Apparatus for multiplexing between on-board units in a vehicle

• US 6,243,018 B1
• Filed: 06/04/1999
• Issued: 06/05/2001
• Est. Priority Date: 02/21/1995
• Status: Expired due to Fees

• Current Assignee: Hitachi Car Engineering Company Limited (Hitachi, Ltd.), Hitachi, Ltd.
• Original Assignee: Hitachi Car Engineering Company Limited (Hitachi, Ltd.), Hitachi, Ltd.
• Inventors: Saito, Hiroyuki, Koni, Mitsuru
• Primary Examiner(s): POPE, DARYL C
• Application Number:
  US09/325,648
• Time in Patent Office: 732 Days
• Field of Search: 340/596, 340/597, 340/598, 340/599, 340/647, 340/505, 340/517, 340/508, 340/578, 340/500, 340/501, 340/650, 340/649, 340/651, 340/638, 340/825.06, 375/257, 364/424.045, 364/424.04, 364/424.054, 324/500, 324/509
• US Class Current: 340/650
• CPC Class Codes: B60G 17/0185 for failure detection
• CPC Class Codes: B60G 17/0195 characterised by the regulation being combined with other vehicle control systems conjoint control of vehicle sub-units including control of suspension systems B60W10/22
• CPC Class Codes: B60G 2600/08 Failure or malfunction detecting means
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: B60R 2016/0322 Temporary code for documents to be reclassified to G08C, H04L or H04Q
• CPC Class Codes: B60R 2021/0104 Communication circuits for data transmission
• CPC Class Codes: B60R 2021/01061 between the airbag system and other vehicle electronic systems
• CPC Class Codes: B60R 2021/01115 specific data frames

Abstract

A multiplexing apparatus multiplexes between processing units and a battery unit of a vehicle which are connected to one another by wire harnesses, by grouping a variety of on-board controlled objects into a plurality of neighboring controlled objects and controlling each of respective processing units. The wire harness has electric conductors of which the outer peripheral portion are covered with a first insulating layer, electric conductivity layer which covers the electric conductors, a second insulating the peripheral portion of the electric layer which covers conductivity layer, means for applying an electric potential to said electric conductivity layer, and means for monitoring the electric potential of said electric conductivity layer.

Claims

1. An apparatus for multiplexing between processing units and a battery unit of a vehicle which are connected to one another by a wire harness, by grouping a variety of controlled on-board objects into a plurality of neighboring controlled objects and controlling each of the groups by respective processing units, in which said wire harness comprises:

electric conductors, each having an outer peripheral portion covered with a first insulating layer,

electric conductivity layer which covers said electric conductors,

a second insulating layer which covers the outer peripheral portion of said electric conductivity layer,

means for applying an electric potential for monitoring shorting to said electric conductivity layer, and

means for monitoring the electric potential of said electric conductivity layer with respect to ground variations of said electric potential indicating shorting between said electric conductivity layer and ground, whereby potential failure in said electric conductors is anticipated.

2. A multiplexing apparatus according to claim 1, wherein said electric conductivity layer is formed by a thin mesh wire.

3. A multiplexing apparatus according to claim 1, further comprising alarm means for raising an alarm to a driver, and control means for starting up said alarm means to raise the alarm.

4. A multiplexing apparatus according to claim 3, further comprising a power source circuit breaker for cutting off a current supplied from the battery unit, wherein said control means start up said power source circuit breaker to cut off the current from the battery, when said electric conductivity layer is short-circuited to the ground.

5. A multiplexing apparatus according to claim 1, wherein there are provided a plurality of electric conductivity layers between which insulating layers are alternately sandwiched.

6. A multiplexing apparatus according to claim 5, further comprising:

alarm means for raising an alarm to a driver,

a power source circuit breaker for cutting off a current supplied from the battery unit, and

control means for starting up said alarm means to raise the alarm and starting up the power source circuit breaker to cut off the current from the battery unit, when at least one of said electric conductivity layers is short-circuited to ground.

7. A multiplexing apparatus according to claim 1, further comprising:

means for monitoring the electric potential of said electric conductivity layer between respective groups,

means for detecting the short-circuit of the electric conductivity layer to the ground on the basis of the output of said monitoring means, and

circuit breaker for cutting off a current passing through said electric conductor from the power source when the short-circuit of the electric conductivity layer to the ground is detected by said detecting means, whereby potential failure of said electric conductor is anticipated.

8. A multiplexing apparatus according to claim 1, further comprising:

means for monitoring the electric potential of said electric conductivity layer between respective processing units,

means for detecting the short-circuit of the electric conductivity layer to the ground on the basis of the output of said monitoring means, and

alarm means for raising an alarm to a driver when the short-circuit of the electric conductivity layer to the ground is detected by said detecting means, whereby potential failure of said electric conductor is anticipated.

9. A multiplexing apparatus according to claim 4, wherein said power source cutting-off means include a switching element.

10. An apparatus for multiplexing between processing units and a battery unit of a vehicle which are connected to one another by a wire harness, by grouping a variety of controlled on-board objects into a plurality of neighboring controlled objects and controlling each of the groups by respective processing units, in which said wire harness comprises:

electric conductors, each having an outer peripheral portion covered with a first insulating layer,

electric conductivity layer which covers said electric conductors,

a second insulating layer which covers the outer peripheral portion of said electric conductivity layer,

means for applying an electric potential for monitoring shorting to said electric conductivity layer,

means for monitoring the electric potential of said electric conductivity layer with respect to ground variations of said electric potential indicating shorting between said electric conductivity layer and ground, whereby potential failure in said electric conductors is anticipated,

means for monitoring the electric potential of said electric conductivity layer between respective processing units,

means for detecting the short-circuit of the electric conductivity layer to the ground on the basis of the output of said monitoring means, and

alarm means for raising an alarm to a driver when the short-circuit of the electric conductivity layer to the ground is detected by said detecting means, whereby potential failure of said electric conductor is anticipated;

wherein said electrical potential applying means comprise a C-shaped electric conductivity body having a portion which is notched, an electric conductor connected to the electric conductivity body for detecting an electric potential, and a pull-up resistor, and wherein said electric conductivity body is press-bonded to the electric conductor from the outside of the electric conductivity layer which is a thin mesh wire.

11. An apparatus for multiplexing between processing units and a battery unit of a vehicle coupled to one another via wire harnesses, by grouping a variety of controlled on-board objects into a plurality of neighboring controlled objects and controlling each of said groups by respective ones of said processing units, in which at least one of said wire harnesses comprises:

electrical conductors having an outer peripheral portion covered with a first insulating layer;

an electric conductivity layer covering said electrical conductors, wherein an electrical potential for monitoring shorting is applied to said electric conductivity layer;

a second insulating layer covering an outer peripheral portion of said electric conductivity layer; and

an electric potential monitor operatively connected to said electric conductivity layer for detecting short circuits of said electric conductivity layer to ground, whereby a possible occurrence of a short circuit of said electric conductors is anticipated.

12. A multiplexing apparatus according to claim 11, further comprising:

an alarm circuit coupled to an alarm indicator for a vehicle driver; and

a processor for activating the alarm circuit to raise the alarm indicator for the driver.

13. A multiplexing apparatus to claim 12, further comprising:

a power source circuit breaker operatively arranged so as to cut-off a current supplied from the battery unit;

wherein said processor starts up the power source circuit breaker to cut-off the current from the battery when the electric conductivity layer is short-circuited to ground.

14. A multiplexing apparatus to claim 11, wherein said electric potential monitor monitors the electric potential of the electric conductivity layer between respective groups;

a short-circuit detector coupled to the wire harness for detecting a short circuit of the electric conductivity layer to ground on a basis of an output from the monitor; and

a circuit breaker for cutting-off a current passing through said electric conductor from the battery unit when the short-circuit of the electric conductivity layer is detected.

15. An apparatus for detecting a short circuit of a wire harness for a power supply used in a motor vehicle, the wire harness comprising:

electrical conductors having an outer peripheral portion covered with a first insulating layer;

an electric conductivity layer covering said electrical conductors, wherein an electrical potential for monitoring shorting is applied to said electric conductivity layer;

a second insulating layer covering an outer peripheral portion of said electric conductivity layer; and

an electric potential monitor operatively connected to said electric conductivity layer for detecting shorting of said electric conductivity layer to ground, whereby a potential occurrence of a short in said electric conductor is anticipated.