Improved inductive position sensor

Abstract

The present invention relates to an inductive position sensor (1) for a rotating electric motor, comprising a printed circuit board (10) having two substrates (13, 14) on which at least one transmitting element (11) and at least one receiving device (12) are arranged, the transmitting element (11) for emitting an oscillating magnetic field toward a rotating coupling element (20) to generate a modified magnetic field, the receiving device (12) for detecting the modified magnetic field, and a connection connecting at least one transmitting element and at least one receiving element to at least one signal processing element is provided by conductive elements (101, 102) located in a region (30) different from the region (40) where the transmitting element (11) and the receiving element (12) are located, the sensor comprising a ground plane (17) positioned on the region (30) of the conductive elements to extend to the region (40) of the transmitting element (11) and the receiving element (12).

Description

Technical Field

[0001] This invention relates to the field of position sensors, and more particularly to inductive position sensors. Background Technology

[0002] Inductive position sensors, known as eddy current sensors, use oscillating magnetic fields to determine the angular position of a rotating target forming a connecting element. These position sensors are particularly used in electric or hybrid vehicle motors, which include a rotor rotating relative to a stator. The angular position of the rotor relative to the stator is determined. The target is mounted at the end of the rotor shaft or through the rotor shaft to modify the oscillating magnetic field emitted by a transmitter. The target is centered relative to the rotor's axis of rotation. The target includes multiple blades that provide a magnetic field pattern relative to the rotor's axis of rotation.

[0003] The position sensor is fixedly mounted relative to the stator, facing the target and surrounding or facing the end of the rotor. The position sensor includes a printed circuit board (PCB) comprising at least one emitting element for emitting an oscillating magnetic field toward the target, thereby generating a modified oscillating magnetic field of a given frequency. The PCB includes at least one receiving device for detecting the modified oscillating magnetic field and transmitting it to a signal processing unit provided on the PCB to infer the angular position of the target.

[0004] Typically, the coupling element has an outer diameter that is substantially the same as the outer diameter of the transmitting antenna. However, in some cases, the sensor needs to be positioned facing a different coupling element, for example, one with an outer diameter larger than that of the transmitting / receiving antenna. The disadvantage of this situation is that when the coupling element is larger than both the transmitting and receiving elements, significant interference occurs during angle measurements, which degrades performance.

[0005] For sensors consisting of only two substrate layers forming the electronic board, the ground plane cannot be extended sufficiently to correct for interference problems due to their configuration. In fact, the ground plane cannot overlap with certain electrical connections, such as conductive elements connecting transmitting and / or receiving components to the signal processing unit. Therefore, when the outer diameter of the connecting element is larger than the outer diameter of the antenna, the conductive element acts as an interfering element for angle measurements.

[0006] Therefore, the object of the present invention is to overcome one of the shortcomings of the prior art by proposing a position sensor whose configuration is improved to limit interference and improve performance. Summary of the Invention

[0007] To this end, the present invention proposes an inductive position sensor for a rotating electric motor, comprising a printed circuit board having two substrates on which at least one transmitting element and at least one receiving device are arranged. The transmitting element is used to emit an oscillating magnetic field toward a rotating coupling element to generate a modified magnetic field, and the receiving device is used to detect the modified magnetic field. The connection between the at least one transmitting element and the at least one receiving element and at least one signal processing element is achieved through a conductive element located in a region different from the region where the transmitting element and the receiving element are located. The sensor includes a ground plane positioned on the region of the conductive element to extend to the regions of the transmitting element and the receiving element.

[0008] Therefore, using the sensor according to the invention, when the areas of the connecting element and the conductive element overlap, the conductive element is surrounded within the ground plane and is not covered, and they no longer act as interfering elements.

[0009] According to one embodiment of the invention, the ground plane is segmented into multiple portions, which are arranged to surround the conductive element without covering it.

[0010] According to one embodiment of the present invention, the ground plane is arranged on two substrate layers.

[0011] According to one embodiment of the present invention, different portions of the ground plane are arranged on a first substrate layer and a second substrate layer and connected together by metal vias that pass through the printed circuit board along the thickness of the printed circuit board to reach another lower substrate.

[0012] According to one embodiment of the invention, a portion of the conductive elements located on two different substrate layers of an electronic board are stacked relative to each other.

[0013] According to one embodiment of the invention, a portion of the conductive elements located on two different substrate layers of an electronic board are arranged so as not to overlap with each other.

[0014] The present invention also relates to a motor including a sensor according to the present invention.

[0015] According to one embodiment of the invention, the rotary motor is an electric motor for electric or hybrid vehicles, which includes a rotor that rotates relative to a stator.

[0016] The present invention also relates to the use of a sensor according to the invention for measuring the angular position of the rotor of an electric motor relative to the stator. Attached Figure Description

[0017] Other objects, features, and advantages of the invention will be better understood and will become more apparent from reading the description given below and from the accompanying drawings, which are given by way of example, wherein:

[0018] •[ Figure 1 [This is a schematic diagram of a sensor with two different connecting elements: a) of the same diameter, b) of a diameter larger than the outer diameter of the transmitting antenna.]

[0019] •[ Figure 2 This is a view showing the stacking of two substrate layers of a sensor according to a first embodiment of the present invention.

[0020] •[ Figure 3 [Illustration 1] is a view of a portion of the substrate layer of the sensor according to a second embodiment of the present invention.

[0021] •[ Figure 4 [This is a view of a portion of another substrate layer of the sensor according to a second embodiment of the present invention.]

[0022] •[ Figure 5 [Image 1] is a view of the stacked two substrate layers of a sensor according to a second embodiment of the present invention. Detailed Implementation

[0023] This invention relates to a position sensor 1, such as [ Figure 1 ]to[ Figure 5 As shown in the image.

[0024] and[ Figure 1 The visible connecting element 20 is associated with a sensing position sensor 1 for installation in a rotating electric motor, such as an electric motor in an electric or hybrid vehicle, which includes a rotor rotating relative to the stator. The angular position of the rotor relative to the stator is determined.

[0025] The sensor includes an electronic board 10, on which at least one transmitting antenna 11, at least one receiving element 12 and at least one signal processing unit 13 are arranged.

[0026] According to one embodiment of the present invention, at least one receiving antenna is arranged inside at least one transmitting antenna.

[0027] During sensor operation, at least one transmitting antenna 11 transmits an oscillating magnetic field at a given frequency. A coupling element 20 is positioned to enter and modify this magnetic field. According to one embodiment of the invention, the coupling element is mounted on the end of a rotor shaft to modify the magnetic field emitted by the transmitting antenna 11. The modified magnetic field generates an electromotive force in a receiving element 12. This electromotive force is processed by a signal processing unit 13 to provide an output signal that allows measurement of the position of the coupling element 20.

[0028] According to one embodiment of the invention, the connecting element 20 is a rotating element, for example, rotating together with the rotor of the electric motor.

[0029] According to one embodiment of the present invention, the outer diameter of the connecting element is equal to or greater than the outer diameter of the transmitting antenna.

[0030] According to one embodiment of the invention, the electronic board 10 includes an opening 15 that allows connection to wires or metal connecting elements.

[0031] According to one embodiment of the invention, the number of windings of at least one receiving element 12 is proportional to the number of corner sectors of the connecting element 20.

[0032] According to one embodiment of the present invention, the electronic board 10 consists of two substrate layers.

[0033] According to one embodiment of the present invention, the connection between the transmitting element and the receiving element, as well as the connection to at least one signal processing element, is formed by conductive elements 101, 102.

[0034] According to one embodiment of the present invention, conductive elements 101 and 102 are located in a region 30 that is different from the region 40 where the transmitting element 11 and the receiving element 12 are located.

[0035] According to one embodiment of the present invention, conductive elements 101 and 102 are composed of portions of conductive elements 101 and 102 located on the same substrate layer and portions 111 and 112 of conductive elements 101 and 102 located on two different substrate layers of electronic board 10, with one of the two different substrate layers stacked on the other.

[0036] In the context of this invention, sensor 1 includes a ground plane 17 positioned on region 30 of conductive element to extend to region 40 of transmitting element 11 and receiving element 12.

[0037] Therefore, according to a first variation of the invention, the ground plane 17 is segmented into 171, 172, 173, that is, it is formed by a plurality of portions 171, 172, 173 arranged to surround the conductive elements 101, 102 without covering them.

[0038] In the context of this invention, the ground plane 17 is arranged on two substrate layers 13, 14.

[0039] Different portions 171, 172, and 173 of the ground plane are arranged on the first substrate layer 13 and the second substrate layer 14 and are connected together by a metal via 174, which passes through the upper substrate 13 along the thickness of the upper substrate 13 to reach the lower substrate 14.

[0040] The upper substrate 13 and the lower substrate 14 are defined by the fact that they are stacked relative to the two substrates. Therefore, regardless of the orientation of the sensor 1, there are an upper substrate and a lower substrate.

[0041] According to this variation of an embodiment of the invention, such as [ Figure 2As shown, portions 111 and 112 include conductive elements 101 and 102 located on two different substrate layers 13 and 14 of the electronic board, with the conductive elements 101 and 102 stacked relative to each other. Therefore, on each substrate, there is at least one ground plane portion 17 bypassing the conductive elements 101 and 102. In this way, when the substrates are stacked, due to the via 174 (see […]), Figure 5 The group of connected parts, and most of the area 30 where conductive elements 101 and 102 are located is covered by the ground plane 17.

[0042] According to a variation of the invention, the ground plane 17 is segmented as in the first variation, and the conductive elements on the two different substrate layers 13, 14 of the electronic board located in portions 111, 112 are arranged not to overlap. Therefore, the conductive elements in portions 111, 112 are offset such that they are located on at least two substrate layers 13, 14, but not overlapping with each other, as... Figure 5 As shown.

[0043] The offset of the conductive elements on each substrate allows the ground plane 17 to extend over the two substrate layers 13 and 14. Therefore, the ground plane 17 is composed of multiple portions 171, 172, and 173 located on each of the two substrate layers 13 and 14 of the electronic board 10. The portions 171, 172, and 173 of the ground plane 17 are connected together by multiple metal vias 174 passing through the thickness of the electronic board 10. That is, at least one portion exists on one substrate layer, and another portion exists on the other substrate layer.

[0044] Therefore, using the sensor 1 according to the invention, when the areas of the connecting element and the conductive element overlap, the conductive elements 101 and 102 are surrounded within the ground plane and are not covered, and they no longer act as interfering elements.

[0045] The present invention also relates to a motor including the sensor 1 as described above.

[0046] The scope of this invention is not limited to the details given above, and many other specific embodiments are permissible without departing from the scope of application of this invention. Therefore, this embodiment should be considered illustrative and modifications can be made without departing from the scope defined by the claims.

Claims

1. An inductive position sensor (1) for a rotating electric motor, comprising a printed circuit board (10) having two substrates (13, 14) on which at least one transmitting element (11) and at least one receiving device (12) are arranged, the transmitting element for emitting an oscillating magnetic field toward a rotating coupling element (20) to generate a modified magnetic field, the receiving device (12) for detecting the modified magnetic field, the connection between the at least one transmitting element (11) and the at least one receiving element (12) and at least one signal processing element (13) being realized by conductive elements (101, 102) located in a region (30) different from the region (40) where the transmitting element (11) and the receiving element (12) are located, the sensor being characterized in that it includes a ground plane (17) positioned on the region (30) of the conductive elements (101, 102) to extend to the region (40) of the transmitting element (11) and the receiving element (12).

2. The sensor (1) according to claim 1, wherein, The ground plane (17) is segmented into multiple parts (171, 172, 173), which are arranged to surround the conductive element (101, 102) without covering the conductive element (101, 102).

3. The sensor (1) according to claim 1 or 2, wherein, The ground plane (17) is arranged on two substrate layers (13, 14).

4. The sensor (1) according to claim 2 or 3, when subordinate to claim 2, wherein, Different portions (171, 172, 173) of the ground plane (17) are arranged on the first substrate layer (13) and the second substrate layer (14) and are connected together by metal vias (174) that pass through the printed circuit board (10) along the thickness of the printed circuit board (10) to reach another lower substrate (14).

5. The sensor (1) according to any one of claims 1 to 4, wherein, A portion (111, 112) of the conductive elements (101, 102) located on two different substrate layers (13, 14) of the electronic board (10) are stacked relative to each other.

6. The sensor (1) according to any one of claims 1 to 4, wherein, A portion (111, 112) of the conductive elements (101, 102) located on two different substrate layers (13, 14) of the electronic board (10) are arranged so as not to overlap with each other.

7. An electric motor comprising a sensing position sensor (1) according to any one of claims 1 to 6.

8. The rotary electric motor according to claim 7, wherein, The rotary motor is an electric motor for electric or hybrid vehicles, and the electric motor includes a rotor that rotates relative to the stator.

9. The use of a sensor (1) according to any one of claims 1 to 6 for measuring the angular position of the rotor of an electric motor relative to the stator.

Images