EP2839246A1

EP2839246A1 - Angular position sensing device and method for making the same

Info

Publication number: EP2839246A1
Application number: EP13726872.8A
Authority: EP
Inventors: Salvador Hernandez-Oliver; Thorsten Munzig
Original assignee: Tyco Electronics AMP GmbH; Tyco Electronics Corp
Current assignee: TE Connectivity Germany GmbH; TE Connectivity Corp
Priority date: 2012-04-16
Filing date: 2013-04-15
Publication date: 2015-02-25
Also published as: CN103376051B; WO2013156916A1; DE212013000100U1; CN103376051A

Abstract

The present disclosure provides a sensor for sensing an angular position range of a rotatable shaft. The sensor comprises an indicating circuit for generating a binary state signal having a first signal state and a second signal state in response to the rotation of a bipolar magnet device that is attached on the rotatable shaft (108) and adapted to rotate together with the rotatable shaft; and an adjusting circuit for adjusting the binary state signal to compensate variations of operating conditions of the sensor. The binary state signal is in the first signal state when the rotatable shaft is within the angular position range and the binary state signal is in the second signal state when the rotatable shaft is beyond the angular position range. The width and/or offset of binary state signal of the sensor can be adjusted to compensate in response to operating condition variations.

Description

ANGULAR POSITION SENSING DEVICE AND

METHOD FOR MAKING THE SAME

Technical Field of the Invention

The present disclosure relates generally to a position sensing device, and in particular, to a position sensing device that detects an angular position range of a rotatable shaft and the method for making the same.

Background of the Disclosure

It is known in the industry to use position sensing devices to detect angular positions of a ratable shaft.

Traditionally, mechanical-contacted position sensing devices are used to detect angular positions of a rotatable shaft. However, mechanical-contacted position sensing devices have some shortcomings including mechanical wear, low angle accuracy and reliability and no diagnostic capability.

There has been a proposal to use an electronic sensing device to detect particular angular positions of a rotatable shaft. However, the proposed electronic sensing device suffers from implementation feasibility and poor performance when it encounters the variations in operating conditions.

Therefore, there is a need to provide position sensing devices that overcome the shortcomings in the existing position sensing devices to detect angular positions of a rotatable shaft.

Summary of the Disclosure

In a first aspect, the present disclosure provides a sensor for sensing an angular position range of a rotatable shaft, which comprises:

an indicating circuit for generating a binary state signal having a first signal state and a second signal state in response to the rotation of a bipolar magnet device that is attached on the rotatable shaft and adapted to rotate together with the rotatable shaft; and

an adjusting circuit for adjusting the binary state signal to compensate variations of operating conditions of the sensor;

wherein the binary state signal is in the first signal state when the rotatable shaft is within the angular position range and the binary state signal is in the second signal state when the rotatable shaft is beyond the angular position range.

In a second aspect, the present disclosure provides a method for sensing an angular position range of a rotatable shaft on which a magnet device is mounted, which comprises the steps of:

generating a binary state signal having a first signal state and a second signal state in response to the rotation of a bipolar magnet device that is attached on the rotatable shaft and adapted to rotate together with the rotatable shaft; and

adjusting the binary state signal to compensate variations of operating conditions of the sensor;

Still in the second aspect, the method further comprises the steps of:

generating one or more reference voltages;

comparing the sensed voltage with the one or more of the reference voltages in the field operation;

generating a first binary output or a second binary output based on the comparison result in the field operation.

In a third aspect, the present disclosure provides a method for sensing an angular position range of a rotatable shaft on which a magnet device is mounted, which comprises the steps of: generating a function line when the bipolar magnet device is rotating around the rotatable shaft in a simulation or calibration process;

generating one or more reference voltages based on a function line in the simulation or calibration process;

rotating the rotatable shaft by an angle in the field operation;

sensing a voltage in response to magnetic flux density changes caused by the rotation of the magnet device in the field operation;

In a fourth aspect, the present disclosure provides a sensor for sensing an angular position range of a rotatable shaft, which comprises:

a memory means for providing at least two reference voltage points having a first reference voltage point and a second reference voltage point that represent two voltage points on a linear function line;

a sensing device for generating a sensed electrical signal in response to the magnetic flux density changes along two dimensions when the bipolar magnet rotates around the rotatable shaft; and

a comparing means for comparing the voltage of the sensed electrical signal with the two reference voltage points;

wherein the indicating circuit generates the first signal state when the voltage of the sensed electrical signal matches the first reference voltage point or the second reference voltage point; the indicating circuit generates the second signal state when the voltage of the sensed electrical signal is beyond (or outside) the range of the first reference voltage point and the second reference voltage point. In a fifth aspect, the present disclosure provides a sensor for sensing an angular position range of a rotatable shaft, which comprises:

a threshold circuit for providing a threshold voltage on a curve-shaped function line; and

a sensing device for generating a sensed electrical signal in response to the magnetic flux density changes along one dimension when the bipolar magnet (304 A, 304B) rotates around the rotatable shaft;

wherein the indicating circuit generates the first signal state when the voltage of the sensed electrical signal is above (or below) the threshold voltage and generates the second signal state when the voltage of the sensed electrical signal is below (or above) the threshold voltage.

By providing the sensor and the corresponding methods, the present disclosure overcomes the above mentioned shortcomings in the existing art. Description of the Drawings

The present invention will be described with reference to the accompanying drawings, wherein:

Figure 1 depicts a position sensing system 100 according to the present disclosure, which shows a side view of the rotatable shaft 108 in the position sensing system 100;

Figure 2 depicts the position sensing system 100 of Figure 1, which shows the top view of the rotatable shaft 108 shown in Figure 1 ;

Figure 3 depicts the position sensing system 100, which shows the sectional view of the rotatable shaft 108 shown in Figure 2 along the line A-A in Figure 2;

Figures 4A-B depict the magnet device 102 and the sensing device 104 in Figures 1-3 in greater detail;

Figure 5 A depicts one embodiment of the processing circuit 106 in the position sensing system 100 in greater detail;

Figure 5B depicts another embodiment of the processing circuit 106 in the position sensing system 100 in greater detail;

Figure 6 depicts the processing unit 504 shown in Figure 5 in greater detail;

Figures 7A-C illustrate the calibration (or simulation) process using two function lines that are generated in response to the magnetic flux density changes and/or magnetic field changes along two dimensions;

Figures 8A-B illustrate the calibration (or simulation) process using one function line that is generated in response to the magnetic flux density changes and/or magnetic field changes along one dimension;

Figures 9A-B illustrates using either a positive binary state signal 107 or a negative binary state signal 107' to indicate the rotation range for the rotatable shaft 108 shown in Figures 1-3; and

Figure 10 depicts an engine control system 900, in which the output 111 of the processing circuit 106 shown in Figures 1-3 is used to control the engine in an automobile vehicle. Detailed Description of the Disclosure

Reference is now made to the embodiments, examples of which are illustrated in the accompanying drawings. In the detailed description of the embodiments, directional terminology, such as "top," "bottom," "above," "below," "left," "right," etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments of the present disclosure can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. Whenever possible, the same or similar reference numbers and symbols are used throughout the drawings to refer to the same or similar parts. Figure 1 depicts a position sensing system 100 according to the present disclosure, which shows the side view of the rotatable shaft 108 in the position sensing system 100.

In Figure 1, the position sensing system 100 includes a magnet device 102, a sensing device 104 and a processing circuit 106. The sensing device 104 is electrically connected to the processing circuit 106 through a link 109, and the magnet device 102 is mounted on the rotatable shaft 108 and adapted to rotate together with the rotatable shaft 108 around the axis 112 (as shown in Figure 3) of the rotatable shaft 108. The sensing device 104 is positioned above and separated from the magnet device 102 with a distance D (or air gap) 183. When rotating around the axis 112 of the rotatable shaft 108, the magnet device 102 can cause magnetic flux density changes, which in turn causes magnetic field changes, to a position (or a detecting position) where the sensing device 104 is located. The sensing device 104 can generate electrical signals (such as PWM, SENT, etc) when subjected to the magnetic flux density changes from the magnet device 102. As an illustrative embodiment, the sensing device 104 may include a Hall-effect circuitry for generating electrical signals in response to the magnetic field changes caused by the magnetic flux density changes. The sensing device 104 applies the sensed electrical signals to the processing circuit 106, which in turn generates a binary state signal 110 at its output terminal (i.e. link 111) in response to the sensed electrical signals.

As shown in Figure 1, the rotatable shaft 108 can move linearly along its longitude direction and rotate around its axis 112 (as shown in Figure 3). When the rotatable shaft 108 linearly moves along its longitude direction, the processing circuit 106 maintains its binary voltage state at its output 111. In other words, the binary state output 111 of the processing circuit 106 does not change its binary state output in response to the linear motion of the rotatable shaft 108 because the sensing device 104 cannot detect any magnetic flux density changes and/or magnetic field changes from the liner movement of the rotatable shaft. However, when the rotatable shaft 108 rotates around its axis 112, the processing circuit 106 may change its binary voltage state between Vhigh and Vlow at its output 111, depending on the rotation angle of the rotatable shaft 108. In other words, the processing circuit 106 switches its binary state output 111 between Vhigh and Vlow in response to the rotation angle of the rotatable shaft 108.

Figure 2 depicts the position sensing system 100 of Figure 1, which shows the top view of the rotatable shaft 108. In the top view of the rotatable shaft 108, the sensing device 104 should be drawn in a position above the magnet device 102 (with the distance 183D). To better illustrate the principle of the present disclosure, however, the sensing device 104 is illustratively positioned at the lateral side of the rotatable shaft 108 in Figure 2, but using a dot line 129 to reflect the above-below positional relationship between the magnet device 102 and the sensing device 104.

As shown in Figure 2, the magnet device 102 has a length L along the longitude direction of the rotatable shaft 108 to ensure that the sensing device 104 is always within the effective detecting region of the magnet device 102 when the rotatable shaft 108 linearly moves along its longitude direction. The dotted line 114 indicates a center line along the longitude direction of the rotatable shaft 108 and the dotted lines 115 and 117 define a rotation range (-L1, +L1) of interest. In other words, when the rotatable shaft 108 rotates left and right around the axis 112, the center line 114 rotate towards the dotted lines 115 and 117, respectively. Figure 3 depicts the position sensing system 100 of Figure 2, which shows the sectional view of the rotatable shaft 108 along the line A-A in Figure 2.

As shown in Figure 3, the rotatable shaft 108 can rotate from its center position (as indicated by the center line 113 in the diameter direction of the rotatable shaft 108 on the rotatable shaft 108) towards its left until it reaches its left rotation limitation -Lm (as indicated dotted line 121) or towards right until it reaches its right rotation limitation +Lm (as indicated by dotted line 123). The center line 113 passes and dissects the axis 112 of the rotatable shaft 108. Hence, the two dotted lines 121 and 123 define a whole rotation movement range (-Lm, +Lm) for the rotatable shaft 108. Within the whole rotation movement range (-Lm, +Lm), the two dotted lines 115 and 117 define an internal rotation movement range, or a rotation range, (-L1, +L1) for the rotatable shaft 108. In the embodiment as shown in Figure 3, the whole rotation movement range and the internal rotation movement range are symmetrical in reference to the axis 112 of and the center line 113 on the rotatable shaft 108. That is, the rotation ranges between -Lm and -LI are equal to those between +Lm and +L1, respectively, in reference to the axis 112 and the center line 113. However, non- symmetrical arrangements of the rotation movement ranges are possible to a person skilled in the art. In addition, it is possible to expand the whole rotation movement range (-Lm, +Lm) of the rotatable shaft 108 to 360 degrees. To clearly define the positional relationships among the components in Figures 1-3, it should be noted that the center line 113 at the diameter direction of the rotatable shaft 108 is a straight line that passes through the axis 112 and is normal to the center line 114 along the longitude direction of the rotatable shaft 108(see Fig.2).

Working together, the sensing device 104 and the processing circuit 106 can detect the angular position of the rotatable shaft 108 and generating a binary state indication signal 107 on the output 111. Specifically, the processing circuit 106 can generate a first signal state (a high voltage state Vhigh as shown in Figure 3 or a low voltage state Vlow as shown in Figure 9B) when the rotatable shaft 108 is within the rotation range (-L1, +L1); the processing circuit 106 generates a second signal state (a low voltage state Vlow as shown in Figure 3 or a high voltage state Vhigh as shown in Figure 9B) when the rotatable shaft 108 is outside (or beyond) the rotation range (-L1, +L1). The binary state indication signal 107 is then applied to an ECU (Engine Control Unit) through the output terminal 111 of the processing circuit 106 (as shown Figure 10). Figure 4A depicts one embodiment of the magnet device 102 and the sensing device

104 shown in Figures 1-3. As shown in Figure 4A, the magnet device 102 includes a magnet 304A having a south pole and a north pole. The south pole of the magnet 304A is attached on the surface of the rotation shaft 108. The front surface 305 of the sensing device 104 and the surface of the north pole of the magnet 304 A are positioned facing with each other. The south pole and north pole of the magnet 304A are aligned with the center line 113 on the rotatable shaft 108. The sensing device 104 is separated from the magnet 304 A by a distance (or air gap) D 183 and coplanar with the magnet 304 A. As shown in Figure 2, the magnet 304A has a length L and a center line 114 along the longitude direction of the rotatable shaft 108. To more effectively detecting the magnetic flux density changes from the magnet 304A, as one embodiment, the sensitive point of the sensing device 104 is aligned with the center line 114 of the magnet 304A.

The sensing device 104 includes a sensing element 302, which can be a Hall-effect sensing device or magneto -resistive (MR) sensing device that is capable of generating an electrical signal when exposed to a rotating magnetic field. More specifically, a Hall-effect sensing element 302 can be a current-carrying semi-conductor membrane to generate a low voltage perpendicular to the direction of the current flow when subjected to magnetic flux density changes/magnetic field changes normal to the surface of the membrane. As shown in Figure 4 A, the magnetic flux density changes/magnetic field changes within the air gap 183D along three dimensions 303 (Bx, By, Bz). The sensing device 104 is typically designed to detect the magnetic field changes along one of the Bx, or By, or both. The sensing element 302 can be configured on a detecting position that is sensitive and responsive to the magnetic flux density changes/magnetic field changes caused by the rotating magnet 304A. In Figure 4A, B stands for magnetic flux density; Bx indicates the magnetic flux density measurement along the radial direction of the shaft 108 and perpendicular to the sensing element 302; and By indicates the magnetic flux density measurement that is tangential to the shaft 108 and coplanar to the sensing element 302.

Figure 4B depicts another embodiment of the magnet device 102 in great detail. In Figure 4B, the magnet device 102 and the sensing device 104 are the same with those shown in Figure 4A, except that the orientation of the magnet 304B is different from that of the magnet 304 A in Figure 4 A. As shown in Figure 4B, the magnet device 102 includes a magnet 304B having a north pole and a south pole. The north pole of the magnet 304B is attached on the surface of the rotation shaft 108. The surface 305 of the sensing device 104 and the surface of the south pole of the magnet 304B are positioned facing with each other. The north pole and south pole of the magnet 304B are aligned with the center line 113 on the rotatable shaft 108. By the same principle as described in connection with Figure 4 A, the magnetic field changes within the air gape along three dimensions 303 (Bx, By, Bz). The sensing device 104 is designed to detect the magnetic field changes along one of the Bx or By, or both.

Figure 5 A depicts one embodiment of the processing circuit 106 in the position sensing system 100 in greater detail. As shown in Figure 5 A, the processing circuit 106 includes an A/D convertor 502, a digital processing unit 504 and an indicating circuit 508, all of which are electronically connected together through links 503, 505 and 507. Being electrically connected to the sensing device 104 through the link 109, the A/D convertor 502 receives analog electronic signals as inputs from the sensing device 104, processes the analog electronic signals into digital electronic signals, and applies the digitized electronic signals to the processing unit 504 through the link 503. The processing unit 504 then processes the digitized electronic signals to determine whether the rotatable shaft 108 is within the rotation range (-L1, +L1). Based on its determination, the processing unit 504 sets the binary state output 111 of the indicating circuit 508 into a first signal state (a high voltage state Vhigh as shown in Figure 3 or a low voltage state Vlow as shown in Figure 9B) when the rotatable shaft 108 is within the rotation range (-L1, +L1); the processing unit 504 sets the binary state output 111 of the indicating circuit 508 into a second signal state (a low voltage state Vlow as shown in Figure 3 or a high voltage state Vhigh as shown in Figure 9B) when the rotatable shaft 108 is outside (or beyond) the rotation range (-L1, +L1).

More specifically, the binary state output 111 of the indicating circuit 508 can be set either in a high voltage state (Vhigh) or a low voltage state (Vlow) depending on the two control signals on the links 505 and 507, namely, the state control signal (having a first control signal state and a second control signal state) on the link 505 and the trigger signal (or a trigger pulse) on the link 507. When the processing unit 504 applies a trigger pulse onto the link 507 and a state control signal onto the link 505, the indicating circuit 508 is set into a voltage state that is the same to that of the state control signal as being applied on the link 505. When no trigger signal is applied onto the link 507, the indicating circuit 508 remains its current output state regardless the state signal being applied on the link 505. As an embodiment, the logic function of the indicating circuit 508 can be implemented by using a J-K register or a D register.

Therefore, when the processing unit 504 determines that the rotatable shaft 108 is within the rotation range (-L1, +L1), it applies a first control signal state (a high control state signal or a low control state signal) on the link 505 and a trigger signal on the link 507, which sets the indicating circuit 508 into the first signal state (a high voltage state Vhigh as shown in Figure 3 or a low voltage state Vlow as shown in Figure 9B). When the processing unit 504 determines that the rotatable shaft 108 is outside (or beyond) the rotation range (-L1, +L1), it applies a second control signal state (a low control state signal or a high control state signal) on the link 505 and a trigger signal on the link 507, which sets the indicating circuit 508 into the second signal state (a low voltage state Vlow as shown in Figure 3 or a high voltage state Vhigh as shown in Figure 9B).

Figure 5B depicts another embodiment of the processing circuit 106 in the position sensing system 100 in greater detail. As shown in Figure 5B, the processing circuit 106' includes an analog processing unit 924 and a polarity circuit 928. The analog processing unit 924 has an input that is coupled to the link 109 and an output that is coupled to the polarity circuit 928 through a link 925. The polarity circuit 928 has an output that is coupled to the output terminal 111.

The analog processing unit 924 receives electronic signals from the sensing device 104 and processes them to generate a first state trigger signal when the rotatable shaft 108 is within the rotation range (-L1, +L1) and to generate a second state trigger signal when the rotatable shaft 108 is outside (or beyond) the rotation range (-L1, +L1). In response to the first state trigger signal, the polarity circuit 928 is set to a first state signal (a high voltage state Vhigh as shown in Figure 3 or a low voltage state Vlow as shown in Figure 9B); in response to the second state trigger signal, the polarity circuit 928 is set to a second state signal (a low voltage state Vlow as shown in Figure 3 or a high voltage state Vhigh as shown in Figure 9B). The processing unit 924 includes a threshold circuit for setting a threshold voltage.

More specifically, a threshold voltage is calibrated (or simulated) using the process in connection with the description for Figures 8A-B. The calibrated (or simulated) threshold voltage is then set within the analog processing unit 924. When the sensed voltage from the sensing device 104 is greater or equal to the threshold voltage, the analog processing unit 924 generates a first state trigger signal to set the polarity circuit 928 into a first state signal (a high voltage state Vhigh as shown in Figure 3 or a low voltage state Vlow as shown in Figure 9B). When the sensed voltage from the sensing device 104 is less than the threshold voltage, the analog processing unit 924 generates a second state trigger signal to set the polarity circuit 928 into a second state signal (a low voltage state Vlow as shown in Figure 3 or a high voltage state Vhigh as shown in Figure 9B).

The analog processing unit 924 can be implemented using a low-pass filter or some similar devices.

Figure 6 depicts the processing unit 504 shown in Figure 5 in greater detail. As shown in Figure 6, the processing unit 504 includes a processor (or CPU) 602, a register 604, a memory device 606, an I/O circuit 608 and a buss 610. The processor 602, register 604, memory device 606 and I/O circuit 608 are coupled to the buss 610 through links 603, 605, 607 and 609, respectively. The memory device 606 can store programs (i.e., a set of instructions), parameters (such as the reference voltages as shown in Figures 7B and 8A) and data (including the digitized electronic signals), the registers 604 can store (or cache) the parameters and data, and the I/O circuit 608 can receive input signals into and send output signals out of the processing unit 504 (such as to the links 505 and 507). The registers 604 can provide and remain signals based on the contents stored therein for one or more CPU operation cycles so that the processor 602 can perform operations within the CPU operation cycles. By executing the programs stored in the memory device 606, the processor (or CPU) 602 can control the operation of the registers 604, memory device 606 and I/O circuit 608 and can perform reading/writing operations on the registers 604 and memory device 606. The I/O circuit 608 can receive input signals from the A/D converter 502 and send out the output signals to the indicating circuit 508. To perform comparison logic operation, the processor (or CPU) 602 includes a logic operation unit (not shown) having a comparator 612, which can perform comparing operation from two sources of inputs 613 and 615 to generate a comparison result on output 617. The processor (or CPU) 602 can determine the subsequent operation based on the comparison result on output 617. More specifically, based on the comparison results, the processor (or CPU) 602 can generate desirable state control signal and the trigger signal (or a trigger pulse) and send them to the links 505 and 507. Figure 7A depicts two function lines (704, 706) that are generated by the sensing device

104 in response to the magnetic flux density changes and/or magnetic field changes in the air gap 183 D along Bx and By dimensions. Specifically, when the magnet device 102 is constantly rotating around the axis 112 of the rotatable shaft 108, the sensing device 104 generates electrical signals (or output voltages) that comply with the cos-shaped function line 704 and a sin-shaped curve function line 706 in response and proportional to the magnetic flux density changes and/or magnetic field changes generated by the magnet device 102 along Bx and By dimensions, respectively. These two function lines 704 and 706 can be observed from an oscilloscope while the magnet device 102 is rotating around the axis 112 if the output (at the link 109) of the sensing device 104 is applied to the oscilloscope. In the coordinate system as shown in Figure 7A, the Y coordinate indicates the voltage changes on the cos-shaped line 704 and sin-shaped line 706 while the X coordinate indicates the rotation angle changes of the rotatable shaft 108. As one embodiment, the sensing device 104 can be implemented by using 3D Hall Sensing Devices available in the market, but only using its processing capabilities in two dimensions (i.e. X and Y dimensions). Doing so saves circuit design costs and reduces implementation time. Figure 7B depicts a calibration (or simulation) process to generate a linear function 722 before installing the position sensing system 100 in field use. In performing the calibration (or simulation) process, a processing device (such as the processing circuit 106 including the processing unit 504) processes the two sets of the analog electronic signals that comply with the cos-shaped line 704 and sin-shaped line 706 (shown in figure 7A) to generate a linear function line 722. It should be understood that the voltage changes shown in Figure 7B are outputs/electronic signals that are proportional to the magnetic flux density changes Bx and By along both X and Y dimensions. In the coordinate system for the linear function line 722 as shown in Figure 7B, the Y coordinate indicates the voltage changes on the linear function line 722 while the X coordinate indicates the rotation angle changes on the rotatable shaft 108.

Specifically, in the processing circuit 106, the A/D converter 502 receives the two sets of the analog electronic signals (that comply with the cos-shaped line 704 and sin-shaped line 706) from the sensing device 104, converts them into two sets of digital electronic signals, and applies the two sets of the digitized electronic signals to the I/O circuit 608 in the processing unit 504. After receiving the two sets of the digitized electronic signals, the processor (CPU) 602 in the processing unit 504 stores them into the memory device 606 and then transform the two sets of the digitized electronic signals into one set of the electronic signals that comply with the linear function line 722 shown in Figure 7B. The processor (CPU) 602 in the processing unit 504 transforms the two sets of the digitized electronic signals by using a set of mathematical equations as follows: (1) output voltage.1 (V.1) = a function of angle = m x (angle) + b = m x 9 + b tan(9) = sin(9) /cos(9) = Bx/By

Θ = arctan(B) = arc (sin(9) /cos(9)) = arc (Bx/By)

output voltage.1 (V.1) = m x arc ((sin(9) /cos(9)) = m x arc (Bx/By) + b

output voltage.2 (V.2) = m x arc (k x (sin(9) /cos(9)) + b = m x arc [k x (Bx/By)] + b In the process that is reflected in above five equations, m, b and k are three calibrated/simulated linear function constants, where m represents the slope of the linear function, b defines the starting point of the output in reference to the angle measured, and k is a constant that is used to adjust/compensate the function line 722 for its linearity to accurately reflect the angular position range when operation condition variations; sin(9) and cos(9) represent the function lines 704 and 706 shown in Figures 7A, respectively; equation (4) represents the voltage outputs as shown by the function line 722 in Figure 7B; and equation (5) represents the voltage outputs with adjustment/compensation using the constant k. When k = 1, equation (4) equals to equation (5). By setting different constant k, the two reference voltages on the function line 722 are adjusted/compensated so that the width and offset (positional offset) of the binary state outputs can be adjusted/compensated in response to the variations of operation conditions.

To further transform the linear function output into a binary-state output, the processor (CPU) 602 further identifies two reference voltage points (or two reference voltages) Vfl and Vf2 in the calibration (or simulation) process. Specifically, as shown in Figure 7B, two reference voltages Vfl and Vf2 are identified in reference to the two rotation angles corresponding to the dotted lines 115 (-L1) and 117 (+L1), respectively. To keep the dotted lines 115 and 117 symmetrical to the center rotation angle corresponding to the dotted line 113, the processor (CPU) 602 can first identify the center reference voltage Vc in reference to the center dotted line 113 on the rotatable shaft 108. With the center reference voltage Vc, the processor (CPU) 602 then identifies the two reference voltages Vfl and Vf2 that are symmetrically arranged in reference to the center reference voltage Vc. Figure 7C depicts a scheme to form a binary state signal 107 having a first signal state

(a high voltage Vhigh) and a second signal state (a low voltage Vlow) based on the linear function line 722 in the calibration (or simulation) process. As shown in Figure 7C, the binary state signal 107 is formed by matching all voltage points (or voltages) on the linear function line 722 that are equal to or between the two reference voltage points (or voltages) as a first binary state signal (a high voltage Vhigh); and by matching all voltage points (including the two reference voltages) on the linear function line 722 that are smaller than the first reference voltage Vfl or is greater than the second reference voltage Vf2 as a second binary state signal (a low voltage Vlow). The electronic signals as shown in Figures 7B-C can also be observed from an oscilloscope when the calibration (or simulation) outputs are applied to the oscilloscope.

As an alternative embodiment, the processor 602 identifies two pairs of voltage points on the linear function line 722 in the calibration (or simulation) process with each pair of the voltage points being clustered together (spaced at 0.2 degree for example). The processor 602 then assigns a first reference voltage Vfl to the first pair of the voltage points and assigns a second reference voltage Vf2 to the second pair of the voltage points. Such a scheme has advantage of being able to use the existing 3D Hall Device (in which two pairs of reference voltages are availably provided) to implement the embodiments, thus saving costs and reducing design time.

In Figures 7A-C, to cope with (or counteract) the variations in the operating conditions of the position sensing system 100 (including the variations in air gaps and temperature and the parameter variations in used components), the width and offset (or positional offset) of the binary state signal 107 can be compensated by adjusting the linear function line 722, which leads to the adjustment/compensation of the center reference voltage Vc and the two reference voltages Vfl and Vf2. The offset of the binary state signal 107 here refers to the relative position of the binary state signal 107 in reference to rotation angle of the rotatable shaft 108. After these two reference voltages Vfl and Vf2 are generated in the calibration (or simulation) process, they are stored into the memory device 506 so that the processing circuit 504 can later use them to detect the rotation range of the rotatable shaft 108 in field use of the position sensing system 100. It should be noted that, by using the process reflected in the equations (l)-(5), two curved function lines 704 and 706 as shown in Figure 7A are transformed to a linear function line 722 as shown in Figure 7B. It should be appreciated that using one linear function 722 to transform an angle range into a binary state signal is not or less impacted by magnetic flux density changes caused by air gap changes, temperature effects, or magnet malfunction, which leads to an improved detecting accuracy. It should further be appreciated the symmetrical characteristics of the binary state signal 107 in reference to the center line 113 can also be better adjusted and maintained using the scheme shown in Figures 7A-7C. Figure 8 A depicts a function line (704 or 706) shown in Figure 7 A, which is used in performing calibration (or simulation) process to generating a threshold reference voltage 712 (or 714). Specifically, when the magnet device 102 is constantly rotating around the axis 112 of the rotatable shaft 108, the sensing device 104 generates electrical signals that comply with the sin-shaped line 704 in response to the magnetic flux density changes/magnetic field changes generated by the magnet device 102 along the By dimension.

In performing the calibration (or simulation) process, a processing device (such as the processing circuit 106) processes the analog electronic signals that comply with the sin-shaped line 706 (shown in figure 7A) to generate a threshold voltage 712. Specifically, within the processing circuit 106, the A/D converter 502 receives analog electronic signals (that comply sin-shaped line 706) from the sensing device 104, converts them into digital electronic signals, and applies the digitized electronic signals to the I/O circuit 608 in the processing unit 504. After receiving the digitized electronic signals, the processor (CPU) 602 in the processing unit 504 stores them into the memory device 606 and then transform the digitized electronic signals into the threshold voltage 712 using the mathematical formula (6) as follows:

(6)Threshold voltage 712=(Voltage Max 715 - Voltage Min 716)x(Percentage Value) In the present disclosure, the Percentage Value is selected as 70%. Figure 8B depicts a scheme to form a binary state signal 107 having a first signal state (a high voltage Vhigh) and a second signal state (a low voltage Vlow) based on the sin-shaped line 706 in the calibration (or simulation) process. Based on the mathematic formula (6), the digital processing circuit 106 shown in Figure 5 A (or the analog processing circuit 106' shown in Figure 5B) generates the binary state signal 107 by matching all voltage points (or voltages) on the positive half-cycle of the sin-shaped line 706 that are equal to or greater than the threshold voltage 712 as a first binary state signal (a high voltage Vhigh); and by matching all voltage points (or voltages) on the positive half-cycle of the sin-shaped line 706 that are small than the threshold voltage 712 as a second binary state signal (a low voltage Vlow). The electronic signals as shown in Figures 8A-B can be observed from an oscilloscope when the calibration (or simulation) outputs are applied to the oscilloscope. Even though the calibration (simulation) process in connection with Figures 8A-B uses the sensed electric signals on the positive half-cycle of the sin-shaped line 706, it should be noted that the principle of the present disclosure also applies to the sensed electric signals on the negative half-cycle of the sin-shaped line 706. When the negative half-cycle of the sin-shaped line 706 is used, the threshold voltage 712 should use a mathematical formula (7) as follows:

(7)Threshold voltage 714=(Voltage Max 718 - Voltage Min 720)x(Percentage Value)

Based on the mathematical formula (7), the digital processing circuit 106 shown in Figure 5 A (or the analog processing circuit 106 shown in Figure 5B) generates the binary state signal 107 by matching all voltage points (or voltages) on the negative half-cycle of the sin-shaped line 706 that are equal to or smaller than the threshold voltage 714 as a first binary state signal (a high voltage Vhigh); and by matching all voltage points (or voltages) on the negative half-cycle of the sin-shaped line 704 that are greater than the threshold voltage 714 as a second binary state signal (a low voltage Vlow). In Figures 8A-B, to cope with (or counteract) the variations in the operating condition of the position detecting system 100 (including the variations in air gaps and temperature and the parameters variations in components), the width of the binary state signal 107 can be compensated by adjusting the value of the threshold voltage 412. According to one embodiment, the threshold voltage 712 (or 714) generated in the calibration (or simulation) process is stored into the memory device 606 so that the processing circuit 602 can later use them to detect the rotation range of the rotatable shaft 108 in field use. According to another embodiment, the threshold voltage 712 (or 714) generated in the calibration (or simulation) process is set into the analog processing unit 924 so that the analog processing unit 924 can use it to detect the rotation range of the rotatable shaft 108 in field use.

Even though in Figures 8A-B, the threshold based binary signal can provide adjustment/compensation capability only for width, not offset, it uses more simple electrical architecture (such as ID Speed Hall device) than the linear function based one (Multiple Dimension Hall Device).

It should be noted that Figures 8A-B illustrates the calibration (or simulation) process by using the sin- shaped line 706. The principle in connection with Figures 8A-B also applies to the output of the con-shaped line 704 (as shown in Figure 7A) because, comparing with the cyclic sin-shaped line 706, the cyclic cos-shaped line 704 will match the cyclic sin-shaped line 706 if the cos-shaped line 704 is shifted by 90 degree. Thus, the same principle can also be applied to the output of cos-shaped line 704. In the present disclosure, the calibration (or simulation) process is performed by using the processing circuit 106. However, to a person skilled in the art, any similar processing device can be used to perform the calibration (or simulation) process.

It should be noted that the electronic-contactless sensing devices inevitably encounter operating condition variations in manufacturing and/or in operation, including, but not limited to, the variations in air gaps, temperature and the parameter variations in the components used. The adjustment/compensation capability is critical for measurement accuracy, especially for detecting the neutral position range for a gear shaft on automobile vehicles. The basis for the adjustment/compensation (including width and/or offset) is the usage of a binary state signal to indicate an angular position range. To facilitate maintenance of the position sensing system 100, the calibration (or simulation) process can be performed in field use by executing the calibration (or simulation) programs that are stored in the processing circuit 106. The adjustment/compensation process can also be performed in field use by reprogramming the reference voltage(s) in the processing circuit 106. Figures 9A-B illustrates that either a positive binary state signal 107 or a negative binary state signal 107' can be used to indicate the rotation range (-L1, +L1) for the rotatable shaft 108.

Specifically, as shown in Figure 9A, when the rotatable shaft 108 is within the rotation range (-L1, +L1), the digital processing circuit 106 (or processing circuit 106') shown in Figure 5 A sets the indicating circuit 508 in a high voltage state Vhigh as indicated by line 907; when the rotatable shaft 108 is beyond (or outside of) the rotation range (-L1, +L1), the digital processing circuit 106 (or processing circuit 106') sets the indicating circuit 508 in a low voltage state Vlow as indicated by line 909.

Alternatively, as shown in Figure 9B, the binary state signal 107' can be a reverse of the binary state signal 107. Therefore, in Figure 9B, when the rotatable shaft 108 is within the rotation range (-L1, +L1), the processing circuit 106 (or processing circuit 106') shown in Figure 5 A sets the indicating circuit 508 in a low voltage state Vlow as indicated by line 917; when the rotatable shaft 108 is beyond (or outside of) the rotation range (-L1, +L1), the processing unit 504 sets the indicating circuit 508 in a high voltage state Vhigh as indicated by line 919.

Figure 10 depicts an engine control system 900 in which the binary output 111 of the processing circuit 106 (or processing circuit 106') is used to control the engine in an automobile vehicle. In Figure 10, the engine control system 900 includes the sensing device 104, the processing circuit 106 and an ECU (Engine Control Unit) 902. In the engine control system 900, the rotatable shaft 108 is used as a gear shift lever and the rotation range (-L1, +L1) reflects the neutral position range of the gear shift lever.

As shown in Figure 10, the ECU (Engine Control Unit) 902 receives the binary state signal on link 111 as its input from the processing circuit 106 (or processing circuit 106') and receives the input 903 from clutch sensing circuitry (not shown) of the automobile vehicle. The input 903 indicates whether the clutch of the automobile vehicle is being pressed. When the ECU 902 detects that the gear shift lever stays within the neutral position range based on the binary state signal on link 111 for a certain period of time (5 seconds for example), it shuts down the engine of the automobile vehicle to save gas. When the ECU 902 detects that the clutch of the automobile vehicle is being pressed based on the inputs on the link 903, the ECU 902 further detects whether the gear shift lever is within the neutral position range based on the binary state signal on link 111. The ECU 902 starts the engine only when the gear shift lever is within the neutral position range. Therefore, the detection accuracy of the neutral position range for the gear shift lever is important to ensure the appropriate operation of the automobile vehicle. It should be appreciated that a narrow and/or symmetrical binary state signal 107 is especially desirable when the position sensing system 100 is used to detect the neutral position range for the gear shift lever in an automobile vehicle.

In field use, the digital processing circuit 106 as shown in Figure 5 A (or the analog processing circuit 106' as shown in Figure 5B) sets the indicating circuit 508 (or the polarity circuit 928 ) into the first signal state and the second signal state in response to the rotation of the rotatable shaft 108 using the steps as follows:

In field use, according to one embodiment, when the rotatable shaft 108 is being rotated with a rotation angle, the sensing device 104 generates electronic signals in response to the magnetic flux density changes and/or magnetic field changes caused by the magnet device 102 along X dimension and/or Y dimension. The sensed voltages comply with the description in connection with Figures 7A-C or Figures 8A-B. If the sensed voltage is obtained using the process described in connection with Figures

7A-C, the sensing device 104 generates two electrical signals that comply with the cos-shaped line 704 and sin-shaped line 706, respectively. Upon receiving the two electrical signals, the processor (CPU) 602 transforms them to one sensed voltage by using the Equations (1-5) in connection with Figures 7A-C. Therefore, the sensed voltage should comply with the liner function line 722 shown in Figure 7B. If the sensed voltage is obtained using the process in connection with Figures 8A-B, the sensing device 104 generates one electrical signal that comply with the cos-shaped line 704 or sin-shaped line 706 and sends the electrical signal to the processor (CPU) 602. Therefore, the sensed voltage should comply with the cos-shaped line 704 or sin-shaped curve 706 shown in Figure 7 A.

When the sensed voltage is obtained using the process described in connection with Figures 7A-C, the processor (CPU) 602 compares the sensed voltage with the two reference voltages Vfl and Vf2. In the comparison, if the value of the sensed voltage is equal to one of, or is between, the values of the two reference voltages Vfl and Vf2, the processor (CPU) 602 generates corresponding state control signal and trigger signal on the links 505 and 507, respectively, to set the indicating circuit 508 into a first signal state (a high voltage state Vhigh as shown in Figure 3 or a low voltage state Vlow as shown in Figure 9B). If the value of the sensed voltage is smaller than the first reference voltage Vfl or is greater than the second reference voltage Vf2, the processor (CPU) 602 generates corresponding state control signal and trigger signal on the links 505 and 507, respectively, to set the indicating circuit 508 into a second signal state (a low voltage state Vlow as shown in Figure 3 or a high voltage state Vhigh as shown in Figure 9B). When the sensed voltage is obtained using the process (or method) described in connection with Figures 8A-B, the processor (CPU) 602 compares the sensed voltage with the threshold voltage 712 (or 714). If the value of the sensed voltage is equal to or is greater than the threshold voltage 712 (or the value of the sensed voltage is equal to or is smaller than the threshold voltage 714), the processor (CPU) 602 generates corresponding state control signal and trigger signal on the links 505 and 507, respectively, to set the indicating circuit 508 into a first signal state (a high voltage state Vhigh as shown in Figure 3 or a low voltage state Vlow as shown in Figure 9B). If the value of the sensed voltage is smaller than the threshold voltage 712 (or the value of the sensed voltage is greater than the threshold voltage 714), the processor (CPU) 602 generates the corresponding state control signal and trigger signal on the links 505 and 507, respectively, to set the indicating circuit 508 into a second signal state (a low voltage state Vlow as shown in Figure 3 or a high voltage state Vhigh as shown in Figure 9B).

During the comparison process, under the control of the processor (CPU) 602, the two reference voltages Vfl and Vf2, or the two threshold voltages 712 and 714 are stored in the registers 604 in the processing unit 504. The sensed voltage is applied to the input 613 of the comparator 612 and the two reference voltages Vfl and Vf2, or one of the two threshold voltages 712 and 714) are applied to the input 615 of the comparator 612. The processor (CPU) 602 obtains the comparison results from the output 617 of the comparator 612. Based on the comparison results from the output 617, the processor (CPU) 602 generates the state control signal and trigger signal on the links 505 and 506.

The programs (or instruction sets) to perform the specific steps for setting the indicating circuit 508 can be stored in the memory device 606 and executed by the processor (CPU) 602.

In field use, according to another embodiment, when the rotatable shaft 108 is being rotated with a rotation angle, the sensing device 104 generates an electronic signal in response to the magnetic flux density changes and/or magnetic field changes caused by the magnet device 102 along one dimension (X dimension and/or Y dimension). The sensed electronic signal complies with descriptions in connection with Figures 8A-B.

When the sensed voltage of the electric signal from the sensing device 104 is greater or equal to the threshold voltage, the analog processing unit 924 generates a first state trigger signal to set the polarity circuit 928 into a first state signal (a high voltage state Vhigh as shown in Figure 3 or a low voltage state Vlow as shown in Figure 9B). When the sensed voltage of the electric signal from the sensing device 104 is less than the threshold voltage, the analog processing unit 924 generates a second state trigger signal to set the polarity circuit into a second state signal (a low voltage state Vlow as shown in Figure 3 or a high voltage state Vhigh as shown in Figure 9B).

To reduce the costs for an ECU system, it is desirable to simplify the architecture of its control unit. One item of doing so is to change the input of the processing circuit 106 or the sensor 104 into a logic binary input at this control unit. This can be realized on sensor side with a mechanical switch with disadvantages of low measurement accuracy and poor reliability. The present disclosure provides a feasible architecture by utilizing 3D hall technology (linear based) or speed sensor (threshold based) technology to enable logic binary input signal with improves measurement accuracy and reliability.

It is apparent to those skilled in the art that various modifications and variations can be made to the embodiments described herein without departing from the spirit and scope of the present disclosure. Thus, it is intended that the specification cover the modifications and variations of the various embodiments described herein, provided such modification and variations come within the scope of the appended claims and their equivalents.

Claims

Claims:

1. A sensor for sensing an angular position range of a rotatable shaft (108), the sensor comprising:

an indicating circuit (508) for generating a binary state signal having a first signal state and a second signal state in response to the rotation of a bipolar magnet device (102) that is attached on the rotatable shaft (108) and adapted to rotate together with the rotatable shaft; and

an adjusting circuit (504) for adjusting the binary state signal to compensate variations of operating conditions of the sensor;

2. The sensor of claim 1, the sensor further comprising:

a memory means (604) for providing at least two reference voltage points having a first reference voltage point and a second reference voltage point that represent two voltage points on a linear function line (722);

a sensing device (104) for generating a sensed electrical signal in response to the magnetic flux density changes along two dimensions when the bipolar magnet (102) rotates with the rotatable shaft (108); and

a comparing means (602) for comparing the voltage of the sensed electrical signal with the two reference voltage points;

wherein the indicating circuit (508) generates the first signal state when the voltage of the sensed electrical signal matches the first reference voltage point or the second reference voltage point.

3. The sensor of claim 2, wherein:

the indicating circuit (508) generates the first signal state when the voltage of the sensed electrical signal is between the range of the first reference voltage point and the second reference voltage point.

4. The sensor of claim 3, wherein:

the indicating circuit (508) generates the second signal state when the voltage of the sensed electrical signal is outside the range of the first reference voltage point and the second reference voltage point.

5. The sensor of claim 1, further comprising:

a memory means (604) for providing at least two pairs of reference voltage points having a first pair of reference voltage points and a second pair of reference voltage points that represent four voltage points on a linear function line (722),

wherein the first pair of reference voltage points are assigned with a first voltage value and the second pare of reference voltage points are assigned with a second voltage value; a sensing device (104) for generating a sensed electrical signal in response to the magnetic flux density changes along two dimensions when the bipolar magnet (102) rotates around the rotatable shaft (108); and

a comparing means (602) for comparing the sensed electrical signal with the first assigned voltage value and the second assigned voltage value;

wherein the indicating circuit (508) generates the first signal state when the voltage of the sensed electrical signal matches the first assigned voltage value or the second assigned value or when the voltage of the sensed electrical signal is within the range between first assigned voltage value and the second assigned value,

wherein the indicating circuit (508) generates the second signal state when the voltage of the sensed electrical signal is less than the first assigned voltage value or is greater than the second assigned voltage value.

6. The sensor of any of claims 2 to 5, wherein:

the sensing device (104) is physically separated from the bipolar magnet (304A, 304B) with a distance (or air gap).

7. The sensor of claims 6, wherein:

the liner function line (722) is calibrated/simulated prior to the installation of the sensor under an operating condition in response to the magnetic flux density changes in two dimensions when the bipolar magnet (304 A, 304B) rotates with the rotatable shaft for 360 degrees.

8. The sensor of claim 6, wherein:

the binary state signal switches between the first signal state and the second signal state in response to angular position changes of the rotatable shaft (108).

9. The sensor of claim 6, wherein:

the angular position range of the rotatable shaft is a neutral position range on a gear shift lever.

10. The sensor of claim 6, wherein:

the adjusting circuit (504) adjusts width or offset of the binary state signal to compensate variations of the operating condition of the sensor including variations in air gaps and temperature and parameter variations in components used in the sensor.

11. The sensor of claim 10, wherein:

the adjusting circuit (504) generates a K scaling factor to adjust the width and offset of the binary state signal to compensate variations in air gaps and temperature and parameter variations in the components used in the sensor.

12. The sensor of claim 1, further comprising:

a threshold circuit (604, 924) for providing a threshold voltage on a curve-shaped function line (704, 706); and

a sensing device (104) for generating a sensed electrical signal in response to the magnetic flux density changes along one dimension when the bipolar magnet (304 A, 304B) rotates around the rotatable shaft (108);

wherein the indicating circuit (508) generates the first signal state when the voltage of the sensed electrical signal is above (or below) the threshold voltage and generates the second signal state when the voltage of the sensed electrical signal is below (or above) the threshold voltage.

13. The sensor of claim 12, wherein:

the sensing device (104) is physically separated from the bipolar magnet with a distance (or an air gap).

14. The sensor of claim 12, wherein:

the threshold voltage, the curve-shaped function line (704, 706) are calibrated prior to installation of the sensor under an operating condition in response to the magnetic flux density changes in one dimension when the bipolar magnet rotates around the rotatable shaft for 360 degrees.

15. The sensor of claim 12, wherein:

16. The sensor of any of claims 12 to 15, wherein:

17. The sensor of claim 16, wherein:

the adjusting circuit (504) adjusts width of the binary state signal to compensate variations of operating condition including variations in air gaps and temperature and parameter variations in components used, by monitoring and updating the min and max peaks of the electronic signals that comply with the curve-shaped function line (704, 706).

18. The sensor of claim 17, wherein:

the adjusting circuit (504) generates a threshold factor to adjust the width and offset of the binary state signal to compensate variations of operating condition including variations in air gaps and temperature and parameter variations in the components used in the sensor.

19. A method for sensing an angular position range of a rotatable shaft on which a magnet device is mounted, the method comprising the steps of:

20. The method of claim 19, further comprising the steps of:

generating one or more reference voltages;

21. The method of claim 20, wherein the generating step:

generating a first binary output if the rotatable shaft is within the angular position arrange, and generating a second binary output if the rotatable shaft is beyond the angular position range in the field operation.

22. A method for sensing an angular position range of a rotatable shaft on which a magnet device is mounted, the method comprising the steps of: generating at least a function line when the bipolar magnet device is rotating around the rotatable shaft in a simulation or calibration process;

generating one or more reference voltages based on the function line in the simulation or calibration process;

rotating the rotatable shaft by an angle in field operation;

generating a first signal state and a second signal state based on the comparison result in the field operation.

23. The method of claim 22, wherein the generating step:

generating a first signal state output if the rotatable shaft is within the angular position arrange, and generating a second signal state output if the rotatable shaft is beyond the angular position range in the field operation.

24. The method of claim 23, further comprising the step of:

adjusting the one or more reference voltages in response to the operation conditions of the sensor in the simulation or calibration process or in the field operation.

25. The method of any of claims 19 to 24, wherein:

the function line is a linear function line in response to magnetic flux density changes along two dimensions; and

the reference voltages are two voltages on the linear function line.

26. The method of claim 25, wherein:

the function line is a linear function line in response to magnetic flux density changes along the two dimensions; and

each of the two reference voltages corresponds to a pair of voltage points on the linear function line.

27. The method of claim 26, wherein:

the voltage is sensed in response to the magnetic flux density changes along the two dimensions.

28. The method of any of claims 19 to 24, wherein:

the function line is a curve-shaped function line in response to magnetic flux density changes along one dimension; and

the reference voltage is a threshold voltage that horizontally cuts through the curve-shaped function line.

29. The method of claim 28, wherein:

the voltage is sensed in response to the magnetic flux density change along the one dimension.

30. A sensor for sensing an angular position range of a rotatable shaft (108), the sensor comprising:

a sensing device (104) for generating a sensed electrical signal in response to the magnetic flux density changes along two dimensions when the bipolar magnet (102) rotates around the rotatable shaft (108); and

a comparing means (602) for comparing the voltage of the sensed electrical signal with the two reference voltage points; wherein the indicating circuit (508) generates the first signal state when the voltage of the sensed electrical signal matches the first reference voltage point or the second reference voltage point; and the indicating circuit (508) generates the second signal state when the voltage of the sensed electrical signal is beyond (or outside) the range of the first reference voltage point and the second reference voltage point.

31. The sensor of claim 30, further comprising:

the memory means (604) provides at least two pairs of reference voltage points having a first pair of reference voltage points and a second pair of reference voltage points that represent four voltage points on a linear function line (722), wherein the first pair of reference voltage points are assigned with a first voltage value and the second pare of reference voltage points are assigned with a second voltage value;

32. The sensor of any of claims 30 and 31 , wherein:

33. The sensor of claims 32, wherein: the liner function line (722) is calibrated/simulated prior to the installation of the sensor under an operating condition in response to the magnetic flux density changes in two dimensions when the bipolar magnet (304A, 304B) rotates around the rotatable shaft for 360 degrees.

34. The sensor of claim 33, wherein:

35. The sensor of claim 33, wherein:

36. The sensor of claim 33, further comprising:

an adjusting circuit (504) adjusts width or offset of the binary state signal to compensate variations of the operating condition of the sensor including variations in air gaps and temperature and parameter variations in components used in the sensor.

37. The sensor of claim 36, wherein:

38. A sensor for sensing an angular position range of a rotatable shaft (108), the sensor comprising:

39. The sensor of claim 38, wherein:

40. The sensor of claim 38, wherein:

41. The sensor of claim 40, wherein:

42. The sensor of any of claims 38 to 41, wherein:

43. The sensor of claim 42, wherein:

said adjusting circuit (504) adjusts width of the binary state signal to compensate variations of operating condition including variations in air gaps and temperature and parameter variations in components used, by monitoring and updating the min and max peaks of the electronic signals that comply with the curve-shaped function line (704, 706).

44. The sensor of claim 43, wherein: