trouble condition is detected, appropriate corrective action is taken. One corrective action includes varying the transmitted energy until the sensor signal strength is within a prescribed range.

Claims

1. An aircraft security system comprising:

an onboard computer;

one or more cluster controllers remotely located from said onboard computer;

a plurality of sensors associated with and controlled by each of said cluster controllers, each of said sensors generating a sensor signal in response to sensing a security condition;

means for communication between said onboard computer and said cluster controllers, each of said cluster controllers transmitting said sensor signal to said onboard computer for generation of a security indication; and

said onboard computer including means for storing type information and operating parameters for each of said plurality of sensors and for transmitting the type information and the operating parameters to the associated cluster controller when said system is to be put into operation, said type information and operating parameters identifying the type and operating characteristics of each of said sensors.

2. An aircraft security system as defined in claim 1 wherein said onboard computer further includes

means for interrogating each of said cluster controllers when said system in initialized to obtain an initial signal strength generated by each of said sensors in response to sensing a predetermined condition,

means for storing said initial signal strength for each of said sensors,

means for interrogating each of said cluster controllers when said system is to be put into operation to obtain a present signal strength generated by each of said sensors in response to sensing said predetermined condition, and

means for indicating a trouble condition when the difference between said present signal strength and said initial signal strength for a sensor is outside a prescribed range.

3. An aircraft security system as defined in claim 1 wherein at least one of said sensors includes a transmitter and a receiver, wherein said transmitter sends a known signal to said receiver and wherein said onboard computer includes

means for interrogating the specified cluster controller with which the transmitter and the receiver are associated to obtain a present signal strength generated by said receiver in response to said known signal, when said system is to be put into operation, and

means for sensing that said present signal strength is outside a prescribed range and for directing the specified cluster controller to vary the energy sent by said transmitter to said receiver until said present signal strength is within said prescribed range.

14. A security system as defined in claim 1 further including means associated with said onboard computer for transmitting said security indication to a remote location.

4. A method for operating an aircraft security system including an onboard computer, one or more cluster controllers remotely located from the onboard computer and connected by a communication link to said onboard computer, and a plurality of sensors associated with and controller by each of the cluster controllers, each of said sensors generating a sensor signal in response to sensing a security condition, each of said cluster controllers transmitting said sensor signal to said onboard computer for generation of a security indication, said method comprising the steps of:

storing type information and operating parameters for each of said plurality of sensors in said onboard computer, said type information and operating parameters identifying the type and operating characteristics of each of said sensors; and

transmitting the type information and the operating parameters to the respective cluster controllers when said system is to be put into operation.

5. A method for operating an aircraft security system as defined in claim 4 further including the steps of

interrogating each of said cluster controllers to obtain an initial signal strength generated by each of said sensors in response to sensing a predetermined condition when said system is initialized,

storing said initial signal strength for each of said sensors in said onboard computer,

interrogating each of said cluster controllers when said system is to be put into operation to obtain a present signal strength generated by each of said sensors in response to sensing said predetermined condition, and

indicating a trouble condition when the difference between said present signal strength and said initial signal strength is outside a prescribed range.

6. A method for operating an aircraft security system as defined in claim 4 further including

providing sensors including at least one transmitter and one receiver,

transmitting a known signal from said transmitter to said receiver,

interrogating the cluster controller to which the transmitter and receiver are connected to obtain a present signal strength generated by said receiver in response to said known signal, when said system is to be put into operation,

sensing that said present signal strength is outside a prescribed range, and

directing the cluster controller to vary the energy sent by said transmitter to said receiver until said present signal strength is within said prescribed range.

7. A security system comprising:

a central computer;

one or more cluster controllers remotely located from said computer;

a plurality of sensors associated with and controlled by each of said cluster controllers, each of said sensors generating a sensor signal in response to sensing a security condition;

means for communication between said computer and said cluster controllers, each of said cluster controllers transmitting said sensor signal to said onboard computer for generation of a security indication; and

said computer including means for storing type information and operating parameters for each of said plurality of sensors and for transmitting the type information and the operating parameters to the associated cluster controller when said system is to be put into operation, said type information and operating parameters identifying the type and operating characteristics of each of said sensors.

8. A sensing and communication system comprising:

a computer;

one or more cluster controllers remotely located from said computer;

a plurality of sensors associated with and controlled by each of said cluster controllers, each of said sensors generating a sensor signal in response to sensing a prescribed condition;

means for communication between said computer and said cluster controllers, each of said cluster controllers transmitting said sensor signal to said onboard computer; and

said computer including means for storing type information and operating parameters for each of said plurality of sensors and for transmitting the type information and the operating parameters to the associated cluster controller when said system is to be put into operation, said type information and operating parameters identifying the type and operating characteristics of each of said sensors.

9. A sensing and communication system as defined in claim 8 wherein said computer further includes

means for interrogating each of said cluster controllers when said system is initialized to obtain an initial signal strength generated by each of said sensors in response to sensing a predetermined condition,

means for storing said initial signal strength for each of said sensors,

means for interrogating each of said cluster controllers when said system is to be put into operation, to obtain a present signal strength generated by each of said sensors in response to sensing said predetermined condition, and

means for indicating a trouble condition when the difference between said present signal strength and said initial signal strength for a sensor is outside a prescribed range.

10. A sensing and communication system as defined in claim 8 wherein at least one of said sensors includes a transmitter and a receiver, wherein said transmitter sends a known signal to said receiver and wherein said computer includes

means for interrogating the specified cluster controller with which the transmitter and the receiver are associated to obtain a present signal strength generated by said receiver in response to said known signal when said system is to be put into operation, and

means for sensing that said present signal strength is outside a prescribed range and for directing the specified cluster controller to vary the energy sent by said transmitter to said receiver until said present signal strength is within said prescribed range.

11. A method for operating a sensing and communication system including a computer, one or more cluster controllers remotely located from the computer and connected by a communication link to said computer, and a plurality of sensors associated with and controlled by each of the cluster controllers, each of said sensors generating a sensor signal in response to sensing a prescribed condition, each of said cluster controllers transmitting said sensor signal to said computer, said method comprising the steps of:

storing type information and operating parameters for each of said plurality of sensors in said computer, said type information and operating parameters identifying the type and operating characteristics of each of said sensors; and

transmitting the type information and the operating parameters to the respective cluster controllers when said system is to be put into operation.

12. A method for operating a sensing and communication system as defined in claim 11 further including the steps of

interrogating each of said cluster controllers when said system is initialized to obtain an initial signal strength generated by each of said sensors in response to sensing a predetermined condition,

storing said initial signal strength of each of said sensors in said computer,

interrogating each of said cluster controllers when said system is to be put into operation to obtain a present signal strength generated by each of said sensors in response to sensing said predetermined condition, and

indicating a trouble condition when the difference between said present signal strength and said initial signal strength is outside a prescribed range.

13. A method for operating a sensing and communication system as defined in claim 11 further including

providing sensors including at least one transmitter and one receiver,

transmitting a known signal from said transmitter to said receiver,

interrogating the cluster controller to which the transmitter and receiver are connected to obtain a present signal strength generated by said receiver in response to said known signal when said system is to be put into operation,

sensing that said present signal strength is outside a prescribed range, and

directing the cluster controller to vary the energy sent by said transmitter to said receiver until said present signal strength is within said prescribed range.