Redundant ground connection of a device connected to data exchange cables

Abstract

The invention relates to the connection to ground of a centralized electronic management device (51) of at least a first (9) and a second (13) electronic component, the two components exchanging data with the management device. FIG. 3

Description

Title of the invention: Redundant ground connection of a device connected to data exchange cables

[0001] The present invention relates to the field of electrical management of the electronics of a land motor vehicle. In particular, it relates to a redundant ground connection of a centralized electronic management device for at least a first and a second electronic component, the device exchanging data with the components via cables specifically configured for data exchange.

[0002] The term “motorized land vehicle” means any type of vehicle such as a motor vehicle, a moped, an airplane, a train, a motorcycle, a warehouse storage robot, etc.

[0003] Internal vehicle networks now rely on a significant number of cables dedicated to high-speed data transmission. These cables, such as Ethernet cables or LVDS (Low Voltage Differential Signaling) cables, are configured for high-speed data transmission and therefore have specific shielding not suitable for high currents (greater than 3 Amperes).

[0004] This is illustrated by [Fig. 1], which schematically represents a part of the motor vehicle comprising the centralized electronic management device 51, here called IVI for In-Vehicle Infotainment, connected to a plurality of electronic components, and for example to: - a connectivity box 9, BSRF for radio frequency servicing box, connected to the device 51 by an Ethernet cable 7 having a shield 1 and connected to ground 10; - a Head-Up Vision unit, HUD 13, connected to device 51 by an LVDS HSD Ethernet cable, high speed data, 11 having shielding 4 and connected to ground 12; - a display management component 15 connected by an LVDS HSD cable 19 to the device 51; and - a handset management component 17 connected by an LVDS HSD cable 21 to the device 51.

[0005] The device 51 is connected to a ground 3 by a dedicated cable 5, the cable 5 being configured to be able to support relatively high currents, for example 25 amperes.

[0006] However, the centralized electronic management device is powered in such a way that it is likely to generate a significant current between itself and ground, for example, 25 Amperes. As disclosed by US document 5,040,168, the ground is taken from the vehicle's metal body.

[0007] Thus, if the ground connection of the centralized electronic management system fails (loss of ground connection), this current is transmitted to the high-speed transmission cables whose shielding is not suitable for these current values. The resulting cable deterioration is likely to lead to electrical contact with the vehicle body, which is used as ground, and therefore an aggravated short circuit (ACS).

[0008] For example, in [Fig.2], a loss of connection 16 occurs and disconnects the device 51 from ground 3. The current whose path is illustrated in references 55 and 56 therefore joins the other available grounds, for example the grounds 10 and 12 of components 9 and 13. In doing so, it passes through the high-speed cables 7 and 11 which are not suitable for such intensities.

[0009] There is a need to reduce the risks of aggravated short circuits due to the transmission of a large current in cables dedicated to high-speed data transmission.

[0010] The present invention improves the situation.

[0011] To this end, a first aspect of the invention relates to a motorized land vehicle comprising: - a centralized electronic management device for at least one first and one second electronic component; - the first electronic component, connected by a first cable to the management device, the first component also being connected to a ground linked to the vehicle body; - the second electronic component, connected by a second cable to the management device, the second component also being connected to ground; - the first and second cables being respectively configured for data exchange between the first component and the device and between the second component and the device, therefore, the first and second cables each have a shield defined for a predetermined maximum current,

[0012] characterized in that the electronic management device comprises a first connection to ground and a second connection to ground.

[0013] Thus, redundancy is introduced in the ground connection of the device. This technical solution offers the best compromise between simplicity and efficiency.

[0014] Indeed, it involves a simple installation, the second connection being made to ground, which is typically the vehicle body, easily accessible throughout the vehicle and therefore requiring few additional wires (reduced size and weight). It does not involve modifications to the device or electronic components, such as the addition of a decoupling capacitor, which would further introduce electromagnetic compatibility issues.

[0015] Despite its simple implementation, the redundancy is effective insofar as it appears that the majority of connection losses are due to a disconnection from the connection to the vehicle body. Adding a second connection therefore halves the probability of a connection loss.

[0016] In one embodiment, the predetermined maximum current is between 2 and 3 Amperes.

[0017] In one embodiment, the predetermined maximum current is 2.5 Amperes.

[0018] In one embodiment, the first and / or second connection to ground the device includes a wire with shielding defined for a maximum current of 25 Amperes.

[0019] In one embodiment, the first and second connections of the device to ground are obtained by splicing an initial connection of the device to ground.

[0020] In one embodiment, the splice is a Y-splice.

[0021] Other features and advantages of the invention will become apparent from an examination of the detailed description below, and the accompanying drawings in which:

[0022] [Fig.1] is a diagram illustrating an electronic system according to the prior art;

[0023] [Fig.2] is a diagram illustrating an electronic system facing a loss of connection with a mass according to the prior art;

[0024] [Fig.3] is a diagram illustrating an electronic system according to an embodiment of the invention.

[0025] The invention is described below in its non-limiting application to the case of a device relating to an infotainment system in a motor vehicle. Other applications, such as a connectivity unit mounted on the handlebars of an electric bicycle or placed on a moped headlight, are also conceivable.

[0026] Figure 3 illustrates a centralized electronic management device for a plurality of electronic components according to an embodiment of the invention.

[0027] Figure 3 incorporates the references described above in the introduction with reference to Figures 1 and 2. In particular, the motorized land vehicle comprises: - the centralized electronic management device 51 of a first electronic component 9 and a second electronic component 13; - the first electronic component, connected by a first cable 7 to the management device, the first component also being connected to a ground 10 linked to the vehicle body; - the second electronic component, connected by a second cable 11 to the management device, the second component also being connected to ground 12 (the grounds are represented by two references but physically correspond to the same ground, the vehicle body); - The first and second cables are configured respectively for data exchange between the first component and the device and between the second component and the device; therefore, each cable has a shield designed for a predetermined maximum current. In one embodiment, the predetermined maximum current is between 2 and 3 Amperes. In another embodiment, the predetermined maximum current is 2.5 Amperes.

[0028] The electronic management device includes a first connection 62 to ground and a second connection 64 to ground.

[0029] In one embodiment, the first connection 62 and / or the second connection 64 to the ground of the device comprises a wire having a shield defined for a maximum current of 25 Amperes.

[0030] In one embodiment, the first and second connections of the device to ground are obtained by splicing 66 onto an initial connection of the device to ground. A splice here is a join between two flexible metallic assemblies (e.g., copper electrical or telecommunications wires), with a connection added by splicing onto the existing connection. The join is obtained by braiding or twisting them. In one embodiment, the splice is a Y-splice.

[0031] The present invention is not limited to the embodiments described above by way of example; it extends to other variants.

[0032] Thus, an embodiment has been described in which the invention is implemented for a device connected to a device related to an infotainment system of a motor vehicle. However, the invention can be implemented for any type of electronic device connected to other electronic components linked to said device by high-speed data transmission cables not suitable for high currents.

Claims

Demands

1. Motor vehicle comprising: - an infotainment system (51) allowing centralized electronic management of at least a first and a second electronic component; - the first (9) electronic component, connected by a first cable (7) to the infotainment system, the first component being further connected to a ground linked to the body of the vehicle; - the second (13) electronic component, connected by a second cable (11) to the infotainment system, the second component being further connected to ground;- the first and second cables being respectively configured for data exchange between the first component and the infotainment system and between the second component and the infotainment system, therefore, the first and second cables each have a shield defined for a predetermined maximum current, characterized in that the infotainment system is connected to ground by a first connection (62) and a second connection (64) obtained by splicing (66) an initial connection of the device to ground.;

2. Vehicle according to claim 1, in which the predetermined maximum current is between 2 and 3 Amperes.

3. Vehicle according to claim 2, wherein the predetermined maximum current is 2.5 Amperes.

4. Vehicle according to any one of the preceding claims, wherein the first and / or second connection to the ground of the device comprises a wire having a shield defined for a maximum current of 25 Amperes.

Images