Redundant control system
Example implementations described herein are directed to a plurality of control functions connected via a communication network and synchronized, where the control functions communicate packets including control data, the function identifier for the function associated with the control data, and time identifier such as a time identifier representing the synchronized time associated with the control data. Example implementations determine control data associated with the function identifier and the time identifier from one or more packets that has the same function identifier and time identifier, received in the certain time period based on the time specified by the time identifier.
1. A method to manage data packets from time synchronized apparatuses through a network scheme, the method comprising:
receiving, by a processor, the data packets from the time synchronized apparatuses via redundant communication paths, each of the data packets having a time identifier which is with a time synchronized by and across the time synchronized apparatuses;
selecting, by the processor, ones of the data packets received within a certain time period based on a current time associated with time synchronized by the time synchronized apparatuses;
selecting, by the processor, packets having a same time identifier and a same function identifier from the selected ones of the data packets received in real-time to ensure reliability through redundancy;
processing, by the processor, the selected packets having the same time identifier and the same function identifier to provide output to a controller application of the time synchronized apparatuses; and
for a data packet of the data packets being received by the processor at a time past a scheduled time of use as stipulated by associated time identifier, determining occurrence of transmission abnormality associated with the data packet, removing the data packet from selection;
for the redundant communication path exhibiting multiple instances of communication delays associated with time identifiers of a number of data packets:
identifying the redundant communication path as being abnormal, and
modifying the redundant communication path to address abnormality.
2. The method of claim 1 , wherein the processing the selected packets having the same time identifier and the function identifier to provide the output to the controller application of the time synchronized apparatuses comprises determining control information for execution by the controller application from a first received packet of the selected packets having the same time identifier and the function identifier.
3. The method of claim 1 , wherein the processing the selected packets having the same time identifier and the function identifier to provide the output to the controller application of the time synchronized apparatuses comprises determining control information for execution by the controller application from a majority decision process applied on the selected packets having the same time identifier and the function identifier.
4. The method of claim 1 , wherein the processing the selected packets having the same time identifier and the function identifier to provide the output to the controller application of the time synchronized apparatuses comprises determining control information for execution by the controller application from a statistical calculation of the control information of the each of the selected packets having the same time identifier and the function identifier.
5. The method of claim 1 , further comprising, for a function associated with the function identifier of the controller application indicating that data in the selected packets having the same time identifier and the function identifier do not match conducting one or more of:
requesting retransmission of the data packets;
providing a notification of non-receipt of the data packets; or
executing safety processing.
6. The method of claim 1 , further comprising, when no packet is received within a time period associated with the time identifier, conducting one or more of:
requesting retransmission of the data packets;
providing a notification of non-receipt of the data packets; or
executing safety processing.
7. The method of claim 1 , wherein the time identifier is a sequence value associated with a time.
8. The method of claim 1 , further comprising:
storing the received data packets in a storage device; and
outputting stored packet information of the received packets in response to a request.
9. The method of claim 8 , wherein a first function of the controller application of the time synchronized apparatuses associated with the function identifier synchronizes to a second function of the time synchronized apparatuses that transmitted the data packets through one or more of:
a context of the second function at a specified time;
the stored packet information provided by the storage device in response to the request; or
the received data packets.
10. The method of claim 9 , wherein the first function is configured not to output to another function until synchronization to the context of the second function has occurred.
11. The method of claim 1 , further comprising executing redundant functions on one more devices, the redundant functions being configured to send the data packets having the same time identifier and function identifier.
12. The method of claim 11 , wherein a function of the controller application is configured to transmit the selected packets having the same time identifier and the function identifier to one of the redundant functions of the time synchronized apparatuses that is redundant to the function of the controller application.
13. The method of claim 11 , further comprising:
for a change of a communication point of a function of the controller application in a network; changing one or more of an apparatus of the time synchronized apparatuses that operates the function of the controller application or a communication path to a destination function.
14. The method of claim 1 , wherein functions of the time synchronized apparatuses are connected via a network with the redundant communication paths.
15. A non-transitory computer readable medium, storing instructions to manage data packets from time synchronized apparatuses through a network scheme, the instructions comprising:
receiving, by a processor, the data packets from the time synchronized apparatuses via redundant communication paths, each of the data packets having a time identifier which is with a time synchronized by and across the time synchronized apparatuses;
selecting, by the processor, ones of the data packets received within a certain time period based on a current time associated with time synchronized by the time synchronized apparatuses;
selecting, by the processor, packets having a same time identifier and a same function identifier from the selected ones of the data packets received in real-time to ensure reliability through redundancy;
processing, by the processor, the selected packets having the same time identifier and the same function identifier to provide output to a controller application of the time synchronized apparatuses; and
for a data packet of the data packets being received by the processor at a time past a scheduled time of use as stipulated by associated time identifier, determining occurrence of transmission abnormality associated with the data packet, removing the data packet from selection;
for the redundant communication path exhibiting multiple instances of communication delays associated with time identifiers of a number of data packets:
identifying the redundant communication path as being abnormal, and
modifying the redundant communication path to address abnormality.