Distributed avionics

• US 8,543,263 B2
• Filed: 06/17/2010
• Issued: 09/24/2013
• Est. Priority Date: 06/17/2010
• Status: Active Grant

• Current Assignee: Saab AB
• Original Assignee: Saab AB
• Inventors: Danielsson, Torkel, Pettersson, Anders, Hkegrd, Jan
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): ALHARBI, ADAM MOHAMED
• Application Number:
  US13/704,890
• Publication Number:
  US 20130138271A1
• Time in Patent Office: 1,195 Days
• Field of Search: None
• US Class Current: 701/3
• CPC Class Codes: G06F 17/00 Digital computing or data processing equipment or methods, specially adapted for specific functions information retrieval, database structures or file system structures therefor G06F16/00
• CPC Class Codes: G06F 9/4887 involving deadlines, e.g. rate based, periodic
• CPC Class Codes: H04L 67/12 specially adapted for proprietary or special-purpose networking environments, e.g. medical networks, sensor networks, networks in vehicles or remote metering networks
• CPC Class Codes: H04L 67/61 taking into account QoS or priority requirements
• CPC Class Codes: H04L 69/28 Timers or timing mechanisms used in protocols

Abstract

A distributed avionics system arranged in an aerial vehicle for controlling at least one avionics function. A plurality of avionics processing subsystems are interconnected in a network. Each avionics processing subsystem includes a processor arranged to process at least one task so as to provide a set of data messages including at least one unit of data related to controlling the at least one avionics function on basis of provided input data, related to conditions of the at least one avionics function. A memory module is in operative connection with the processor and is arranged to store instructions for the processor to process the at least one task. At least one of the avionics processing subsystems is arranged to transmit at least one synchronization cycle start signal onto the network.

Claims

1. A distributed avionics system arranged in an aerial vehicle for controlling at least one avionics function, the system comprising:

a plurality of avionics processing subsystems interconnected in a network, each avionics processing subsystems comprising;

a processor arranged to process at least one task so as to provide a set of data messages comprising one or more units of data related to controlling the at least one avionics function on basis of provided input data, related to conditions of the at least one avionics function,

a memory module in operative connection with the processor and arranged to store instructions for the processor to process said at least one task,

wherein at least one of the avionics processing subsystems is arranged to transmit at least one synchronization cycle start signal onto the network,

each avionics processing subsystem is arranged to generate a repeating set of periodic processing time frames by detecting repeatedly subsequent instants of time, based on a first predetermined interval and the at least one cycle start signal,

each avionics processing subsystem is arranged to select within each of the generated processing time frames at least one task set to process, based on a predetermined schedule,

each avionics processing subsystem is arranged to select the order in which to process each of at least one task within each of the selected at least one task set, based on a predetermined processing rate associated to each of the at least one task, determined from a set of system global processing rates in descending order of said associated processing rate,

wherein each of the processing subsystems is arranged to generate a plurality of periodic communication time frames by detecting repeatedly subsequent instants of time within each generated processing time frame, based on a second predetermined periodic time interval, and wherein each of the processing subsystems comprise a network interface and transmission control unit arranged to control the network interface to perform scheduled transmissions of data packets, wherein said transmission control unit is provided with access to memory means comprising scheduling information relating to a timing table statically allocating to said plurality of communication time frames a predetermined number of data packets, each comprising a predetermined subset of data messages from said set of data messages.

2. The distributed avionics system according to claim 1, wherein at least one of the tasks within at least one task set, allocated to at least one of the avionics processing subsystems of the plurality of avionics processing subsystems is arranged to be dependent on at least one of one or more units of data provided by at least one previously processed task allocated to a different avionics processing subsystems of the plurality of avionics processing subsystems in order to provide one or more units of data related to controlling the at least one avionics function.

3. The distributed avionics system according to claim 1, wherein the scheduling information is based on determined end-to-end communication delay constraints associated to communication of the data messages between processes allocated to different system nodes.

5. The distributed avionics system according to claim 1, wherein each of the avionics processing subsystems is arranged to select within each of the generated processing time frames at least one task set to process, based on a predetermined sequence of task sets, further comprises to select within each of the generated processing time frames at least one task set to process for a predetermined time frame each in a predetermined memory address space each.

4. The distributed avionics system according to claim i, the scheduling information is configured so as to prevent communication time frame over-run wherein at least one of the data packets is transported on the network for a plurality of consecutive communication time frames.

6. A method of operating a distributed avionics system for controlling at least one avionics function, the method comprising:

providing input data, related to conditions of the at least one avionics function, providing the input data to the memory unit of the processing subsystems for later processing by at least one task in order to provide a set data message comprising one or more units of data related to controlling the at least one avionics function,

synchronize the avionics processing subsystems in time by generating at least one cycle start signal onto the network,

wherein the method further comprises in each of the processing subsystems;

generating a repeating set of periodic processing time frames by detecting repeatedly subsequent instants of time, based on a first predetermined interval and the at least one cycle start signal,

selecting within each of the generated processing time frames at least one task set to process, based on a predetermined schedule,

selecting the order in which to process each of at least one task within each of the selected at least one task set, based on a predetermined processing rate associated to each of the at least one task, determined from a set of system global processing rates in descending order of said associated processing rate,

wherein the method further comprises in each of the processing subsystems;

generating a set of periodic communication time frames by detecting repeatedly subsequent instants of time within each generated processing time frame, based on a second predetermined periodic time interval,

perform scheduled transmissions of data packets, based on scheduling information relating to a timing table statically allocating to each of the plurality of said periodic communication time frames a predetermined number of data packets, each comprising a predetermined subset of data messages from said set of data messages.

7. The method according to claim 6, further comprising:

transmitting the data packets along two independent paths formed in the network, based on a plurality of traffic control modules.

8. The method according to claim 6, wherein each of the processing subsystems is configured to:

select within each of the generated processing time frames at least one task set to process, based on a predetermined sequence of task sets, and

select within each of the generated processing time frames at least one task set to process for a predetermined time frame each in a predetermined memory address space each.

9. A computer programme product, comprising:

a non-transitory computer readable medium; and

a programme code recorded on the computer readable medium for performing when said computer programme is run on a computer a method for operating a distributed avionics system for controlling at least one avionics function, the method comprising

providing input data, related to conditions of the at least one avionics function,

providing the input data to the memory unit of the processing subsystems for later processing by at least one task in order to provide a set data message comprising one or more units of data related to controlling the at least one avionics function,

synchronize the avionics processing subsystems in time by generating at least one cycle start signal onto the network,

wherein the method further comprises in each of the processing subsystems

generating a repeating set of periodic processing time frames by detecting repeatedly subsequent instants of time, based on a first predetermined interval and the at least one cycle start signal,

selecting within each of the generated processing time frames at least one task set to process, based on a predetermined schedule,

selecting the order in which to process each of at least one task within each of the selected at least one task set, based on a predetermined processing rate associated to each of the at least one task, determined from a set of system global processing rates in descending order of said associated processing rate,

wherein the method further comprises in each of the processing subsystems

generating a set of periodic communication time frames by detecting repeatedly subsequent instants of time within each generated processing time frame, based on a second predetermined periodic time interval,

perform scheduled transmissions of data packets, based on scheduling information relating to a timing table statically allocating to each of the plurality of said periodic communication time frames a predetermined number of data packets, each comprising a predetermined subset of data messages from said set of data messages.