GB2639889A

GB2639889A - Coaxial cable

Info

Publication number: GB2639889A
Application number: GB2404361.4A
Authority: GB
Inventors: Pahontu Nicolae; Schultheiss Anton
Original assignee: Continental Autonomous Mobility Germany GmbH
Current assignee: Aumovio Autonomous Mobility Germany GmbH
Priority date: 2024-03-27
Filing date: 2024-03-27
Publication date: 2025-10-08
Also published as: GB202404361D0

Abstract

The first cable 1 comprises electrical inner and outer conductors 2, 3, a dielectric layer 5 made of a solid material and arranged between the inner and outer conductors 2, 3. The dielectric layer 5 acts as a light conductor 6. An electrically insulating protection jacket 4 surrounds the outer electrical conductor 3. The second cable (figs 2a, 2b) comprises electrical inner and outer conductors 2, 3, a dielectric layer 5 made of a solid material and arranged between the inner and outer conductors (2, 3). A light conductor (6) surrounds the outer electrical conductor 3. The third cable (figs 3a, 3b) comprises electrical inner and outer conductors 2, 3, a dielectric layer 5 made of a solid material and arranged between the inner and outer conductors (2, 3). The inner electrical conductor (2) is hollow or tubular allowing an optical fibre cable (6) to be located within the inner electrical conductor (2). An assistance system for a vehicle is described wherein the sensors and the electrical power system are interconnected by the coaxial cables.

Description

Description Coaxial cable

The invention relates to a coaxial cable, in particular for connecting components of an assistance system of a vehicle, comprising an electrical inner conductor, an electrically conductive outer conductor surrounding the inner conductor, a dielectric layer made of a solid material and arranged between the inner conductor and the outer conductor and enclosing the inner conductor, and an electrically insulating protection jacket surrounding the outer conductor. The invention further relates to a system, in particular an assistance system, for a vehicle, comprising a sensor and an electrical component, wherein the sensor and the electrical component are connected by means of such a coaxial cable.

Vehicles today usually have a number of different sensors, for example cameras, radar sensors and/or lidar sensors, which are assigned to one assistance system or to more assistance systems of the vehicle and in particular provide information about the vehicle's surroundings, for example about obstacles or objects in the surroundings of the vehicle. Such assistance systems include, for example, surround view systems, parking assistance systems, brake assistance systems or driving assistance systems that take over partial or complete control or guidance of the vehicle as part of semi-autonomous or autonomous operation or driving of the vehicle. The sensors are typically distributed around the vehicle in the front, side and/or rear of the vehicle and are usually installed on the body or coverings or in the interior of the vehicle.

Components of such assistance systems, as well as various vehicle components in general, are usually connected to each other by wire. For this purpose, the vehicle typically has a corresponding cable harness, which is sometimes designed as an electro-optical cable harness. Such an electro-optical cable harness is used in particular to transmit data and energy via electrical conductors and to at least partially synchronize the components, in particular some sensors, of the vehicle via optical conductors, and usually comprises several different types of cable for this purpose. Newer systems are also known, which comprise one or more radiation or light sources that illuminate the field of view of one or more sensors. In many cases the placement of the light sources is different from the place of the sensors. Often, the light source shall generate light pulses, particularly laser pulses. The spectrum of the light source is specific to the application, in visible or non-visible domain (e.g., ultraviolet or infrared). For fulfilling the application requirements there are many cases when the remote sensor(s) shall be synchronized with the generated light pulses. There are applications which imply very accurate synchronization, particularly in a nanosecond range. In addition, there are cases when laser light pulses are generated based with crystals that shall ensure the necessary energy and timings. Such laser light pulses are affected by jitter. There is no precise moment in time when the laser light pulse is generated. In such applications the best solution for an accurate synchronization is to use a fraction of the light from the laser light pulse itself. This fraction of light will be coupled from the laser light pulse to the sensor that shall be synchronized. As example for such an application is a camera sensor with gated images.

However, when using cables or cable harnesses, especially in vehicles, there is a need to reduce the weight and size of the cables or cable harnesses without losing system properties or compromising system performance. At the same time, the cables or cable harnesses should be easy to manufacture and install, and be as flexibly and universally applicable as possible for different installation situations.

In view of the foregoing, it is an object of the present invention to provide a coaxial cable, in particular for connecting components of an assistance system of a vehicle, which can be easily manufactured and installed and which can be used or applied as universally and flexibly as possible, and which at the same time has small dimensions, in particular a small diameter, and a low weight.

According to one aspect of the invention, a coaxial cable, in particular for connecting components of an assistance system of a vehicle, is provided, comprising an electrical inner conductor, an electrically conductive outer conductor surrounding the inner conductor, a dielectric layer made of a solid material and arranged between the inner conductor and the outer conductor and enclosing the inner conductor, a light conductor, and an electrically insulating protection jacket, in particular completely, surrounding the outer conductor.

An essential idea of the invention is that different transmission media are combined or bundled in a single coaxial cable, wherein the coaxial cable is designed as an electro-optical coaxial cable with electrical conductors and a light conductor.

Thus, in accordance with the present invention, a compact coaxial cable, in particular for connecting components of an assistance system of a vehicle, is provided, which can be easily manufactured and installed and which can be used or applied as universally and flexibly as possible, and which at the same time has small dimensions, in particular a small diameter, and a low weight.

Advantageously, the coaxial cable has a circular cross section. Preferably, the electrical inner conductor, the electrically conductive outer conductor, the dielectric layer, the light conductor, and the electrically insulating protection jacket are arranged concentrically to each other, particularly wherein the electrical inner conductor and/or the electrically conductive outer conductor and/or the dielectric layer and/or the light conductor and/or the electrically insulating protection jacket has or have a circular or ring-shaped cross section.

The coaxial cable has at least one light conductor. However, the coaxial cable can also have more than one light conductor.

Advantageously, the light conductor or the multiple light conductors are designed as optical waveguides or light waveguides.

According to an advantageous embodiment, the light conductor is designed as a one-piece material layer surrounding the inner conductor. Thereby, the inner conductor is centrally guided, i.e., the inner conductor, in a radial direction, is arranged in the center of the coaxial cable, wherein the inner conductor is surrounded by the light conductor. Particularly, the inner conductor comprises an electrically conductive core, wherein the electrically conductive core is constructed as a single wire consisting of metal, preferably copper, or as a core of a bundle of metal wires, preferably copper wires.

The one-piece material layer can directly or indirectly surround the inner conductor, wherein in particular the material layer completely surrounds the inner conductor in the circumferential direction. Therefore, when seen in a radial direction, the one-piece material layer can be arranged directly adjacent to the inner conductor, but, when seen in radial direction, one or more other components of the coaxial cable, for example the dielectric layer and/or the outer conductor, can also be arranged between the inner conductor and the one-piece material layer.

The coaxial cable has at least one light conductor, wherein the at least one light conductor is formed as a one-piece material layer surrounding the inner conductor.

However, the coaxial cable can also have more than one light conductor, with some or all of the multiple light conductors being formed as a one-piece material layer surrounding the inner conductor.

According to a further advantageous embodiment, the dielectric layer is designed as the light conductor. Thus, the dielectric layer also represents the one-piece material layer forming the light conductor.

According to a further advantageous embodiment, as an alternative or in addition, the one-piece material layer is arranged between the outer conductor and the protection jacket. A material layer forming the light conductor can therefore only be arranged between the outer conductor and the and the protection jacket. However, it is also possible that in addition to the light conductor, which is arranged as the material layer between the outer conductor and the protection jacket, a further light conductor is formed by the dielectric layer.

According to a further advantageous embodiment, the inner circumferential wall of the outer conductor is designed to be light-reflecting. Thereby, the entire inner circumferential wall of the outer conductor or only a part of the inner circumferential wall of the outer conductor can be configured to reflect light. The inner circumferential wall is the radially inner circumferential surface of the outer conductor facing the inner conductor.

According to a further advantageous embodiment, the outer circumferential wall of the outer conductor is designed to be light-reflecting. Thereby, the entire outer circumferential wall of the outer conductor or only a part of the outer circumferential wall of the outer conductor can be configured to reflect light. The outer circumferential wall is the radially outer circumferential surface of the outer conductor facing away from the inner conductor or facing the protection jacket.

According to a further advantageous embodiment, the electrical inner conductor is designed as a tubular electrical inner conductor, wherein the light conductor is arranged within said tubular electrical inner conductor. Thereby, advantageously, the light conductor is centrally guided, i.e., the light conductor, in a radial direction, is arranged in the center of the coaxial cable, wherein the light conductor is surrounded by the electrical inner conductor, and particularly wherein the light conductor is designed as a one piece material layer. Preferably, the light conductor comprises a coating on its outer surface or outer circumferential wall.

Thereby, advantageously, the light conductor, particularly with a coating on its outer surface, the electrical inner conductor, the dielectric layer, and the electrically conductive outer conductor are arranged, in this order from the inside to the outside of the coaxial cable, directly adjacent to each other. Therefore, for example, the electrical inner conductor directly bears or rests against the light conductor, particularly against a coating on the outer surface of the light conductor, the dielectric layer directly bears or rests against the electrical inner conductor, and the electrically conductive outer conductor directly bears or rests against the dielectric layer.

According to a further advantageous embodiment, the electrical inner conductor is formed by a, particularly thin, metallic braid, for example as a copper braid, particularly woven around the light conductor, or by a metallization of the outer surface of the light conductor. In an advantageous embodiment, in which the light conductor comprises a coating on its outer surface or outer circumferential wall, the electrical inner conductor is formed by a metallic braid, for example as a copper braid, which is woven around the coating, or by a metallization of the coating on its outer surface.

According to a further advantageous embodiment, the electrically conductive outer conductor comprises a, particularly copper, braid and/or a, particularly aluminum, foil. Advantageously, the electrically conductive outer conductor is designed as a shielding layer.

According to a further advantageous embodiment, the coaxial cable is designed for the transmission of data, light pulses for synchronization and supply energy.

Thereby, according to a further advantageous embodiment, the light conductor is designed as a synchronization line for transmitting the light pulses and/or as a data transmission line for transmitting the data, and wherein the inner conductor and the outer conductor are designed for transmitting the supply energy, in particular for the power supply. With such a light conductor, in particular a fast and precise synchronization can be achieved. Advantageously, the light conductor is designed as the synchronization line for transmitting the light pulses and as the data transmission line for transmitting the data, wherein the inner conductor and the outer conductor are designed for transmitting the supply energy, in particular for the power supply. Hereby, particularly high data rates can be transmitted. Alternatively, the light conductor is advantageously designed as the synchronization line for transmitting the light pulses, wherein the inner conductor and the outer conductor are designed for transmitting the supply energy, in particular for the power supply, and as the data transmission line for transmitting the data.

According to another aspect of the invention, a system, in particular an assistance system, for a vehicle, is provided, comprising a sensor and an electrical component, wherein the sensor and the electrical component are connected by means of a coaxial cable according to the invention.

The advantages and the advantageous and preferred embodiments described for the coaxial cable according to the invention also apply accordingly to the system according to the invention.

In particular, the sensor is arranged remote or spatially separated from the electrical component.

Advantageously, the sensor is designed as a lidar sensor, as a radar sensor or as a camera, preferably as a surroundings camera or an interior camera, preferably as a camera of a surround view system of the vehicle.

According to an advantageous embodiment, the electrical component is designed as a radiation source unit, particularly as a light source unit, which is configured to emit light pulses for synchronizing the sensor, wherein the light pulses are transmitted to the sensor via the coaxial cable.

Alternatively, according to a further advantageous embodiment, the electrical component comprises a radiation source unit, particularly a light source unit, which is configured to emit light pulses for synchronizing the sensor, wherein the light pulses are transmitted to the sensor via the coaxial cable. Preferable, the electrical component is further designed to read out and/or process the sensor signal data transmitted by the sensor via the coaxial cable and/or to control the sensor and, in particular, comprises a computing device comprising a microprocessor or microcontroller for this purpose.

The drawings described herein are used to provide a further understanding for the present invention, and constitute a part of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation to the present invention. In the drawings: FIG. la shows in a cross-section a coaxial cable according to a preferred embodiment of the invention; FIG. lb shows in a cut-back side view the coaxial cable according to FIG. la; FIG. 2a shows in shows in a cross-section a coaxial cable according to another preferred embodiment of the invention; FIG. 2b shows in a cut-back side view the coaxial cable according to FIG. 2a; FIGi. 3a shows in a cross-section a coaxial cable according to another preferred embodiment of the invention, and FIG. 3b shows in a longitudinal section the coaxial cable according to FIG. 3a.

The following describes the present invention in detail with reference to the accompanying drawings and in combination with embodiments. It should be noted that, without conflicts, the embodiments in the present invention and features in the embodiments may be combined with each other. Parts corresponding to each other are always provided with the same reference signs in all figures.

FIGS. la and lb show a coaxial cable 1 according to a preferred embodiment of the invention in different views. FIG. la shows the coaxial cable 1 in a cross-section, FIG lb shows the coaxial cable 1 in a cut-back side view.

The coaxial cable 1 is configured for connecting components of an assistance system of a vehicle, namely a camera of a surround view system of the vehicle with a remote control unit of the vehicle, wherein the control unit comprises a light source unit configured to emit light pulses for synchronizing the camera. The coaxial cable 1 is designed for the transmission of data, light pulses for synchronization and supply energy between the control unit and the camera.

The coaxial cable 1 comprises an electrical inner conductor 2 and an electrically conductive outer conductor 3 surrounding the inner conductor 1. The inner 2 conductor and the outer conductor 3 are designed for transmitting the supply energy, i.e., for the power supply. Also, the outer conductor 3 shields the inner conductor 1 from interference radiation. The coaxial cable 1 further comprises an electrically insulating protection jacket 4 surrounding the outer conductor 3. Between the inner conductor 2 and the outer conductor 3 a dielectric layer 5 is arranged. The dielectric layer 5 is made of a solid material as a single piece or one-piece material layer and directly surrounds the inner conductor 2, wherein it completely encloses the inner conductor 2 in the circumferential direction. The dielectric layer 5 simultaneously acts as a light conductor 6 and is made of a respective solid material suitable for this purpose. The dielectric layer 5 or the light conductor 6 is designed as the synchronization line for transmitting the light pulses and as the data transmission line for transmitting the data between the control unit and the camera. To further improve the light transmission, the inner circumferential wall 7 of the outer conductor 3 is designed to be light-reflecting.

In this way, with combining these different transmission media in a single coaxial cable 1, wherein the light conductor 6 is designed as a one-piece material layer surrounding the electrical inner conductor 2, a very compact coaxial cable 1 with small dimension and a low weight is provided, which can be easily manufactured and installed and which can be used or applied very universally and flexibly. Furthermore, it particularly enables a fast and precise synchronization.

FIGS. 2a and 2b show a coaxial cable 1 according to another preferred embodiment of the invention in different views. FIG. 2a shows the coaxial cable 1 in a cross-section, FIG. 2b shows the coaxial cable 1 in a cut-back side view.

The coaxial cable 1 essentially corresponds to the coaxial cable 1 in FIGS. la and I b. In contrast to the embodiment in FIGS. 1a and 1b, the dielectric layer 5 does not act as a light conductor 6. Rather, the light conductor 6, which is also designed as a one-piece material layer completely surrounding the inner conductor 1, here is arranged between the outer conductor 3 and the protection jacket 4. The light conductor 6 here is also designed as the synchronization line for transmitting the light pulses and as the data transmission line for transmitting the data between the control unit and the camera. To further improve the light transmission, the outer circumferential wall 8 of the outer conductor 3 is designed to be light-reflecting.

FIGS. 3a and 3b show a coaxial cable 1 according to another preferred embodiment of the invention in different views. FIG. 3a shows the coaxial cable 1 in a cross-section, FIG. 3b shows the coaxial cable 1 in a a longitudinal section.

The coaxial cable 1 essentially corresponds to the coaxial cable 1 in FIGS. la and 1 b. In contrast to the embodiment in FIGS. la and 1 b, the electrical inner conductor 2 is designed as a tubular electrical inner conductor, wherein the light conductor 6 is arranged within said electrical inner conductor 2. Thereby, the light conductor 6 is centrally guided, i.e., the light conductor 6, in a radial direction, is arranged in the center of the coaxial cable 1. The light conductor 6 comprises a coating 9 on its outer circumferential wall facing the electrical inner conductor 2. So, the light conductor 6 or its coating 9 is surrounded by the electrical inner conductor 2. The electrical inner conductor 2 is formed by a metallic braid, and the electrically conductive outer conductor 3 comprises a copper braid and an aluminum foil.

By such a coaxial cable design, particularly a superior performance in data bandwidth and low loss of the light conductor 6 enable unidirectional optical transmission from sensor to control unit, along with a data link based on RF frequency multiplexing or time multiplexing data transmission systems and also enables DC power supply. In an exemplary configuration of the camera as a high resolution camera, for example a 25 megapixel camera with 20 gigabits per second video payload, the asymmetrical data streaming goes over the light conductor 6 and a high speed bidirectional control channel using LVDS (Low-Voltage-Differential-Signaling) or automotive ethernet and a DC power supply particularly go over the electrical inner conductor 2 and the electrically conductive outer conductor 3.

Claims

Patent claims 1. Coaxial cable (1), in particular for connecting components of an assistance system of a vehicle, comprising an electrical inner conductor (2), an electrically conductive outer conductor (3) surrounding the inner conductor (2), a dielectric layer (5) made of a solid material and arranged between the inner conductor (2) and the outer conductor (3) and enclosing the inner conductor (2), a light conductor (6), and an electrically insulating protection jacket (4) surrounding the outer conductor (3).
2. Coaxial cable (1) according to claim 1, wherein the light conductor (6) is designed as a one-piece material layer surrounding the inner conductor (1).
3. Coaxial cable (1) according to claim 2, wherein the dielectric layer (5) is designed as the light conductor (6).
4. Coaxial cable (1) according to claim 2 or 3, wherein the one-piece material layer is arranged between the outer conductor (3) and the protection jacket (4).
5. Coaxial cable (1) according to one of claim 2 to 4, wherein the inner circumferential wall (7) of the outer conductor (3) is designed to be light-reflecting.
6. Coaxial cable (1) according to one of claim 2 to 5, wherein the outer circumferential wall (8) of the outer conductor (3) is designed to be light-reflecting.
7. Coaxial cable (1) according to claim 1, wherein the electrical inner conductor (2) is designed as a tubular electrical inner conductor, and wherein the light conductor (6) is arranged within said tubular electrical inner conductor.
8. Coaxial cable (1) according to claim 7, wherein the electrical inner conductor is formed by a metallic braid, particularly woven around the light conductor, or by a metallization of the outer surface of the light conductor.
9. Coaxial cable (1) according to one of claims 1, 7-8, wherein the electrically conductive outer conductor (3) comprises a braid and/or a foil.
10. Coaxial cable (1) according to one of the preceding claims, designed for the transmission of data, light pulses for synchronization and supply energy.
11. Coaxial cable (1) according to claim 10, wherein the light conductor (6) is designed as a synchronization line for transmitting the light pulses and/or as a data transmission line for transmitting the data, and wherein the inner conductor (2) and the outer conductor (3) are designed for transmitting the supply energy, in particular for the power supply.
12. System, in particular an assistance system, for a vehicle, comprising a sensor and an electrical component, wherein the sensor and the electrical component are connected by means of a coaxial cable (1) which is configured according to one of the preceding claims.
13. System according to claim 12, wherein the electrical component is designed as a radiation source unit, particularly as a light source unit, which is configured to emit light pulses for synchronizing the sensor, wherein the light pulses are transmitted to the sensor via the coaxial cable.
14. System according to claim 12, wherein the electrical component is designed as a control unit which comprises a radiation source unit, particularly a light source unit, which is configured to emit light pulses for synchronizing the sensor, wherein the light pulses are transmitted to the sensor via the coaxial cable.