DE102024001072A1 - Arrangement and method for compensating an initial magnetic field in a vehicle - Google Patents

Abstract

The invention relates to an arrangement for compensating an initial magnetic field in a vehicle having at least one seat, wherein the at least one seat has at least one electrically conductive, metallic seat structure (1), wherein a voltage source, in particular a battery (3), is arranged to provide a current through the metallic seat structure (1) to generate a counter field for superimposing the initial magnetic field, wherein at least one control unit (5.1, 5.2, 5.3) is arranged and configured to control and/or regulate the current as a function of a strength and/or location of the initial magnetic field in order to at least partially cancel out the initial magnetic field.

Description

The invention relates to an arrangement for compensating an initial magnetic field in a vehicle according to the preamble of claim 1 and a method for compensating an initial magnetic field in a vehicle according to the preamble of claim 10.

The ongoing transformation from combustion engine vehicles to electric vehicles leads to increased and unwanted emission loads for the occupants and thus necessary protective measures regarding the effects of magnetic fields on exposed groups of people (children, passive/active implant wearers, etc.).

In electric vehicles, numerous high-voltage components (including batteries and inverters) are often interconnected with shielded high-voltage cables. Depending on their arrangement relative to the occupants and due to constantly increasing power requirements (during charging and/or driving), these cables and high-voltage components can become a source of magnetic interference for the occupants. These emissions cannot be avoided in principle; they can only be minimized through protective measures and/or clever component and wiring harness packaging (including Pareto optimization).

However, the measures mentioned can lead to significant space and weight disadvantages as well as to complex and expensive special solutions due to multi-criteria optimization (Pareto).

All known electric vehicle architectures reduce the increased magnetic field emission load either through necessary protective measures such as shielding plates, paints, coatings or through increased spatial separation (magnetic field decrease proportional to the distance between source and sink) between the interference source and the interior (sink).

DE 2 120 159 B2 describes an arrangement for compensating for magnetic fields induced by the earth's field on vehicles using measuring probes for detecting the earth's field and means for compensating the vehicle's own fields as a function of the position and change in position of the vehicle in the earth's field, wherein a differentiating element is provided by which changes in electrical control variables for the currents flowing in compensation windings for compensating the induced fields are detected and amplified to compensation windings comprising electrically highly conductive parts in such a way that the eddy currents generated in these parts are compensated with regard to their magnetic fields, wherein the differentiating element is fed by an electrical control variable which is proportional to the change in the earth's field.

The invention is based on the object of providing a novel arrangement and a novel method for compensating an initial magnetic field in a vehicle.

The object is achieved according to the invention by an arrangement for compensating an initial magnetic field in a vehicle having the features of claim 1 and by a method for compensating an initial magnetic field in a vehicle having the features of claim 10.

Advantageous embodiments of the invention are the subject of the subclaims.

An arrangement for compensating an initial magnetic field in a vehicle having at least one seat, in particular a plurality of seats, is proposed. According to the invention, the at least one seat has at least one electrically conductive, metallic seat structure, wherein a voltage source, in particular a battery, is arranged to provide a current through the metallic seat structure to generate a counter-field for superimposing the initial magnetic field. Furthermore, at least one control unit is arranged and configured to control and/or regulate the current as a function of the strength and/or location of the initial magnetic field in order to at least partially cancel the initial magnetic field.

In one embodiment, the metallic seat structure has at least one magnetic field antenna and/or at least one seat mat and/or at least one seat heater through which the current for generating the opposing field can flow.

In one embodiment, at least one sensor is provided to detect the occupancy of at least one seat by a person, wherein the at least one control unit is configured to initiate a current flow only through the respective seat structure of at least one seat occupied by a person in order to protect the person sitting there from an excessively strong magnetic field. However, this is not necessary for unoccupied seats.

In one embodiment, the at least one sensor is designed as a seat sensor (for example a seat occupancy sensor and/or weight sensor) and/or as a belt sensor for detecting a fastened seat belt.

In one embodiment, the control unit is configured to stop the generation of the opposing field by the seat structure of at least one seat when no current is drawn from the voltage source or the respective seat is no longer occupied. The control unit can detect this, for example, itself or through communication with other control units.

In one embodiment, the at least one control unit is configured to determine how much current is currently being drawn from the voltage source, for example to drive the vehicle, to use the level of the drawn current to infer the strength of the initial magnetic field, to use this to determine how strong the opposing field must be in order to at least largely or approximately cancel out the initial magnetic field for the person sitting on the respective seat, and to set the current required for this in the seat structure.

In one embodiment, the at least one control unit is configured to cyclically determine whether and to what extent current is still being drawn from the voltage source and to regulate the current through the seat structure accordingly.

In one embodiment, the voltage source includes contactors and fuse elements configured to provide the current through the metallic seat structure.

According to one aspect of the present invention, a vehicle with an electric drive and a voltage source designed as a battery (for example a high-voltage battery and/or a low-voltage battery) is proposed, wherein the vehicle further comprises an arrangement for compensating an initial magnetic field as described above.

According to one aspect of the present invention, a method for compensating an initial magnetic field in a vehicle having at least one seat, in particular a plurality of seats, is proposed. The at least one seat has at least one electrically conductive, metallic seat structure, wherein a current is provided from a voltage source, in particular a battery, through the metallic seat structure in order to generate a counter-field for superimposing the initial magnetic field. The current is controlled and/or regulated as a function of the strength and/or location of the initial magnetic field in order to at least partially cancel the initial magnetic field.

According to the solution according to the invention, it can be detected by means of at least one seat occupancy sensor and/or weight sensor and/or a belt detection on at least one seat, in particular several or all seats of a vehicle, in particular with an electric drive, whether the assigned seat is occupied.

By means of a magnetic field antenna, a counter field can be generated in correlation to an initial magnetic field, which is caused, for example, by a battery or a cable, in order to overlap with it and, if possible, at least partially cancel it out.

In particular, a counter-field with a suitable amplitude and location is generated. This allows initial magnetic fields caused by electrical components to be minimized and/or eliminated for the seat positions occupied by people. Magnetic field compensation can be optimized depending on vehicle constraints (e.g., country-specific requirements, current strength, installation space, etc.).

The present invention proposes a measure for avoiding increased magnetic field emission loads for interior passengers by means of counter-field generation for magnetic field compensation.

This results in a highly integrated, cost- and space-optimized solution.

The solution involves compensating for the inherent magnetic fields with a specially generated counter-magnetic field. The required minimum amount of energy can be drawn directly from the high-voltage battery.

First, the existing seat and/or weight sensors (for the seat belt warning, among other things) detect whether a seat is occupied or not. A counter magnetic field is then generated for the corresponding seat using a (metallic) body shell, an existing (metallic) seat structure, and/or a seat heater (also often fitted as standard) with wires or even thin (metallized) surfaces. These structures can be used to design a magnetic field antenna, eliminating the need for additional components. The metallic material can be a magnetically compatible material, such as steel, iron, or similar alloys together with cobalt, nickel, and/or copper, or brass.

The existing structures (body shell, seat supports, heating wires) are adapted as a counter magnetic field antenna in correlation to the generating field and with regard to the vehicle boundary conditions (including country-specific requirements, current strength, installation space, etc.). For this purpose, preliminary magnetic field simulations can be performed. These results can be used to coordinate the amplitude, precise positioning, and overall antenna design. Control and, if necessary, regulation can be achieved, for example, via existing seat control units (for heating, ventilation, and/or massage).

With this described counter magnetic field generation, the resulting total magnetic field at the seat position occupied by people can be minimized and/or eliminated.

By minimizing and/or eliminating magnetic fields, other measures (e.g., shielding plates, foils, paints, etc.) for protecting vehicle occupants can be reduced. This results in additional space and cost savings for future vehicle architectures. Furthermore, they enable further highly integrated approaches for high-voltage batteries in vehicles if appropriate magnetic field compensation structures are considered.

Embodiments of the invention are explained in more detail below with reference to drawings.

• 1 eine schematische Ansicht einer Sitzstruktur eines Fahrzeugs, und
• 2 schematische Ansichten beispielhafter Magnetfeldantennen.

Showing:

• 1 a schematic view of a seat structure of a vehicle, and
• 2 schematic views of exemplary magnetic field antennas.

Corresponding parts are provided with the same reference numerals in all figures.

1 is a schematic view of a seat structure 1 of a vehicle, in particular a vehicle with an electric drive. In the vehicle, initial magnetic fields are generated by high-voltage components (including battery 3, inverter) and high-voltage lines.

A seat sensor 2 can be arranged on the seat structure 1.

To generate a magnetic counterfield, metallic seat structures 1 or metallic seat mats, for example a seat heater, are used with metal wires that are connected to a voltage source, in particular a battery 3, for example a high-voltage battery or a low-voltage battery with, for example, 12V or 48V, which is connected to the seat structure 1 via supply lines 4. The generation of the counterfield is controlled by a control unit 5.1, 5.2, 5.3, for example a seat heater control unit 5.1 or a battery control unit 5.3. In this case, a current flow through the seat structure 1 is set depending on the initial magnetic field. This current flow generates a counterfield through the geometric seat structure 1 that overlaps with the initial magnetic field and, if possible, at least approximately cancels it out. For this purpose, the control units 5.1 to 5.3 involved can communicate with each other via a bus system 6, for example via CAN, LIN, etc. Existing contactors and fuse elements 7 (for example in or on the voltage source 3) can be used to switch the current flow for the counter field generation on and off.

To initialize the generation of the opposing field, a seat sensor 2 located in one, several, or all seats of the vehicle (optionally combined with the detection of a fastened seat belt) can be used to query whether the assigned seat position is occupied via at least one control unit 5.2 assigned to the seat sensor 2. Only in this case must an opposing field be generated to protect the occupants.

The participating control units 5.1, 5.2, and 5.3 can then communicate with each other to determine how much current is currently being drawn from battery 3. Based on the level of the drawn current, the strength of the initial magnetic field can be determined, thus determining how strong the opposing field must be and how much current is required.

Subsequently, the contactor and fuse elements 7 are released for a current flow through the at least one seat structure 1 by the battery control unit 5.3.

This induces a counter magnetic field for the respective seat, which overlays the initial magnetic field and, if possible, at least largely or almost completely cancels it out.

Control units 5.1, 5.2, and 5.3 can cyclically query each other to determine whether and to what extent power is still being drawn. Accordingly, the current flow within seat structure 1 can be adjusted depending on the battery currents.

If the battery system is inactive and/or the seat sensor 2 detects that the assigned seat position is no longer occupied, the contactor and fuse elements 7 can be opened to stop the generation of the opposing field.

2 shows exemplary schematic views of magnetic field antennas 8.

Magnetic field antennas 8 are antenna structures that are quite simple to implement in terms of their geometric design. They essentially consist of one or more so-called magnetic field loops that are interconnected and connected to the battery 3 via supply lines 4. Depending on the current flowing through them, the respective loop surface generates a counter magnetic field that is tuned to the initial magnetic field. This tuning can be performed as part of a structural design during the pre-development of the vehicle, i.e., the structures of the initial field (including size, position, area) are measured (module structure, cell connectors, forward and return conductor busbars, etc.) and transferred to the counter field antenna. One or more such magnetic field antennas 8 can be implemented within the seat structure 1.

The features and advantages described herein with respect to an arrangement for compensating an initial magnetic field in a vehicle may also relate to a vehicle and method described herein and vice versa.

List of reference symbols

1

Seat structure

2

Seat sensor

3

battery

4

supply line

5.1

Control unit, seat heating control unit

5.2

control unit

5.3

Control unit, battery control unit

6

bus system

7

Contactors and fuse elements

8

magnetic field antenna

QUOTES CONTAINED IN THE DESCRIPTION

This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 2 120 159 B2 [0006]

Claims (10)

Arrangement for compensating an initial magnetic field in a vehicle with at least one seat, characterized in that the at least one seat has at least one electrically conductive, metallic seat structure (1), wherein a voltage source, in particular a battery (3), is arranged to provide a current through the metallic seat structure (1) to generate a counter field for superimposing the initial magnetic field, wherein at least one control unit (5.1, 5.2, 5.3) is arranged and configured to control and/or regulate the current as a function of a strength and/or location of the initial magnetic field in order to at least partially cancel out the initial magnetic field. Arrangement according to Claim 1 , characterized in that the metallic seat structure (1) has at least one magnetic field antenna (8) and/or at least one seat mat and/or at least one seat heater. Arrangement according to Claim 1 or 2 , characterized by at least one sensor for detecting the occupancy of at least one seat by a person, wherein the control device (5.1, 5.2, 5.3) is configured to cause a current flow only through the respective seat structure (1) of at least one seat occupied by a person. Arrangement according to Claim 1 , characterized in that the at least one sensor is designed as a seat sensor (2) and/or as a belt sensor for detecting a fastened seat belt. Arrangement according to one of the preceding claims, characterized in that the control device (5.1, 5.2, 5.3) is configured to terminate the generation of the opposing field by the seat structure (1) of the at least one seat when no current is drawn from the voltage source or the respective seat is no longer occupied. Arrangement according to one of the preceding claims, characterized in that the at least one control device (5.1, 5.2, 5.3) is configured to determine how much current is currently being drawn from the voltage source, to use the level of the drawn current to deduce the strength of the initial magnetic field, to determine how strong the opposing field must be and to set the current required for this in the seat structure (1). Arrangement according to Claim 6 , characterized in that the at least one control device (5.1, 5.2, 5.3) is configured to cyclically determine whether and to what extent current is still being drawn from the voltage source and to regulate the current through the seat structure (1) accordingly. Arrangement according to one of the preceding claims, characterized in that the voltage source comprises contactors and fuse elements (7) configured to provide the current through the metallic seat structure (1). Vehicle with an electric drive and a voltage source designed as a battery (3), characterized by an arrangement according to one of the preceding claims. Method for compensating an initial magnetic field in a vehicle with at least one seat, characterized in that the at least one seat has at least one electrically conductive, metallic seat structure (1), wherein a current is provided from a voltage source, in particular a battery (3), through the metallic seat structure (1) in order to generate a counter field for superimposing the initial magnetic field, wherein the current is controlled and/or regulated as a function of a strength and/or location of the initial magnetic field in order to at least partially cancel out the initial magnetic field.