FR2853171A1 - Electrical assembly for motor vehicle, has electrical units connected to power distribution network by current carrier bundles that are routed at short distance from electrical ground input of bundles - Google Patents

Abstract

The assembly has electrical units (200, 300) connected to a power distribution network by current carrier bundles, where each electrical unit processes the electrical signals of data. The signals are transmitted and electrical power is provided to each electrical unit by the bundles. The current carrier bundles are routed at a short distance from an electrical ground input of the bundles.

Description

i

  The present invention relates to a set of electrical elements equipping a transport vehicle, such as an automobile for example.

  More particularly, the invention relates to a plurality of these elements each processing electrical information signals received or to be transmitted and each operating by supplying electrical energy.

  With the development of electronic communication technologies, the information exchanged within a vehicle, such as an automobile, increases significantly.

  Current developments tend to exchange more information at high speed through high speed transmission media, such as for example optical fibers or twisted copper pairs.

  But the economic costs of such broadband transmission media are significantly higher than those of conventional speed transmission media.

  In addition, the increasing number of electrical and electronic devices equipping vehicles means an increase in the number, volume and weight of on-board cables.

  For illustration, and with reference to FIG. 1, an example of architecture of a network of computers referenced 100, 200, 300 up to the number N, is shown, each computer or controller requiring at least: - a cable d electrical power supply (10b, 20b, 30b or 40b) plugging into the general electrical power supply cable 1; and - a signal cable (10a, 20a, 30a or 40a) plugging into the cable of the general data bus 2 to transmit between electrical computers 25 information signals.

  This diagram clearly shows that by increasing the number of electrical devices, the number of cables, the volume required to house them, and the weight of the cables also increase.

  This complexification of the electrical and electronic architecture then risks limiting in the future the emergence of new equipment and services distributed between devices of an automobile.

  In order to overcome these problems, the Applicant recently proposed to apply the technology of "carrier currents" to the automobile.

  With reference to FIG. 2, an example of architecture is shown using carrier currents in the network of computers, referenced 100, 200, 300 up to the number N, of an automobile.

  Each computer 100, 200, 300, ..., N is electrically connected to the rest 10 of the electrical assembly by means of the electrical energy distribution network 3 and by means of a single respective electrical wired link 10, 20, 30, 40.

  This wired link 10, 20, 30, or 40 provides: - the transport of electrical energy; and - transmission of electrical data signals; to the respective computer 100, 200, 300 or N on the same support.

  This data transmission superimposed on the energy transport is called "data transmission by carrier currents", and is conveyed between the computers by the energy distribution network 3.

  This data transmission system by carrier currents thus makes it possible to reduce the number of electric cables in a vehicle by approximately half compared to the example referenced in FIG. 1, thus making it possible to reduce costs, volume and weight. Cables.

  However, the implementation of systems using carrier current technology is typically accompanied by significant electrical and / or electromagnetic interference and attenuation, which can greatly disturb the quality of the signals, in particular for the following reasons: power supply 3 is a particularly dispersive propagation medium; - For frequencies above about 30 MHz, the middle of the power supply beam 3 becomes radiant; - "electro-mechanical" noises (such as for example a contact implemented) are commonly created in a vehicle, producing harmonic frequencies on the signals of the carrier currents capable of electrically harming the quality of the data thus transmitted; the electromechanical noises usually encountered are in frequencies below 1 MHz; - the signals transmitted by carrier currents having frequencies typically belonging to the MHz range, echo phenomena are liable to appear, thus causing multiple signal paths and therefore parasitic interference; - random pulses can also be created and hinder the transmission of information; - depending on the paths and the length of the transmission links, the signal bandwidth is not often stationary and uniform.

  All these electrical and electromagnetic nuisances on the quality of the information transmitted are as many constraints which weigh on the electrical equipment composing the electrical elements 100, 200, 300, ..., N of the vehicle.

  The present invention seeks to solve these problems by proposing an electrical assembly equipping a transport vehicle, comprising a network 25 of electrical elements and electrical bundles, the electrical elements, supplied with electrical energy, being each capable of processing electrical signals from data received or to be transmitted, the electric signals being transmitted and the electric energy being supplied to each electric element by a same electric beam so as to carry out a transmission of the data by carrier currents, characterized in that the electric beams are routed at short distance from the electrical grounding of the beams so as to limit parasites and electrical or electromagnetic attenuations of the transmitted data.

  Preferred aspects of the invention are: - in the event of a portion of a bundle moving away from the ground connection, an extension of the ground connection is arranged and routed at short distance along the portion of the beam; - The extension of the mass gain along short distance the beam portion 10 is achieved by means of a twisted wire connection with the beam portion; - the electrical earth connection is the chassis of the vehicle; the electrical connections are configured so that the electrical elements are connected in series, and that they are connected together by the same bundle; - the electrical elements are mounted in a "garland" (also called "daisy chain" in English); the electrical elements each comprise: a modem capable of extracting and injecting data signals 20 into a carrier current beam; o an electric energy regulator; o at least one electrical component capable of processing electrical data signals; the electrical elements each further comprise a connector capable of connecting to the "daisy chain"; - The signals are signals modulated in frequency on a carrier, the frequencies being between 1 MHz and 30 MHz.

  Other aspects, aims and advantages of the present invention will appear better on reading its following detailed description, given by way of nonlimiting example and made with reference to the appended drawings in which: FIG. 1 represents a connection device and supply of electrical appliances to each other according to the state of the art.

  FIG. 2 represents a device for connecting and supplying electrical devices to each other according to the invention.

  Figure 3 shows a principle of connection of the electrical elements together according to the invention.

  FIG. 4 represents a diagram of the electrical connection of an electrical element to a ground connection.

  FIG. 5 represents a diagram of the electrical connection of an electrical element to a ground connection according to the invention.

  FIG. 6 represents means for connecting electrical elements 15 to one another.

  FIG. 7 represents a diagram of the means for connecting electrical elements to one another according to the invention.

  An object of the present invention is to adapt the carrier current technology to transport vehicles, such as automobiles, by reducing the electrical and electromagnetic nuisances therein.

  In this document, the term “electrical element” means: electrical or electronic device capable of equipping a transport vehicle for a specific application, having means for supplying electrical energy and means for receiving 25 electrical data signals allowing respectively to provide the energy and transmit the data necessary for its operation; the frequency ranges of the data received and emitted by an electrical element are advantageously included in the invention between approximately 1 MHz and 30 MHz, in order to lie beyond the frequency ceiling of said electromechanical noise and below the threshold of said radiation from the network d power supply 3.

  "bundle": path of transport of electrical energy, such as for example a copper wire.

  The electrical energy of the electrical assembly according to the invention is supplied by an electrical source equipping the vehicle in question, such as a direct current automobile battery.

  With reference to FIG. 3, a first electrical element 200 and a second electrical element 300 are respectively connected to the energy distribution network 3 by means of a carrier current beam 20 and a carrier current beam 30.

  The source of the electrical energy advantageously delivers a continuous electrical voltage, which is for a current conventional automobile typically between approximately 12 volts and approximately 42 volts.

  This DC voltage (or not) constitutes the carrier voltage U, the amplitude of which will be modulated over time by the electrical elements (generators and receivers of frequency signals), generating frequency information of frequency F, and frequency information of frequency F2.

  In a particular configuration, F1 represents a low level and F2 a high level of a digital signal.

  The electrical energy and the electrical data are therefore transported by the same carrier current.

  The electrical element 200 according to the invention comprises - a regulator 220; a modem 230; electrical components 210, such as here a microcontroller 211, switches / transistors 212, an actuator 213.

  The carrier current is transmitted to the electric element 200 by means of the link 20, and more particularly to the regulator 220 and to the modem 230 of the electric element 200 by the respective branches 21 and 22 of the bundle 20.

  The regulator 220 transforms the value of the electrical voltage received at 21 into a value of the operating electrical voltage of the electrical components 210 and of the modem 230.

  The regulator 220 can thus, for example, transform 42 Volts into Volts in order to operate the electronic components 210 and the modem 230.

  The regulator 220 thus supplies the electrical components 210 and the modem 230 with energy via the respective beams 23 and 24.

  The modem 230 is an interface between the electrical components 210 and the electrical supply network 3.

  Communication between the modem 230 and the electrical supply network 3 takes place via the beam 22.

  Communication between the modem 230 and the electrical components 20 210 takes place by means of a reception link 25 (also denoted RX) and a transmission link 26 (still denoted TX).

  The modem 230 is able to receive, via the transmission link 26, the data signals from the electrical components 210 and to inject these data signals into the network 3, via the beam 22, on carrier currents.

  The modem 230 is therefore able to process the data signals received from the electrical components 210 so as to transform them into frequency data signals superimposable on the carrier currents of the network 3.

  Thus, for example, if the data signals received from the electrical components 210 are digital signals, the modem 230 will modulate them to give high frequency analog data signals to be superimposed on the carrier current of the network 3, of frequency IF for the low level and frequency F2 for the high level.

  Conversely, the modem 230 is able to process the frequency data signals received from the carrier currents of the network 3, via the beam 22, so as to transform them into data signals transmitted to the electrical components 210, by through the receiving link 25.

  The electrical components 210 are, for their part, capable of processing electrical data signals received from the modem 230 and of sending to the modem 230, in order to fulfill specific functions within the vehicle.

  These electrical components 210 can, for example, fulfill a computer, controller or other function.

  The electrical components 210 can for example be integrated into multimedia, telematics, "by wire" systems, in motor controllers, in ABS applications, etc. The entire electrical element 200 is connected to a ground 240.

  Similarly, the electrical element 300 according to the invention comprises a regulator 320; - a modem 330; - electrical components 310, such as here a microcontroller 311, switches / transistors 312, an actuator 313; - a mass 340.

  In this application according to the invention, it can be seen that the electrical elements 200 and 300 can communicate with each other by means of the electrical supply network 3.

  The performance of the information transmission system using such a power supply network 3 as an information medium depends in particular on the characteristics and configuration of the physical transmission channel.

  Since the infrastructure of a transport vehicle in which the electrical data is transmitted is controlled (unlike the 5 remote communication systems), it is then possible to adjust the characteristics of the physical channel so as to improve the quality of the signals transmitted, and relieving the modem 230 of some of its constraints.

  A judicious choice of characteristics of the physical data transmission channel can thus be decisive for obtaining a quality of the transmitted signals, in particular when using carrier current technology as here.

  And can notably significantly reduce electrical and electromagnetic interference which would disturb the quality of the signals, in particular for the reasons detailed above.

  With reference to FIG. 5, a first improvement in the quality of the signal transmitted by carrier currents according to the invention is found by routing electrical connections in the vehicle.

  In a transport vehicle, the electrical ground connection is usually its chassis.

  With reference to FIG. 4, a bundle (or cable) 20 is arranged according to the state of the art to supply an electrical element 200.

  A portion of cable 20b of cable 20 is held along the chassis portion 1000 by fixing means 11 01 (thus protecting it against interference), but another portion of cable 20a of cable 20 moves away from the chassis in order to connect to the electrical element 200.

  According to the state of the art, the electrical element is protected from interference by means of a connection 2010 with a part of chassis 2000.

  However, the cable portion 20a remains poorly protected from interference due to its distance from the ground connection 1000. And the quality of the signal is then disturbed.

  With reference to FIG. 5, instead of connecting the electrical element 200 to the chassis 2000 independently of the cable portion 20a, this connection is made according to the invention via the cable portion 20a, thus making it possible to protect both the cable portion 20a and the electrical element 200 of the interference.

  An extension 1010 of the ground connection is thus provided and located a short distance from the cable portion 20a.

  This extension 1010 is advantageously a wired connection included in the cable portion 20a and twisted with the other wired connections of the cable 20, located between the electrical element 200 and the chassis 1000.

  The assembly of the cable 20 of the element 200 is thus routed at a short distance from the earth connection 1000.

  Advantageously, all of the cables (or bundles) connecting the electrical elements 100, 200, 300, ..., N equipping the vehicle are thus located a short distance from the ground connection 1000 (this is ie the chassis).

  With reference to FIG. 7, a second improvement in the quality of the signal transmitted by carrier currents according to the invention is found by configuring electrical connections in the vehicle.

  With reference to FIG. 6, the connections 80 and 90 of the prior art between the electrical supply network 3 and two respective particular bundles 20 and 30 supplying two controllers 200 and 300 respectively, are liable to form splices. at their level, when used over time.

  These splices 80 and 90 then cause in particular multiple reflections 25 (or echoes) and weakening in signal amplitude.

  With reference to FIG. 7, this problem is overcome by mounting the electrical elements 200 and 300 in series, and connected together by the same cable 3 in which the carrier currents circulate.

  Thus disappear any connection between bundles, and therefore any problem of splices 80 and 90 linked to the connections between bundles. he

  According to the invention, the cable 3 forms bends 3a and 3b in order to connect to the respective electrical elements 200 and 300, via connectors 250 and 350 respectively.

  The connections in the connector between the electrical circuit of the cable 3 5 and the electrical element 200 or 300 are advantageously made by means of PIN links.

  This network of electrical elements mounted together in series on the entire electrical network is a configuration called "daisy chain".

  With this configuration, the number of electrical elements mounted on the chain therefore has little or no influence on the quality of the signal transported.

  And the splice problems are disappearing too.

  Tests of frequency and time measurement by transmission and reflection on part of the wiring of a vehicle were carried out by the Applicant.

  These tests concerned real cabling, fitted with its loads, only disconnected at its end-load connectors in order to connect the measuring instruments.

  Analysis of the results has shown that the adoption of certain rules for routing the beams in the vehicle according to the invention (comprising the two rules discussed with reference to FIGS. 5 and 7) improves the quality of the transmitted signals, in particular guaranteeing the highest possible signal-to-noise ratio at the input of electrical components 210 and 310, an optimally widened bandwidth and a loss in neighboring signal amplitude for all types of links.

  These cabling (or routing of beams) rules thus make it possible to reliably use the carrier current technology, and in particular high-speed carrier currents (from 2 to 25 Mbits), in transport vehicles such as automobiles.

Claims (9)

  1. Electrical assembly equipping a transport vehicle, comprising a network of electrical elements and electrical bundles, the electrical elements, supplied with electrical energy, being each capable of processing electrical data signals received or transmitted, the electrical signals being transmitted and the electric energy being supplied to each electric element 10 by a same electric beam so as to carry out a transmission of the data by carrier currents, characterized in that the electric beams are routed at a short distance from the electrical grounding of the beams so as to limit the parasites and the electrical or electromagnetic attenuations of the transmitted data.   2. Electrical assembly according to the preceding claim, characterized in that in the event of a portion of the bundle moving away from the ground connection, an extension of the ground connection is arranged and routed at short distance along the portion beam.   3. Electrical assembly according to the preceding claim, characterized in that the extension of the ground connection along the short distance the beam portion is produced by means of a twisted wire connection with the beam portion.   4. Electrical assembly according to one of the preceding claims, characterized in that the electrical earth connection is the chassis of the vehicle.   5. Electrical assembly according to one of the preceding claims, characterized in that the electrical elements are connected in series, and are connected together by the same bundle.   6. Electrical assembly according to the preceding claim, characterized in that the electrical elements are mounted in a "daisy chain" (also called "daisy chain" in English).   7. Electrical assembly according to one of the preceding claims, characterized in that the electrical elements each comprise: - a modem capable of extracting and injecting data signals into a carrier current beam; - an electric energy regulator; at least one electrical component capable of processing electrical data signals.   8. Electrical assembly according to the preceding claim, characterized in that the electrical elements each further comprise a connector capable of connecting to the "daisy chain".   9. Electrical assembly according to the preceding claim, characterized in that the signals are signals modulated in frequency on a carrier, the frequencies being between 1 MHz and 30 MHz.