Redundant angular position sensor and associated methods of use

Abstract

A redundant angular position sensor includes a first angular position sensor and a second angular position sensor. The first angular position sensor includes a first excitation coil, a first sense coil, and a second sense coil. The second angular position sensor includes a second excitation coil, a third sense coil, and a fourth sense coil. Each of the first, second, third, and fourth sense coils includes a respective clockwise winding portion and a respective counterclockwise winding portion. The redundant angular position sensor further includes a rotatable inductive coupling element positioned in overlapping relationship with the sense coils and separated therefrom by a gap, wherein the rotatable inductive coupling element includes four substantially uniformly radially spaced sector apertures.

Description

[0001] Cross-reference of related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 110,307, filed November 5, 2020, and U.S. Non-Provisional Patent Application No. 17 / 146,875, filed January 12, 2021, the entire contents of which are incorporated herein by reference. Background Technology

[0003] Many industries, including the automotive, industrial, and aerospace sectors, have stringent reliability requirements for their position sensing systems. Potentiometers are commonly known in the art for use in position sensing systems, specifically for determining the displacement angle of motor control or regulating elements. While potentiometers are a relatively inexpensive solution for position sensing, they are also susceptible to adverse environmental conditions and can fail over time due to repeated operation. To overcome the drawbacks of potentiometer-based sensing systems, non-contact position sensors are increasingly being used to meet stringent reliability requirements. Non-contact position sensors are currently known in the art and can be based on various principles, including induction, capacitance, Hall effect, or magnetoresistive principles.

[0004] A non-contact sensor based on the principle of induction is often referred to as an inductive position sensor or resolver. An inductive position sensor includes a coil assembly having one or more excitation coils and two or more sensing coils. In operation of the inductive position sensor, alternating current (AC) is injected into the excitation coil, resulting in a time-varying magnetic field near the excitation coil. This time-varying magnetic field is sufficient to induce a time-varying voltage in the sensing coil due to the mutual magnetic coupling between the excitation coil and the sensing coil. To determine the angular position of a rotatable target relative to the coil assembly, a conductive target is rotatably positioned within the time-varying magnetic field between the excitation coil and the sensing coil, and separated from the coil by an air gap. The presence of the rotatable target in the time-varying magnetic field, relative to its position, alters the mutual magnetic coupling between the excitation coil and the sensing coil. This change in mutual coupling between the excitation coil and the sensing coil changes the induced time-varying voltage in the sensing coil. Since the change in voltage induced in the sensing coil relative to both the angular position of the rotatable target relative to the coil assembly is approximately sinusoidal, the time-varying voltage in the sensing coil can be measured, and the angular position of the rotatable target can be calculated from the measurement.

[0005] Coil assemblies formed on one or more printed circuit boards (PCBs) to provide position sensors are known in the art. The demand for position sensors that are lightweight, low-cost, highly reliable, and noise-resistant is increasing. While known inductive position sensors meet many of these requirements, various safety-critical applications also require sensor redundancy. For example, in the automotive industry, brake pedals, accelerator pedals, and engine throttle mechanisms require redundant sensor solutions so that if one sensor fails, the redundant sensors continue to operate correctly.

[0006] Therefore, there is a need in the art for a non-contact angular position sensor that meets the requirements of sensing accuracy and redundancy. Summary of the Invention

[0007] In various embodiments, the present invention provides a system and method for sensing the angular position of a rotatable inductively coupled element using redundancy. The system and method of the present invention provide an improved, non-contact, inductive angular position sensor that provides redundancy while still meeting sensing accuracy requirements with a reduced shape factor.

[0008] In a particular embodiment, the present invention provides a redundant angular position sensor comprising a first angular position sensor and a second angular position sensor, wherein the first angular position sensor is positioned adjacent to the second angular position sensor. The first angular position sensor includes a first excitation coil, a first sensing coil, and a second sensing coil, each of the first and second sensing coils including a corresponding clockwise winding portion and a corresponding counterclockwise winding portion. The second angular position sensor includes a second excitation coil, a third sensing coil, and a fourth sensing coil, each of the third and fourth sensing coils including a corresponding clockwise winding portion and a corresponding counterclockwise winding portion. The redundant angular position sensor further includes a rotatable inductive coupling element positioned overlapping and separated from the first, second, third, and fourth sensing coils by gaps, wherein the rotatable inductive coupling element includes four sector openings radially spaced substantially uniformly around the rotatable inductive coupling element.

[0009] In a particular embodiment, a first excitation coil forms a first semicircular region defining a first internal region, and a first sensing coil and a second sensing coil are positioned within the first internal region, and a second excitation coil forms a second semicircular region defining a second internal region, and a third sensing coil and a fourth sensing coil are positioned within the second internal region.

[0010] In addition, the first corner position sensor also includes a first voltage source and a first grounding node, and the second corner position sensor also includes a second voltage source independent of the first voltage source and a second grounding node independent of the first grounding node.

[0011] In another embodiment, the present invention provides a method for redundantly sensing the angular position of a rotatable inductively coupled element. The method includes: establishing magnetic coupling between a first excitation coil, a first sensing coil, and a second sensing coil of a first angular position sensor to sense a time-varying voltage in the first and second sensing coils, wherein each of the first and second sensing coils includes a corresponding clockwise winding portion and a corresponding counterclockwise winding portion; and establishing magnetic coupling between the second excitation coil of the second angular position sensor and a third and a fourth sensing coil to sense a time-varying voltage in the third and fourth sensing coils, wherein each of the third and fourth sensing coils includes a corresponding clockwise winding portion and a corresponding counterclockwise winding portion. The method further includes: rotating a rotatable inductive coupling element, the rotatable inductive coupling element comprising four sector openings radially spaced substantially uniformly around the rotatable inductive coupling element, the rotatable inductive coupling element overlapping with and separated from the first, second, third, and fourth sensing coils by gaps, the rotational position of the sector openings of the rotatable inductive coupling element causing a change in the magnetic coupling between the first excitation coil, the first sensing coil, and the second sensing coil in response to the rotation of the rotatable inductive coupling element, and causing a change in the magnetic coupling between the second excitation coil, the third sensing coil, and the fourth sensing coil. The method further includes: measuring the time-varying voltage induced in the first and second sensing coils due to the change in magnetic coupling; determining the angular position of the rotatable inductive coupling element relative to the first and second sensing coils; measuring the time-varying voltage induced in the third and fourth sensing coils due to the change in magnetic coupling; and determining the angular position of the rotatable inductive coupling element relative to the third and fourth sensing coils.

[0012] Thus, in various embodiments, the present invention provides a redundant angular position sensor and a method for redundantly sensing the angular position of a rotatable inductively coupled element. Attached Figure Description

[0013] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate various embodiments and, together with the description of the embodiments, serve to explain the principles discussed below. Unless otherwise specified, the drawings mentioned in this brief description should not be construed as being drawn to scale.

[0014] Figure 1A redundant angular position sensor according to an embodiment of the present invention is shown, the redundant angular position sensor comprising a first angular position sensor and a second angular position sensor.

[0015] Figure 2 The coil layout of a redundant angular position sensor, including a first angular position sensor and a second angular position sensor, according to an embodiment of the present invention is shown.

[0016] Figure 3A The diagram shows the winding turns of the first sensing coil of a redundant angular position sensor positioned on the first PCB layer of a multilayer circuit board according to an embodiment of the present invention.

[0017] Figure 3B The diagram shows the winding turns of the first sensing coil of a redundant angular position sensor positioned on the second PCB layer of a multilayer circuit board according to an embodiment of the present invention.

[0018] Figure 3C The diagram shows the winding turns of the second sensing coil of a redundant angular position sensor positioned on the first PCB layer of a multilayer circuit board according to an embodiment of the present invention.

[0019] Figure 3D The diagram shows the winding turns of the second sensing coil of a redundant angular position sensor positioned on the second PCB layer of a multilayer circuit board according to an embodiment of the present invention.

[0020] Figure 3E The counterclockwise winding portion of the first excitation coil of a redundant angular position sensor according to an embodiment of the present invention is shown.

[0021] Figure 3F The clockwise winding portion of the first excitation coil of a redundant angular position sensor according to an embodiment of the present invention is shown.

[0022] Figure 4A The diagram shows the winding turns of the third sensing coil of a redundant angular position sensor positioned on the first PCB layer of a multilayer circuit board according to an embodiment of the present invention.

[0023] Figure 4B The diagram shows the winding turns of the third sensing coil of a redundant angular position sensor positioned on the second PCB layer of a multilayer circuit board according to an embodiment of the present invention.

[0024] Figure 4C The diagram shows the winding turns of the fourth sensing coil of a redundant angular position sensor positioned on the first PCB layer of a multilayer circuit board according to an embodiment of the present invention.

[0025] Figure 4DThe diagram shows the winding turns of the fourth sensing coil of a redundant angular position sensor positioned on the second PCB layer of a multilayer circuit board according to an embodiment of the present invention.

[0026] Figure 4E The counterclockwise winding portion of the second excitation coil of a redundant angular position sensor according to an embodiment of the present invention is shown.

[0027] Figure 4F The clockwise winding portion of the second excitation coil of a redundant angular position sensor according to an embodiment of the present invention is shown.

[0028] Figure 5A This is a schematic diagram illustrating an angular position sensor in a 0° rotational position according to an embodiment of the present invention.

[0029] Figure 5B This is a schematic diagram illustrating an angular position sensor in a 22.5° rotational position according to an embodiment of the present invention.

[0030] Figure 5C This is a schematic diagram illustrating an angular position sensor in a 45° rotational position according to an embodiment of the present invention.

[0031] Figure 5D This is a schematic diagram illustrating an angular position sensor in a 67.5° rotational position according to an embodiment of the present invention.

[0032] Figure 6 This is a graphical illustration of the voltage change of the sensing coil relative to the position of the rotatable inductive coupling element according to an embodiment of the present invention.

[0033] Figure 7 This is a flowchart illustrating a method for redundantly sensing the angular position of a rotatable inductively coupled element according to an embodiment of the present invention.

[0034] Figure 8 This is a flowchart illustrating a method for determining the angular position of a rotatable inductively coupled element using a first angular position sensor with redundant angular position sensors.

[0035] Figure 9 This is a flowchart illustrating a method for determining the angular position of a rotatable inductively coupled element using a second angular position sensor with redundant angular position sensors. Detailed Implementation

[0036] Reference will now be made in detail to various embodiments, examples of which are illustrated in the accompanying drawings. While various embodiments are discussed herein, it should be understood that they are not intended to be limiting. Rather, the proposed embodiments are intended to cover alternative forms, modifications, and equivalents that may be included within the spirit and scope of the various embodiments defined by the appended claims. Furthermore, numerous specific details are set forth in this particular embodiment to provide a thorough understanding. However, the embodiments may be practiced without one or more of these specific details. In other instances, well-known methods, procedures, components, and circuits have not been described in detail to avoid unnecessarily obscuring aspects of the said embodiments.

[0037] It should be understood that although the terms first, second, third, etc., may be used herein to describe various elements, components, regions, layers, and / or portions, these elements, components, regions, layers, and / or portions should not be limited by these terms. These terms are used only to distinguish one element, component, region, layer, or portion from another region, layer, or portion. Therefore, the first element, component, region, layer, or portion discussed below may be referred to as the second element, component, region, layer, or portion without departing from the teachings of the invention.

[0038] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms (such as those defined in common dictionaries) shall be interpreted as having the meaning consistent with their meaning in the context of the relevant field and shall not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0039] In various embodiments, the present invention provides a redundant angular position sensor comprising a first angular position sensor and a second angular position sensor independent of the first angular position sensor, wherein the voltage source and ground node of the first angular position sensor are independent of the voltage source and ground node of the second angular position sensor. Redundancy is provided by combining two independent angular position sensors in the redundant angular position sensor of the present invention. Furthermore, the first and second angular position sensors of the redundant angular position sensor are implemented on two printed circuit boards (PCBs), thereby providing a cost-effective solution. Generally, the first angular position sensor includes a first excitation coil and two sensing coils positioned within a region defined by the outer periphery of the excitation coil or two sensing coils, and the second angular position sensor includes a second excitation coil and two sensing coils positioned within a region defined by the outer periphery of the second excitation coil or two sensing coils. In one embodiment, positioning the coil pattern of the sensing coils within an internal region formed by each of the respective excitation coils provides redundancy with a reduced form factor.

[0040] refer to Figure 1 The redundant angular position sensor 100 of the present invention includes a first angular position sensor and a second angular position sensor. The first angular position sensor has a first excitation coil 105 including a counterclockwise winding portion 105A and a clockwise winding portion 105B, and the second angular position sensor has a second excitation coil 110 including a counterclockwise winding portion 110A and a clockwise winding portion 110B. The first and second sensing coils of the first angular position sensor are positioned inside a semi-circular region formed by the first excitation coil 105. The third and fourth sensing coils of the second angular position sensor are positioned inside the semi-circular region formed by the second excitation coil 110, as shown below. Figure 2 As shown.

[0041] like Figure 1 As shown, the redundant angular position sensor 100 additionally includes a rotatable inductive coupling element 150, the radius of which is 188 substantially equal to the radius 186 of the first excitation coil 105 and / or substantially equal to the radius 184 of the second excitation coil 110. The rotatable inductive coupling element 150 also includes a plurality of sector openings 160, 165, 170, 175, each of the sector openings having an angle equal to the angle of a winding portion of one of the sensing coils of the first and / or second angular position sensors. In a particular embodiment, the rotatable inductive coupling element 150 comprises a non-ferromagnetic conductive material. Figure 1As shown, in a particular embodiment, the rotatable inductive coupling element 150 can be described as comprising four 90° sectors 162, 167, 172, 177, wherein each of the 90° sectors 162, 167, 172, 177 includes a sector opening with an angle of 22.5° and a non-ferromagnetic conductive sector with an angle of 67.5°. Specifically, the rotatable inductive coupling element 150 includes: a first 90° sector 162, which includes a first sector opening 160 with an angle of 22.5° and a first non-ferromagnetic conductive sector 161 with an angle of 67.5°; a second 90° sector 167, which includes a second sector opening 165 with an angle of 22.5° and a second non-ferromagnetic conductive sector 166 with an angle of 67.5°; a third 90° sector 172, which includes a third sector opening 170 with an angle of 22.5° and a third non-ferromagnetic conductive sector 171 with an angle of 67.5°; and a fourth 90° sector 177, which includes a fourth sector opening 175 with an angle of 22.5° and a fourth non-ferromagnetic conductive sector 176 with an angle of 67.5°. Thus, the first sector opening 160 includes 25% of the first 90° sector 162, and the first non-ferromagnetic conductive sector 161 includes 75% of the first 90° sector 162; the second sector opening 165 includes 25% of the second 90° sector 167, and the second non-ferromagnetic conductive sector 166 includes 75% of the second 90° sector 167; the third sector opening 170 includes 25% of the third 90° sector 172, and the third non-ferromagnetic conductive sector 171 includes 75% of the third 90° sector 172; and the fourth sector opening 175 includes 25% of the fourth 90° sector 177, and the fourth non-ferromagnetic conductive sector 176 includes 75% of the fourth 90° sector 177. Generally, the combination of all four sector openings includes approximately 25% of the total area of ​​the rotatable inductive coupling element 150, and the remaining 75% of the total area of ​​the rotatable inductive coupling element 150 is made of a non-ferromagnetic conductive material. The rotatable inductive coupling element 150 is positioned to overlap with the first excitation coil 105 and the second excitation coil 110 and to separate them by a gap 180. In a particular embodiment, the rotatable inductive coupling element 150 is made of a non-ferromagnetic conductive material.

[0042] Figure 2 Showing more details Figure 1 The redundant angular position sensor's coil layout 200 and associated circuitry. (e.g.) Figure 2As shown, the coil layout 200 includes a first angular position sensor 202, which includes a first excitation coil 105, a first sensing coil 225, and a second sensing coil 221. The first sensing coil 225 includes a clockwise winding portion 220 and a counterclockwise winding portion 222, and the second sensing coil 221 includes a clockwise winding portion 224 and a counterclockwise winding portion 226. The clockwise winding portions 220 and 222 of the first sensing coil 225 and the clockwise winding portions 224 and 226 of the second sensing coil 221 are each positioned in corresponding equal sectors within a first inner region defined by the first excitation coil 105 forming a first semi-circular region. The coil layout 200 additionally includes a second angular position sensor 204 that operates independently of the first angular position sensor 202. The second angular position sensor 204 includes a second excitation coil 110, a third sensing coil 235, and a fourth sensing coil 231. The third sensing coil 235 includes a clockwise winding portion 230 and a counterclockwise winding portion 232, and the fourth sensing coil 231 includes a clockwise winding portion 234 and a counterclockwise winding portion 236. The clockwise winding portions 230 and 232 of the third sensing coil 235 and the clockwise winding portions 234 and 236 of the fourth sensing coil 231 are each positioned in corresponding equal sectors within a second inner region defined by the second excitation coil 110 forming the second semi-circular region. In this invention, a clockwise winding portion is defined as a winding portion in which the direction of the current flowing through the winding portion is clockwise when the current flowing through the counterclockwise winding portion is in a counterclockwise direction, and a counterclockwise winding portion is defined as a winding portion in which the direction of the current flowing through the winding portion is counterclockwise when the current flowing through the clockwise winding portion is in a clockwise direction. Those skilled in the art will recognize that the excitation signal is an AC signal, therefore, the terms clockwise and counterclockwise, as used throughout, do not imply a fixed direction, but rather that the current flows in opposite directions at any given time.

[0043] As shown in the figure, the winding portions 220 and 222 of the first sensing coil 225 and the winding portions 224 and 226 of the second sensing coil 221 are each alternatively positioned within a corresponding sub-sector of the four equal sub-sectors of the main sector 190 of the first excitation coil 105. In a particular embodiment, the first sensing coil 225 and the second sensing coil 221 of the first angular position sensor 202 are positioned within the main sector 190 of the first excitation coil 105 having a central angle of approximately 90°. Specifically, the first winding portion 220 of the first sensing coil 225 is located in a first sub-sector 192 with a central angle of approximately 22.5°, the first winding portion 224 of the second sensing coil 221 is located in a second sub-sector 194 with a central angle of approximately 22.5°, the second winding portion 222 of the first sensing coil 225 is located in a third sub-sector 196 with a central angle of approximately 22.5°, and the second winding portion 226 of the second sensing coil 221 is located in a fourth sub-sector 198 with a central angle of approximately 22.5°.

[0044] As also shown in the figure, the winding portions 230, 232 of the third sensing coil 235 and the winding portions 234, 236 of the fourth sensing coil 231 are each alternatively positioned within a corresponding sub-sector of the four equal sub-sectors of the main sector 290 of the second excitation coil 110. In a particular embodiment, the third sensing coil 235 and the fourth sensing coil 231 of the second sensor 204 are positioned within the main sector 290 of the second excitation coil 110, which has a central angle of approximately 90°. Specifically, the first winding portion 230 of the third sensing coil 235 is located in a first sub-sector 292 with a central angle of approximately 22.5°, the first winding portion 234 of the fourth sensing coil 231 is located in a second sub-sector 294 with a central angle of approximately 22.5°, the second winding portion 232 of the third sensing coil 235 is located in a third sub-sector 296 with a central angle of approximately 22.5°, and the second winding portion 236 of the fourth sensing coil 231 is located in a fourth sub-sector 298 with a central angle of approximately 22.5°.

[0045] from Figure 1 It can be seen that when each of the winding portions 220, 222, 224, 226, 230, 232, 234, 236 of the first angular position sensor 202 and the second angular position sensor 204 is positioned in a sub-sector with a central angle of approximately 22.5°, each of the sector openings 160, 165, 170, 175 of the rotatable inductive coupling element 150 has a central angle of approximately 22.5°.

[0046] like Figure 2As shown, each of the first excitation coil 105 and the second excitation coil 110 forms a 180° arc, which has two sides connected by a line segment. The length of the line segment between the two sides of the arc is referred to herein as the diameter of the excitation coil. As shown, the diameter 205 of the first excitation coil 105 (where diameter 205 defines the boundary of the first semicircular region formed by the first excitation coil 105) and the diameter 210 of the second excitation coil 110 (where diameter 210 defines the boundary of the second semicircular region formed by the second excitation coil 105) are positioned adjacent to each other to form a complete circle around the first sensing coil 225, the second sensing coil 221, the third sensing coil 235, and the fourth sensing coil 231.

[0047] like Figure 2 As shown, the first angular position sensor 202 includes a first voltage source 270 and a first ground node 280, and the second angular position sensor 204 includes a second voltage source 275 and a second ground node 285. In this invention, the first voltage source 270 is independent of the second voltage source 275, and the first ground node 280 is independent of the second ground node 285. The redundant angular position sensor 100 of this invention also includes a first voltage sensing circuit 260 coupled to the first angular position sensor 202 and a second voltage sensing circuit 265 coupled to the second angular position sensor 204. Specifically, the first voltage sensing circuit 260 is coupled to a first sensing coil 225 and a second sensing coil 221, and the second voltage sensing circuit 265 is coupled to a third sensing coil 235 and a fourth sensing coil 231.

[0048] In operation, the first excitation coil 105 and the second excitation coil 110 of the corresponding first angular position sensor 202 and second angular position sensor 204 are excited with a high-frequency signal (such as a 5MHz signal) to generate an alternating current (AC) magnetic field. The AC magnetic field generated by the first excitation coil 105 is coupled to the first sensing coil 225 and the second sensing coil 221, and the AC magnetic field generated by the second excitation coil 110 is coupled to the third sensing coil 235 and the fourth sensing coil 231, thereby generating voltages in the corresponding winding portions 220, 222, 224, 226, 230, 232, 234, and 236 of the sensing coils 221, 225, 231, and 235. Positioning the rotatable inductive coupling element 150 within the magnetic field induces eddy currents in the rotatable inductive coupling element 150, which attenuates the time-varying magnetic field in the regions of the corresponding winding portions 220, 222, 224, 226, 230, 232, 234, 236 of the sensing coils 221, 225, 231, 235 covered by the rotatable inductive coupling element 150. Because eddy currents are induced in the rotatable inductive coupling element 150, the time-varying voltages induced in the corresponding winding portions 220, 222, 224, 226, 230, 232, 234, 236 of the sensing coils 221, 225, 231, 235 covered by the rotatable inductive coupling element 150 are attenuated, and the time-varying voltages induced in the corresponding winding portions 220, 222, 224, 226, 230, 232, 234, 236 of the sensing coils 221, 225, 231, 235 not covered by the rotatable inductive coupling element 150 (i.e., those covered by one of the sector openings 160, 165, 170, 175) are not attenuated.

[0049] The position interference of the rotatable inductive coupling element 150 generates an AC magnetic field, resulting in the generation of modulated cosine and sine waveforms by the sensing coils 221, 225, 231, and 235. These modulated cosine and sine waveforms are provided to the corresponding voltage sensing circuits 260 and 265. In a particular embodiment, with the rotatable inductive coupling element 150 present, the first voltage sensing circuit 260 can receive a modulated cosine signal from the first sensing coil 225 and a modulated sine signal from the second sensing coil 221. The first voltage sensing circuit 260 then demodulates the received signals and calculates position information by performing an arctangent calculation of the ratio of the cosine and sine signals. Additionally, with the rotatable inductive coupling element 150 present, the second voltage sensing circuit 265 can receive a modulated cosine signal from the third sensing coil 235 and a modulated sine signal from the fourth sensing coil 231. Then, the second voltage sensing circuit 265 demodulates the received signal and calculates the position information by performing an arctangent calculation of the ratio of the cosine signal to the sine signal.

[0050] To provide a redundant angular position sensor, separate voltage sources 270 and 275 and separate grounding nodes 280 and 285 are established for each of the two independent excitation coils 105 and 110. In addition, independent cosine sensing coils 225 and 235 and sine sensing coils 221 and 231 are provided to complete the redundancy.

[0051] During operation, although one of the angle position sensors 202 and 204 may be disabled due to a short circuit, for example, due to a short circuit between the corresponding voltage sources 270 and 275 and the corresponding ground nodes 280 and 285, the other angle position sensor 202 and 204 will continue to operate. Thus, a single fault at a specific component of the first angle position sensor 202 or the second angle position sensor 204 will not cause both angle position sensors 202 and 204 to fail.

[0052] In certain implementations, to provide the necessary redundancy for critical applications, a single failure must not cause the outputs of both angle position sensors 202 and 204 to exceed 5% of their nominal sensor outputs. However, in existing sensor designs employing circular excitation coils, the excitation coils are interleaved, and therefore, when a short circuit exists between the voltage source and ground at one of the excitation coils, mutual inductive coupling effects can cause the other sensor to also enter a failure mode. In contrast, in the angle position sensor 100 proposed in this invention, since the two sensors 202 and 204 are completely independent and have very small mutual coupling effects, the redundant angle position sensor 100 can meet the safety requirements.

[0053] Figure 3A and Figure 3B The first sensing coil 225 of the first angular position sensor 202 is shown in more detail. The winding turns of the first sensing coil 225 can be positioned on two different layers of a printed circuit board (PCB). Figure 3A A view is provided of the winding turns 225A of the first sensing coil 225 positioned on the first layer of the PCB, and Figure 3B A view is provided of the winding turns 225B of the first sensing coil 225 positioned on the second layer of the PCB. (See attached image.) Figure 3A As shown, the first sensing coil 225 ( Figure 2 The first winding turn 222A of the counterclockwise winding portion 222 of the first sensing coil 225 is positioned on the first layer of the PCB, and the second winding turn 222B of the counterclockwise winding portion 222 of the first sensing coil 225 is positioned on the second layer of the PCB, as follows. Figure 3B As shown. The first winding turn 222A and the second winding turn 222B are connected through a through hole 345. Additionally, as... Figure 3AAs shown, the first sensing coil 225 ( Figure 2 The first winding turn 220A of the clockwise winding portion 220 of the first sensing coil 225 is positioned on the first layer of the PCB, and the second winding turn 220B of the clockwise winding portion 220 of the first sensing coil 225 is positioned on the second layer of the PCB, as follows. Figure 3B As shown. The first winding turn 220A and the second winding turn 220B are connected through a through-hole 344. Additional through-holes 340, 341, 342, and 343 are used to provide connections between PCB layers, as is known in the art. As shown in the figure, in Figure 3A and Figure 3B In an exemplary embodiment, the current travels counterclockwise 315 in the first winding turn 222A and the second winding turn 222B of the counterclockwise winding portion 222 of the first sensing coil 221, and clockwise 317 in the first winding turn 220A and the second winding turn 220B of the clockwise winding portion 220 of the first sensing coil 221. As mentioned above, the excitation signal is an AC signal; therefore, the terms clockwise and counterclockwise, as used throughout, do not imply fixed directions, but rather that the current flows in opposite directions at any given time.

[0054] Figure 3C and Figure 3D The first angular position sensor 202 is shown in more detail. Figure 2 The second sensing coil 221. The winding turns of the second sensing coil 221 can be positioned on two different layers of a printed circuit board (PCB). Figure 3C A view is provided of the winding turns 221A of the second sensing coil 221 positioned on the first layer of the PCB, and Figure 3D A view of the winding turns 221B of the second sensing coil 221, positioned on the second layer of the PCB, is provided. (See attached image.) Figure 3C As shown, the second sensing coil 221 ( Figure 2 The first winding turn 226A of the counterclockwise winding portion 226 of the second sensing coil 221 is positioned on the first layer of the PCB, and the second winding turn 226B of the counterclockwise winding portion 226 of the second sensing coil 221 is positioned on the second layer of the PCB, as follows. Figure 3D As shown. The first winding turn 226A and the second winding turn 226B are connected through a through hole 347. Additionally, as... Figure 3C As shown, the second sensing coil 225 ( Figure 2 The first winding turn 224A of the clockwise winding portion 224 of the second sensing coil 221 is positioned on the first layer of the PCB, and the second winding turn 224B of the clockwise winding portion 224 of the second sensing coil 221 is positioned on the second layer of the PCB, as follows. Figure 3DAs shown. The first winding turn 224A and the second winding turn 224B are connected through a through hole 346. As shown in the figure, in Figure 3C and Figure 3D In an exemplary embodiment, the current travels in a counterclockwise direction 319 in the first winding turn 226A and the second winding turn 226B of the counterclockwise winding portion 226 of the second sensing coil 221, and the current travels in a clockwise direction 321 in the first winding turn 224A and the second winding turn 224B of the clockwise winding portion 224 of the second sensing coil 221.

[0055] refer to Figure 3E and Figure 3F The winding portions 105A and 105B of the first excitation coil 105 of the first angular position sensor 202 are shown in more detail. Figure 3E The counterclockwise winding portion 105A of the first excitation coil 105 is shown, and Figure 3F A clockwise winding portion 105B of a first excitation coil 105 is shown. In a particular embodiment, a counterclockwise winding portion 105A is positioned on a first layer of a PCB, and a clockwise winding portion 105B is positioned on a second layer of the PCB. The first and second layers can be connected via one or more through-holes, as is known in the art. In operation, a center-tapped voltage source 270 is supplied to the counterclockwise winding portion 105A and the clockwise winding portion 105B of the first excitation coil 105, such that current flows through them. Figure 3E The counterclockwise winding portion 105A flows in a counterclockwise direction of 390°, and... Figure 3F The clockwise winding portion 105B shown flows in a clockwise direction 392. As previously described, the first excitation coil 105 generates an AC magnetic field in response to receiving a center-tapped voltage source 270, which is then coupled to the first sensing coil 225 and the second sensing coil 221 according to the position of the rotatable inductive coupling element 150.

[0056] Figure 4A and Figure 4B Showing more details Figure 2 The third sensing coil 235 of the second angular position sensor 204. The winding turns of the third sensing coil 235 can be positioned on two different layers of a printed circuit board (PCB). Figure 4A A view of the winding turns 235A of the third sensing coil 235 on the first layer of the PCB is provided, and Figure 4B A view of the winding turns 235B of the third sensing coil 235 on the second layer of the PCB is provided. Figure 4A As shown, the third sensing coil 235 ( Figure 2The first winding turn 232A of the counterclockwise winding portion 232 of the third sensing coil 235 is positioned on the first layer of the PCB, and the second winding turn 232B of the counterclockwise winding portion 232 of the third sensing coil 235 is positioned on the second layer of the PCB, as follows. Figure 4B As shown. The first winding turn 232A and the second winding turn 232B are connected through a through hole 445. Additionally, as... Figure 4A As shown, the first winding turn 230A of the clockwise winding portion 230 of the third sensing coil 235 is positioned on the first layer of the PCB, and the third sensing coil 235 ( Figure 2 The second winding turn 230B of the clockwise winding portion 230 is positioned on the second layer of the PCB, as shown below. Figure 4B As shown. The first winding turn 230A and the second winding turn 230B are connected through a through-hole 444. Additional through-holes 440, 441, 442, and 443 are used to provide connections between PCB layers, as is known in the art. As shown in the figure, in Figure 4A and Figure 4B In an exemplary embodiment, the current travels in a counterclockwise direction 415 in the first winding turn 232A and the second winding turn 232B of the counterclockwise winding portion 232 of the third sensing coil 231, and the current travels in a clockwise direction 417 in the first winding turn 230A and the second winding turn 230B of the clockwise winding portion 230 of the third sensing coil 235.

[0057] Figure 4C and Figure 4D Showing more details Figure 2 The fourth sensing coil 231 of the second angular position sensor 204. The winding turns of the fourth sensing coil 231 can be positioned on two different layers of the printed circuit board (PCB). Figure 4C A view of the winding turns 231A of the fourth sensing coil 231 on the first layer of the PCB is provided, and Figure 4D A view of the winding turns 231B of the fourth sensing coil 231 on the second layer of the PCB is provided. (See attached image.) Figure 4C As shown, the first winding turn 236A of the counterclockwise winding portion 236 of the fourth sensing coil 235 is positioned on the first layer of the PCB, and the second winding turn 236B of the counterclockwise winding portion 236 of the fourth sensing coil 231 is positioned on the second layer of the PCB. Figure 4D As shown. The first winding turn 236A and the second winding turn 236B are connected through a through hole 447. Additionally, as... Figure 4D As shown, the first winding turn 234A of the clockwise winding portion 234 of the fourth sensing coil 231 is positioned on the first layer of the PCB, and the second winding turn 234B of the clockwise winding portion 234 of the fourth sensing coil 231 is positioned on the second layer of the PCB. Figure 4D As shown. The first winding turn 234A and the second winding turn 234B are connected through through hole 446. As shown in the figure, in Figure 4C and Figure 4D In an exemplary embodiment, the current travels in a counterclockwise direction 419 in the first winding turn 236A and the second winding turn 236B of the counterclockwise winding portion 236 of the fourth sensing coil 231, and the current travels in a clockwise direction 421 in the first winding turn 234A and the second winding turn 234B of the clockwise winding portion 234 of the fourth sensing coil 231.

[0058] refer to Figure 4E and Figure 4F Showing more details Figure 2 The winding portions 110A and 110B of the second excitation coil 110 of the second angular position sensor 204. Figure 4E The counterclockwise winding portion 110A of the second excitation coil 110 is shown, and Figure 4F A clockwise winding portion 110B of the second excitation coil 110 is shown. In a particular embodiment, the first winding portion 110A is positioned on a first layer of a PCB, and the second winding portion 110B is positioned on a second layer of the PCB. The first and second layers can be connected via one or more through-holes, as is known in the art. In operation, a center-tapped voltage source 275 is supplied to the counterclockwise winding portion 110A and the clockwise winding portion 110B of the second excitation coil 110, such that current flows through them. Figure 4E The counterclockwise winding portion 110A flows in a counterclockwise direction of 490, and... Figure 4F The clockwise winding portion 110B shown flows in a clockwise direction 492. As previously described, the second excitation coil 110 generates an AC magnetic field in response to receiving a center-tapped voltage source 275, which is then coupled to the third sensing coil 235 and the fourth sensing coil 231 according to the position of the rotatable inductive coupling element 150.

[0059] like Figures 5A to 5DAs shown, when the rotatable inductive coupling element 150 rotates 90° around the central axis 500, the magnitude of the time-varying voltage induced in the winding portions 220, 222, 224, 226 of the first angular position sensor 202 and the winding portions 230, 232, 234, 236 of the second angular position sensor 204 varies based on the position of the sector openings 160, 165, 170, 175 of the rotatable inductive coupling element 150 relative to the angular position sensors 202 and 204. Although the following description assumes that one or more of the sector openings 160, 165, 170, 175 of the rotatable inductive coupling element 150 are positioned substantially aligned with one of the winding portions of the first angular position sensor 202 and the second angular position sensor 204, it should be understood that, due to the positioning of any of the sector openings 160, 165, 170, 175 relative to the corresponding winding portions 220, 222, 224, 226, 230, 232, 234, 236 of the first angular position sensor 202 and the second angular position sensor 204 as the rotatable inductive coupling element 150 rotates, one or more of the winding portions 220, 222, 224, 226, 230, 232, 234, 236 of the winding portion 220, 222, 224, 226, 230, 232, 234, 236 may be partially covered by the rotatable inductive coupling element 150.

[0060] exist Figure 5A In the process, when the rotatable sensing coupling element 150 is at the 0° position of rotation around the central axis 500, the first sector opening 165 of the rotatable sensing coupling element 150 is positioned in the second angular position sensor 204. Figure 2 The third sensing coil 235 is positioned above the counterclockwise winding portion 232 of the first angular position sensor 202, and the second sector opening 175 is positioned above the first angular position sensor 202. Figure 2 Above the clockwise winding portion 224 of the second sensing coil 221 of the second angular position sensor 204. Additionally, the clockwise winding portion 230 of the third sensing coil 235 of the second angular position sensor 204, the counterclockwise winding portion 226 of the second sensing coil 221 of the first angular position sensor 202, the clockwise winding portions 220 and 222 of the first sensing coil 225 of the first angular position sensor 202, and the second angular position sensor 204 ( Figure 2 The clockwise winding portion 234 and the counterclockwise winding portion 236 of the fourth sensing coil 231 are covered by the rotatable inductive coupling element 150.

[0061] exist Figure 5B In, with Figure 5AIn contrast, when the rotatable sensing coupling element 150 rotates 22.5° clockwise around the central axis 500, the first sector opening 165 of the rotatable sensing coupling element 150 is positioned above the counterclockwise winding portion 236 of the fourth sensing coil 231 of the second angular position sensor 204. Figure 2 ), and the second sector opening 175 is positioned above the clockwise winding portion 220 of the first sensing coil 225 of the first angular position sensor 202 ( Figure 2 Additionally, the clockwise winding portion 234 of the fourth sensing coil 231 of the second angle position sensor 204, the counterclockwise winding portion 222 of the first sensing coil 225 of the first angle position sensor 202, the clockwise winding portion 224 and the counterclockwise winding portion 226 of the second sensing coil 221 of the first angle position sensor 202, and the second angle position sensor 204 ( Figure 2 The clockwise winding portion 230 and the counterclockwise winding portion 232 of the third sensing coil 235 are covered by the rotatable inductive coupling element 150.

[0062] exist Figure 5C In, with Figure 5B In contrast, when the rotatable sensing coupling element 150 rotates another 22.5° clockwise around the central axis 500, the third sector opening 160 of the rotatable sensing coupling element 150 is positioned above the clockwise winding portion 230 of the third sensing coil 235 of the second angular position sensor 204. Figure 2 ), and the fourth sector opening 170 is positioned above the counterclockwise winding portion 226 of the second sensing coil 221 of the first angular position sensor 202 ( Figure 2 Additionally, the counterclockwise winding portion 232 of the third sensing coil 235 of the second angle position sensor 204, the clockwise winding portion 224 of the second sensing coil 221 of the first angle position sensor 202, the clockwise winding portion 220 and the counterclockwise winding portion 222 of the first sensing coil 221 of the first angle position sensor 202, and the second angle position sensor 204 ( Figure 2 The clockwise winding portion 234 and the counterclockwise winding portion 236 of the fourth sensing coil 231 are covered by the rotatable inductive coupling element 150.

[0063] exist Figure 5D In, with Figure 5C In contrast, when the rotatable sensing coupling element 150 rotates another 22.5° clockwise around the central axis 500, the third sector opening 160 of the rotatable sensing coupling element 150 is positioned above the clockwise winding portion 234 of the fourth sensing coil 231 of the second angular position sensor 204. Figure 2), and the fourth sector opening 170 is positioned above the counterclockwise winding portion 222 of the first sensing coil 225 of the first angular position sensor 202 ( Figure 2 Additionally, the counterclockwise winding portion 236 of the fourth sensing coil 231 of the second angle position sensor 204, the clockwise winding portion 220 of the first sensing coil 225 of the first angle position sensor 202, the clockwise winding portion 224 and the counterclockwise winding portion 226 of the second sensing coil 221 of the first angle position sensor 202, and the second angle position sensor 204 ( Figure 2 The clockwise winding portion 230 and the counterclockwise winding portion 232 of the third sensing coil 231 are covered by the rotatable inductive coupling element 150.

[0064] When the rotatable inductive coupling element 150 rotates through Figures 5A to 5D At each of the positions shown, the time-varying voltage sensed in the first angle position sensor 202 is measured by the first voltage sensing circuit 260, and the time-varying voltage sensed in the second angle position sensor 204 is measured by the second voltage sensing circuit 265. Figure 2 The voltage measured by voltage sensing circuits 260 and 265 is a sine and cosine function of the rotation angle of sector openings 160, 165, 170, and 175 of rotatable inductive coupling element 150 relative to angular position sensors 202 and 204.

[0065] When sector openings are 165 and 175, as... Figure 5A When positioned in this manner, the time-varying magnetic field is attenuated in the clockwise winding portion 230 of the third sensing coil 235 of the second angle position sensor 204, the counterclockwise winding portion 226 of the second sensing coil 221 of the first angle position sensor 202, the clockwise winding portions 220 and 222 of the first sensing coil 225 of the first angle position sensor 202, and the clockwise winding portions 234 and 236 of the fourth sensing coil 231 of the second angle position sensor 204. However, the time-varying magnetic field is not attenuated in the counterclockwise winding portion 232 of the third sensing coil 235 of the second angle position sensor 204 or in the clockwise winding portion 224 of the second sensing coil 221 of the first angle position sensor 202. Thus, the time-varying voltage induced in the winding portions 220 and 222 of the first angle position sensor 202 is the same, and the time-varying voltage induced in the counterclockwise winding portion 226 is different from that induced in the first angle position sensor 202. Figure 2The time-varying voltage induced in the clockwise winding portion 224 of the first sensing coil 225 is different from the time-varying voltage induced in the counterclockwise winding portion 232 of the second angular position sensor 204. These differences in the induced voltages are measured by voltage sensing circuits 260 and 265, respectively. The first voltage sensing circuit 260 determines the ratio of the measured value of the time-varying voltage of the first sensing coil 225 to the measured value of the time-varying voltage of the second sensing coil 221 to determine the angular position of the rotatable inductive coupling element 150 relative to the positions of the first sensing coil 225 and the second sensing coil 221. Additionally, the second voltage sensing circuit 265 determines the ratio of the measured time-varying voltage of the third sensing coil 235 to the measured time-varying voltage of the fourth sensing coil 231, thereby determining the angular position of the rotatable inductive coupling element 150 relative to the positions of the third sensing coil 235 and the fourth sensing coil 231. The above has already addressed... Figure 5A The sector openings 165 and 175 shown are described in detail. It should be understood that, for example... Figures 5B to 5D The location of the sector openings shown in each of the diagrams can describe similar changes in time-varying voltages.

[0066] Figure 6 A graph showing the net voltage (y-axis) induced in sensing coils 221 and 225 relative to the angular position (x-axis) of the rotatable coupling element 150 is shown. Figure 6 As shown in graph 600, in such Figure 5A When the position of the first sector opening 165 shown is considered to be the zero rotation reference point, the net voltage 602 induced in the clockwise winding portion 220 and the counterclockwise winding portion 222 of the first sensing coil 225 is zero because the winding portions 220 and 222 of the first sensing coil 225 are both covered by the rotatable inductive coupling element 150. However, the net voltage 604 induced in the second sensing coil 221 is at a negative peak because the clockwise winding portion 224 of the second sensing coil 221 is not covered at all by the rotatable inductive coupling element 150, and the counterclockwise winding portion 226 is completely covered by the rotatable inductive coupling element 150. Furthermore, in the case of… Figure 5AWhen the position of the second sector opening 175 shown is considered to be the zero rotation reference point, the net voltage 608 induced in the clockwise winding portion 234 and the counterclockwise winding portion 236 of the fourth sensing coil 231 is zero because the winding portions 234 and 236 of the fourth sensing coil 231 are both covered by the rotatable inductive coupling element 150. However, the net voltage 606 induced in the third sensing coil 235 is at a negative peak value because the counterclockwise winding portion 232 of the third sensing coil 235 is not covered at all by the rotatable inductive coupling element 150, and the counterclockwise winding portion 230 is completely covered by the rotatable inductive coupling element 150.

[0067] The peak values ​​of the sine and cosine functions of the time-varying voltages of sensing coils 221, 225, 231, and 235 depend on the gap 180 between the winding portions of sensing coils 221, 225, 231, and 235 and the rotatable inductive coupling element 150, as well as the number of winding turns of the two excitation coils 105 and 110.

[0068] Figure 6 The curve 600 assumes that both the first angular position sensor 202 and the second angular position sensor 204 are operable, i.e., no short circuit or open circuit has occurred. Generally speaking, Figure 6 Graph 600 shows the voltage magnitude changes of the first sensing coil 225 and the second sensing coil 221 relative to the positions of the sector openings 170 and 175 of the rotatable inductive coupling element 150, and the voltage magnitude changes of the third sensing coil 235 and the fourth sensing coil 231 relative to the positions of the sector openings 160 and 165. The voltage magnitude changes of the first sensing coil 225 and the second sensing coil 221 are sensed by the first voltage sensing circuit 260, and the voltage magnitude changes of the third sensing coil 235 and the fourth sensing coil 231 are sensed by the second voltage sensing circuit 265. The measurement results can be further processed to provide a target angular position. For example, if the first voltage sensing circuit 260 measures the voltage 604 of the first sensing coil 225 as zero voltage and the voltage 602 of the second sensing coil 221 as a negative peak voltage, the angular position of the rotatable inductive coupling element 150 can be determined to be 22.5° based on the comparison of the measured voltages, which is equivalent to Figure 5B The configuration shown is as follows. Additionally, if the second voltage sensing circuit 265 measures the voltage 606 of the third sensing coil 235 as zero voltage and measures the voltage of the fourth sensing coil 231 as a negative peak voltage, the angular position of the rotatable inductive coupling element 150 at 22.5° can be determined based on the comparison of the measured voltages. This is also equivalent to... Figure 5B The configuration shown.

[0069] Therefore, when both angular position sensors 202 and 204 are operating, either sensor 202 or 204 can be used to determine the angular position of the rotatable inductive coupling element 150. Thus, if one of the angular position sensors 202 or 204 malfunctions, the other sensor will continue to operate to determine the angular position of the rotatable inductive coupling element 150.

[0070] Graph 600 shows the voltage values ​​of sensing coils 221, 225, 231, and 235 of the rotatable inductive coupling element 150 between the 0°, 22.5°, 45°, 67.5°, and 90° positions. Between these positions, one or more winding portions of the sensing coils 221, 225, 231, and 235 may be partially covered by one of the sector openings 160, 165, 170, and 175 of the rotatable inductive coupling element 150, resulting in sensed voltage values ​​between maximum and minimum values, as shown.

[0071] Figure 7 A flowchart of a method 700 for redundantly sensing the angular position of a rotatable inductively coupled element according to an embodiment of the present invention is shown.

[0072] exist Figure 7 At operation 705, the method includes establishing magnetic coupling between a first excitation coil, a first sensing coil, and a second sensing coil of a first angular position sensor to induce a time-varying voltage in the first and second sensing coils. The first excitation coil forms a first semi-circular region of the first angular position sensor and further defines a first internal region therein. The first internal region is located distal from the first excitation coil relative to a central axis, i.e., the axis of rotation relative to a rotatable inductive coupling element. The first and second sensing coils are positioned within the first internal region. Each of the first and second sensing coils includes a corresponding clockwise winding portion and a corresponding counterclockwise winding portion. (Reference) Figure 2 A magnetic coupling is established between the first excitation coil 105, the first sensing coil 225, and the second sensing coil 221 of the first angular position sensor 202 to induce a time-varying voltage in the first sensing coil 225 and the second sensing coil 221.

[0073] At operation 710, the method further includes: establishing magnetic coupling between a second excitation coil and a third sensing coil and a fourth sensing coil of the second angular position sensor to induce a time-varying voltage in the third and fourth sensing coils, wherein the second excitation coil forms a second semicircular region and further defines a second inner region, wherein the second inner region is located distal from the second excitation coil relative to a central axis, i.e., the axis of rotation relative to the rotatable inductive coupling element, and the third and fourth sensing coils are positioned within the second inner region, wherein each of the third and fourth sensing coils includes a corresponding clockwise winding portion and a corresponding counterclockwise winding portion. Reference Figure 2 A magnetic coupling is established between the second excitation coil 110, the third sensing coil 235 and the fourth sensing coil 231 of the second angular position sensor 204 to induce a time-varying voltage in the third sensing coil 235 and the fourth sensing coil 231.

[0074] At operation 715, the method continues by rotating a rotatable inductive coupling element comprising four sector openings radially spaced substantially uniformly around the rotatable inductive coupling element. The rotatable inductive coupling element overlaps with and is separated from the first, second, third, and fourth sensing coils by gaps. The rotational position of the sector openings of the rotatable inductive coupling element, in response to the rotation of the rotatable inductive coupling element, causes a change in the magnetic coupling between the first excitation coil and the first and second sensing coils, and also causes a change in the magnetic coupling between the second excitation coil and the third and fourth sensing coils. (Reference) Figure 1 and Figure 2 The rotatable inductive coupling element 150, having four sector openings 160, 165, 170, 175 substantially radially spaced around it, is positioned to overlap with the first sensing coil 225, the second sensing coil 221, the third sensing coil 235, and the fourth sensing coil 231. Figures 5A to 5D As shown, the rotatable inductive coupling element 150 rotates about axis 500 to cause a change in the magnetic coupling between the first excitation coil 105, the first sensing coil 225 and the second sensing coil 221 in response to the rotation of the rotatable inductive coupling element 150, and to cause a change in the magnetic coupling between the second excitation coil 110 and the third sensing coil 235 and the fourth sensing coil 231.

[0075] At operation 720, the method continues by measuring the time-varying voltage induced in the first and second sensing coils due to changes in magnetic coupling, and determining the angular position of the rotatable inductive coupling element relative to the positions of the first and second sensing coils. (See reference) Figure 2In the presence of the rotatable inductive coupling element 150, the first voltage sensing circuit 260 receives a modulated cosine signal from the first sensing coil 225 and a modulated sine signal from the second sensing coil 221.

[0076] At operation 725, the method continues by measuring the time-varying voltage induced in the third and fourth sensing coils due to changes in magnetic coupling, and determining the angular position of the rotatable inductive coupling element relative to the positions of the third and fourth sensing coils. (See reference) Figure 2 In the presence of the rotatable inductive coupling element 150, the second voltage sensing circuit 265 receives a modulated cosine signal from the third sensing coil 235 and a modulated sine signal from the fourth sensing coil 231. The second voltage sensing circuit 265 then demodulates the received signals and calculates position information by performing an arctangent calculation of the ratio of the cosine and sine signals.

[0077] Figure 8 This is a flowchart illustrating a method for determining the angular position of a rotatable inductively coupled element using a first angular position sensor with redundant angular position sensors.

[0078] exist Figure 8 At operation 805, the method includes receiving a cosine signal from a first sensing coil and a sine signal from a second sensing coil.

[0079] At operation 810, the method continues by performing an arctangent calculation of the ratio of the cosine signal from the first sensing coil to the sine signal from the second sensing coil to determine the angular position of the rotatable inductively coupled element relative to the first angular position sensor. (See reference...) Figure 2 and Figure 6 The first voltage sensing circuit 260 receives a cosine signal 602 from the first sensing coil 225 and a sine signal 604 from the second sensing coil 221, and calculates the position information of the rotatable inductive coupling element 150 relative to the first angular position sensor 202 by performing an arctangent calculation of the ratio of the cosine signal 602 and the sine signal 604.

[0080] At operation 815, the method continues, continuing to measure the time-varying voltages in the first and second sensing coils due to changes in magnetic coupling, and, in the event of a fault at the second angular position sensor, continuing to determine the angular position of the rotatable inductively coupled element relative to the first and second sensing coils. (Reference) Figure 2 When a fault occurs at the second angular position sensor 204, the first voltage sensing circuit 260 continues to measure the time-varying voltage in the first sensing coil 225 and the second sensing coil 221.

[0081] Figure 9 This is a flowchart illustrating a method for determining the angular position of a rotatable inductively coupled element using a second angular position sensor with redundant angular position sensors.

[0082] exist Figure 9 At operation 905, the method includes receiving a cosine signal from a third sensing coil and a sine signal from a fourth sensing coil.

[0083] At operation 910, the method continues by performing an arctangent calculation of the ratio of the cosine signal from the third sensing coil to the sine signal from the fourth sensing coil to determine the angular position of the rotatable inductively coupled element relative to the second angular position sensor. (See reference) Figure 2 and Figure 6 The second voltage sensing circuit 265 receives a cosine signal 606 from the third sensing coil 235 and a sine signal 608 from the fourth sensing coil 231, and calculates the position information of the rotatable inductive coupling element 150 relative to the second angular position sensor 204 by performing an arctangent calculation of the ratio of the cosine signal 606 and the sine signal 608.

[0084] At operation 915, the method continues, measuring the time-varying voltage induced in the third and fourth sensing coils due to changes in magnetic coupling, and, in the event of a fault at the first angular position sensor, determining the angular position of the rotatable inductive coupling element relative to the third and fourth sensing coils. (Reference) Figure 2 When a fault occurs at the first angular position sensor 202, the second voltage sensing circuit 265 continues to measure the time-varying voltage in the third sensing coil 235 and the fourth sensing coil 231.

[0085] The above-described embodiment, in which the excitation coil extends radially further than the sensing coil, i.e., when viewed from the axis of rotation of the rotatable inductive coupling element, each of the first and second excitation coils is distal to the associated sensing coil; however, this does not imply any limitation. In another embodiment (not shown), the first and second sensing coils extend radially further than the first excitation coil, and the first and second sensing coils form a first semicircular region defining a first inner region, wherein the first excitation coil is formed within the inner region of the first semicircular region. Similarly, the third and fourth sensing coils extend radially further than the second excitation coil, and the third and fourth sensing coils form a second semicircular region defining a second inner region, wherein the second excitation coil is formed within the inner region of the second semicircular region. In this embodiment, when viewed from the longitudinal axis of rotation, each of the excitation coils is located proximal to the associated sensing coil, which may require an increased current in the excitation coil compared to the distal embodiment described above.

[0086] In one implementation, the portions of the redundant angular position sensor can be implemented as a single semiconductor die in an integrated circuit. Alternatively, the integrated circuit may include multiple semiconductor dies electrically coupled together, such as a multi-chip module packaged in a single integrated circuit package.

[0087] The system and method of the present invention provide an improved non-contact sensing method that utilizes coil assemblies that can be implemented on two layers of printed circuit boards (PCBs) to provide redundant measurements.

[0088] In various embodiments, portions of the system of the present invention can be implemented in a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC). Those skilled in the art will understand that the various functions of the circuit elements can also be implemented as processing steps in a software program. Such software can be used in, for example, digital signal processors, microcontrollers, or general-purpose computers.

[0089] Unless otherwise specifically stated as is evident from the discussion, it should be understood that throughout this specification, discussions using terms such as “measure,” “determine,” “generate,” “apply,” “send,” “encode,” “lock,” etc., may refer to the actions and processes of a computer system or similar electronic computing device that manipulates and transforms data represented as physical (electronic) quantities in the registers and memories of the computer system into other data represented similarly as physical quantities in the memory or registers of the computer system or other such information storage, transmission, or display devices.

[0090] Furthermore, to discuss and understand embodiments of the invention, it should be understood that various terms are used by those skilled in the art to describe the techniques and methods. In addition, numerous specific details are set forth in this specification for the purpose of explanation in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention can be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring the invention. These embodiments have been described in sufficient detail to enable those skilled in the art to practice the invention, and it should be understood that other embodiments can be utilized, and logical, mechanical, electrical, and other changes can be made without departing from the scope of the invention.

Claims

1. A redundant angular position sensor, comprising: A first angle position sensor, the first angle position sensor comprising: First excitation coil; A first sensing coil and a second sensing coil, each of the first sensing coil and the second sensing coil including a corresponding clockwise winding portion and a corresponding counterclockwise winding portion; The second angle position sensor includes: A second excitation coil, wherein the second angular position sensor is positioned adjacent to the first angular position sensor; A third sensing coil and a fourth sensing coil, each of the third sensing coil and the fourth sensing coil including a corresponding clockwise winding portion and a corresponding counterclockwise winding portion; and A rotatable inductive coupling element is positioned to overlap with and separate from the first, second, third, and fourth sensing coils by gaps, wherein the rotatable inductive coupling element includes four sector openings that are radially spaced substantially uniformly around the rotatable inductive coupling element.

2. The redundant angular position sensor of claim 1, wherein the first excitation coil forms a first semi-circular region defining a first internal region, and wherein the first sensing coil and the second sensing coil are positioned within the first internal region.

3. The redundant angular position sensor of claim 1, wherein the second excitation coil forms a second semi-circular region defining a second inner region, and wherein the third sensing coil and the fourth sensing coil are positioned within the second inner region.

4. The redundant angular position sensor according to claim 1, wherein the first angular position sensor further includes a first voltage source and a first grounding node, and the second angular position sensor further includes a second voltage source independent of the first voltage source and a second grounding node independent of the first grounding node.

5. The redundant angular position sensor according to claim 1, wherein the first excitation coil and the second excitation coil each include a corresponding clockwise winding portion and a corresponding counterclockwise winding portion.

6. The redundant angular position sensor of claim 2, wherein each of the respective clockwise winding portion and the respective counterclockwise winding portion of the first sensing coil and the second sensing coil is alternatively located in a corresponding sector of four equal sectors of the first internal region.

7. The redundant angular position sensor according to claim 6, wherein each of the four equal sectors is a 22.5° sector.

8. The redundant angular position sensor of claim 3, wherein each of the respective clockwise winding portion and the respective counterclockwise winding portion of the third sensing coil and the fourth sensing coil is alternatively located in a corresponding sector of four equal sectors of the second internal region.

9. The redundant angular position sensor according to claim 8, wherein each of the four equal sectors is 22.5°.

10. The redundant angular position sensor of claim 1, wherein the four sector openings occupy approximately 25% of the area of ​​the rotatable inductive coupling element.

11. The redundant angular position sensor of claim 1, wherein approximately 75% of the area of ​​the rotatable inductive coupling element is made of a non-ferromagnetic conductive material.

12. The redundant angular position sensor according to claim 1, further comprising: A first voltage sensing circuit, the first voltage sensing circuit being coupled to the first sensing coil and the second sensing coil; as well as A second voltage sensing circuit is coupled to the third sensing coil and the fourth sensing coil.

13. A redundant angular position sensor, comprising: A first angle position sensor, the first angle position sensor comprising: A first excitation coil having a clockwise winding portion and a counterclockwise winding portion, wherein the first excitation coil forms a first semi-circular region defining a first internal region; A first sensing coil and a second sensing coil, the first sensing coil and the second sensing coil being positioned within a first internal region defined by a first excitation coil, each of the first sensing coil and the second sensing coil including a respective clockwise winding portion and a respective counterclockwise winding portion, and each of the respective clockwise winding portion and the respective counterclockwise winding portion of the first sensing coil and the second sensing coil being alternatively positioned within one of four 22.5° sectors of a 90° sector forming the first internal region; A first voltage source coupled to the first excitation coil and a first grounding node; The second angle position sensor includes: A second excitation coil having a clockwise winding portion and a counterclockwise winding portion, wherein the second excitation coil forms a second semicircular region defining a second internal region, and wherein the diameter of the second semicircular region formed by the second excitation coil is positioned adjacent to the diameter of the first semicircular region formed by the first excitation coil. A third sensing coil and a fourth sensing coil are positioned within the second inner region, each of the third sensing coil and the fourth sensing coil including a corresponding clockwise winding portion and a corresponding counterclockwise winding portion, and each of the corresponding clockwise winding portion and the corresponding counterclockwise winding portion of the third sensing coil and the fourth sensing coil is alternatively positioned within one of four 22.5° sectors of a 90° sector forming the second inner region; A second voltage source and a second grounding node, wherein the second voltage source is coupled to the second excitation coil independently of the first voltage source, and the second grounding node is coupled to the second excitation coil independently of the first grounding node; and A rotatable inductive coupling element is positioned to overlap with and separate from the first, second, third, and fourth sensing coils by gaps, wherein the rotatable inductive coupling element includes four 22.5° sector openings that are radially spaced substantially uniformly around the rotatable inductive coupling element.

14. A method for redundantly sensing the angular position of a rotatable inductively coupled element, the method comprising: A magnetic coupling is established between the first excitation coil, the first sensing coil, and the second sensing coil of the first angular position sensor to induce a time-varying voltage in the first sensing coil and the second sensing coil, wherein each of the first sensing coil and the second sensing coil includes a corresponding clockwise winding portion and a corresponding counterclockwise winding portion; A magnetic coupling is established between the second excitation coil, the third sensing coil, and the fourth sensing coil of the second angular position sensor to induce a time-varying voltage in the third sensing coil and the fourth sensing coil, wherein each of the third sensing coil and the fourth sensing coil includes a corresponding clockwise winding portion and a corresponding counterclockwise winding portion; A rotatable inductive coupling element includes four sector openings that are substantially uniformly and radially spaced around the rotatable inductive coupling element. The rotatable inductive coupling element overlaps with and is separated from the first, second, third, and fourth sensing coils by gaps. The rotational position of the sector openings of the rotatable inductive coupling element, in response to the rotation of the rotatable inductive coupling element, causes a change in the magnetic coupling between the first excitation coil, the first sensing coil, and the second sensing coil, and also causes a change in the magnetic coupling between the second excitation coil, the third sensing coil, and the fourth sensing coil. Measure the time-varying voltage induced in the first sensing coil and the second sensing coil due to the change in the magnetic coupling; Determine the angular position of the rotatable inductive coupling element relative to the positions of the first sensing coil and the second sensing coil; Measure the time-varying voltage induced in the third and fourth sensing coils due to the change in magnetic coupling; Determine the angular position of the rotatable inductive coupling element relative to the positions of the third sensing coil and the fourth sensing coil.

15. The method of claim 14, wherein the first excitation coil forms a first semi-circular region defining a first internal region of the first angular position sensor, and wherein the first sensing coil and the second sensing coil are positioned within the first internal region.

16. The method of claim 14, wherein the second excitation coil forms a second semi-circular region defining a second internal region of the second angular position sensor, and wherein the third sensing coil and the fourth sensing coil are positioned within the second internal region.

17. The method of claim 14, wherein rotating the rotatable inductive coupling element at least partially positions the first sector opening in the sector opening above at least one of the corresponding clockwise winding portion or the corresponding counterclockwise winding portion of the first sensing coil or the second sensing coil to cause the change in the magnetic coupling between the first excitation coil and the first sensing coil or the second sensing coil, and at least partially positions the second sector opening in the sector opening above at least one of the corresponding clockwise winding portion or the corresponding counterclockwise winding portion of the third sensing coil or the fourth sensing coil to cause the change in the magnetic coupling between the second excitation coil and the third sensing coil or the fourth sensing coil.

18. The method of claim 14, wherein measuring the time-varying voltage induced in the first and second sensing coils due to the change in magnetic coupling and determining the angular position of the rotatable inductive coupling element relative to the position of the first and second sensing coils further comprises: It receives a cosine signal from the first sensing coil and a sine signal from the second sensing coil; as well as An arctangent calculation is performed on the ratio of the cosine signal from the first sensing coil to the sine signal from the second sensing coil to determine the angular position of the rotatable inductively coupled element relative to the first angular position sensor.

19. The method of claim 14, wherein measuring the time-varying voltage induced in the third and fourth sensing coils due to the change in magnetic coupling and determining the angular position of the rotatable inductive coupling element relative to the position of the third and fourth sensing coils further comprises: It receives a cosine signal from the third sensing coil and a sine signal from the fourth sensing coil; as well as An arctangent calculation is performed on the ratio of the cosine signal from the third sensing coil to the sine signal from the fourth sensing coil to determine the angular position of the rotatable inductive coupling element relative to the second angular position sensor.

20. The method of claim 14, further comprising: A first voltage source and a first ground node are provided for the first angular position sensor, and a second voltage source and a second ground node are provided for the second angular position sensor, wherein the second voltage source is independent of the first voltage source and the second ground node is independent of the first ground node.

21. The method of claim 14, further comprising: The time-varying voltage in the first and second sensing coils continues to be measured due to the change in the magnetic coupling, and when a fault occurs at the second angular position sensor, the angular position of the rotatable inductive coupling element relative to the positions of the first and second sensing coils continues to be determined.

22. The method of claim 14, further comprising: The time-varying voltage induced in the third and fourth sensing coils due to the change in magnetic coupling continues to be measured, and when a fault occurs at the first angular position sensor, the angular position of the rotatable inductive coupling element relative to the position of the third and fourth sensing coils continues to be determined.

23. The method of claim 14, wherein the size of each of the sector openings of the rotatable inductive coupling element is designed to substantially cover one of the corresponding clockwise winding portions or the corresponding counterclockwise winding portions of the first sensing coil, the second sensing coil, the third sensing coil, and the fourth sensing coil.

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