Inductive sensor system

Abstract

The invention relates to an inductive sensor system. The inductive sensor system may include: an upper rotor including an upper target having a first metal pattern; a lower rotor including a lower target having a second metal pattern; and a fixed circuit board positioned between the upper rotor and the lower rotor. The circuit board includes: one or more transmitter coil groups configured to generate an electromagnetic field; and one or more receiver coil sets for sensing relative angular displacement motion between the upper rotor and the lower rotor. The one or more transmitter coil sets and the one or more receiver coil sets are cyclically wound.

Description

Technical Field

[0001] The present disclosure generally relates to an inductive sensor system including an inductive torque and position sensor assembly. More specifically, some embodiments of the present disclosure relate to an inductive torque and position sensor assembly for a steering system of a vehicle that determines the torque applied to a steering wheel and the position of a steering shaft by using electromagnetic principles such as inductance. Background Art

[0002] The steering system used in automobiles generally includes an input shaft connected to a steering wheel. The input shaft is then connected to an output shaft through a torsion bar, and the output shaft is in turn mechanically connected to the wheels through a connecting rod. Thus, rotation of the steering wheel causes the wheels of the car to pivot through the input shaft, torsion bar, output shaft and steering linkage.

[0003] In many cases, it is very desirable to determine the angular position of the input shaft or output shaft and the angular deflection between the input shaft and the output shaft of the steering mechanism. The angular position of the input shaft can indicate which way the driver wants to steer, so that the steering wheel can be matched to the wheels. The degree of angular deflection between the input shaft and the output shaft, i.e., the angular deflection of the torsion bar, is then used by the controller to detect the applied steering wheel torque and then determine the appropriate amount of assistance provided by the power steering for the vehicle.

[0004] Furthermore, there has recently been a trend towards electronically controlled steering systems, such as steer-by-wire systems without a mechanical linkage between the steering wheel and the wheels. In such steer-by-wire systems, the absolute position of the input shaft and the torque applied to the steering wheel can be used to electrically control the wheels. Summary of the invention

[0005] The features and advantages of the present disclosure will be more readily understood and apparent from the following detailed description and claims of the present application, which should be read in conjunction with the accompanying drawings.

[0006] According to some embodiments of the present disclosure, an inductive sensor system may include: an upper rotor, the upper rotor including an upper target having a first metal pattern; a lower rotor, the lower rotor including a lower target having a second metal pattern; and a fixed circuit board, the circuit board being positioned between the upper rotor and the lower rotor, the circuit board including: one or more transmitter coil groups, the one or more transmitter coil groups being configured to generate an electromagnetic field; one or more receiver coil groups, the one or more receiver coil groups being used to sense relative angular displacement movement between the upper rotor and the lower rotor, wherein the one or more transmitter coil groups and the one or more receiver coil groups are circularly wound.

[0007] The one or more circularly wound receiver coil groups for sensing the relative angular displacement movement between the upper rotor and the lower rotor may be positioned radially outside the first metal pattern of the upper target and the second metal pattern of the lower target, and the one or more circularly wound transmitter coil groups may be positioned radially inside the first metal pattern of the upper target and the second metal pattern of the lower target.

[0008] The one or more circularly wound receiver coil groups for sensing the relative angular displacement movement between the upper rotor and the lower rotor may be positioned radially inside the first metal pattern of the upper target and the second metal pattern of the lower target, and the one or more circularly wound transmitter coil groups may be positioned radially inside the first metal pattern of the upper target and the second metal pattern of the lower target.

[0009] At least one of the one or more receiver coil groups that are circularly wound for sensing the relative angular displacement movement between the upper rotor and the lower rotor can be radially positioned outside the first metal pattern of the upper target and the second metal pattern of the lower target, and another receiver coil group or other receiver coil groups among the one or more receiver coil groups that are circularly wound for sensing the relative angular displacement movement between the upper rotor and the lower rotor can be radially positioned inside the first metal pattern of the upper target and the second metal pattern of the lower target, and the one or more transmitter coil groups that are circularly wound can be radially positioned inside the first metal pattern of the upper target and the second metal pattern of the lower target, respectively.

[0010] The circuit board may include a further upper receiver coil set for sensing the angular position of the upper rotor.

[0011] The circuit board may include a further lower receiver coil set for sensing the angular position of the lower rotor.

[0012] The inductive sensor system may further include an auxiliary rotor rotatably engaged with the upper rotor and having a third metal pattern; and an auxiliary transmitter coil group and an auxiliary receiver coil group included in the circuit board or disposed on an upper surface of the circuit board.

[0013] The inductive sensor system may further include an auxiliary rotor rotatably engaged with the lower rotor and having a third metal pattern; and an auxiliary transmitter coil group and an auxiliary receiver coil group included in the circuit board or disposed on a lower surface of the circuit board.

[0014] The inductive sensor system may further include an auxiliary rotor rotatably engaged with the upper rotor or the lower rotor and having a magnetic material; and a sensor configured to sense a magnetic field and positioned below or above the auxiliary rotor.

[0015] The one or more receiver coil groups may include an upper receiver coil group and a lower receiver coil group, the upper receiver coil group and the other upper receiver coil groups may be arranged on the upper surface of the circuit board, the lower receiver coil group and the other lower receiver coil groups may be arranged on the lower surface of the circuit board, and the one or more transmitter coil groups may be arranged on the upper surface of the circuit board, on the lower surface of the circuit board, or inside the circuit board.

[0016] The one or more receiver coil groups may include an upper receiver coil group and a lower receiver coil group, the circuit board may have multiple layers including an upper layer and a lower layer, the upper receiver coil group and the other upper receiver coil groups may be arranged on the upper layer of the circuit board or between the upper layers of the circuit board, the lower receiver coil group and the other lower receiver coil groups may be arranged on the lower layer of the circuit board or between the lower layers of the circuit board, and the one or more transmitter coil groups may be arranged on the upper surface or the lower surface of the circuit board, or between the upper surface and the lower surface of the circuit board.

[0017] The first metal pattern of the upper target and / or the second metal pattern of the lower target may have a plurality of circumferentially adjacent lobes.

[0018] The third metal pattern of the auxiliary rotor may have a substantially semicircular or polygonal shape.

[0019] The upper rotor and the auxiliary rotor may have gear teeth engaged with each other.

[0020] The lower rotor and the auxiliary rotor may have gear teeth engaged with each other.

[0021] A transmission ratio between the upper rotor and the auxiliary rotor may be in the range of 1.8 to 2.7.

[0022] The upper rotor may be included in or coupled to an upper shaft coupled to a steering wheel, the lower rotor may be included in or coupled to a lower shaft, and a torsion bar may be coupled between the upper shaft and the lower shaft.

[0023] According to certain embodiments of the present disclosure, an inductive sensor system may include: an upper rotor, the upper rotor including an upper target having a first metal pattern; a lower rotor, the lower rotor including a lower target having a second metal pattern; an auxiliary rotor, the auxiliary rotor being rotatably engaged with the upper rotor or the lower rotor; and a fixed circuit board, the circuit board being positioned between the upper rotor and the lower rotor, the circuit board including: one or more transmitter coil groups, the one or more transmitter coil groups being configured to generate an electromagnetic field; one or more receiver coil groups for sensing relative angular displacement movement between the upper rotor and the lower rotor; and one or more receiver coil groups for sensing the angular position of the upper rotor and / or the lower rotor, wherein the one or more transmitter coil groups and the one or more receiver coil groups for sensing the relative angular displacement movement between the upper rotor and the lower rotor are circularly wound.

[0024] The auxiliary rotor has a third metal pattern, and an auxiliary transmitter coil group and an auxiliary receiver coil group are included in the circuit board or disposed on a surface of the circuit board.

[0025] The inductive sensor system may further include a sensor configured to sense a magnetic field and positioned below or above the auxiliary rotor, wherein the auxiliary rotor rotatably engaged with the upper rotor or the lower rotor includes a magnetic material.

[0026] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Various embodiments according to the present disclosure will be described with reference to the accompanying drawings, wherein:

[0028] Figure 1 is a cross-sectional view of a steering column having an inductive sensor system according to an embodiment of the present disclosure.

[0029] Figure 2 is a top view of an inductive sensor system according to an embodiment of the present disclosure.

[0030] Figure 3is a bottom view of an inductive sensor system according to an embodiment of the present disclosure.

[0031] Figure 4A is a graph for illustrating a linear torque signal generated by an inductive torque assembly of an inductive sensor system according to an embodiment of the present disclosure.

[0032] Figure 4B is a graph for illustrating output signals of a primary position sensor assembly and an auxiliary position sensor assembly of an inductive sensor system according to an embodiment of the present disclosure.

[0033] Figure 5 is a conceptual diagram for illustrating a controller and a process of detecting torque applied to a steering wheel according to an embodiment of the present disclosure.

[0034] Figure 6 is a block diagram of a controller according to an embodiment of the present disclosure.

[0035] Corresponding numerals and symbols in the different figures generally refer to corresponding parts unless otherwise indicated.The figures are drawn to clearly illustrate the relevant aspects of the embodiments and are not necessarily drawn to scale. DETAILED DESCRIPTION

[0036] In the following detailed description, reference is made to the accompanying drawings which form a part of the present disclosure, and in which specific embodiments in which the invention may be practiced are shown by way of illustration. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it should be understood that other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the spirit and scope of the invention. Therefore, the following detailed description should not be considered restrictive, and the scope of the invention is limited only by the appended claims and their equivalents. The same reference numerals in the figures refer to the same parts, which should be apparent from the context of use.

[0037] Figure 1 is a cross-sectional view of a steering column having an inductive sensor system according to an embodiment of the present disclosure.

[0038] An inductive sensor system according to an embodiment of the present disclosure may include a torque sensor assembly and an angle sensor assembly. The torque sensor assembly requires information about the torque applied to the steering wheel that is proportional to the relative position between the upper shaft and the lower shaft. The angle sensor assembly requires absolute position information of the upper shaft or the lower shaft. The angle sensor assembly provides an output signal that is proportional to the rotation angle of the upper shaft or the lower shaft.

[0039] The vehicle has a steering column 100, which includes an upper shaft (or input shaft) 110 and a lower shaft (or output shaft) 120. The upper shaft 110 can be mechanically connected or fixed to the steering wheel 105, and the lower shaft 120 can be mechanically connected to the wheel in a traditional mechanical steering system or a feedback actuator (e.g., an electric motor) in a steer-by-wire steering system. The upper shaft 110 and the lower shaft 120 can be axially aligned with each other.

[0040] The upper shaft 110 and the lower shaft 120 are connected by a beam or torsion bar 130. The torsion bar 130 can be configured to allow the upper shaft 110 and the lower shaft 120 to rotate slightly relative to each other in response to torque applied to the steering wheel 105.

[0041] The upper rotor 210 is fixedly coupled to the upper shaft 110 or is a part of the upper shaft 110. The upper rotor 210 is configured to be rotatable together with the upper shaft 110. For example, the upper rotor 210 may be a floating printed circuit board (PCB).

[0042] The lower rotor 230 is fixedly coupled to the lower shaft 120 or is a part of the lower shaft 120. The lower rotor 230 is configured to be rotatable together with the lower shaft 120. For example, the lower rotor 230 may be a floating PCB.

[0043] The stator 300 (e.g., a fixed circuit board) may be positioned between the upper rotor 210 and the lower rotor 230. The stator 300 is coaxially mounted around the steering column 100. For example, the stator 300 may be adjacent to the torsion bar 130. Alternatively, the stator 300 may be adjacent to the upper rotor 210 or the lower rotor 230. The stator 300 may be fixed by being directly or indirectly coupled to the vehicle body. Thus, the stator 300 does not move relative to the steering column 100, while the upper rotor 210 may rotate with the upper shaft 110, and the lower rotor 230 may rotate with the lower shaft 120 relative to the stator 300. The stator 300 may be arranged parallel to the upper rotor 210 and / or the lower rotor 230.

[0044] Figure 5 The oscillator 400 shown in the figure can be configured to oscillate at a high frequency (for example, but not limited to, 2 MHz to 4 MHz). The oscillator 400 can be electrically connected to one or more excitation or transmitter coil groups 312 and / or 322 and an auxiliary excitation or transmitter coil group 315 to excite one or more relative angular displacement receiver coil groups 311 and 321, an upper angular position receiver coil group 313, a lower angular position receiver coil group 323, and an auxiliary receiver coil group 314.

[0045] One or more excitation or transmitter coil groups 312 and / or 322 are included in the stator 30 and / or are disposed on the upper surface and / or lower surface of the stator 300. For example, the excitation or transmitter coil groups 312 and / or 322 may be formed by conductive traces on the upper surface or lower surface of the stator 300 or conductive paths on the multi-layer PCB of the stator 300. As an example, at least a portion of one coil in the excitation or transmitter coil groups 312 and / or 322 is placed on one layer of the multi-layer PCB of the stator 300, and at least a portion of another coil in the excitation or transmitter coil groups 312 and / or 322 is placed on another layer of the multi-layer PCB of the stator 300. The excitation or transmitter coil groups 312 and / or 322 are electrically connected to the oscillator 400. The excitation or transmitter coil groups 312 and / or 322 generate an electromagnetic field above the upper target 211 of the upper rotor 210 and the lower target 231 of the lower rotor 230 by the radio frequency signal generated by the oscillator 400. Figure 1 , one excitation or transmitter coil set 312 for one transmission channel is disposed on the upper surface of the stator 300, and another excitation or transmitter coil set 322 for another transmission channel is disposed on the lower surface of the stator 300. However, the excitation or transmitter coil set may be positioned on either the upper surface of the stator 300 or the lower surface of the stator 300. Alternatively, one or more excitation or transmitter coil sets may be positioned between multiple layers of the multi-layer PCB of the stator 300.

[0046] The upper target 211 may be included in the upper rotor 210 or attached to the upper rotor 210. The upper target 211 may be a conductive coupler. The upper target 211 may be placed near the excitation or transmitter coil assembly 312 and / or 322. The upper target 211 may have a first metal pattern. For example, the upper target 211 may include a closed conductive ring or multiple conductive rings. The upper target 211 may have, for example but not limited to, a multi-lobate shape having multiple circumferentially adjacent lobes. The upper target 211 may be configured to affect the electromagnetic field generated by the excitation or transmitter coil assembly 312 and / or 322.

[0047] The lower target 231 may be included in the lower rotor 230 or attached to the lower rotor 230. The lower target 231 may be a conductive coupler. The lower target 231 may be placed near the excitation or transmitter coil assembly 322 and / or 312. The lower target 231 may have a second metal pattern. For example, the lower target 231 may include a closed conductive ring or multiple conductive rings. The lower target 231 may have, for example but not limited to, a multi-lobed shape with multiple circumferentially adjacent lobes. The second metal pattern of the lower target 231 may be the same as or different from the first metal pattern of the upper target 211. The lower target 231 may be configured to affect the electromagnetic field generated by the excitation or transmitter coil assembly 312 and / or 322.

[0048] One or more relative angular displacement receiver coil groups 311 and 321 for sensing the relative angular displacement movement between the upper rotor 210 and the lower rotor 230 are included in the upper surface and / or the lower surface of the stator 300, or are disposed on the upper surface and / or the lower surface of the stator 300. For example, the relative angular displacement receiver coil groups 311 and / or 321 may be formed by conductive traces on the upper surface and / or the lower surface of the stator 300 or conductive paths on the multilayer PCB of the stator 300. The relative angular displacement receiver coil groups 311 and 321 may be placed near the upper target 211 and the lower target 231, and positioned within the electromagnetic field generated by the transmitter coil groups 312 and / or 322. The relative angular displacement receiver coil groups 311 and 321 may be configured to generate a signal (e.g., voltage or current) in response to the induction of the electromagnetic field generated by the transmitter coil groups 312 and 322 and changed by the upper target 211 and the lower target 231. The relative angular displacement receiver coil assembly 311 and / or 321 is electrically connected to Figure 5 and Figure 6 The controller 500 shown in FIG. 1 is used to output a signal (eg, a voltage or a current) to the controller 500 .

[0049] The relative angular displacement receiver coil group 311 and / or 321 for sensing the relative angular displacement movement between the upper rotor 210 and the lower rotor 230 can be radially positioned outside the metal pattern of the upper target 211 and the lower target 231. The relative angular displacement receiver coil group 311 and / or 321 is circularly wound. The winding diameter of the relative angular displacement receiver coil group 311 and / or 321 for sensing the relative angular displacement movement between the upper rotor 210 and the lower rotor 230 is larger than the winding diameter of the excitation or transmitter coil group 312 and / or 322. The relative angular displacement receiver coil group 311 and / or 321 for sensing the relative angular displacement movement between the upper rotor 210 and the lower rotor 230 can surround the excitation or transmitter coil group 312 and / or 322. By arranging the relative angular displacement receiver coil group 311 and / or 321 for sensing the relative angular displacement movement between the upper rotor 210 and the lower rotor 230 radially outside the metal pattern of the upper target 211 and / or the lower target 231, the rotation accuracy for sensing the torque applied to the steering column 100, such as the relative angular displacement movement between the upper rotor 210 and the lower rotor 230, can be improved.

[0050] Alternatively, the relative angular displacement receiver coil groups 311 and / or 321 for sensing the relative angular displacement movement between the upper rotor 210 and the lower rotor 230 may be radially positioned inside the metal patterns of the upper target 211 and the lower target 231. Alternatively, one or more of the relative angular displacement receiver coil groups 311 and / or 321 for sensing the relative angular displacement movement between the upper rotor 210 and the lower rotor 230 may be radially positioned inside the metal patterns of the upper target 211 and the lower target 231, while the remaining other one or others of the relative angular displacement receiver coil groups 311 and / or 321 for sensing the relative angular displacement movement between the upper rotor 210 and the lower rotor 230 may be radially positioned outside the metal pattern of the upper target 211.

[0051] The reference signal can be determined from a combination of receiver signals that are substantially independent of the angular position of the upper target 211 of the upper rotor 210 and the angular position of the lower target 231 of the lower rotor 230, and this can be used to determine the number of revolutions. Alternatively, a separate reference coil group 316 and / or 326 can be included in the stator 30, or disposed on the upper and / or lower surfaces of the stator 300. For example, the reference coil group 316 and / or 326 can be included in the stator 300 to provide a reference signal. The reference coil group 316 and / or 326 can be formed by conductive traces on the upper and / or lower surfaces of the stator 300 or conductive paths on a multilayer PCB of the stator 300. The reference coil assemblies 316 and / or 326 may have a similar configuration as the relative angular displacement receiver coil assemblies 311 and / or 321, but may also be configured in such a manner that the reference current or voltage induced in the reference coil by the transmitter coil is substantially independent of the position of the upper target 211 of the upper rotor 210 and the lower target 231 of the lower rotor 230. The angular position or rotation of the upper target 211 of the upper rotor 210 and the lower target 231 of the lower rotor 230 does not affect the voltage or current induced in the reference coil assemblies 316 and / or 326. However, common mode signals (e.g., electromagnetic interference, changes in exciter voltage, changes caused by temperature changes, and changes in the gap between the upper target 211 of the upper rotor 210 and the stator 300 and the gap between the lower target 231 of the lower rotor 230 and the stator 300) will affect the current or voltage induced in the reference coil group 316 and / or 326 in the same way as they affect the voltage or current induced in the relative angular displacement receiver coil group 311 and / or 321. The influence of common mode factors can be suppressed by using the difference or ratio of the output signal of the relative angular displacement receiver coil group 311 and / or 321 and the output signal of the reference coil group 316 and / or 326. The reference coil group 316 and / or 326 can be circularly wound. The winding diameter of the reference coil group 316 and / or 326 can be smaller than the winding diameter of the relative angular displacement receiver coil group 311 and / or 321 used to sense the relative angular displacement movement between the upper rotor 210 and the lower rotor 230 and the winding diameter of the excitation or transmitter coil group 312 and / or 322, so as to minimize the influence of the electromagnetic field associated with the excitation or transmitter coil group 312 and / or 322 and the upper target 211 of the upper rotor 210 or the lower target 231 of the lower rotor 230.

[0052] Torque determination may be performed based on the output signals of the relative angular displacement receiver coil assembly 311 and / or 321. Output signals such as output voltage or current of the relative angular displacement receiver coil assembly 311 and / or 321 may be used to sense the relative angular displacement movement between the upper rotor 210 and the lower rotor 230. The relative angular displacement movement between the upper rotor 210 and the lower rotor 230 is directly related to the torque or twist applied to the steering wheel 105. For example, Figure 4A As shown in , by having a cyclically wound relative angular displacement receiver coil set 311 and / or 321, the output signal of the relative angular displacement receiver coil set 311 and / or 321 can be processed to provide a single linear signal on the torque applied to the steering wheel 105. Figure 5 An exemplary embodiment of a process for generating a single linear signal on the torque applied to the steering wheel 105 is described.

[0053] Since each of the relative angular displacement receiver coil assemblies 311 and / or 321 includes an even number of counter-wound loops, the output voltage on the relative angular displacement receiver coil assemblies 311 and / or 321 can indicate zero deflection between the upper shaft 110 and the lower shaft 120, while a positive voltage can indicate torque in one direction between the upper shaft 110 and the lower shaft 120, and a negative voltage can indicate torque in another direction between the upper shaft 110 and the lower shaft 120.

[0054] Figure 5 is a conceptual diagram for illustrating a controller and a process of detecting torque applied to a steering wheel according to an embodiment of the present disclosure.

[0055] The controller 500 may include an electronic circuit such as an ASIC. The controller 500 is configured as a microprocessor configured to execute non-transient computer executable instructions that are appropriately stored in firmware, software, or otherwise used to perform functions. The ends of the relative angular displacement receiver coil groups 311 and / or 321 and the reference coil groups 316 and 326 are connected to the controller 500 to process their output signals. The controller 500 may have a processor that is programmed to output the magnitude and direction of the relative angular displacement between the upper shaft 110 and the lower shaft 120 and the absolute rotational position of the upper shaft 110 and / or the lower shaft 120.

[0056] The oscillator 400 is connected to the ends of the excitation or transmitter coil groups 312 and / or 322. The oscillator 400 provides an excitation signal 510, such as an alternating current, to the excitation or transmitter coil groups 312 and / or 322, thereby generating an alternating electromagnetic field, which then induces a signal in the excitation or transmitter coil groups 312 and / or 322 by inductive coupling. The inductive coupling between the excitation or transmitter coil groups 312 and 322 and the receiver coil groups 311 and 321 is changed (e.g., reduced) by the targets 211 and 231 of the rotors 210 and 230. However, the inductive coupling between the excitation or transmitter coil groups 312 and 322 and the reference coil groups 316 and 326 is insensitive to the angular position of the targets 211 and 231 of the rotors 210 and 230. In contrast, the output signals 520 of the receiver coil assemblies 311 and 321 are sensitive to the angular positions of the targets 211 and 231 of the rotors 210 and 230, such that the ratio of the output signals 520 of the receiver coil assemblies 311 and 321 to the output signals of the reference coil assemblies 316 and 326 is related to the angular positions of the targets 211 and 231 of the rotors 210 and 230 while also being corrected for common mode factors as described above.

[0057] The demodulator 530 demodulates the output signal 520 formed by combining the output signals of the receiver coil groups 311 and 321 and the output signals of the reference coil groups 316 and 326, the analog-to-digital converter (ADC) 540 converts the demodulated output signal into an analog signal, and the digital signal processor (DSP) 550 processes the converted analog signal to output an output signal indicating the torque applied to the steering wheel 105. Figure 4A As shown in , the output signal indicative of the torque applied to the steering wheel 105 may be a linear output voltage as a function of the angular displacement between the upper rotor 210 and the lower rotor 230 .

[0058] However, the relative angular displacement receiver coil set 311 and / or 321 cannot provide the absolute angular rotational position of the upper rotor 210 and the lower rotor 230 .

[0059] In order to determine the absolute angular rotational position of the upper rotor 210 and the lower rotor 230, an auxiliary or satellite rotor 220 may also be included.

[0060] The auxiliary or satellite rotor 220 may be rotatably engaged with the upper rotor 210. For example, the upper rotor 210 and the auxiliary or satellite rotor 220 may have gear teeth that mesh with each other. The number of teeth of the upper rotor 210 is different from the number of teeth of the auxiliary or satellite rotor 220, so that the upper rotor 210 and the auxiliary or satellite rotor 220 rotate at different speeds. The axis of rotation of the auxiliary or satellite rotor 220 is parallel to and spaced from the axis of rotation of the upper shaft 110.

[0061] In a first exemplary embodiment for a position sensor assembly (inductive sensing type), an auxiliary target 221 having a conductive material such as a metal (e.g., aluminum or copper) may be included in or attached to the auxiliary or satellite rotor 220. The auxiliary target 221 may be a conductive connector. The auxiliary target 221 may have, for example but not limited to, a partial circular or polygonal shape such as a semicircle or a semi-polygon. The auxiliary target 221 rotates over the auxiliary excitation or transmitter coil assembly 315 and dissipates the magnetic field generated by the auxiliary excitation or transmitter coil assembly 315, thereby generating an imbalance in the auxiliary receiver coil assembly 314, and thus generating an output voltage in the auxiliary receiver coil assembly 314 according to the angular position of the auxiliary target 221.

[0062] An auxiliary receiver coil set 314 and an auxiliary excitation or transmitter coil set 315 for sensing the absolute angular rotational position of the upper rotor 210 and / or the lower rotor 230 are included in one of the two surfaces of the stator 300, or are disposed on one of the two surfaces of the stator 300 (e.g., the upper surface of the stator 300). For example, the auxiliary receiver coil set 314 and the auxiliary excitation or transmitter coil set 315 can be formed by conductive traces on the upper surface of the stator 300 or conductive paths on the multilayer PCB of the stator 300 at a position such that the auxiliary receiver coil set 314 faces the auxiliary target 221. The auxiliary receiver coil set 314 includes a plurality of oppositely wound circumferentially adjacent rings electrically connected in series to each other. The auxiliary receiver coil set 314 and the auxiliary excitation or transmitter coil set 315 are electrically connected to the controller 500 to output a signal associated with the angular position of the auxiliary target 221 of the auxiliary or satellite rotor 220. The auxiliary receiver coil set 314 can have any shape for sensing the absolute angular rotational position, such as a substantially sinusoidal or polygonal shape. The auxiliary excitation or transmitter coil assembly 315 may be endlessly wound, but may have any shape if desired.

[0063] An upper angular position receiver coil assembly 313 for sensing the absolute angular rotation position of the upper rotor 210 is included in or disposed on the upper surface of the stator 300. For example, the upper angular position receiver coil assembly 313 may be formed by a conductive trace on the upper surface of the stator 300 or a conductive path on a multilayer PCB of the stator 300 at a position such that the upper angular position receiver coil assembly 313 faces the upper target 211. The upper angular position receiver coil assembly 313 includes a plurality of oppositely wound circumferentially adjacent rings electrically connected in series to each other. The upper angular position receiver coil assembly 313 is electrically connected to the controller 500 to output a signal associated with the angular position of the upper rotor 210. For example, the upper angular position receiver coil assembly 313 may include a sine receiver coil and a cosine receiver coil. The sine receiver coil and the cosine receiver coil included in the upper angular position receiver coil assembly 313 are surrounded by an excitation or transmitter coil assembly 312 and / or 322. The upper angular position receiver coil set 313 may have any shape useful for sensing absolute angular rotational position, such as a substantially sinusoidal or polygonal shape.

[0064] The lower angular position receiver coil assembly 323 for sensing the absolute angular rotation position of the lower rotor 230 is included in the lower surface of the stator 300 or is disposed on the lower surface of the stator 300. For example, the lower angular position receiver coil assembly 323 can be formed by a conductive trace on the lower surface of the stator 300 or a conductive path on the multilayer PCB of the stator 300 at a position such that the lower angular position receiver coil assembly 323 faces the lower target 231. The lower angular position receiver coil assembly 323 includes a plurality of oppositely wound circumferentially adjacent rings electrically connected in series to each other. The lower angular position receiver coil assembly 323 is electrically connected to the controller 500 to output a signal associated with the angular position of the lower rotor 230. For example, the lower angular position receiver coil assembly 323 may include a sine receiver coil and a cosine receiver coil. The sine receiver coil and the cosine receiver coil included in the lower angular position receiver coil assembly 323 are surrounded by the excitation or transmitter coil assembly 312 and / or 322. The lower angular position receiver coil set 323 may have any shape useful for sensing absolute angular rotational position, such as a substantially sinusoidal or polygonal shape.

[0065] In a second exemplary embodiment for a position sensor assembly (magnetic sensing type), a magnetic sensor (e.g., a Hall effect sensor) can be used to detect the absolute angular position of the upper rotor 210 and / or the lower rotor 230. For example, the auxiliary target 221 can include magnetic material of such a permanent magnet, and the auxiliary receiver coil set 314 and the auxiliary excitation or transmitter coil set 315 can be replaced with magnetic sensors such as Hall effect sensors. The magnetic field between the magnetic material of the auxiliary target 221 and the magnetic sensor can vary as a function of the angular displacement of the auxiliary target 221 of the auxiliary or satellite rotor 220.

[0066] Reference Figure 4B , the angular position of the upper rotor 210 and the angular position of the auxiliary or satellite rotor 220 are shown over multiple rotations, for example, four rotations. The output signal of the upper angular position receiver coil set 313 associated with the upper target 211 of the upper rotor 210 has a first periodic pattern, and the output signal of the auxiliary receiver coil set 314 associated with the auxiliary target 221 of the auxiliary or satellite rotor 220 has a second periodic pattern. The output signal of the upper angular position receiver coil set 313 repeats a first number of times during each rotation of the upper rotor 210, while the output signal of the auxiliary receiver coil set 314 repeats a second number of times during each rotation of the auxiliary or satellite rotor 220. Therefore, since the output signal of the upper angular position receiver coil set 313 and the output signal of the auxiliary receiver coil set 314 overlap only after a certain number of revolutions, the absolute angular rotational position of the upper rotor 210 or the steering wheel 105 can be calculated based on the output signal of the upper angular position receiver coil set 313 and the output signal of the auxiliary receiver coil set 314 programmed by the processor of the controller 500.

[0067] For example, by utilizing Fournier's principle by using the mathematical difference or relationship between the output signals of the upper angular position receiver coil set 313 and the output signals of the auxiliary receiver coil set 314, the absolute angular rotational position of the upper rotor 210 or steering wheel 105 may be calculated.

[0068] Likewise, the absolute angular position of the lower rotor 230 may be calculated in a manner similar to that described above for the upper rotor 210 .

[0069] Figures 1 to 3 The auxiliary or satellite rotor 220 is shown engaged with the upper rotor 210 and positioned above the stator 300. However, the auxiliary or satellite rotor 220 may be engaged with the lower rotor 230 and positioned below the stator 300, alternatively or additionally.

[0070] In some embodiments of the present disclosure described above, the torque sensor assembly and the angle sensor assembly share the same transmitter and the same target (e.g., the same conductive connector) to save components and reduce possible interference between the two sensor assemblies. However, each of the torque sensor assembly and the angle sensor assembly may have its own transmitter and target.

[0071] Figure 6 is a block diagram of a controller according to an embodiment of the present disclosure.

[0072] The controller 500 may include a first processor 610 , a second processor 620 , an electronic control unit (ECU) 1 , and an ECU 2 .

[0073] The first processor 610 includes an oscillator 400 configured to provide an excitation signal (TX12) to a first channel of an excitation or transmitter coil assembly 312 or 322, which can be inductively associated with the upper target 211 of the upper rotor 210 and the lower target 231 of the lower rotor 230. The first channel and the second channel of the relative angular displacement receiver coil assembly 311 and / or 321 for the torque sensor assembly receive electromagnetic signals affected by the upper target 211 of the upper rotor 210 and the lower target 231 of the lower rotor 230, and output a first channel relative angular displacement receiver output signal (RXT1) and a second channel relative angular displacement receiver output signal (RXT2) to the first processor 610, respectively. The first processor 610 outputs a first channel torque output signal (T1) and a second channel torque output signal (T2) to the ECU 1 in response to the first channel relative angular displacement receiver output signal (RXT1) and the second channel relative angular displacement receiver output signal (RXT2). The upper sine angular position receiver coil and the upper cosine angular position receiver coil included in the upper angular position receiver coil group 313 for sensing the absolute angular rotational position of the upper rotor 210 receive electromagnetic signals affected by the upper target 211 of the upper rotor 210, and output first sine angular position receiver output signals (S1-RXUR) and first cosine angular position receiver output signals (C1-RXUR), respectively, to the first processor 610. The auxiliary sine receiver coil and the auxiliary cosine receiver coil included in the auxiliary receiver coil group 314 receive electromagnetic signals affected by the auxiliary target 221 of the auxiliary or satellite rotor 220, and output first auxiliary sine angular position receiver output signals (S1-RXS) and first auxiliary cosine angular position receiver output signals (C1-RXS), respectively, to the first processor 610. The first processor 610 outputs a first upper target position output signal (P1) and a second upper target position output signal (P2) to ECU 1 in response to the first sine angular position receiver output signal (S1-RXUR), the first cosine angular position receiver output signal (C1-RXUR), the first auxiliary sine angular position receiver output signal (S1-RXS) and the first auxiliary cosine angular position receiver output signal (C1-RXS).

[0074] The second processor 620 includes an oscillator 400 configured to provide an excitation signal (TX34) to a second channel of the excitation or transmitter coil assembly 312 or 322, which can be inductively associated with the upper target 211 of the upper rotor 210 and the lower target 231 of the lower rotor 230. The third channel and the fourth channel of the relative angular displacement receiver coil assembly 311 and / or 321 for the torque sensor assembly receive electromagnetic signals affected by the upper target 211 of the upper rotor 210 and the lower target 231 of the lower rotor 230, and output a third channel relative angular displacement receiver output signal (RXT3) and a fourth channel relative angular displacement receiver output signal (RXT4), respectively, to the second processor 620. The second processor 620 outputs a third channel torque output signal (T3) and a fourth channel torque output signal (T4) to the ECU 2 in response to the third channel relative angular displacement receiver output signal (RXT3) and the fourth channel relative angular displacement receiver output signal (RXT4). The lower sine angular position receiver coil and the lower cosine angular position receiver coil included in the lower angular position receiver coil group 323 for sensing the absolute angular rotational position of the lower rotor 230 receive electromagnetic signals affected by the lower target 231 of the lower rotor 230, and output the second sine angular position receiver output signal (S2-RXUR) and the second cosine angular position receiver output signal (C2-RXUR), respectively, to the second processor 620. The second auxiliary sine angular position receiver coil and the second auxiliary cosine angular position receiver coil included in the auxiliary receiver coil group 314 receive electromagnetic signals affected by the auxiliary target 221 of the auxiliary or satellite rotor 220, and output the second auxiliary sine angular position receiver output signal (S2-RXS) and the second auxiliary cosine angular position receiver output signal (C2-RXS), respectively, to the second processor 620. The second processor 620 outputs a first lower target position output signal (P3) and a second lower target position output signal (P4) to ECU 2 in response to the second sine angular position receiver output signal (S2-RXUR), the second cosine angular position receiver output signal (C2-RXUR), the second auxiliary sine angular position receiver output signal (S2-RXS) and the second auxiliary cosine angular position receiver output signal (C2-RXS).

[0075] like Figure 4A As shown in FIG. 1 , ECU 1 and ECU 2 can use the first channel torque output signal (T1), the second channel torque output signal (T2), the third channel torque output signal (T3), and the fourth channel torque output signal (T4) to calculate the relative angular displacement movement between the upper rotor 210 and the lower rotor 230 to determine the torque applied to the steering wheel 105, and as shown in FIG. Figure 4BAs shown in the figure, the absolute angular positions of the lower rotor 230 and the upper rotor 210 can be calculated using the first upper target position output signal (P1), the second upper target position output signal (P2), the first lower target position output signal (P3) and the second lower target position output signal (P4) to determine the absolute angular positions of the upper rotor 210 and the lower rotor 230.

[0076] Although the exemplary embodiments have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.

[0077] In the present disclosure, relational terms such as first and second etc. can be used only to distinguish one entity or action from another entity and action without necessarily requiring or implying any actual relationship or order between these entities or actions. In addition, depending on the context, words such as "connect" or "coupled to" used when describing the relationship between different elements do not mean that a direct physical connection must be established between these elements. For example, two elements can be connected to each other in physical, electronic, logical or any other manner by one or more additional elements. Unless otherwise specified, the term "connect" or "coupled" can refer to direct or indirect connection.

[0078] A single integrated element or step may provide multiple elements or steps. Alternatively, a single element or step may be divided into separate multiple elements or steps.

[0079] The disclosure of “a” or “an” to describe one element or step does not intend to exclude other elements or steps.

[0080] Although the term first, second, third etc. can be used herein to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms can be used to distinguish an element, component, region, layer or part from another element, component, region, layer or part. Unless the context clearly indicates, otherwise such as "first", "second" and other numerical terms used in this article do not mean sequence or order. Therefore, without departing from this teaching, the first element, component, region, layer or part discussed can be referred to as the second element, component, region, layer or part.

[0081] The terms "comprises," "includes," "contains," "covers," "has," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a method, article, or apparatus that includes a list of features is not necessarily limited to only those features, but may also include other features not expressly listed or inherent to the method, article, or apparatus. In addition, unless expressly stated otherwise, "or" refers to an inclusive or, not an exclusive or. For example, condition A or B may be satisfied by any of the following conditions: A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); and A and B are both true (or exist).

[0082] Although various embodiments of the claimed invention have been described above with a certain degree of particularity or with reference to one or more separate embodiments, those skilled in the art may make many modifications to the disclosed embodiments without departing from the spirit or scope of the claimed invention. The use of the terms "approximately", "approximately" or "substantially" means that the value of an element has a parameter that is expected to be close to a specified value or position. However, as is well known in the art, there may be slight changes to prevent the value from being exactly the same as described. Therefore, the expected difference such as a 10% difference is an acceptable reasonable difference that is expected and known by those of ordinary skill in the art relative to the statements or ideal goals of one or more embodiments of the present disclosure. It should also be understood that the terms "top" and "bottom", "left side" and "right side", "up" or "down", "first", "second", "before", "after" and other similar terms are only used for the purpose of description and ease of reference, and are not intended to be limited to any orientation or configuration of any element or sequence of operations of various embodiments of the present disclosure.

[0083] In addition, the scope of the present application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, and material compositions, devices, methods, and steps described in the specification. Those of ordinary skill in the art will readily understand from this disclosure that, according to the embodiments and alternative embodiments, processes, machines, manufactures, material compositions, devices, methods, or steps that currently exist or are later developed to perform substantially the same functions or achieve substantially the same results as the corresponding embodiments described herein may be utilized. Therefore, the appended claims are intended to include such processes, machines, manufactures, material compositions, devices, methods, or steps within their scope.

[0084] CROSS-REFERENCE TO RELATED APPLICATIONS

[0085] This application claims the benefit and priority of U.S. patent application serial number 63 / 547,533, entitled “INDUCTIVE TORQUE & ABSOLUTE POSITION SENSOR,” filed on November 6, 2023, and U.S. patent application serial number 63 / 562,229, entitled “INDUCTIVE TORQUE & ABSOLUTE POSITION SENSOR,” filed on March 6, 2024, which are hereby incorporated by reference in their entirety.

Claims

1. An inductive sensor system, the inductive sensor system comprising: an upper rotor including an upper target having a first metal pattern; a lower rotor including a lower target having a second metal pattern; as well as a fixed circuit board, the circuit board being positioned between the upper rotor and the lower rotor, the circuit board comprising: one or more transmitter coil sets configured to generate an electromagnetic field; one or more receiver coil assemblies for sensing relative angular displacement motion between the upper rotor and the lower rotor, Wherein, the one or more transmitter coil assemblies and the one or more receiver coil assemblies are circularly wound.

2. The inductive sensor system according to claim 1, wherein: The one or more receiver coil sets wound endlessly for sensing relative angular displacement motion between the upper rotor and the lower rotor are positioned radially outside the first metal pattern of the upper target and the second metal pattern of the lower target, and The one or more transmitter coil groups wound in a loop are positioned radially inside the first metal pattern of the upper target and the second metal pattern of the lower target.

3. The inductive sensor system according to claim 1, wherein: The one or more receiver coil sets wound endlessly for sensing relative angular displacement motion between the upper rotor and the lower rotor are positioned radially inside the first metal pattern of the upper target and the second metal pattern of the lower target, and The one or more transmitter coil groups wound in a loop are positioned radially inside the first metal pattern of the upper target and the second metal pattern of the lower target.

4. The inductive sensor system according to claim 1, wherein: At least one of the one or more receiver coil groups wound circularly for sensing the relative angular displacement movement between the upper rotor and the lower rotor is positioned radially outside the first metal pattern of the upper target and the second metal pattern of the lower target, and another receiver coil group or other receiver coil groups of the one or more receiver coil groups wound circularly for sensing the relative angular displacement movement between the upper rotor and the lower rotor are positioned radially inside the first metal pattern of the upper target and the second metal pattern of the lower target, and The one or more transmitter coil groups wound in a loop are radially positioned inside the first metal pattern of the upper target and the second metal pattern of the lower target, respectively.

5. The inductive sensor system according to claim 1, wherein: The circuit board includes a further upper receiver coil set for sensing the angular position of the upper rotor.

6. The inductive sensor system according to claim 5, wherein: The circuit board includes a further lower receiver coil set for sensing the angular position of the lower rotor.

7. The inductive sensor system according to claim 1, further comprising: an auxiliary rotor rotatably engaged with the upper rotor and having a third metal pattern; as well as An auxiliary transmitter coil assembly and an auxiliary receiver coil assembly are included in the circuit board or disposed on an upper surface of the circuit board.

8. The inductive sensor system according to claim 1, further comprising: an auxiliary rotor rotatably engaged with the lower rotor and having a third metal pattern; as well as An auxiliary transmitter coil assembly and an auxiliary receiver coil assembly are included in the circuit board or disposed on a lower surface of the circuit board.

9. The inductive sensor system according to claim 1, further comprising: an auxiliary rotor rotatably engaged with the upper rotor or the lower rotor and having a magnetic material; as well as A sensor is configured to sense a magnetic field and is positioned below or above the auxiliary rotor.

10. The inductive sensor system according to claim 6, wherein: the one or more receiver coil assemblies comprising an upper receiver coil assembly and a lower receiver coil assembly, The upper receiver coil group and the other upper receiver coil groups are arranged on the upper surface of the circuit board, The lower receiver coil group and the other lower receiver coil groups are disposed on a lower surface of the circuit board, and The one or more transmitter coil groups are disposed on an upper surface of the circuit board, on a lower surface of the circuit board, or inside the circuit board.

11. The inductive sensor system according to claim 6, wherein: the one or more receiver coil assemblies comprising an upper receiver coil assembly and a lower receiver coil assembly, The circuit board has multiple layers including an upper layer and a lower layer, The upper receiver coil group and the other upper receiver coil groups are arranged on the upper layer of the circuit board or between the upper layers of the circuit board, The lower receiver coil group and the other lower receiver coil groups are disposed on the lower layer of the circuit board or between the lower layers of the circuit board, and The one or more transmitter coil groups are disposed on an upper surface or a lower surface of the circuit board, or between the upper surface and the lower surface of the circuit board.

12. The inductive sensor system of claim 1, wherein: The first metal pattern of the upper target and / or the second metal pattern of the lower target has a plurality of circumferentially adjacent lobes.

13. The inductive sensor system according to claim 7, wherein: The third metal pattern of the auxiliary rotor has a substantially semicircular or polygonal shape.

14. The inductive sensor system according to claim 7, wherein: The upper rotor and the auxiliary rotor have gear teeth engaged with each other.

15. The inductive sensor system of claim 8, wherein: The lower rotor and the auxiliary rotor have gear teeth engaged with each other.

16. The inductive sensor system of claim 14, wherein: A transmission ratio between the upper rotor and the auxiliary rotor is in the range of 1.8 to 2.

7.

17. The inductive sensor system of claim 1, wherein: The upper rotor is included in an upper shaft coupled to a steering wheel, or is coupled to the upper shaft coupled to the steering wheel, The lower rotor is included in, or coupled to, the lower shaft, and A torsion bar is coupled between the upper shaft and the lower shaft.

18. An inductive sensor system, comprising: an upper rotor including an upper target having a first metal pattern; a lower rotor including a lower target having a second metal pattern; an auxiliary rotor rotatably engaged with the upper rotor or the lower rotor; as well as a fixed circuit board, the circuit board being positioned between the upper rotor and the lower rotor, the circuit board comprising: one or more transmitter coil sets configured to generate an electromagnetic field; one or more receiver coil sets for sensing relative angular displacement motion between the upper rotor and the lower rotor; and one or more receiver coil sets for sensing the angular position of the upper rotor and / or the lower rotor, The one or more transmitter coil assemblies and the one or more receiver coil assemblies for sensing the relative angular displacement movement between the upper rotor and the lower rotor are circularly wound.

19. The inductive sensor system of claim 18, wherein: The auxiliary rotor has a third metal pattern, and An auxiliary transmitter coil assembly and an auxiliary receiver coil assembly are included in the circuit board or disposed on a surface of the circuit board.

20. The inductive sensor system of claim 18, further comprising a sensor configured to sense a magnetic field and positioned below or above the auxiliary rotor, in, The auxiliary rotor rotatably engaged with the upper rotor or the lower rotor includes a magnetic material.

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