Predicting bus idle time based on obtained usage data of a bus

• US 9,298,577 B2
• Filed: 09/19/2012
• Issued: 03/29/2016
• Est. Priority Date: 09/19/2012
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Mabuchi, Mitsuhiro
• Primary Examiner(s): SNYDER, STEVEN G
• Application Number:
  US14/424,631
• Publication Number:
  US 20150220412A1
• Time in Patent Office: 1,287 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: G06F 11/3048 where the topology of the computing system or computing system component explicitly influences the monitoring activity, e.g. serial, hierarchical systems
• CPC Class Codes: G06F 11/3051 Monitoring arrangements for monitoring the configuration of the computing system or of the computing system component, e.g. monitoring the presence of processing resources, peripherals, I/O links, software programs verification or detection of system hardware configuration G06F11/2247
• CPC Class Codes: G06F 11/3065 Monitoring arrangements determined by the means or processing involved in reporting the monitored data error or fault reporting or logging G06F11/0766
• CPC Class Codes: G06F 11/3423 where the assessed time is active or idle time
• CPC Class Codes: H04J 3/0652 Synchronisation among time division multiple access [TDMA] nodes, e.g. time triggered protocol [TTP] bus network with centralized control in which slots are of a TDMA packet structure H04L12/4035
• CPC Class Codes: H04L 12/28 characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks] wireless communication networks H04W ; arrangements for dividing the transmission path H04W40/00
• CPC Class Codes: H04L 12/40 Bus networks
• CPC Class Codes: H04L 12/4135 using bit-wise arbitration
• CPC Class Codes: H04L 2012/40215 Controller Area Network CAN
• CPC Class Codes: H04L 47/10 Flow control; Congestion control
• CPC Class Codes: H04L 47/741 Holding a request until resources become available
• CPC Class Codes: H04L 47/822 Collecting or measuring resource availability data
• CPC Class Codes: H04L 47/83 based on usage prediction

Abstract

In order to provide a communication apparatus that can reduce the delay in transmission of communication messages even when the bus load is heavy, a data transmission module is connected to a communication bus, over which communication messages are transferred, in such a manner that the data transmission module can transmit/receive the communication messages to/from the communication bus. A bus monitoring unit included in the data transmission module detects, for a given time period, the timings at which communication messages are flowing over the communication bus, and acquires the detection results as usage status data of said time period. The data transmission module further includes: a usage status predicting unit that predicts, on the basis of the acquired usage status data of the detection time period, an idle timing at which no communication messages are flowing over the communication bus; and a data transmitting unit that transmits communication messages to the communication bus at the predicted idle timing.

Claims

1. A communication apparatus that is connected to a communication line, through which communication messages are transferred, to be capable of transmitting and receiving communication messages, the communication apparatus comprising:

a detecting unit that detects a period in which a communication message flows through the communication line over a fixed detection period of time and that obtains a detection result thereof as usage status data of this detection period;

a predicting unit that, based on the obtained usage status data of the detection period, predicts an idle time in which a communication message does not flow through the communication line; and

a transmitting unit that transmits a communication message to the communication line in the predicted idle time, wherein

the detection period includes a plurality of periodically consecutive determination periods,

the detecting unit repeatedly detects a period in which a communication message flows to the communication line for each of the determination periods, and

based on a detection result of one of the determination periods included in the usage status data, the predicting unit predicts an idle time of a following detection period corresponding to the one of the determination periods.

2. The communication apparatus according to claim 1, wherein, based on one or more pieces of usage status data including usage status data corresponding to a latest detection period, the predicting unit predicts an idle time of a following detection period subsequent to the latest detection period.

3. The communication apparatus according to claim 1, wherein

the predicting unit

obtains one or more detection results from a to-be-targeted determination period in the one or more pieces of usage status data,

calculates a communication message based on the obtained one or more detection results, and

compares, with a threshold value, a ratio at which the calculated communication message does not flow through the communication line, thereby predicting an idle period of the following detection period corresponding to the to-be-targeted determination period.

4. The communication apparatus according to claim 1, wherein, each time a detection result is obtained with respect to each determination period of the latest detection period, the predicting unit predicts an idle time of the following detection period corresponding to a determination period for which the detection result has been obtained.

5. The communication apparatus according to claim 1, wherein the predicting unit predicts the idle period in consideration of a weight based on utility that is set in the usage status data.

6. The communication apparatus according to claim 5, wherein the weight is set to be highest with respect to the usage status data of the latest detection period, and

the older the usage status data, the lower the weight becomes.

7. The communication apparatus according to claim 1, wherein the detecting unit does not include communication messages transmitted from the transmitting unit in the obtained usage status data.

8. The communication apparatus according to claim 1, wherein the detection period is periodically set in a range of from 100 ms to 10 s.

9. The communication apparatus according to claim 1, wherein the detection period is set in accordance with a period of a communication message having a longest transmission period of a plurality of communication messages.

10. The communication apparatus according to any claim 1, wherein the detection period is set in accordance with a period that is a lowest common multiple of transmission periods of a plurality of communication messages.

11. The communication apparatus according to claim 1, wherein

a part of or an entirety of the communication line is mounted in a vehicle, and the communication message is based on a Controller Area Network (CAN) protocol.

12. A communication method that is used by a communication apparatus to transmit communication messages, wherein the communication apparatus is connected to a communication line, through which communication messages are transferred, the communication method comprising:

detecting a period in which a communication message flows through the communication line over a fixed detection period of time and obtaining a detection result thereof as usage status data of this detection period;

based on the obtained usage status data of the detection period, predicting an idle time in which a communication message does not flow through the communication line; and

transmitting a communication message to the communication line in the predicted idle time, wherein

the detection period includes a plurality of periodically consecutive determination periods,

in the obtaining of the usage status data, a period in which a communication message flows to the communication line is repeatedly detected for each of the determination periods, and

in the predicting an idle time, based on a detection result of one of the determination periods included in the usage status data, an idle time of a following detection period corresponding to the one of the determination periods is predicted.