DE102022209298A1 - Sensor arrangement for a vehicle - Google Patents

Abstract

The invention relates to a sensor arrangement (1) for a vehicle, with an inductive displacement sensor (10), which is designed to determine a current position of a movable body, and a magnetic sensor (20), which is designed to determine a starting position of the movable body to detect, wherein the inductive displacement sensor (10) comprises at least one movable coupling device (12) coupled to the movable body with at least one electrically conductive coupling element (12.1) and at least one stationary circuit carrier (5), wherein on the at least one circuit carrier (5) at least one excitation structure (14) and at least one receiving structure (16) are arranged, which extends along a movement path of the at least one coupling device (12) between a starting position and a target position, wherein a first evaluation and control unit (18) is designed, at least to evaluate a measurement signal induced in the at least one receiving structure (16) and to determine the current position of the at least one coupling device (10) and the movable body, the magnetic sensor (20) having a magnet (22) and a second evaluation and control unit ( 24) with a magnetic sensor element (26), the magnet (22) being arranged on the at least one coupling device (12) and the second evaluation and control unit (24) on the at least one circuit carrier (5) in the area of the at least one Receiving structure (14) is arranged so that the magnetic sensor element (26) of the second evaluation and control unit at least partially overlaps the magnet (22) in the starting position of the at least one coupling device (12).

Description

The invention relates to a sensor arrangement for a vehicle.

Brake systems for vehicles are known from the prior art, which are equipped with a pedal travel sensor for detecting the brake pedal position. For example, magnetic or inductive displacement sensors can be used for this purpose. In addition, in today's vehicles, the activation of the brake lights is usually carried out by sensing or evaluating the brake pressure in the hydraulic system. Simple pressure switches are no longer common. In addition, a start function for starting up the systems via activation using the brake pedal is being considered for future vehicle generations, so that the start button can be omitted.

From the DE 10 2015 206 500 A1 an inductive displacement sensor is known, which comprises a coil system with a planar primary coil for generating a magnetic field and two planar secondary coils arranged within the primary coil for sensing a position of a target, which is movable along the secondary coils. The secondary coils each have a crossover. Here, the two identical secondary coils are arranged spatially separated from one another, with the crossing of each secondary coil being aligned parallel to the direction of movement of the target.

From the DE 60 2004 006 168 T2 an inductive position sensor is known which has at least one flat substrate on which a transmitting antenna and a receiving antenna are formed; and an intermediate coupling element that is designed to be moved relative to the at least one flat substrate along a measuring direction transverse to the flat substrate. According to the position of the intermediate coupling element along the measuring direction, the electromagnetic coupling between the transmitting antenna and the receiving antenna varies, wherein at least the transmitting antenna or the receiving antenna has a first coil about a first axis and a second coil about a second axis that is transverse to the first axis .

Disclosure of the invention

The sensor arrangement for a vehicle with the features of independent claim 1 has the advantage that a reduction in installation space and costs is possible by integrating the magnetic sensor into the inductive displacement sensor. In addition, no additional housing or fastening elements are required for the magnetic sensor. Depending on the safety concept, the magnetic sensor can be used to monitor the safety-relevant displacement sensor. This allows the functional safety of the sensor arrangement to be increased.

Embodiments of the present invention provide a sensor arrangement for a vehicle, with an inductive displacement sensor, which is designed to determine a current position of a movable body, and a magnetic sensor, which is designed to detect a starting position of the movable body. The inductive displacement sensor comprises at least one movable coupling device coupled to the movable body with at least one electrically conductive coupling element and at least one stationary circuit carrier. At least one exciter structure and at least one receiving structure are arranged on the at least one circuit carrier, which extends along a movement path of the at least one coupling device between a starting position and a target position. Here, a first evaluation and control unit is designed to evaluate at least one measurement signal induced in the at least one receiving structure and to determine the current position of the at least one coupling device and the movable body. The magnetic sensor includes a magnet and a second evaluation and control unit with a magnetic sensor element. The magnet is arranged on the at least one coupling device and the second evaluation and control unit is arranged on the at least one circuit carrier in the area of the at least one receiving structure so that the magnetic sensor element of the second evaluation and control unit moves the magnet in the starting position of the at least one coupling device at least partially overlapped.

By arranging the second evaluation and control unit of the magnetic sensor in the area of the at least one receiving structure of the inductive sensor, no additional space is required on the at least one circuit carrier. Furthermore, the arrangement of the magnet of the magnetic sensor on the at least one coupling device enables the magnet to be integrated in a space-neutral manner. In a particularly advantageous embodiment of the sensor arrangement, a common electrical ground can be used by the inductive displacement sensor and the magnetic sensor, so that a reduction in the electrical connections is possible. Both sensors can still work completely independently of each other and be powered by separate supply voltages and output separate output signals. The inductive displacement sensor can be moved via the at least one electrically conductive coupling element of the at least one Coupling device detects the current position of the at least one movable body as an absolute or differential displacement sensor.

Embodiments of the sensor arrangement according to the invention can preferably be used as a pedal travel sensor of a brake pedal. The inductive displacement sensor determines the current position of the brake pedal and the magnetic sensor detects the starting position of the brake pedal. Here, the second evaluation and control unit can advantageously be integrated into a brake light switching function, which activates the brake light during a braking process, and into a wake-up function, which starts or activates all systems in the vehicle. The second evaluation and control unit has a very low quiescent current consumption and can generate and output a switching signal. The magnetic sensor element can detect the starting position of the at least one coupling device or the movable body, preferably based on the Hall effect. Alternatively, the magnetic sensor element can determine the starting position of the at least one coupling device or the movable body based on magnetoresistive (MR) effects, such as the AMR effect (anisotropic magnetoresistive effect), the GMR effect (giant magnetoresistive effect) or the TMR -Effect (tunnel magnetoresistive effect).

In the present case, an evaluation and control unit can be understood to mean an electrical assembly or electrical circuit which prepares, processes or evaluates detected sensor signals. The evaluation and control unit can preferably be designed as an ASIC component (ASIC: application-specific integrated circuit). The evaluation and control unit can have at least one interface, which can be designed in hardware and/or software. In the case of hardware training, the interfaces can, for example, be part of the ASIC component. However, it is also possible that the interfaces are their own integrated circuits or at least partially consist of discrete components. In the case of software training, the interfaces can be software modules that are present, for example, on a microcontroller alongside other software modules.

The measures and further developments listed in the dependent claims make advantageous improvements to the sensor arrangement for a vehicle specified in independent claim 1 possible.

It is particularly advantageous that the at least one exciter structure can be coupled to at least one oscillator circuit, which couples a periodic alternating signal into the at least one exciter structure during operation. Here, the at least one electrically conductive coupling element of the at least one coupling device influences an inductive coupling between the at least one exciter structure and the at least one receiving structure depending on its current position. Since magnetic and inductive sensor principles do not influence or impair each other, it is possible to integrate the magnetic sensor between the receiving structures or excitation structures of the inductive sensor. The second evaluation and control unit can be placed, for example, as an SMD component in a small package between the conductor tracks of the at least one receiving structure, without negatively influencing the function of the inductive sensor.

In an advantageous embodiment of the sensor arrangement, the second evaluation and control unit can output a switching signal when the magnet moves out of the detection range of the magnetic sensor element of the second evaluation and control unit due to a movement of the at least one coupling device. Here, the position of the second evaluation and control unit can be coordinated with the position of the magnet in order to detect the starting position of the at least one coupling device or the movable body in accordance with the requirements.

In a further advantageous embodiment of the sensor arrangement, the at least one receiving structure can have at least one receiving coil. In addition, the at least one receiving coil can each have a periodically repeating loop structure, which can be distributed over several layers of the at least one stationary circuit carrier. Furthermore, the at least one excitation structure can have at least one excitation coil, which can run circumferentially on the edge of the at least one circuit carrier. The at least one circuit carrier has a required area corresponding to the movement path of the movable body and a surface of the at least one coupling device, which is occupied by the at least one excitation coil and by the at least one receiving coil of the inductive sensor.

In a further advantageous embodiment of the sensor arrangement, the at least one movable coupling device can comprise a slider on which the at least one electrically conductive coupling element can be arranged. Here, the slider of the at least one coupling device can be designed as a plastic component and can be guided along the movement path by at least one guide element. In addition, the glider can the at least one coupling device has a recess in which the magnet can be arranged. The magnet of the magnetic sensor is directly coupled to the movement path by the slider. The magnet can, for example, be designed as a rare earth magnet (NdFeB), AINiKo, hard ferrite, etc. The magnetization direction of the magnet runs perpendicular to the plane of the at least one circuit carrier and to the second evaluation and control unit. The installation space for the magnet is available due to the design of the slider or can be viewed as neutral to the overall installation space requirement of the sensor arrangement. The magnet can be secured against falling out by the at least one electrically conductive coupling element mounted on the slider. Alternatively, gluing the magnet is also possible. The at least one coupling element can be designed, for example, as a stamped and bent part.

In a further advantageous embodiment of the sensor arrangement, the slider can be coupled to the movable body by at least one driver. This enables a simple connection of the at least one coupling device to the movable body.

An exemplary embodiment of the invention is shown in the drawings and is explained in more detail in the following description. In the drawings, like reference numerals designate components or elements that perform the same or analogous functions.

Brief description of the drawings

• 1 shows a schematic perspective top view of an exemplary embodiment of a sensor arrangement according to the invention.
• 2 shows a schematic perspective view of a section of the sensor unit according to the invention 1 without circuit carrier.
• 3 shows a schematic perspective view of the exemplary embodiment of the sensor unit according to the invention 1 and 2 from underneath.

Embodiments of the invention

How out 1 to 3 As can be seen, the illustrated embodiment of a sensor arrangement 1 according to the invention for a vehicle includes an inductive displacement sensor 10, which determines a current position of a movable body, not shown, and a magnetic sensor 20, which detects a starting position of the movable body. The inductive displacement sensor 10 comprises at least one movable coupling device 12 coupled to the movable body with at least one electrically conductive coupling element 12.1 and at least one stationary circuit carrier 5. At least one excitation structure 14 and at least one receiving structure 16 are arranged on the at least one circuit carrier 5, which extend along a movement path of the at least one coupling device 12 extends between a start position and a target position. Here, a first evaluation and control unit 18 evaluates at least one measurement signal induced in the at least one receiving structure 16 and determines the current position of the at least one coupling device 10 and the movable body. The magnetic sensor 20 comprises a magnet 22 and a second evaluation and control unit 24 with a magnetic sensor element 26. The magnet 22 is arranged on the at least one coupling device 12 and the second evaluation and control unit 24 is on the at least one circuit carrier 5 in the area the at least one receiving structure 14 is arranged so that the magnetic sensor element 26 of the second evaluation and control unit at least partially overlaps the magnet 22 in the starting position of the at least one coupling device 12.

In the exemplary embodiment shown, an excitation structure 14 is coupled to an oscillator circuit, not shown, which couples a periodic alternating signal into the excitation structure 14 during operation. The excitation structure 16 shown has an excitation coil which runs all around the edge of the at least one circuit carrier 5. Depending on its current position, the at least one electrically conductive coupling element 12.1 influences an inductive coupling between the at least one exciter structure 14 and the at least one receiving structure 16. The illustrated receiving structure 16 comprises a plurality of receiving coils, each of which has a periodically repeating loop structure. The loop structures are distributed over several layers of the stationary circuit carrier 5 so that overlaps can easily be avoided. The sections of the repeating loop structures arranged in different layers are electrically connected to one another via plated-through holes.

How out 1 to 3 It can also be seen that the illustrated embodiment of the sensor arrangement 1 has two movable coupling devices 12, 12A, 12B, each of which includes a slider 13, 13A, 13B in order to implement a differential measuring principle. Here, a first coupling device 12A includes a first slider 13A and a second coupling device 12B includes a second slider 13B. There are two electrically conductive coupling elements 12.1 on each of the two sliders 13A, 13B arranged. The sliders 13, 13A, 13B of the two coupling devices 12, 12A, 12B are each designed as plastic components and are guided along the movement path by at least one guide element 14. In the exemplary embodiment shown, two guide elements 14 designed as guide pins are held in a frame on which the two sliders 13A, 13B are mounted in a sliding manner. The sliders 13, 13A, 13B can each be coupled to the movable body by a fork-shaped driver 13.1. The movable body can be, for example, a pedal rod of a brake pedal.

Depending on the application or requirement, the magnet 22 can optionally be installed in one of the sliders 13A, 13B. Like in particular 2 As can further be seen, the first slider 13A of the first coupling device 12A has a recess 28 in which the magnet 22 of the magnetic sensor 20 is arranged. The magnetic sensor element 26 of the second evaluation and control unit 24 is designed as a Hall sensor element in the exemplary embodiment shown and outputs a switching signal when the magnet 22 moves out of the detection range of the magnetic sensor element 26 of the second evaluation and control unit due to a movement of the first coupling device 12A Control unit 24 moves. The magnet 22 is designed, for example, as a rare earth magnet (NdFeB), AINiKo, hard ferrite, etc., with the magnetization direction running perpendicular to the plane of the circuit carrier 5 or to the magnetic sensor element 26 designed as a Hall sensor element.

With an appropriate arrangement, a double and therefore redundant design with two magnets 22 and two second evaluation and control units 24 is also possible. In this embodiment, a magnet 22 is arranged in both sliders 13A, 13B.

Like in particular 1 It can also be seen that the circuit carrier 5 has a first section arranged on the edge of the frame 3, in which the first evaluation and control unit 18 is arranged, which is designed as an ASIC component, and a laterally arranged second section on which electrical contact points 7 are arranged for contacting the sensor arrangement 1. In addition, the circuit carrier 5 includes a third section inserted into the frame 3, on which the excitation coil of the excitation structure 14 and the reception coils of the reception structure 16 are arranged. The surface extent of the third section of the circuit carrier 5 is adapted to the movement path of the sliders 13A, 13B and the surface of the electrically conductive coupling elements 12.1 predetermined by the frame 3.

How out 1 to 3 It can also be seen that the structure of the inductive displacement sensor 10 is supplemented by the magnetic sensor 20 in a space-neutral manner. The second evaluation and control unit 24 is placed as an ASIC component on an upper layer of the circuit carrier 5 between the conductor tracks of the receiving coils of the receiving structure 16 without negatively influencing the function of the inductive displacement sensor 10. The distance between the conductor tracks of the receiving structure 16 is determined depending on the function. Therefore, the second evaluation and control unit 24 is positioned so that the conductor tracks for connecting the second evaluation and control unit 24 do not cross or intersect with the conductor tracks of the receiving structure 16. The second evaluation and control unit 24 is placed in such a way that the switching behavior of the second evaluation and control unit 24 relative to the magnet 22 embedded at the bottom of the first slider 13A is in the required ranges in order to determine the starting position of the movable body or the first coupling device 12A or .of the first slider 13A according to the requirements. For fine tuning, the magnet 22 and the second evaluation and control unit 24 can be moved within certain limits and their position relative to one another optimized. The electrical connection of the second evaluation and control unit 24 is led to the external contact points 7. This can be done in different positions of the circuit carrier 5 in order not to cross the rotating transmission coil of the excitation structure 14. The second evaluation and control unit 24 has its own standby supply with a very low power consumption and outputs the switching signal when the magnet 22 moves out of the detection range of the magnetic sensor element 26 of the second evaluation and control unit due to a movement of the first coupling device 12A Control unit 24 moves. The first evaluation and control unit 18 and second evaluation and control unit 24 have a common ground connection. The electrically conductive coupling elements 12.1 arranged on the sliders 13, 13A, 13B are designed as stamped and bent parts in the exemplary embodiment shown. Here, one of the electrically conductive coupling elements 12.1 holds the magnet 22 in the recess 28 position and fixes it. Alternatively, it is also possible to glue the magnet 22 in the recess 28.

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was generated automatically and is included solely for the better information of the reader. The 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 102015206500 A1 [0003]
• DE 602004006168 T2 [0004]

Claims (10)

Sensor arrangement (1) for a vehicle, with an inductive displacement sensor (10), which is designed to determine a current position of a movable body, and a magnetic sensor (20), which is designed to detect a starting position of the movable body, wherein the inductive displacement sensor (10) comprises at least one movable coupling device (12) coupled to the movable body with at least one electrically conductive coupling element (12.1) and at least one stationary circuit carrier (5), with at least one excitation structure (5) on the at least one circuit carrier (5). 14) and at least one receiving structure (16) is arranged, which extends along a movement path of the at least one coupling device (12) between a starting position and a target position, wherein a first evaluation and control unit (18) is designed, at least one in the at least to evaluate a measurement signal induced by a receiving structure (16) and to determine the current position of the at least one coupling device (10) and the movable body, the magnetic sensor (20) having a magnet (22) and a second evaluation and control unit (24). magnetic sensor element (26), wherein the magnet (22) is arranged on the at least one coupling device (12) and the second evaluation and control unit (24) on the at least one circuit carrier (5) in the area of the at least one receiving structure (14) is arranged so that the magnetic sensor element (26) of the second evaluation and control unit at least partially overlaps the magnet (22) in the starting position of the at least one coupling device (12). Sensor arrangement (1). Claim 1 , characterized in that the at least one exciter structure (14) is coupled to at least one oscillator circuit, which couples a periodic alternating signal into the at least one exciter structure (14) during operation, the at least one electrically conductive coupling element (12.1) depending on its current position influences an inductive coupling between the at least one exciter structure (14) and the at least one receiving structure (16). Sensor arrangement (1). Claim 1 or 2 , characterized in that the second evaluation and control unit (24) outputs a switching signal when the magnet (22) moves out of the detection range of the magnetic sensor element (26) of the second evaluation and control unit due to a movement of the at least one coupling device (12). (24) moves. Sensor arrangement (1) according to one of the Claims 1 until 3 , characterized in that the at least one receiving structure (16) has at least one receiving coil. Sensor arrangement (1). Claim 4 , characterized in that the at least one receiving coil each has a periodically repeating loop structure, which is distributed over several layers of the at least one stationary circuit carrier (5). Sensor arrangement (1) according to one of the Claims 1 until 5 , characterized in that the at least one excitation structure (16) has at least one excitation coil, which runs circumferentially on the edge of the at least one circuit carrier (5). Sensor arrangement (1) according to one of the Claims 1 until 6 , characterized in that the at least one movable coupling device (12) comprises a slider (13) on which the at least one electrically conductive coupling element (12.1) is arranged. Sensor arrangement (1). Claim 7 , characterized in that the slider (13) of the at least one coupling device (12) is designed as a plastic component and is guided along the movement path by at least one guide element (14). Sensor arrangement (1). Claim 7 or 8th , characterized in that the slider (13) of the at least one coupling device (12) has a recess (28) in which the magnet (22) is arranged. Sensor arrangement (1) according to one of the Claims 7 until 9 , characterized in that the slider (13) can be coupled to the movable body by at least one driver (13.1).

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