Method of identifying nodes in a computer network in a motor vehicle air conditioning installation

• US 20040078097A1
• Filed: 08/26/2003
• Published: 04/22/2004
• Est. Priority Date: 02/26/2001
• Status: Active Grant

• Current Assignee: Valeo Climatisation
• Original Assignee: Valeo Climatisation
• Inventors: Puzenat, Bertrand, Rede, Laurent, Aubry, Vincent, Bruzy, Christophe
• Granted Patent: US 7,869,918 B2
• Time in Patent Office: Days
• US Class Current: 700/48
• CPC Class Codes: G05B 19/042 using digital processors G05B19/05 takes precedence
• CPC Class Codes: G05B 2219/21028 Address of module determined by position
• CPC Class Codes: G05B 2219/21039 Slaves, modules in daisy chain, each handles control data, transmits to next
• CPC Class Codes: G06F 12/0661 and decentralised selection
• CPC Class Codes: G06F 12/0684 with feedback, e.g. presence or absence of unit detected by addressing, overflow detection

Abstract

In a motor vehicle air conditioning installation comprising a central control unit (12), a computer network (14) connected to the central control unit (12) and a plurality of peripherals (10₁, 10₂, 10₃, . . . , 10_n) connected to nodes (N₁, N₂, N₃, . . . , N_n) of the computer network, the peripherals are connected in series via a common conductor (18). The installation comprises means (120) for inputting at the level of each peripheral an electric signature on a common conductor, means (130) for detecting an electric signal depending upon the electric signatures of the peripherals situated upstream on the common conductor (18), means for generating a data item representing the relative position of the peripheral on the basis of the electric signal detected, and means for identifying the node of the network to which it is connected on the basis of the relative position data item generated. The identification of the node of the network permits the assignment of an address or monitoring of the connection of the peripheral from the central control unit.

Claims

1. Method of identification of the nodes (N₁, N₂, N₃, . . . , N_n) of a computer network in an air conditioning installation of a motor vehicle comprising a plurality of peripherals (10₁, 10₂, 10₃, . . . , 10_n) connected to respective nodes of a computer network connected to a central control unit (12), characterised in that it comprises the steps which consist of:

inputting at the level of each peripheral an electric signature on a common conductor (14;

16;

18),

detecting at the level of each peripheral an electric signal depending upon the electric signatures of the peripherals situated upstream on the common conductor (14;

16;

18),

generating at the level of each peripheral a data item representing a relative position of the peripheral on the basis of the electric signal detected at the level of this peripheral, and

identifying each node of the network on the basis of the relative position data collected by the peripheral connected to this node;

2. Method as claimed in claim 1, characterised in that at the level of each peripheral the signal is picked up on a shunt (130) inserted into the common conductor (14;

18;

19) connecting the peripherals in series.

3. Method as claimed in claim 2, characterised in that the common conductor is a conductor (18;

19) connecting the peripherals to a reference potential.

4. Method as claimed in claim 3, characterised in that the reference potential is an earth potential.

5. Method as claimed in claim 2, characterised in that the common conductor is the computer network (14) connecting the peripherals (10₁, 10₂, 10₃, . . . , 10_n) to the central control unit (12).

6. Method as claimed in any one of claims 1 to 5, characterised in that the electric signature is input on the common conductor (14;

18) by a current source (120) in the form of a current of predetermined constant intensity.

7. Method as claimed in any one of claims 1 to 5, characterised in that the electric signature is input on the common conductor (19) by a voltage source in the form of a current of predetermined constant voltage.

8. Method as claimed in any one of claims 1 to 5, characterised in that the electric signature is input on the common conductor (14;

18;

19) by a generator of signals of predetermined waveform.

9. Method as claimed in claim 6, characterised in that the data item representing the relative position of a peripheral is generated on the basis of the measurement of the intensity of the current passing through the common conductor (14;

18) at the level of this peripheral.

10. Method as claimed in claim 7, characterised in that the data item representing the relative position of a peripheral is generated on the basis of the measurement of the intensity of a voltage appearing on the common conductor (19) at the level of this peripheral.

11. Method as claimed in any one of claims 1 to 10, characterised in that after input of the electric signatures at the level of the peripherals, a data string is transmitted by the central control unit (12) over the computer network (14), the data string comprising relative position data of peripherals each associated with a respective address data item, and each peripheral extracts from the data string transmitted the address data item associated with the relative position data item corresponding to that generated at the level of this peripheral.

12. Method as claimed in any one of claims 1 to 7, characterised in that a data item for the address of a peripheral is generated on the basis of the detection of the current passing through the common conductor (14;

18) at the level of this peripheral.

13. Method as claimed in any one of claims 1 to 7, characterised in that a data item for the address of a peripheral is generated on the basis of the detection of a voltage appearing on the common conductor (19) at the level of this peripheral.

14. Method as claimed in any one of claims 11 to 13, for the programming of addresses of the nodes (N₁, N₂, N₃, . . . , N_n) of the network, characterised in that the address data item extracted at the level of a peripheral is memorised as the address of the network node to which this peripheral is connected.

15. Method as claimed in claim 14, characterised in that the address data item is stored in a volatile manner such that the programming of addresses is reinitialised at each powering-up of the air conditioning device, and that the peripherals of one and the same type are undifferentiated when the air conditioning device is not powered up.

16. Method as claimed in claim 11 for monitoring of connection of peripherals (10₁, 10₂, 10₃, . . . , 10_n) on the nodes (N₁, N₂, N₃, . . . , N_n) of the computer network, characterised in that the address data item extracted at the level of a peripheral is compared with an address data item stored in a permanent manner at the level of this peripheral.

17. Method as claimed in any one of claims 1 to 9, characterised in that a data item representing thee electric signatures of the peripherals is generated and this data item is collected by the central control unit (12).

18. Motor vehicle air conditioning installation comprising a central control unit (12), a computer network connected to the central control unit (12) and a plurality of peripherals (10₁, 10₂, 10₃, . . . , 10_n) connected to nodes (N₁, N₂, N₃, . . . , N_n) of the computer network, characterised in that the peripherals are connected in series via a common conductor (14;

18;

19), and the installation comprises;

means for inputting at the level of each peripheral an electric signature on a common conductor (14;

18;

19),

means for detecting at the level of each peripheral an electric signal depending upon the electric signatures of the peripherals situated upstream on the common conductor (14;

18;

19),

means for generating at the level of each peripheral a data item representing a relative position of the peripheral on the basis of the electric signal detected at the level of this peripheral, and

means for identifying each node of the network on the basis of the relative position data collected by the peripheral connected to this node.

19. Installation as claimed in claim 18, characterised in that the common conductor is a conductor (18;

19) connecting the peripherals to a reference potential.

20. Installation as claimed in claim 19, characterised in that the reference potential is an earth potential.

21. Installation as claimed in claim 18, characterised in that the common conductor is the computer network (14) connecting the peripherals to the central control unit (12).

22. Installation as claimed in any one of claims 18 to 21, characterised in that the means for detecting the electric signal on the common conductor (14;

16;

18) comprise a shunt (130) inserted in the common conductor at the level of each peripheral.

23. Installation as claimed in any one of claims 18 to 22, characterised in that the means for inputting an electric signature comprise a constant current source (120).

24. Installation as claimed in claim 23, characterised in that the means for generating a data item representing a relative position comprise means for measuring (140) the intensity of the current passing through the common conductor (14;

18) at the level of each peripheral.

25. Installation as claimed in any one of claims 18 to 22, characterised in that the means for inputting an electric signature comprise a constant voltage source.

26. Installation as claimed in claim 25, characterised in that the means for generating a data item representing a relative position comprise means for measuring (140) the voltage on the common conductor (19) at the level of each peripheral.

27. Installation as claimed in any one of claims 18 to 22, characterised in that the means for inputting an electric signature comprise a generator of signals of predetermined waveform.

28. Installation as claimed in any one of claims 18 to 26, characterised in that each peripheral comprises means for comparing the relative position data item generated on the basis of the detection of the electric signal with relative position data transmitted over the computer network (14) in association with address data.

29. Installation as claimed in claim 23, characterised in that the means for generating a data item representing a relative position associated with an address data item comprise means for detecting the intensity of the current passing through the common conductor (14;

18) at the level of each peripheral.

30. Installation as claimed in claim 25, characterised in that the means for generating a data item representing a relative position associated with an address data item comprise means for detecting a voltage appearing on the common conductor (19) at the level of each peripheral.

31. Installation as claimed in any one of claims 28 to 30, characterised in that each peripheral comprises means for recording the corresponding address data item in an address memory.

32. Installation as claimed in claim 31, characterised in that the address memory is a volatile memory.

33. Installation as claimed in any one of claims 28 to 30, characterised in that each peripheral comprises means for comparing the address data item associated with the corresponding relative position data item with that generated with a pre-recorded address data item.