Blackboard-centric layered software architecture

• US 6,647,407 B1
• Filed: 10/19/2000
• Issued: 11/11/2003
• Est. Priority Date: 12/23/1997
• Status: Expired due to Term

• Current Assignee: Simmonds Precision Products, Inc. (Rtx Corporation)
• Original Assignee: Simmonds Precision Products, Inc. (Rtx Corporation)
• Inventors: Rhoads, Thomas Edward II, Chaffee, Mark Robert, Clark, Harold Frederick Jr., Darwin, Keith Patrick
• Primary Examiner(s): Follansbee, John
• Assistant Examiner(s): BULLOCK JR, LEWIS ALEXANDER
• Application Number:
  US09/691,982
• Time in Patent Office: 1,118 Days
• Field of Search: 709/102, 709/103, 709/100
• US Class Current: 718/102
• CPC Class Codes: G06F 8/24 Object-oriented
• CPC Class Codes: G06N 5/043 Distributed expert systems; Blackboards

Abstract

A computer software architecture for an embedded computer system. The architecture includes a hierarchy of software object classes. One classification includes a common information blackboard object. Data is written to the blackboard object by processes in a protected manner, and is otherwise globally readable by all processes. A run-time executive is provided to schedule and coordinate processes. Processes register with the run-time executive at start-up. One process can know the existence and generation of data by another process. The architecture is layered in increasing levels of system abstraction. In one embodiment, the embedded system is an airborne fuel gauging subsystem.

Claims

1. A method of controlling an execution of a plurality of processes within a software architecture comprising a hierarchical multiplicity of layers of software objects, said execution of processes being controllable within each layer and among the multiplicity of layers, each process of the plurality including a scheduling request and performable tasks, said method comprising the steps of:

receiving a registration request from each process executable within the software architecture, each said registration request identifying the process and process performable tasks thereof;

registering each process in response to the corresponding request thereof;

receiving scheduling requests from said executable processes;

scheduling the registered processes in accordance with said scheduling requests; and

coordinating task sequencing of the execution of processes within and among the multiplicity of layers of the software architecture based on said scheduling of registered processes.

2. The method of claim 1 wherein the steps of receiving registration requests and registering are performed at start-up of the software architecture.

3. The method of claim 1 wherein the steps of scheduling and coordinating are performed during run-time of the software architecture.

4. The method of claim 1 wherein the registered processes are scheduled in a cyclical, multi-threaded manner.

5. The method of claim 1 including the step of coordinating includes the steps of:

building a work list sequence of tasks for each process; and

executing tasks of the processes from said corresponding work list sequences thereof based on the scheduling of the registered processes.

6. The method of claim 5 wherein the registered processes are each scheduled in a cyclical manner which defines a process cycle for each registered process.

7. The method of claim 6 wherein the work list sequence of tasks is built for each process at the start of each process cycle determined from the step of scheduling;

and wherein the tasks of each work list sequence are executed during the process cycles of their corresponding processes based on the step of scheduling.

8. The method of claim 7 wherein the tasks of each work list sequence are executed by background calls.

9. A Run-time executive interfaceable with a hierarchical multiplicity of layers of software objects for controlling an execution of a plurality of processes within each layer and among the multiplicity of layers, each process of the plurality including a scheduling request and performable tasks, said run-time executive comprising:

means for receiving a registration request from each executable process, each said registration request identifying the process and process performable tasks thereof;

means for registering each process in response to the corresponding request thereof;

means for receiving scheduling requests from said executable processes;

means for scheduling the registered processes in accordance with said scheduling requests; and

means for coordinating task sequencing of the execution of processes within and among the multiplicity of layers based on said scheduling of registered processes.

10. The run-time executive of claim 9 wherein the means for receiving registration requests and registering means are operative to perform at a software start-up.

11. The run-time executive of claim 9 wherein the scheduling means and coordinating means are operative to perform during software run-time.

12. The run-time executive of claim 9 wherein the scheduling means includes means for scheduling registered processes in a cyclical, multi-threaded manner.

13. The run-time executive of claim 9 wherein the coordinating means includes:

means for building a work list sequence of tasks for each process; and

means for executing tasks of the processes from said corresponding work list sequences thereof based on the scheduling of the registered processes.

14. The run-time executive of claim 13 wherein the scheduling means includes means for scheduling the registered processes in a cyclical manner which defines a process cycle for each registered process.

15. The run-time executive of claim 14 wherein the building means includes means for building a work list sequence of tasks each process at the start of each process cycle determined from the scheduling means;

and wherein the executing means includes means for executing the tasks of each work list sequence during the process cycles of their corresponding processes based on the scheduling of the scheduling means.

16. The run-time executive of claim 15 including means for executing the tasks of each work list sequence by background calls.

17. The run-time executive of claim 9 wherein the hierarchical multiplicity of layers of software objects are embeddable in an aircraft subsystem that determines a parameter of an aircraft;

and wherein the coordinating means includes means for coordinating processes comprising;

processes that are executed for determining the parameter; and

processes that are inherent to the infrastructure of the multiplicity of layers of software objects.

18. The run-time executive of claim 17 wherein the aircraft subsystem comprises a system for determining fuel quantity in a fuel tank of the aircraft.