Fault-tolerant solid-state flight data recorder

• US 5,289,377 A
• Filed: 08/12/1991
• Issued: 02/22/1994
• Est. Priority Date: 08/12/1991
• Status: Expired due to Fees

• Current Assignee: TRW Inc. (Northrop Grumman Corporation)
• Original Assignee: TRW Inc. (Northrop Grumman Corporation)
• Inventors: Upton, Eric L., Enyedy, Arthur G., Yokote, Timothy A., Stockton, Grant J.
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): NGUYEN, TAN QUANG
• Application Number:
  US07/744,050
• Time in Patent Office: 925 Days
• Field of Search: 364/424.03, 364/424.04, 364/424.06, 364/131, 364/133, 364/134, 360/5, 371/21.1, 371/1, 371/2, 371/9.1, 371/11.1, 371/40.1
• US Class Current: 701/35
• CPC Class Codes: G11C 5/02 Disposition of storage elements, e.g. in the form of a matrix array
• CPC Class Codes: G11C 5/04 Supports for storage elements , e.g. memory modules; Mounting or fixing of storage elements on such supports

Abstract

A flight data recorder for reliable, high-speed storage of flight data employs a distributed, modular architecture in which an array of controller/memory modules is arranged in parallel controller/memory chains and the memory in the individual controller/memory modules is partitioned into submodules. This distributed architecture allows failed controller/memory modules or failed memory submodules to be bypassed, thus providing fault tolerances for both controller and memory functions. The modular architecture allows the number of controller/memory modules to be easily configured to accommodate any required storage size, while the number of parallel controller/memory chains can be configured to accommodate any required data rate.

Claims

1. A fault-tolerant flight data recorder, comprising:

a demultiplexer for converting a serial input data stream into a parallel data stream;

a distributed array of controller/memory modules arranged in one or more parallel controller/memory chains for storing the parallel data stream, the controller/memory modules being arranged in parallel pairs in each controller/memory chain, the memory in each controller/memory module being partitioned into memory submodules to allow failed controller/memory modules or failed memory submodules to be bypassed to provide fault tolerance for both controller and memory functions; and

a multiplexer for converting the parallel data stream from the controller/memory chains into a serial output data stream when the parallel data stream is retrieved from the flight data recorder.

2. The fault-tolerant flight data recorder as set forth in claim 1, and further including:

an error correction encoder for encoding the data for error correction before storage in the controller/memory chains; and

an error correction decoder for correcting the data for any errors when the data is retrieved from the flight data recorder.

3. The fault-tolerant flight data recorder as set forth in claim 2, wherein the demultiplexer and the error correction encoder include a pair of parallel demultiplexers and a pair of parallel error correction encoders to provide redundant input channels.

4. The fault-tolerant flight data recorder as set forth in claim 2, wherein the multiplexer and the error correction decoder include a pair of parallel multiplexers and a pair of parallel error correction decoders to provide redundant output channels.

5. The fault-tolerant flight data recorder as set forth in claim 3, wherein each controller/memory chain includes an input channel selector for switching from one input channel to the other if a failure occurs in one input channel.

6. The fault-tolerant flight data recorder as set forth in claim 4, wherein each controller/memory chain includes an output channel selector for switching from one output channel to the other if a failure occurs in one output channel.

7. The fault-tolerant flight data recorder as set forth in claim 1, wherein each controller/memory module includes:

a controller for performing various control functions for the flight data recorder.

8. The fault-tolerant flight data recorder as set forth in claim 7, wherein the controller in each controller/memory module is connected by a data bus and a controller bus to the two controllers in the following parallel pair of controller/memory modules.

9. The fault-tolerant flight data recorder as set forth in claim 8, wherein the controllers perform five basic control functions, the five basic control functions being a reset mode, a controller test mode for identifying and bypassing failed controllers, a memory test mode for ing parallel pair of controller/memory modules.

10. The fault-tolerant flight data recorder as set forth in claim 9, wherein each controller includes:

a port multiplexer for receiving data and control signals on the data and control buses from a designated controller in the preceding parallel pair of controller/memory modules;

a data register for temporarily storing data and control signals;

controller test means for performing the controller test on the two controllers in the following parallel pair of controller/memory modules;

a memory controller for controlling and addressing the memory module; and

memory test means for performing the memory test on the memory submodules, a memory submodule being found defective only if the number of errors exceeds some preset threshold.

11. A fault-tolerant data recorder, comprising:

one or more parallel controller/memory chains for storing data, the controller/memory modules being arranged in parallel pairs in each controller/memory chain, each controller/memory chain having a distributed array of controller/memory modules to allow failed controller/memory modules to be bypassed to provide fault tolerance for both controller and memory functions.

12. The fault-tolerant data recorder as set forth in claim 11, and further including:

a demultiplexer for converting a serial input data stream into a parallel data stream for storage in the controller/memory chains; and

a multiplexer for converting the parallel data stream from the controller/memory chains into a serial output data stream when the data is retrieved from the data recorder.

13. The fault-tolerant data recorder as set forth in claim 12, and further including:

an error correction encoder for encoding the data for error correction before storage in the controller/memory chains; and

an error correction decoder for correcting the data for any errors when the data is retrieved from the data recorder.

14. The fault-tolerant data recorder as set forth in claim 12, wherein each controller/memory module includes:

a controller for performing various control functions for the data recorder; and

a memory module partitioned into submodules for storing the data.

15. The fault-tolerant data recorder as set forth in claim 14, wherein the controller in each controller/memory module is connected by a data bus and a controller bus to the two controllers in the following parallel pair of controller/memory modules.

16. The fault-tolerant data recorder as set forth in claim 15, wherein the controllers perform five basic control functions, the control functions or modes of operation being a reset mode, a controller test mode for identifying and bypassing failed controllers, a memory test mode for identifying and bypassing failed memory submodules, a write mode and a read mode.

17. The fault-tolerant data recorder as set forth in claim 16, wherein each controller includes:

a port multiplexer for receiving data and control signals on the data and control buses from a designated controller in the preceding parallel pair of controller/memory modules;

a data register for temporarily storing data and control signals;

controller test means for performing the controller test on the two controllers in the following parallel pair of controller/memory modules;

a memory controller for controlling and addressing the memory module; and

memory test means for performing the memory test on the memory submodules, a memory submodule being found defective only if the number of errors exceeds some preset threshold.

18. A fault-tolerant method for storing data, comprising the step of:

storing data in one or more parallel controller/memory chains, the controller/memory modules being arranged in parallel pairs in each controller/memory chain, each controller/memory chain having a distributed array of controller/memory modules in which failed controller/memory modules are bypassed to provide fault tolerance for both controller and memory.

19. The fault-tolerant data storage method as set forth in claim 18, and further including the steps of:

converting a serial input data stream into a parallel data stream for storage in the controller/memory chains; and

converting the parallel data stream from the controller/memory chains into a serial output data stream when the data is retrieved from the data recorder.

20. The fault-tolerant data storage method as set forth in claim 19, and further including the steps of:

encoding the data for error correction before storage in the controller/memory chains; and

correcting the data for any errors when the data is retrieved from the data recorder.

21. The fault-tolerant data storage method as set forth in claim 18, wherein each controller/memory module includes a controller for performing various control functions for the data recorder and a memory module partitioned into submodules for storing the data.

22. The fault-tolerant data storage method as set forth in claim 21, wherein the controller in each controller/memory module is connected by a data bus and a controller bus to the two controllers in the following parallel pair of controller/memory modules.

23. The fault-tolerant data storage method as set forth in claim 22, wherein the controllers perform five basic control functions, the control functions or modes of operation being a reset mode, a controller test mode for identifying and bypassing failed controllers, a memory test mode for identifying and bypassing failed memory submodules, a write mode and a read mode.