Position sensor with varying output slope

Abstract

A position sensor with a varying output slope is presented. Some embodiments of the position sensor according to some embodiments include a position sensor comprising: a transmitting coil; a receiving coil, the receiving coil comprising at least one polarity change; a target configured to pass through the receiving coil; and a controller configured to drive the transmitting coil, receive a signal from the receiving coil and provide a position response indicating a target position on the receiving coil, wherein the position response exhibits a first linear region of a first slope and a second linear region of a second slope.

Description

Technical Field

[0001] Embodiments of the present invention relate to position sensors, and more particularly, to position sensors having a varying output slope. Background Art

[0002] Position sensors are used in a variety of settings to measure the position of one component relative to another. Inductive position sensors can be used in automotive, industrial, and consumer applications for absolute rotational and linear motion sensing. In many inductive position sensing systems, a transmitting coil is used to induce eddy currents in a metal target that slides or rotates over a set of receiving coils. The receiving coil receives the magnetic field generated by the eddy currents and the transmitting coil and provides a signal to a processor. The processor uses the signal from the receiving coil to determine the position of the metal target over the set of coils. The processor, transmitting coil, and receiving coil can all be formed on a printed circuit board (PCB).

[0003] One of the challenges in designing a position sensor is meeting user requirements. Typically, a position sensor is being designed to replace an existing technology, so the housing and output signal of the new position sensor should match that of the existing technology. A typical position sensor provides a linear output signal based on the target position.

[0004] Therefore, there is a need to develop position sensors with modified output signals. Summary of the invention

[0005] A position sensor is provided. Some embodiments of the position sensor according to some embodiments include a position sensor comprising: a transmitting coil; a receiving coil, the receiving coil comprising at least one polarity change; a target configured to pass through the receiving coil; and a controller configured to drive the transmitting coil, receive a signal from the receiving coil, and provide a position response indicating a target position on the receiving coil, wherein the position response exhibits a first linear region of a first slope and a second linear region of a second slope.

[0006] In some embodiments, a position sensor includes: a receiving coil including a first receiving coil and a second receiving coil geometrically formed on a printed circuit board (PCB), wherein at least one of the first receiving coil and the second receiving coil is configured to include at least one phase change; and a transmitting coil formed on the PCB around the receiving coil, wherein a position response when a target passes through the receiving coil includes a plurality of linear regions with different slopes.

[0007] These and other embodiments are discussed below with reference to the figures. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1A and Figure 1B A typical operation of a position sensor is shown.

[0009] Figure 2 Shows Figure 1B The typical response of a position sensor is shown in relation to the position output signal.

[0010] Figure 3 The relationship between the target response of the position sensor and the position output signal is shown.

[0011] Figure 4 A position sensor according to some embodiments of the present invention is shown.

[0012] Figure 5 Shows Figure 4 The physical change of polarity in the receiving sensor coil of a position sensor is shown.

[0013] Figure 6 Another view of the physical change of polarity in the receiving sensor coil of a position sensor is provided.

[0014] Fig. 7A and Figure 7B Operation of a receiving sensor coil according to some embodiments is demonstrated.

[0015] Fig. 8A and Figure 8B The sine voltage and cosine voltage are shown respectively as a function of the target position which is in the first half period and through the flat area of ​​the receiving sensor coil in the position sensor.

[0016] Fig. 9A and Fig. 9B The relationship between the result output and the position is shown for the first half of the first period of the receiving sensor coil and the first half of the second period of the receiving sensor coil in the position sensor, respectively.

[0017] Fig.10 A rotational position sensor according to some embodiments of the present invention is shown.

[0018] Fig.11A and Fig. 11B Another embodiment of a rotational position sensor in accordance with some embodiments is shown.

[0019] Fig. 12A , Fig. 12B and Fig. 12C Data and results derived from a rotational position sensor according to some embodiments are shown.

[0020] Fig.13 is a photograph of a rotational position sensor according to some embodiments.

[0021] These and other aspects of embodiments of the invention are discussed further below. DETAILED DESCRIPTION

[0022] In the following description, the specific details of describing some embodiments of the present invention are set forth. However, it will be apparent to those skilled in the art that some embodiments may be implemented without some or all of these specific details. The specific embodiments disclosed herein are illustrative, rather than restrictive. Those skilled in the art will appreciate that other elements, although not specifically described herein, are still within the scope and spirit of the present invention.

[0023] This specification illustrates aspects of the invention, and the embodiments should not be viewed as limiting the claims defining the protected invention. Various changes may be made without departing from the spirit and scope of this specification and claims. In some instances, well-known structures and techniques are not shown or described in detail in order not to confuse the present invention.

[0024] Embodiments of the present invention provide a position sensor with a variable output signal. Specifically, the position sensor according to some embodiments includes one or more phase changes so that the slope of the position output signal according to the target position can be modified.

[0025] Figure 1A and Figure 1B The operation of a typical positioning system 100 is shown. Figure 1A and Figure 1B The operation of a linear position sensor is shown, but the operation of a rotary position sensor is identical. Figure 1A As shown, the positioning system includes a transmit / receive control circuit 102, which is coupled to drive a transmit coil 106 and receive signals from a receive coil 104. In most configurations, the receive coil 104 is located within the transmit coil 106, however, in Figure 1A 1, they are shown separately for the purpose of clarity. The receive coil 104 is typically physically located within the boundaries of the transmit coil 106. Embodiments of the present invention may include the transmit coil 106, two receive coils 104, and an integrated circuit (IC) 102 that drives the transmit coil 106 and measures signals originating from the receive coils 104 all formed on a printed circuit board (PCB).

[0026] Figure 1B 1 shows the configuration of the transmitting coil 106 and the receiving coil 104 in the linear position positioning system. Figure 1B As shown, a conductive metal target 124 may be positioned above the transmit coil 106 and the two receive coils 104 .

[0027] like Figure 1A As shown, the transmitting coil 106 is driven to form a magnetic field 108. The transmitting coil 106 can be driven at a frequency range or a specific frequency. Figure 1A In FIG. 1 , the magnetic field 108 with the positive current indicated by the arrow is circular around each wire and is as follows: Figure 1A The current direction shown is from the page inside the coil 106 to the page outside the coil 108. The receiving coil 104 is located inside the coil 106, as shown in FIG. Figure 1B The transmitting coil 106 is driven at any frequency capable of generating an electromagnetic field 108 to induce a voltage in the receiving coil 104. In general, there may be any number of receiving coils, however, for ease of discussion, a system with two receiving coils is shown in these examples.

[0028] Figure 1B FIG. 1 shows the arrangement of a sensor receiving coil (RX) 104 within a transmitting coil (TX) 106 of a linear position sensor. Figure 1B As shown, the sensor receiving coil 104 includes a sine wave directional coil RXSIN 112 and a cosine directional signal coil RXCOS110. The sine wave directional coil RXSIN 112 includes sine loops 114, 116, and 118, wherein the coil 112 is wound in an in-phase direction or an anti-phase direction, depicted here as clockwise or counterclockwise, so that voltages are generated in the loops of opposite signs due to the presence of the electromagnetic field 108. As shown, the wiring of the sine wave directional coil 112 provides clockwise rotation in loops 114 and 118 to produce nominally positive polarity, and provides counterclockwise rotation in loop 116 to produce nominally negative polarity. Similarly, the cosine directional coil 110 can include a first loop 120 having a clockwise orientation and a second loop 122 having a counterclockwise orientation. Figure 1B The possible reference directions of the electromotive force are shown, as indicated by the arrows, which are related to Figure 1A The magnetic field generated by the transmitter coil 106 is shown to be consistent.

[0029] exist Figure 1B In the system shown, a transmitting coil (TX) 106 is excited by a circuit 102, which may be an integrated circuit, to generate a variable electromagnetic field (EMF) as shown by a magnetic field 108. The magnetic field 108 is coupled to a receiving coil (RX) 104. If Figure 1BAs shown, a conductive metal target 124 is placed on top of the receiving coil 104, which generates eddy currents in the metal target 124. The eddy currents generate a new electromagnetic field, which is ideally equal and opposite to the field 108, canceling the field in the receiving coil 104 directly below the metal target 124. The receiving coil (RX) 104 captures the variable electromagnetic field 108 generated by the transmitting coil 106 and the electromagnetic field induced by the metal target 124, thereby generating a sinusoidal voltage at the terminals of the receiving coil 104.

[0030] In the absence of the metal target 124, the RX coil 104 ( Figure 1B 110 and RxSin 112 in the figure). When the metal target 124 is placed at a specific position relative to the RX coil 104, the resultant electromagnetic field over the area covered by the metal target 124 is ideally zero, and therefore the voltage at the terminals of the RX coil 104 will have different characteristics depending on the position of the metal target 124 relative to the receive coil 104. The RX coil 104 is designed in such a way that when the metal target 124 sweeps across the receive coil 104, a sinusoidal voltage (Vsin) is generated at the terminals of one RX coil (RxSin 112) and a cosine voltage (Vcos) is generated at the terminals of the other RX coil (RxCos 110). The position of the target relative to the RX coil 104 modulates the amplitude and phase of the voltage at the terminals of the RX coil 104. The output response can be calculated as proportional to the inverse tangent (Vsin / Vcos).

[0031] like Figure 1A As shown and discussed above, the transmitting coil 106, the receiving coil 104, and the transmitting / receiving circuit 102 can be mounted on a single PCB. In addition, the PCB can be configured so that the metal target 124 is positioned above the receiving coil 104 and is separated from the receiving coil 104 by an air gap (AG). The position of the metal target 124 relative to the PCB on which the receiving coil 104 and the transmitting coil 106 are mounted can be determined by processing the signals generated by the sine directional coil 112 and the cosine directional coil 110. Below, the determination of the position of the metal target 124 relative to the receiving coil 104 is described under theoretical ideal conditions.

[0032] exist Figure 1B In this example, the metal target 124 is located at the first position. Figure 1BThe operation of the linear position locator system is depicted. The linear position locator and the rotary position locator operate in the same manner. In the following discussion, the positions associated with the configuration of the cosine oriented coil 110 and the sine oriented coil 112 are given by providing an angular relationship relative to the sinusoidal operation of the sine oriented coil 112. The sinusoidal operation of the sine oriented coil 112 is caused by the leading edge of the metal target 124 and the position of the coils 110 and 112. The actual position of the metal target 124 in such a system can be derived from the angular position measured by the output voltage of the receiving coil 104 and the topology of the receiving coils 110 and 112. In addition, as Figure 1B As shown, the topology of coil 110 and the topology of coil 112 are coordinated to provide an indication of the position of metal target 124 relative to receiving coil 104 .

[0033] Figure 2 Shows Figure 1B The typical output response of the receiving sensor coil is shown in Figure 2. Figure 2 As shown, when the target 124 passes through the range of the sensor coil 104, the relationship between the response and the position is linear. Therefore, the target position can be determined as a linear function of the response signal. Figure 2 The response versus position curve shown is linear, with either a positive or negative slope. Using conventional sensor coils 104 it is not possible to modify this slope or change the slope from a positive slope to a negative slope.

[0034] However, in some applications, it is highly desirable for the sensor output to have both positive and negative slopes as well as a flat region. An example of such a response is Figure 3 In some cases, this response can be processed by a microcomputer Figure 2 The linear response curve shown in Figure 1 is used to produce a position sensor. However, this approach has some significant disadvantages. In particular, this approach significantly increases cost, makes the position sensor slower to respond, and increases time to market. In particular, position sensors made according to this approach require additional calculations compared to those required to process the sine and cosine signals to achieve position determination.

[0035] According to an embodiment of the present invention, the structures of the sine sensor coil and the cosine sensor coil of the sensor coil are modified to provide, for example, Figure 3 The response curve shown in FIG. 1 is a graph of a sine coil and a cosine coil without further processing. Specifically, the coil polarity of the sine coil and the cosine coil is changed at one or more points along the sensor coil. In this way, the slope of the output signal is reversed at these points by the physical modification of the sensor coil. Furthermore, a flat response is produced when the target passes through the polarity change region.

[0036] Figure 4A two-period linear position sensor 400 according to some embodiments of the present invention is shown. Figure 4 As shown, the position sensor 400 includes a transmitting coil 404 and a receiving coil 430. A controller coupled to control the transmitting coil 404 and the received signal from the receiving coil 430 is not explicitly shown, but those skilled in the art will recognize that the functions discussed below are the result of processing the signal from the receiving coil 430.

[0037] Figure 4 A sine coil 408 and a cosine coil 406 are shown, each having two segments extending along the sensor 400. The two segments are Figure 4 420 and 422. The transmitting coil 404 is positioned around the sine coil 408 and the cosine coil 406. Figure 4 A three-dimensional view of position sensor 400 is shown. Thus, sine coil 408 and cosine coil 406 are formed by traces along the top and bottom of a printed circuit board (PCB), which are connected by vias. Thus, top trace 414 and bottom trace 412 are connected by via 410. Sine coil 408 and cosine coil 406 are arranged in this example so that the coil polarity is changed between a first time period and a second time period. The coil polarity is changed by physically interconnecting the traces of sine coil 408 and cosine coil 406 so that the current is opposite to the current normally obtained in a conventional system.

[0038] As discussed in more detail below, the slope of the output signal depends on whether the target 402 is over the first time period 420 or the second time period 422. In addition, when the target 402 is over the polarity change region 424, the output response is flat (excluding some noise generated from the offset that may be applied). Therefore, when the target 402 passes through the receiving coils 406 and 408, the output response will have a first slope in the first time period 420, and the output response will have a second slope that is the negative of the first slope in the second time period 422. When the target is over the polarity change 424, the output response will be flat.

[0039] Figure 5 Implementation of a structural polarity change 424 in a receiving coil 430 is shown. Figure 5 Upper traces 506 and 508 and lower traces 510 and 512 are shown as part of a first receive coil 528 . Figure 5Further shown are upper traces 518 and 520 and lower traces 514 and 516 that form part of a second receive coil 530. In some embodiments, the first receive coil 528 may be the sine coil 408 and the second receive coil 530 may be the cosine coil 406. In some embodiments, depending on the location of the polarity change 424 along the receive coil 430, the first receive coil 528 may be the cosine coil 406 and the second receive coil 530 may be the sine coil 408.

[0040] As shown, traces 506, 508, 510, 512, 514, 516, 518, and 520 can be formed on the top and bottom of the PCB and can transition between the top and bottom of the PCB using vias through the PCB. This arrangement allows traces to be formed in areas with structural polarity changes 424 of the connections discussed below.

[0041] In the conventional structure, the sine coil 408 and the cosine coil 406 do not include polarity switching. Therefore, the upper traces 506 and 508 of the first receiving coil 528 are directly connected, and the lower traces 510 and 512 of the first receiving coil 528 are directly connected, thereby forming the first receiving coil 528. Similarly, in the conventional structure, the traces 518 and 516 of the second receiving coil 530 are connected, and the traces 514 and 520 of the second receiving coil 530 are connected, thereby forming the second receiving coil 530. However, Figure 5 5 shows an embodiment of the present invention in which trace 506 is coupled to trace 512 and trace 508 is coupled to trace 510. Figure 5 In the illustrated embodiment, trace 518 is coupled to trace 520 , and trace 514 is coupled to trace 516 , which provides a polarity reversal in region 424 .

[0042] like Figure 5 As shown, in some embodiments of the present invention, polarity reversal is introduced in both the first receiving coil 528 and the second receiving coil 530. In particular, Figure 5 As shown, in the first receiving coil 528, the trace 506 is connected to the trace 512 through the connecting trace 502, and the trace 510 is connected to the trace 508 through the connecting trace 504. This results in a polarity reversal in the first receiving coil 528. In the second receiving coil 530, as shown in FIG. Figure 5 As shown, by connecting trace 514 to trace 516 and connecting trace 518 to trace 520, polarity reversals are introduced.

[0043] Therefore, if Figure 5As shown, by introducing polarity switching in polarity switching region 424, the response slope provided by receiving coil 430 switches slope when target 402 passes through polarity switching region 424. In addition, when target 402 is above polarity switching region 424, a flat response curve is obtained.

[0044] Figure 6 It shows that Figure 4 and Figure 5 A plan view of the polarity switching region 424 of the position sensor 400 is shown. Figure 6 The illustrated example shows how traces 506, 508, 510, 512, 514, and 516 are arranged on each side of a printed circuit board 612 to configure polarity switching in the first receiving coil 528 and the second receiving coil 530. In particular, via 604 allows trace 506 to switch from the bottom layer of PCB 612 to the top layer of PCB 612 so that trace 518 can cross trace 506 without being connected. Via 602 also allows crossing of traces 510 and 514. Via 606 allows crossing of traces 508 and 520. Via 608 allows crossing of traces 512 and 516. Figure 6 As illustrated in the example shown, connecting trace 504 may be formed on the top side of PCB 612 and connected to traces 508 and 510 through via 612. Connecting trace 502 may be primarily formed on the bottom side of PCB 612 and reach the top side of PCB 612 through via 610 to cross traces 520 and 516. Those skilled in the art will recognize that there are other configurations for configuring the polarity transition in polarity transition region 424.

[0045] Figure 5 and Figure 6 An example is shown where the polarity change region 424 is positioned between the first period 420 and the second period 422 of the two-period position sensor 400. In this case, the first receiving coil 530 corresponds to the cosine coil 406 and the second receiving coil 528 corresponds to the sine coil 408. However, in some embodiments, the polarity change may occur elsewhere in the receiving coil 430. For example, if the polarity change is switched, the first receiving coil 530 may correspond to the sine coil 408 and the second receiving coil 528 may correspond to the cosine coil 406.

[0046] Figure 4 , Figure 5 and Figure 6An embodiment is shown having a linear position sensor including a sensor coil having two periods and configuring a polarity transition between the first period and the second period. Those skilled in the art will appreciate that the position sensor can be formed with a receiving sensor having any number of periods and wherein the polarity transition can be configured at other locations along the receiving coil or at multiple locations along the position sensor as discussed above. Such a structure can be formed to provide a plurality of polarity transitions. Figure 3 Various response curves other than those shown.

[0047] Fig. 7A and Figure 7B The operation of position sensor 400 is shown according to some embodiments. Fig. 7A The polarity of the current loops in sensor coils 406 and 408 is shown. The polarity designations are relative to each other, and except for indicating current loops of opposite polarity, the designations of positive (+) polarity and negative (–) polarity are arbitrary and are provided for ease of explanation only. Additionally, for clarity, sensor coils 406 and 408 are shown separated rather than overlapped as they would be in a position sensor. Fig. 7A and Figure 7B A two-period position sensor is further shown, wherein a phase change occurs between a first period and a second period, such as Figures 4 to 6 As shown.

[0048] Polarity reflects the circular direction of the current in the cross section of the sensor coil. Figure 5 As shown, the cosine coil 406 includes traces 518 and 514, which together form a generally circular structure in which the current flow at any given time is in a particular direction (clockwise or counterclockwise). In a conventional receiving coil, adjacent loops of the sensor coil have current flow in opposite directions, thereby producing a particular polarity relationship in the cross section. In a conventional sensor coil, the polarity changes in each adjacent loop of the coil structure. However, according to an embodiment of the present invention, at at least one point along the sensor coil, the polarity is switched from the conventional process so that two adjacent loops have the same polarity, or a loop is split to provide different polarities in each half loop.

[0049] According to an embodiment of the present invention, Fig. 7A A cosine coil 406 is shown having a first loop 702 with positive polarity and an adjacent loop 704 with negative polarity. At polarity change 424, there is a hardwired polarity change and loop 706 adjacent to loop 704 also has negative polarity. Thus, loop 708 adjacent to loop 706 has positive polarity. The cosine response 722 when target 402 moves across coil 406 is shown in FIG. Figure 7B is shown in .

[0050] Similarly, Fig. 7A The illustrated sine coil 408 shows a positive polarity half loop 710 adjacent to a negative polarity loop 712 of the sine coil 408. The polarity change 424 occurs in the adjacent loop, such as Fig. 7A 4. As shown, the adjacent loops show a half loop 714 with positive polarity and a half loop 716 with negative polarity. The adjacent loop 718 (adjacent to the half loop 716) is positive polarity, and the last loop 720 of the sine coil 408 is negative polarity. The sine response 724 and the cosine response 722 when the target 402 moves across the coil 408 are shown in FIG. Figure 7B The polarity changes in coils 406 and 408 are hardwired into the traces of these coils. In addition, Fig. 7A Cosine coils 406 and 408 are shown with the polarity change occurring at the point where the trace forming coil 406 has the closest positioning and the trace forming coil 408 has the widest spacing. However, the polarity change may be formed at other points along position sensor 400.

[0051] Fig. 8A It shows that Figures 4 to 6 A simulation of the sine response 804 and the cosine response 802 during the first half of the period of the linear position sensor 400 is shown. Figure 8B Shown by Figures 4 to 7A The sine response 804 and cosine response 802 of the polarity change 424 are shown. The results show the simulation tool before any linearization is performed. The Y values ​​are in voltage. However, the X axis represents a moving window indicating position. Fig. 9A Shown based on Fig. 8A The relationship between the simulated target position and the reference value during the first half of the simulated sine response 804 and cosine response 802. As is known, Fig. 9A The response shown is determined by the sine response 804 and the cosine response 802. In addition to the slope being Fig. 9A Instead, it can be determined that the second half of the period of linear position sensor 400 has a similar response. Fig. 9B The response of the first half of the second period is shown. Fig. 9A and Fig. 9B In both cases, calculated values ​​and reference values ​​are shown, but are identical.

[0052] Figures 4 to 6A linear position sensor 400 is shown with a phase change 424 in each of the cosine coil 406 and the sine coil 408. Although the particular example shown shows a phase change 424 occurring in both the cosine coil 406 and the sine coil 408 between the first period 420 and the second period 422 of the two period position sensor 400, in some embodiments, the phase change may be configured at any location along the reference coil 430. Furthermore, there may be more than one phase change along the reference coil 430. Furthermore, in some embodiments, at each phase change location along the reference coil 430, the phase change may be located in only one of the cosine coil 406 or the sine coil 408. Various response curves may be generated by positioning the phase change in each of the cosine coil 406 and the sine coil 408 along the position sensor 400.

[0053] Figure 4 FIG. 9 shows an embodiment of a linear position sensor 400 according to some embodiments. The principles outlined herein may also be incorporated into a rotary position sensor. Thus, according to some embodiments, a rotary position sensor is disclosed that includes the following discussed Fig.10 and Fig. 11B The polarity in the receiving coil changes.

[0054] Fig.10 An example of a rotation position sensor receiving coil 1000 according to some embodiments is shown. A transmitting coil 1030 is also shown. Fig.10 As shown, the receiving coil 1000 includes a first receiving coil 1006 and a second receiving coil 1004 arranged in a circular plane to operate as a rotational position sensor. The transmitting coil 1030 and the receiving coil 1000 are formed on the top and bottom sides of the printed circuit board 1032. In addition, the receiving coil 1000 shows a polarity change region 1002 in the coils 1004 and 1006, wherein the coils 1004 and 1006 are both arranged to produce a polarity change. Fig.10 As shown, the phase change 1002 occurs when the trace of coil 1004 is narrowest and the trace of coil 1006 is widest. In some embodiments, the phase change 1002 may occur when the trace of coil 1004 is widest and the trace of coil 1006 is narrowest. A controller (not shown) is configured to drive the transmitting coil 1030 and receive signals from the first receiving coil 1006 and the second receiving coil 1004 to provide a position response when a target (not shown) rotates over the receiving coil 1000.

[0055] like Fig.10As shown, the second receiving coil 1004 includes traces 1008, 1010, 1012, and 1014 in the polarity change region 1002. In a conventional sensor array, trace 1008 would be connected to trace 1012, and trace 1010 would be connected to trace 1014. Fig.10 In the embodiment of the sensor coil 1000 shown, trace 1008 is connected to trace 1010 , and trace 1014 is connected to trace 1012 , which provides a polarity reversal in the second receiving coil 1004 .

[0056] In addition, the first receiving coil 1006 includes traces 1016, 1018, 1020, and 1022. In a conventional sensor array, traces 1018 and 1016 would be connected, and traces 1020 and 1022 would be connected. Fig.10 The sensor coil 1000 of some embodiments shown provides polarity change by connecting the trace 1016 to the trace 1022 via the connecting trace 1026 and connecting the trace 1018 to the trace 1020 via the connecting trace 1024. Note that the connecting traces 1024 and 1026 overlap, with the trace 1024 being primarily formed on the top side of the circuit board 1032 and the trace 1026 being formed on the bottom side of the circuit board 1032.

[0057] Thus, in the receiving coil 1000 according to some embodiments, a polarity change is provided in both the first receiving coil 1006 and the second receiving coil 1004 by the physical connection of the traces as described above. When a target (not shown) passes over the polarity change, the output response provides a flat area and positive and negative slopes according to the angle, similar to the case described with reference to FIG. 7 in the linear position array according to some embodiments.

[0058] Fig.11A A rotational position sensor 1100 formed on a printed circuit board (PCB) 1110 is shown. As shown, the rotational position sensor 1100 includes a transmitting coil 1102 and a sensor coil 1108 positioned on the PCB 1110. As further shown, the sensor coil 1108 includes a first receiving coil 1104 and a second receiving coil 1106. The rotational position sensor 1100 does not exhibit polarity reversal in either of the coils 1104 and 1106. Therefore, Fig.11A The rotary position sensor shown would provide a conventional position response, for example, a linear position sensor with the angular position of a target positioned above the receiving coil 1108 .

[0059] In contrast, Fig. 11BA position sensor 1150 according to some embodiments of the present invention is shown. The position sensor 1150 includes a transmitting coil 1152, a first receiving coil 1154, and a second receiving coil 1156 formed on a PCB 1170. Fig. 11B In the illustrated embodiment, the second receiving coil 1156 includes a polarity change in region 1160. However, the first receiving coil 1154 does not include a polarity change. Fig. 11B As shown, the second receiving coil 1156 includes traces 1162, 1164, 1166, and 1168, wherein trace 1162 is connected to trace 1164, and trace 1166 is connected to trace 1168, thereby producing a polarity change. In some embodiments, the polarity change may be included in the first receiving coil 1154 instead of the second receiving coil 1156. Alternatively, as Fig.10 As shown, polarity changes are provided in both the first receiving coil and the second receiving coil.

[0060] Fig. 11B The phase change that occurs when the traces of the second receive coil 1156 have the closest spacing is shown. In some embodiments, the phase change can occur when the traces of the second receive coil 1156 have the widest spacing, in which case the traces are connected to the connecting trace as discussed above.

[0061] Fig. 12A The sine response 1202 and cosine response 1204 according to the angular position are shown for an example of the position sensor 1150, where the phase change occurs in the sine coil (labeled as the second receiving coil 1156). There is no similar phase change in the cosine coil. Therefore, the sine response 1202 exhibits a phase change every 180 degrees. Fig. 12B The resulting response as a function of angular position is shown.

[0062] Fig. 12C FIG. 12 shows a position parameter 1202 showing the response of an example rotation sensor according to some embodiments. Fig.10 12 shows the relationship between the calculated response and the target position of the rotation angle in the rotary position sensor shown. The SPA signal 1204 shown in FIG. 12 is the spatial angle defined as the arcoth (sine / cosine) of the position. The SPA signal is usually before calibration and linearization and comes directly from the coil. As shown in FIG. 12, the position response according to the angle includes a response with a first slope 1204, a flat portion 1206 when the target passes through an area where there is a polarity transition, and a response with a second slope 1208 opposite to the slope of the first slope 1204.

[0063] Fig.13FIG. 1 is a photographic view of a rotational position sensor 1300 according to some embodiments of the present invention. The rotational position sensor 1300 may be Fig.10 or Fig. 11B The position sensor shown. The transmitting coil and the receiving coil are formed in a coil 1304 on a printed circuit board (PCB) 1302. As described above, the receiving coil generally includes a first receiving coil and a second receiving coil, generally labeled as a sine coil and a cosine coil. According to an embodiment of the present invention, one or both of the receiving coils include a polarity change. The polarity change is physically wired into the coil. As a result of the polarity change, the output response according to the angle has a first slope, a flat area, and a period of a second slope. In most cases, the second slope is a negative slope of the first slope. Fig.13 Further shown is a target 1308 mounted on a rotating shaft 1310. The shaft 1310 is mounted on the PCB 1302 so that the target 1308 rotates over the coil 1304.

[0064] Control circuit 1306 may also be mounted on printed circuit board 1302. Control circuit 1306 powers the transmit coil and receives signals from the receive coil. Control circuit 1306 may also be configured to generate an output response indicating the position of target 1308 relative to the receive coil of coil 1304.

[0065] The above detailed description is provided to illustrate specific embodiments of the present invention and is not intended to be limiting. Many variations and modifications are possible within the scope of the present invention. The present invention is set forth in the appended claims.

Claims

1. A position sensor, comprising: Transmitting coil; a receiving coil, the receiving coil comprising a first receiving coil and a second receiving coil, at least one of the first receiving coil and the second receiving coil comprising at least one polarity change; a target configured to pass through the receiving coil; and a controller configured to drive the transmitting coil, receive signals from the receiving coil, and provide a position response indicative of a target position on the receiving coil, The position response presents a first linear region with a first positive slope, a second linear region with a second negative slope, and a flat region. 2 . The position sensor of claim 1 , wherein the transmitting coil and the receiving coil form a linear position sensor. 3 . The position sensor according to claim 1 , wherein a polarity change in the at least one polarity change is configured at a position in the first receiving coil where a trace of the first receiving coil has a narrowest interval. 4 . The position sensor of claim 1 , wherein a polarity change in the at least one polarity change is configured at a position in the first receiving coil where a trace of the first receiving coil has the widest spacing.

5. The position sensor of claim 1 , wherein the receiving coil defines a two-period linear position sensor having a first receiving coil and a second receiving coil, and wherein the at least one polarity change includes a first polarity change in the first receiving coil and a second polarity change in the second receiving coil.

6. The position sensor of claim 5, wherein the first polarity change and the second polarity change occur at positions in the receiving coil where the traces of the first receiving coil are at their widest spacing and the traces of the second receiving coil are at their narrowest spacing.

7. The position sensor of claim 6, wherein the position separates a first period of the two-period linear position and a second period of the two-period linear position.

8. The position sensor of claim 1, wherein the transmitter coil and the receiver coil define a rotational position sensor.

9. The position sensor of claim 8, wherein the receiving coil comprises a first receiving coil and a second receiving coil, and wherein the at least one polarity change comprises a first polarity change in the first receiving coil and a second polarity change in the second receiving coil.

10. The position sensor of claim 9, wherein the first polarity change occurs when the traces of the first receiving coil have the widest spacing, and the second polarity change occurs when the traces of the second receiving coil have the narrowest spacing.

11. The position sensor of claim 8, wherein the receiving coil comprises a first receiving coil and a second receiving coil, and wherein the at least one polarity change comprises a polarity change in the first receiving coil.

12. The position sensor of claim 11, wherein the polarity change occurs when the traces of the first receiving coil have the widest spacing.

13. The position sensor of claim 11, wherein the polarity change occurs when the traces of the first receiving coil have the narrowest spacing.

14. A position sensor comprising: a receiving coil, the receiving coil comprising a first receiving coil and a second receiving coil formed in a geometric shape on a printed circuit board PCB, wherein at least one of the first receiving coil and the second receiving coil is configured to include at least one phase change; and a transmitting coil, wherein the transmitting coil is formed on the PCB around the receiving coil, When the target passes through the receiving coil, the position response presents a first linear region with a first positive slope, a second linear region with a second negative slope, and a flat region.

15. The position sensor of claim 14, wherein the first receiving coil is a sine coil and the second receiving coil is a cosine coil.

16. The position sensor of claim 14, wherein the geometric shape is linear.

17. The position sensor of claim 14, wherein the geometric shape is rotational.

18. The position sensor of claim 14, wherein each of the first receive coil and the second receive coil includes a phase change in the at least one phase change.

19. The position sensor of claim 18, wherein the phase change in the first receiving coil occurs at a position where the trace of the first receiving coil has the widest spacing, and the phase change in the second receiving coil occurs at a position where the trace of the second receiving coil has the narrowest spacing.

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