Distributed built-in test equipment system for digital avionics

• US 5,184,312 A
• Filed: 04/26/1991
• Issued: 02/02/1993
• Est. Priority Date: 10/13/1985
• Status: Expired due to Term

• Current Assignee: The Boeing Co.
• Original Assignee: The Boeing Co.
• Inventors: Ellis, Gordon F.
• Primary Examiner(s): Lall, Parshotam S.
• Assistant Examiner(s): ZANELLI, MICHAEL J
• Application Number:
  US07/692,781
• Time in Patent Office: 648 Days
• Field of Search: 364/550, 364/551.01, 364/480, 364/481, 364/424.01, 364/424.03, 364/580, 371/15, 371/16, 371/18, 371/25, 340/507, 340/514, 340/945, 73/178 R
• US Class Current: 702/121
• CPC Class Codes: G05D 1/0077 using redundant signals or controls
• CPC Class Codes: G06F 11/22 Detection or location of defective computer hardware by testing during standby operation or during idle time, e.g. start-up testing

Abstract

A distributed BITE system for a digital avionic system. The avionic system comprises a plurality of LRUs and digital communication devices through which the LRUs can transmit and receive data in a predefined format comprising multiple bit communication words. The avionic system further includes an interface unit (12) and at least one distributed computer system (14, 16, 18). The interface unit includes a control/display unit (20) that comprises a display screen (22) and input device such as a keyboard (24, 26). The digital communication devices may include a first bus (40) through which the interface unit can transmit communication words to the distributed computer system, and a second bus (42, 44, 46) through which the distributed computer system can transmit communication words to the interface unit. The BITE system comprises a distributed BITE program (72, 74, 76) in the distributed computer system, and a passthrough program (78) in the interface unit. The distributed BITE program has an interactive structure wherein the program receives input data including commands provided by an operator and provides output data including fault data for use by the operator. The distributed computer system is adapted to receive its input data over the first bus in the predefined format, and to transmit its output data onto the second bus in the same format. The passthrough program comprises receiving input data from the control/display unit, formatting the input data in the predefined format, and causing the input data to be transmitted to the distributed computer system over the first bus. The passthrough program also comprises receiving output data from the second bus and causing the output data to be transmitted to the control/display unit for display on the display screen thereof.

Claims

1. A digital avionics system designed for installation in an aircraft as an integral part thereof, the system comprising:

a plurality of line replaceable units (LRUs), each designed to transmit an output signal containing information from which faulty operation of said each LRU may be detected;

a distributed computer system, designed for installation in an aircraft as an integral part thereof, coupled to said plurality of LRUs, for receiving said output signals provided by said plurality of LRUs, said computer system comprising a built-in test equipment (BITE) program (a) for performing diagnostic operations using said information in said output signals so as to isolate faulty ones of said plurality of LRUs and (b) for performing test operations after faulty LRUs have been replaced to verify replacement LRUs function properly, said BITE program comprising an interactive, natural language interface for facilitating operation of said BITE program by a user thereof; and

control/display means, designed for installation in the cockpit of the aircraft, coupled to said distributed computer system, for permitting a user of the avionics system to communicate therewith, and for permitting a maintenance technician to operate said BITE program using said interactive, natural language interface.

2. A system according to claim 1, wherein said BITE program is a distributed BITE program distributed within said distributed computer system, further wherein said distributed computer system includes a central computer coupled to selected ones of said plurality of LRUs and to said control/display means, said central computer including a central BITE program for providing fault data with respect to said selected ones of said plurality of LRUs, said control/display means also comprising selection means for permitting a user to select either said distributed BITE program or said central BITE program.

3. A system according to claim 2, wherein said control/display means comprises a screen display and input means, further wherein said central computer further comprises pass-through means, coupled to said distributed computer system (a) for causing input data received from said input means to be formatted in a predefined format and to be transmitted from said input means through said central computer to said distributed computer system and (b) for receiving output data transmitted from said distributed computer system and for transferring such data through said central computer to said screen display for display thereon.

4. A system according to claim 1, wherein said BITE program comprises a plurality of discrete BITE programs distributed within said distributed computer system, each discrete BITE program being designed to perform said diagnostic operations and said test operations with respect to a predetermined group of said plurality of LRUs.

5. A system according to claim 4, wherein said interactive, natural language interface includes first menu means for permitting a user to access a selected one of said plurality of discrete BITE programs, and second menu means for permitting a user to initiate, operate, and terminate, within said selected one of said plurality of discrete BITE programs, said diagnostic operations and said test operations.

6. A system according to claim 1, further wherein the aircraft in which the avionics system is designed to be installed includes a plurality of subsystems for controlling the operation of the aircraft, and wherein said distributed computer system of said avionics system includes:

an application program for controlling the operation of at least a portion of at least one of said plurality of subsystems of the aircraft; and

control means for transferring control between said application program and said BITE program, said control means including interlock means for permitting the transfer of control from said application program to said BITE program only when information in the output signals from selected ones of said plurality of LRUs indicate the aircraft is on the ground.

7. A system according to claim 1, wherein said BITE program comprises:

an in-flight module for storing said information in said output signals from said plurality of LRUs received during a predetermined number of flights; and

a ground module for performing said diagnostic operations and said test operations using said information stored by said in-flight module.

8. A digital avionics system designed for installation in an aircraft as an integral part thereof, the system comprising:

a plurality of line replacement units (LRUs), each designed to transmit an output signal containing information from which faulty operation of said each LRU may be detected;

a distributed computer system, designed for installation in an aircraft as an integral part thereof, coupled to said plurality of LRUs, for receiving said output signals provided by said plurality of LRUs, said computer system comprising a plurality of discrete built-in test equipment (BITE) programs distributed within said distributed computer system each (a) for performing diagnostic operations using said information in said output signals so as to isolate faulty ones of said plurality of LRUs and (b) for performing test operations after faulty LRUs have been replaced to verify replacement LRUs function properly, said distributed computer system including a central computer having (1) a central BITE program (a) for performing diagnostic operations using said information in said output signals so as to isolate faulty ones of said plurality of LRUs and (b) for performing test operations after faulty LRUs have been replaced to verify replacement LRUs function properly and (2) selection means for permitting a user to select either said central BITE program or one of said plurality of discrete BITE programs, said central BITE program and each of said plurality of discrete BITE programs comprising an interactive, natural language interface for facilitating operation thereof by a user of the system;

control/display means, designed for installation in the cockpit of the aircraft and coupled to said distributed computer system, for permitting a user of the avionics system to communicate therewith, and for permitting a maintenance technician to operate said central BITE program and each of said plurality of discrete BITE programs using said interactive, natural language interface, the latter including first menu means for permitting a user to access said central BITE program or a selected one of said plurality of discrete BITE programs, and second menu means for permitting a user to initiate, operate, and terminate, within said central BITE program or said selected one of said plurality of discrete BITE programs, said diagnostic operations and said test operations, said control/display means comprising a screen display and input means; and

wherein said central computer additionally includes pass-through means, coupled to said distributed computer system (a) for causing input data received from said input means to be formatted in a predefined format and to be transmitted from said input means through said central computer to said distributed computer system and (b) for receiving output data transmitted from said distributed computer system and for transferring such data through said central computer to said screen display for display thereon.

9. A digital avionics system designed for installation in an aircraft, the system comprising:

a plurality of line replaceable units (LRUs), each designed (a) to receive an input signal and (b) to transmit an output signal containing information from which faulty operation of said each LRU may be detected;

a distributed computer system, designed for installation in an aircraft and coupled to said plurality of LRUs, for generating and providing said input signals to said plurality of LRUs and for receiving said output signals provided by said plurality of LRUs, said distributed computer system comprising a distributed built-in test equipment (BITE) program distributed within said distributed computer system having (a) an in-flight module for storing said information in said output signals from said plurality of LRUs receiving during a predetermined number of flights and (b) a ground module for performing diagnostic operations using said information stored by said in-flight module so as to isolate faulty ones of said plurality of LRUs and for performing test operations after faulty LRUs have been replaced to verify replacement LRUs function properly; and

interface means, designed for installation in the cockpit of the aircraft and coupled with said distributed computer system, for permitting a maintenance technician to operate said ground module portion of said BITE program.

10. A system according to claim 9, further wherein said interface system includes means for permitting flight personnel to communicate with the avionics system from the cockpit of the aircraft.

11. A system according to claim 9, wherein said distributed computer system comprises a central computer coupled to selected ones of said plurality of LRUs and to said interface means, said central computer including a central BITE program having (a) an in-flight module for storing information in said output signals from said selected ones of said plurality of LRUs received during a predetermined number of flights and (b) a ground module for performing diagnostic operations using said information stored by said in-flight module so as to isolate faulty ones of said selected ones of said plurality of LRUs and for performing test operations after faulty LRUs have been replaced to verify replacement LRUs function properly.

12. A system according to claim 11, wherein said interface means includes a screen display for receiving and displaying data and a keyboard for transmitting data, said central computer additionally including pass-through means, coupled to said distributed computer system, (a) for causing data transmitted from said keyboard to be formatted in a predefined format and to be transmitted from said keyboard via said central computer, to said distributed computer system and (b) for receiving output data transmitted from said distributed computer system and for transferring such data via said central computer to said screen display for display thereon.

13. A built-in test equipment (BITE) system designed to form an integral part of a digital avionic system installed in an aircraft, the avionic system comprising (1) a plurality of line replaceable units (LRUs), each designed (a) to receive an input signal and (b) to transmit an output signal containing information from which faulty operation of said each LRU may be detected, (2) a distributed computer system, coupled to said plurality of LRUs, for generating and providing said input signals to said plurality of LRUs and for receiving said output signals provided by said plurality of LRUs, and (3) interface means for permitting a user to communicate with said distributed computer system, the BITE system comprising:

(a) in-flight means for storing said information in said output signals received by the distributed computer system from the plurality of LRUs;

(b) ground means for performing diagnostic operations using said information stored by said in-flight means so as to isolate faulty ones of said plurality of LRUs and for performing test operations after faulty LRUs have been replaced to verify replacement LRUs function properly;

(c) communication means for providing a user-interactive, natural language interface with said in-flight means and said ground means; and

(d) wherein said in-flight means, said ground means, and said communications means are distributed within said distributed computer system.

14. A system according to claim 13, wherein the aircraft in which the digital avionics system is installed comprises a plurality of subsystems for controlling the operation of the aircraft, each of said subsystems being coupled to selected ones of said plurality of LRUs, further wherein said BITE system comprises:

an application program for controlling the operation of at least a portion of at least one of the subsystems of the aircraft;

control means for transferring control between said application program and said ground means, wherein said control means comprises interlock means for preventing transfer of control between said application program and said ground means except when the aircraft is on the ground.

15. A digital avionics system designed for installation in an aircraft having a plurality of subsystems for controlling the operation of the aircraft, each of said subsystems comprising a plurality of line replaceable units (LRUs), each of which is designed to provide an output signal containing information from which faulty operation of the LRU may be determined, the system comprising:

a distributed computer system designed to be installed in an aircraft so as to be coupled to the LRUs of selected subsystems of the aircraft, said distributed computer system including;

(i) application means for controlling the operation of at least a portion of at least one of said plurality of subsystems of the aircraft;

(ii) built-in-test equipment (BITE) means for performing diagnostic testing of the LRUs of said at least a portion of at least one of the selected subsystems based on information in the output signals of said LRUs; and

(iii) control means for transferring control between said application means and said BITE means, said control means including interlock means for permitting the transfer of control from said application means to said BITE means only when information in the output signals from selected LRUs of the aircraft indicate the aircraft is on the ground.