Communication system and method, and distributed control system and method

• US 20070088883A1
• Filed: 10/12/2006
• Published: 04/19/2007
• Est. Priority Date: 10/13/2005
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Wakabayashi, Shinji
• Granted Patent: US 7,487,266 B2
• Time in Patent Office: Days
• US Class Current: 710/110
• CPC Class Codes: B60G 2600/71 Distributed control; Master - slave controllers; Remote control units
• CPC Class Codes: B60G 2800/97 Engine Management System [EMS]
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 2050/0006 Digital architecture hierarchy
• CPC Class Codes: B60W 2050/065 by reducing the computational load on the digital processor of the control computer
• CPC Class Codes: B60W 50/06 Improving the dynamic response of the control system, e.g. improving the speed of regulation or avoiding hunting or overshoot
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/266 the computer being backed-up or assisted by another circuit, e.g. analogue
• CPC Class Codes: F02D 41/28 Interface circuits

Abstract

A communication system performs bidirectional communication through a same communication path every communication cycle period between a master station and a slave station. From the start of the communication cycle period until an interval period shorter than the communication cycle period elapses, the master station transmits master data represented at a first ratio of first pulse width to the communication cycle period to the slave station. In a remaining period after the interval period in the communication cycle period, the slave station transmits slave data represented at a second ratio of second pulse width to the interval period to the master station.

Claims

1. A communication system comprising:

a master station and a slave station for bidirectional communication therebetween every communication cycle period; and

a same communication path connecting the master station and the slave station for the bidirectional communication,

wherein, from a start of the communication cycle period until an interval period shorter than the communication cycle period elapses, the master station transmits master data represented in a ratio of pulse width to the communication cycle period to the slave station, and

wherein, in a remaining period after the interval period in the communication cycle period, the slave station transmits slave data represented in the ratio of pulse width to the interval period to the master station.

2. The communication system according to claim 1,

wherein the slave station recognizes the start of the communication cycle period by detecting an edge of a pulse representative of the master data.

3. The communication system according to claim 1,

wherein the communication cycle period and the interval period are fixed.

4. The communication system according to claim 1,

wherein the master station serially transmits plural pieces of the master data to the slave station in the interval period.

5. The communication system according to claim 1,

wherein the slave station serially transmits plural pieces of the slave data to the master station in the remaining period.

6. The communication system according to claim 1,

wherein the slave station is provided in plural numbers,

wherein the master station serially outputs plural pieces of the master data including transmission destination specific data specifying each slave station of transmission destination to the communication path in the interval period, and

wherein each slave station receives the master data outputted from the master station in the same interval period as the transmission destination specific data specifying them.

7. The communication system according to claim 6,

wherein the master station outputs the master data other than the transmission destination specific data after outputting the transmission destination specific data.

8. The communication system according to claim 6,

wherein, in response to reception of the transmission destination specific data specifying the slave station, the slave station serially transmit plural pieces of the slave data including transmission source specific data to the master station in the remaining period.

9. The communication system according to claim 8,

wherein the slave station transmit the slave data other than the transmission source specific data after transmitting the transmission source specific data.

10. The communication system according to claim 6, further comprising:

a common bus connecting the master station and each slave station one another,

wherein the common bus forms the communication path among the master station and each slave station.

11. A distributed control system comprising:

the communication system according to claim 1,

wherein the master station and the slave station distributedly control respective control targets.

12. The distributed control system according to claim 11,

wherein the master station generates command data for commanding control state of the control target of the slave station as the master data, and

wherein the slave station generates state amount data representative of state amount of the control targets as the slave data.

13. A communication method of performing bidirectional communication through a same communication path every communication cycle period between a master station and a slave station, the method comprising steps of:

transmitting, from a start of a communication cycle period until an interval period shorter than the communication cycle period elapses, master data represented in a ratio of pulse width to the communication cycle period from the master station to the slave station; and

transmitting, in a remaining period after the interval period in the communication cycle period, transmitting slave data represented in the ratio of pulse width to the interval period from the slave station to the master station.

14. The communication method according to claim 13, further comprising:

Recognizing, in the slave station, the start of the communication cycle period by detecting an edge of a pulse representative of the master data.

15. The communication method according to claim 13,

wherein the communication cycle period and the interval period are fixed.

16. The communication method according to claim 13,

wherein the master station serially transmits plural pieces of the master data to the slave station in the interval period.

17. The communication method according to claim 13,

wherein the slave station serially transmits plural pieces of the slave data to the master station in the remaining period.

18. The communication method according to claim 13,

wherein the slave station is provided in plural numbers,

wherein the master station serially outputs plural pieces of the master data including transmission destination specific data specifying each slave station of transmission destination to the communication path in the interval period, and

wherein each slave station receives the master data outputted from the master station in a same interval period as the transmission destination specific data.

19. The communication method according to claim 18,

wherein the master station outputs the master data other than the transmission destination specific data after outputting the transmission destination specific data.

20. The communication method according to claim 18,

wherein each slave station, receiving the transmission destination specific data specifying the slave station as a responding slave station, serially transmits plural pieces of the slave data including transmission source specific data specifying the responding slave station from the responding slave station to the master station in the remaining period.

21. The communication method according to claim 20,

wherein the responding station transmits the slave data other than the transmission source specific data after transmitting the transmission source specific data.

22. A distributed control method comprising steps of:

performing the bidirectional communication by the communication method according to claim 13;

and

distributedly controlling respective control targets of the master station and the slave station.

23. The distributed control method according to claim 22,

wherein the master station generates command data for commanding control state of the control target of the slave station as the master data;

and

the slave station generates state amount data representative of state amount of the control target as the slave data.

24. A communication system comprising:

a master station and a slave station for bidirectional communication therebetween every communication cycle period; and

a same communication path connecting the master station and the slave station for the bidirectional communication,

wherein the master station, when a master idle period defined by it has elapsed after receiving slave data from the slave station, transmits master data represented in a ratio of pulse width to the master idle period to the slave station, and

wherein the slave station, when a slave idle period defined by it has elapsed after receiving master data from the master station, transmits the slave data represented in a ratio of pulse width to the slave idle period to the master station.

25. The communication system according to claim 24,

wherein the master station sets the master idle period for each reception of the slave data, and

wherein the slave station sets the slave idle period for each reception of the master data.

26. The communication system according to claim 25,

wherein the master station, before transmitting the master data this time after receiving the slave data, sets the master idle period this time, the ratio of which relative to the master idle period immediately before a preceding transmission of the master data represents a type of the master data transmitted this time, and

wherein the slave station, before transmitting the slave data this time after receiving the master data, sets the slave idle period this time, the ratio of which relative to the slave idle period immediately before preceding transmission of the slave data represents a type of the slave data transmitted this time.

27. The communication system according to claim 26,

wherein transmission of the master data is performed earlier than transmission of the slave data after the master station and the slave station are started, and

wherein when the master station receives first slave data after the startup after transmission of first master data after the startup, the master station sets a second master idle period, the ratio of which relative to a pulse width corresponding to the first master data represents the type of master data transmitted second time after the startup.

28. A distributed control system comprising:

the communication system according to claim 24,

wherein the master station and the slave station distributedly control respective control targets.

29. The distributed control system according to claim 28,

wherein the master station generates the command data for commanding control state of the control target of the slave station as the master data, and

wherein the slave station generates state amount data representative of state amount of the control target as the slave data.

30. A communication method of performing bidirectional communication through a same communication path every communication cycle period between a master station and a slave station, the method comprising steps of:

transmitting, when a master idle period has elapsed after receiving slave data from the slave station, master data represented in a ratio of pulse width to the master idle period from the master station to the slave station; and

transmitting, when a slave idle period has elapsed after receiving the master data from the master station, the slave data represented in a ratio of pulse width to the slave idle period from the slave station to the master station.

31. The communication method according to claim 30,

wherein the master station sets the master idle period for each reception of the slave data, and

wherein the slave station sets the slave idle period for each reception of the master data.

32. The communication method according to claim 31,

wherein the master station, before transmitting the master data this time after receiving the slave data, sets the master idle period this time, a ratio of which relative to the master idle period immediately before preceding transmission of the master data represents a type of the master data transmitted this time, and

wherein the slave station, before transmitting the slave data this time after receiving the master data, sets the slave idle period this time, a ratio of which relative to the slave idle period immediately before preceding transmission of the slave data represents a type of the slave data transmitted this time.

33. The communication method according to claim 32,

wherein transmission of the master data is performed earlier than transmission of the slave data after the master station and the slave station are started, and

wherein master station, when receiving a first slave data after the startup after transmission of a first master data after the startup, sets a second master idle period, a ratio of which relative to a pulse width corresponding to the first master data represents a type of master data transmitted second time after the startup.

34. A distributed control method comprising steps of:

performing bidirectional communication method according to claim 30;

and

distributedly controlling respective control targets of the master station and the slave station.

35. The distributed control method according to claim 34,

wherein the master station generates command data for commanding control state of the control target of the slave station as the master data;

and

the slave station generates state amount data representative of state amount of the control target as the slave data.