Stray field robust magnetic sensor system for detecting state of tiltable and rotatable object

Abstract

The invention relates to a stray field robust magnetic sensor system for detecting a state of a tiltable and rotatable object. A sensor system may include an object, a magnet, and a magnetic sensor. The magnet may be connected to the object such that a center of the magnet is offset from an axis of the object. The magnetic sensor may include a first three-dimensional (3D) sensing pixel and a second 3D sensing pixel. The magnetic sensor may be arranged such that the first 3D sensing pixel and the second 3D sensing pixel are at different distances from a tilt point of the object. The magnetic sensor may be arranged such that the first 3D sensing pixel and the second 3D sensing pixel are at different distances from a center of the magnet.

Description

Background Art

[0001] The magnetic sensor may be capable of sensing multiple (e.g., perpendicular) components (e.g., x-component, y-component, and z-component) of a magnetic field in the environment of the magnetic sensor. The magnetic sensor may be used to detect, for example, the motion, linear position, angular position, position in three-dimensional (3D) space, etc. of a magnet attached to an object. The magnetic sensor may be used in a variety of applications, such as automotive applications, industrial applications, or consumer applications. Summary of the invention

[0002] In some implementations, a sensor system includes: an object; a magnet connected to the object, the magnet connected to the object so that the center of the magnet is offset from the axis of the object; and a magnetic sensor including a first 3D sensing pixel and a second 3D sensing pixel, wherein the magnetic sensor is arranged so that the first 3D sensing pixel and the second 3D sensing pixel are at different distances from a tilt point of the object, and wherein the magnetic sensor is arranged so that the first 3D sensing pixel and the second 3D sensing pixel are at different distances from the center of the magnet.

[0003] In some implementations, a sensor system includes: a magnet connected to an object, the magnet connected to the object such that the magnet is not centered on an axis of the object; and a differential 3D sensor, wherein a first 3D sensing pixel of the differential 3D sensor and a second 3D sensing pixel of the differential 3D sensor are at different distances from a tilt point of the object, and wherein the differential 3D sensor is not centered relative to a center of the magnet.

[0004] In some implementations, a device includes a magnet connected to an object capable of being positioned relative to multiple degrees of freedom, wherein the magnet is connected to the object so that a center of the magnet is offset from an axis of the object; and a magnetic sensor for determining a state of the object relative to the multiple degrees of freedom based on a set of magnetic field strengths of a magnetic field generated by the magnet, the magnetic sensor including a first 3D sensing pixel and a second 3D sensing pixel, wherein a distance between the first 3D sensing pixel and a tilt point of the object is different from a distance between the second 3D sensing pixel and the tilt point of the object, and wherein a distance between the first 3D sensing pixel and a center of the magnet is different from a distance between the second 3D sensing pixel and the center of the magnet. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1A and Figure 1B is a diagram of an example implementation of a stray field robust sensor system that may be used to detect the state of a tiltable and rotatable object as described herein.

[0006] Figure 2is a diagram of an example magnetic sensor according to one or more implementations described herein.

[0007] Figure 3 is a diagram illustrating examples associated with measurement resolution achievable by the sensor system described herein. DETAILED DESCRIPTION

[0008] The following detailed description of example implementations refers to the accompanying drawings.The same reference numbers in different drawings may identify the same or similar elements.

[0009] In a given application, an object may be capable of three degrees of freedom (3DoF) motion. For example, an object may be capable of tilting relative to a first tilt direction (e.g., the x-direction), tilting relative to a second tilt direction (e.g., the y-direction), and rotating relative to an axis of the object (e.g., an axis in the z-direction when the object is in an untilted position). The tilting relative to the first tilt direction, the tilting relative to the second tilt direction, and the rotation relative to the axis of the object may be collectively referred to as the "state" of the object. For example, an object may be a joystick (e.g., for gaming applications, nautical applications, aerospace applications, etc.) or a ball joint (e.g., for robotic devices, mechanical applications, multimedia control elements, etc.), etc. Therefore, the state of an object at a given point in time may be of interest to a given application.

[0010] In some such applications, a multi-sensor system (sometimes using different sensing principles) can be implemented to detect the state of an object. For example, a system may include three potentiometers configured to detect the state of an object. However, the reliability of such a multi-potentiometer system is low, and the cost and complexity are high. As another example, an optical sensor system (e.g., a pair of optical sensor systems including photodiodes, light guides, light emitting diodes, etc.) can be used to detect the tilt of an object relative to a first direction and a second direction, and an incremental optical encoder sensor system can be used to detect the rotational position of an object. However, such a multi-optical sensor system brings significant cost and / or complexity increases. As another example, a sensor system may include two magnetic sensors-a first magnetic sensor configured to detect the tilt relative to a first direction and a second direction, and a second magnetic sensor configured to detect the rotational position. However, such a multi-magnetic sensor system increases cost and complexity, and introduces complex mechanics. In addition, such a multi-magnetic sensor system is not stray field robust, which means that the reliability of the multi-magnetic sensor is low.

[0011] Some implementations described herein provide techniques and apparatus for a stray field robust magnetic sensor system that can be used to detect the state of a tiltable and rotatable object. In some implementations, a sensor system includes an object and a magnet connected to the object, the magnet connected to the object so that the center of the magnet is offset from the axis of the object. The sensing system also includes a magnetic sensor that includes a first 3D sensing pixel and a second 3D sensing pixel. Here, the magnetic sensor is arranged so that the first 3D sensing pixel and the second 3D sensing pixel are at different distances from the tilt point of the object, and so that the first 3D sensing pixel and the second 3D sensing pixel are at different distances from the center of the magnet.

[0012] Here, since only a single magnetic sensor and a single magnet are required, the sensor system has reduced complexity and / or reduced cost (e.g., compared to implementations that use multiple sensor systems to detect the state of an object). In addition, due to the use of magnetic sensing principles, the sensor system described herein has an increased lifespan (e.g., due to contactless and therefore wear-free operation), increased miniaturization potential, and increased robustness against, for example, temperature changes and dirt. In addition, the pair of 3D sensing pixels implements differential 3D sensing, which means that the sensor system is robust to stray fields in the environment of the sensor system and further reduces or eliminates the need for system calibration, which reduces production effort and cost. More details are provided below.

[0013] Figure 1A and Figure 1B is a diagram of an example implementation of a stray field robust sensor system 100 that may be used to detect the state of a tiltable and rotatable object as described herein. Figure 1A and Figure 1B As shown, in some implementations, the sensor system 100 may include an object 102 that is capable of tilting about a tilt point 104 , a magnet 106 , and a magnetic sensor 108 including a pair of 3D sensing pixels 110 .

[0014] The object 102 includes an object whose state (e.g., tilt position, rotation position, etc.) is of interest to a given application. For example, the object 102 may include or be included in a joystick (e.g., a three-axis joystick), such as a game joystick, a marine joystick (e.g., for motorboat steering), or an aerospace joystick (e.g., for flight control of an airplane). As another example, the object 102 may include a device capable of 3DoF motion, such as a robotic joint (e.g., shoulder, neck, wrist, etc.), a mechanical joint (e.g., for a steering knuckle, a car suspension system, etc.), or a control element (e.g., a knob, a dial, a wheel, a button, or any combination thereof). In some implementations, the object 102 may be included in a vehicle, for example, for a control system (e.g., a multimedia system, a navigation system, an audio system, a telephone system, etc.). In some implementations, the object 102 is connected to (e.g., attached to, coupled to, fixed to, embedded in, etc.) a magnet 106.

[0015] In some implementations, the object 102 can be tilted (e.g., about the tilt point 104) relative to a first direction (e.g., an x-direction) and a second direction (e.g., a direction substantially perpendicular to the x-direction, such as the y-direction) such that the object 102 can be in a plurality of tilted positions. If the object 102 is not tilted relative to the x-direction or the y-direction, the object 102 can be said to be in an untilted position. In some implementations, the object 102 can be positioned in a plurality of tilted positions in a given direction (e.g., three tilted positions, five tilted positions, nine tilted positions, etc.). For example, the object 102 can be positioned in five tilted positions relative to each tilt direction.

[0016] like Figure 1A and Figure 1B As shown, in some implementations, the object 102 can rotate around an axis of the object 102 (referred to herein as the object axis 112). In some implementations, the object axis 112 is an axis that is substantially parallel to the z-direction (i.e., aligned with the z-direction) and passes through the tilt point 104 when the object 102 is in an untilted position. In some implementations, the object 102 can be positioned in a plurality of rotational positions. For example, in some implementations, the object 102 can be positioned in 8, 16, 32, 44, or more rotational positions. In some implementations, the object 102 can be capable of 360 degrees (°) rotation. In some implementations, the object 102 can be in any rotational position, and the object 102 can be in any tilted position in any direction.

[0017] In some implementations, the object 102 can be in one of a plurality of states, wherein each state is associated with a tilt position relative to a first direction, a tilt position relative to a second direction, and a rotational position. In some implementations, each possible state of the object 102 can be mapped to a corresponding set of magnetic field strengths to allow the state of the object 102 to be determined based on sensing of magnetic field components by the magnetic sensor 108, as described below.

[0018] Magnet 106 includes a magnet connected (e.g., attached, coupled, fixed, etc.) to object 102 such that a state of magnet 106 corresponds to a state of object 102, as described herein. In some implementations, magnet 106 includes a first half forming a north pole (N) and a second half forming a south pole (S), such that magnet 106 includes a pole pair. For example, Figure 1A and Figure 1B As shown, the magnet 106 may include a magnet having a north pole on a first half of the magnet 106 and a south pole on a second half of the magnet 106. As another example, the magnet 106 may include a magnet having a north pole on a first half of the magnet 106, the north pole stacked (e.g., along the z-direction) on a south pole (not shown) on a second half of the magnet 106. Additionally or alternatively, the magnet 106 may include a dipole magnet (e.g., a dipole rod magnet, a circular dipole magnet, an elliptical dipole magnet, etc.), a permanent magnet, an electromagnet, a magnetic tape, etc. In some implementations, the magnet 106 may include, but is not limited to, more than one pole pair.

[0019] In some implementations, the magnet 106 can be composed of a ferromagnetic material (e.g., hard ferrite) and can generate a magnetic field. In some implementations, the magnet 106 can also include a rare earth magnet, which can be advantageous due to the inherent high magnetic field strength of the rare earth magnet. In some implementations, the magnet 106 can be a uniformly magnetized magnet with a residual induction (Br) in the range of 150 millitesla (mT) to about 1400 mT, such as 1000 mT.

[0020] In some implementations, the dimensions (e.g., length, width, height, diameter, radius, etc.) of the magnet 106 can be in the range of about 1 millimeter (mm) to about 15 mm, such as 3 mm. As a specific example, the magnet 106 can have a length, width, and height of about 3 mm (i.e., the magnet 106 can be a 3 mm×3 mm×3 mm cube). It is worth noting that although the magnet 106 is Figure 1A and Figure 1B 1 and 2 as having a square shape, but the magnet 106 may have another shape, such as a rectangle, a circle, an ellipse, a triangle, or a ring, etc.

[0021] In some implementations, magnet 106 can be attached to object 102 in an asymmetrical manner. Figure 1A and Figure 1B As shown, magnet 106 can be connected to object 102 so that the center of magnet 106 is offset from object axis 112. In some implementations, the offset of the center of magnet 106 from object axis 112 can be, for example, in the range of about 0.2 mm to about 5.0 mm, such as 0.5 mm. Figure 1A and Figure 1B As further shown, the magnet 106 can be arranged so that the tilt point 104 is adjacent to the nearest surface of the magnet 106 (e.g., Figure 1A In some implementations, the specific axial distance can be in the range of about 5 mm to about 30 mm. In some implementations, the asymmetric mounting of magnets 106 (e.g., the arrangement of magnets 106 at offsets and axial distances) provides magnetic state separation between states of object 102, such that the state of object 102 can be reliably identified by magnetic sensor 108, as described below.

[0022] Magnetic sensor 108 includes one or more devices for sensing magnetic field components for determining the state of object 102 (e.g., based on the state of magnet 106 relative to magnetic sensor 108). Figure 1A and Figure 1B As shown, the magnetic sensor 108 may include a first 3D sensing pixel 110 and a second 3D sensing pixel 110. The 3D sensing pixel 110 includes a circuit (e.g., one or more integrated circuits), each circuit operating to (separately) sense an x ​​component of a magnetic field, a y component of a magnetic field, and a z component of a magnetic field. The 3D sensing pixel 110 may be, for example, a 3D Hall pixel capable of sensing three magnetic field components based on the Hall effect. In some implementations, the distance between the first 3D sensing pixel 110 and the second 3D sensing pixel 110 may be, for example, in the range of about 1 mm to about 3 mm.

[0023] In some implementations, the first 3D sensing pixel 110 and the second 3D sensing pixel 110 form a differential 3D sensor. For example, the magnetic sensor 108 may include a circuit device configured to combine a first signal corresponding to an x-component of a magnetic field sensed by the first 3D sensing pixel 110 and a second signal corresponding to an x-component of a magnetic field sensed by the second 3D sensing pixel 110 to generate a first combined signal. Here, the first combined signal may represent a difference between the first sensor signal associated with the x-component of the magnetic field and the second sensor signal. Similarly, the magnetic sensor 108 may include a circuit device configured to combine a third signal corresponding to a y-component of a magnetic field sensed by the first 3D sensing pixel 110 and a fourth signal corresponding to a y-component of a magnetic field sensed by the second 3D sensing pixel 110 to generate a second combined signal. Here, the second combined signal may represent a difference between the third sensor signal associated with the y-component of the magnetic field and the fourth sensor signal. In addition, the magnetic sensor 108 may include a circuit device configured to combine a fifth signal with a sixth signal to generate a third combined signal, the fifth signal corresponding to the z component of the magnetic field sensed by the first 3D sensing pixel 110, and the sixth signal corresponding to the z component of the magnetic field sensed by the second 3D sensing pixel 110. Here, the third combined signal may represent the difference between the fifth sensor signal and the sixth sensor signal associated with the z component of the magnetic field. In some implementations, the 3D sensing pixels 110 may be electrically connected in a half-bridge configuration or a full-bridge configuration (e.g., a Wheatstone bridge) to provide a differential circuit device that can be used to generate such a combined sensor signal. Additionally or alternatively, the differential circuit device may be one or more other components, such as a differential amplifier, an adder, a subtractor, a combiner, a logic circuit device, and / or a processor (e.g., a processor that applies differential arithmetic) to differentially combine the signals. In this way, the 3D sensing pixels 110 of the magnetic sensor 108 provide robustness to (homogeneous) external stray magnetic fields, and / or reduce or eliminate the need for calibration.

[0024] In some implementations, the magnetic sensor 108 may include an integrated circuit that includes an integrated controller (e.g., such that the output of the magnetic sensor 108 may include information describing the state of the magnet 106 and / or the state of the object 102). Additional details regarding the magnetic sensor 108 are provided below with reference to Figure 3 Give a description.

[0025] In some implementations, the magnetic sensor 108 can be arranged at a position relative to the magnet 106 so that the 3D sensing pixels 110 of the magnetic sensor 108 can detect a magnetic field component in the environment of the magnetic sensor 108 (e.g., including the magnetic field generated by the magnet 106). In some implementations, the magnetic sensor 108 is arranged so that the first 3D sensing pixel 110 and the second 3D sensing pixel 110 are at different distances from the tilt point 104 of the object 102. That is, in some implementations, the magnetic sensor 108 can be arranged so that the magnetic sensor 108 is not centered on the object 102. In addition, in some implementations, the magnetic sensor 108 can be arranged so that the first 3D sensing pixel 110 and the second 3D sensing pixel 110 are at different distances from the center of the magnet 106. That is, in some implementations, the magnetic sensor 108 can be arranged so that the magnetic sensor 108 is not centered on the magnet 106. In some implementations, such an arrangement of the magnetic sensors 108 , and thus the 3D sensing pixels 110 , enables differential measurements of the magnetic field as described above.

[0026] In some implementations, such as Figure 1A As shown, the magnetic sensors 108 are arranged so that the first 3D sensing pixel 110 and the second 3D sensing pixel 110 are aligned with the tilt axis of the object 102. Such an arrangement of the magnetic sensors 108 can be referred to as a longitudinal arrangement. In some implementations, the arrangement of the longitudinally arranged magnetic sensors 108 has relatively low complexity and relatively low cost.

[0027] Alternatively, if Figure 1B As shown, in some implementations, the magnetic sensor 108 can be arranged so that the first 3D sensing pixel 110 and the second 3D sensing pixel 110 are aligned with the object axis 112 when the object 102 is in a non-tilted position. Such an arrangement of the magnetic sensor 108 can be referred to as a vertical arrangement. In some implementations, the arrangement of the vertically arranged magnetic sensor 108 can improve reliability by increasing state separation (for example, as described below with respect to Figure 3 described above).

[0028] Notably, in both the longitudinal arrangement and the vertical arrangement, the first 3D sensing pixel 110 and the second 3D sensing pixel 110 are at different distances from the tilt point 104 of the object 102. Furthermore, both the first 3D sensing pixel 110 and the second 3D sensing pixel 110 are at different distances from the center of the magnet 106 (e.g., the 3D differential sensor formed by the first 3D sensing pixel and the second 3D sensing pixel is not centered relative to the center of the magnet 106). Therefore, both the longitudinal arrangement and the vertical arrangement enable differential measurements that provide robustness to stray fields and / or reduce or eliminate the need for calibration.

[0029] In some implementations, the magnetic sensor 108 may be configured with mapping information associated with determining the state of the object 102 based on the sensed magnetic field components. The mapping information may include information associated with the state (e.g., information identifying the tilt position, linear position, and / or rotational position corresponding to the state) and a set of magnetic field strengths corresponding to the state, including the magnetic field strength in the x-direction, the magnetic field strength in the y-direction, and the magnetic field strength in the z-direction. The mapping information may include such information for multiple states. For example, using the above example, the mapping information may include information associated with multiple possible states of the object 102 and multiple sets of magnetic field strengths, each set of magnetic field strengths corresponding to a different state in the multiple possible states. In some implementations, the magnetic sensor 108 may be configured with mapping information during a manufacturing process associated with the sensor system 100, a calibration process associated with the sensor system 100, a setup process associated with the sensing system 100, and the like.

[0030] During operation, the 3D sensing pixels 110 of the magnetic sensor 108 can each (individually) sense an x-component of a magnetic field in the environment of the magnetic sensor 108, a y-component of a magnetic field in the environment of the magnetic sensor 108, and a z-component of a magnetic field in the environment of the magnetic sensor 108. The magnetic field can include a magnetic field generated by the magnet 106 and one or more external magnetic fields (e.g., one or more stray magnetic fields, one or more magnetic fields generated by electrical components near the magnetic sensor 108, etc.). The magnetic sensor 108 can then generate a set of differential signals, where each differential signal is associated with a component of the magnetic field. For example, the magnetic sensor 108 can generate a differential x-component signal based on the x-component of the magnetic field sensed by the first 3D sensing pixel 110 and the second 3D sensing pixel 110, generate a differential y-component signal based on the y-component of the magnetic sensor 108 sensed by the first 3D sensing pixel 110 and the second 3D sensing pixel 110, and generate a differential z-component signal based on the z-component of the magnetic sensor 108 sensed by the first 3D sensing pixel 110 and the second 3D sensing pixel 110. In some implementations, the magnetic sensor 108 may output the differential signal set to, for example, a controller (not shown). Additionally or alternatively, the magnetic sensor 108 may compare the differential signal set with mapping information (if configured on the magnetic sensor 108), and determine the state of the object 102 based on the comparison. For example, the magnetic sensor 108 may identify a set of signal levels included in the mapping information that match (e.g., within a threshold) the signal levels generated by the magnetic sensor 108. In this example, the magnetic sensor 108 may determine the state of the object 102 as a state corresponding to the matching mapping information.

[0031] Figure 1A and Figure 1B The number and arrangement of the devices shown are provided as examples. Figure 1A and Figure 1B There may be more devices, fewer devices, different devices, or differently arranged devices than shown. Figure 1A and Figure 1B Two or more of the devices shown may be implemented in a single device, or Figure 1A and Figure 1B The single device shown may be implemented as multiple distributed devices. Additionally or alternatively, a collection of devices (eg, one or more devices) of sensor system 100 may perform one or more functions described as being performed by another collection of devices of sensor system 100.

[0032] Figure 2 is a diagram of an example magnetic sensor 108 according to one or more implementations described herein. Figure 2As shown, the magnetic sensor 108 may include a plurality of sensing elements 210 , an analog-to-digital converter (ADC) 220 , a digital signal processor (DSP) 230 , a memory element 240 , and an interface 250 .

[0033] The magnetic sensor 108 may include a semiconductor chip (e.g., a sensor chip) that includes a plurality of sensing elements 210 that measure or otherwise sense one or more characteristics of a magnetic field (e.g., the amount of magnetic field flux density, field strength, field angle, field direction, field orientation, etc.), and provide one or more sensor signals corresponding to the sensed magnetic field characteristics. For example, the sensing element 210 may be configured to generate a sensor signal (e.g., a voltage) in response to one or more magnetic fields impinging on the sensing element 210. Thus, the sensor signal indicates the magnitude and / or field orientation of at least one magnetic field impinging on the sensing element 210. The semiconductor chip may also include a sensor circuit device for processing and outputting one or more sensor signals generated by the one or more sensing elements 210. In some implementations, the plurality of sensing elements 210 may be distributed over two or more semiconductor chips.

[0034] The magnetic field may be generated by a magnet, a current-carrying conductor (e.g., a wire, a lead frame, or a busbar), the earth, or other magnetic field sources. A given sensing element 210 has a "sensitivity axis" or "sensing axis". The sensing element 210 is sensitive to the magnetic field component of the magnetic field that is projected onto the sensitivity axis or aligned with the sensitivity axis. In addition, the sensing element 210 is substantially insensitive to the magnetic field component of the magnetic field that is not projected onto the sensitivity axis or is not aligned with the sensitivity axis. The magnetic field component may be, for example, the x component of the magnetic field (Bx), the y component of the magnetic field (By), or the z component of the magnetic field (Bz). In the examples described herein, the x component of the magnetic field and the y component of the magnetic field are aligned in-plane with the semiconductor chip, and the z component of the magnetic field is aligned out-of-plane with the semiconductor chip. Therefore, the x component of the magnetic field and the y component of the magnetic field may be referred to as the "in-plane" magnetic field component aligned parallel to the chip plane (e.g., chip surface) of the semiconductor chip. In contrast, the z component of the magnetic field may be referred to as the "out-of-plane" magnetic field component that extends out of the chip plane (e.g., chip surface) of the semiconductor chip. For example, the z-component of the magnetic field extends perpendicular to the chip plane.

[0035] In some implementations, the magnetic sensor 108 includes a set of sensing elements 210 that are sensitive in different directions. For example, the magnetic sensor 108 may include: a first sensing element 210 configured to sense a first magnetic field component (e.g., an x-component of the magnetic field), a second sensing element configured to sense a second magnetic field component (e.g., a y-component of the magnetic field), and a third sensing element configured to sense a third magnetic field component (e.g., a z-component of the magnetic field). In some implementations, such a set of sensing elements 210 may form a 3D sensing pixel 110 as described herein. In some implementations, the magnetic sensor 108 includes multiple sets of such sensing elements 210. Thus, in some implementations, the magnetic sensor 108 may include multiple sets of sensing elements 210, wherein each set of sensing elements 210 forms a 3D sensing pixel 110. In some implementations, each set of sensing elements 210 (i.e., multiple 3D sensing pixels 110) forms a differential 3D sensor, as described herein.

[0036] In some implementations, the sensing element 210 may include one or more Hall-based sensing elements (i.e., Hall sensing elements). A Hall sensing element is a transducer that changes an output voltage (e.g., a Hall voltage) in response to a magnetic field. The Hall sensing element may be, for example, a Hall plate through which current is conducted. The output voltage of the Hall sensing element is based on the Hall effect using the Lorentz force. The Lorentz force deflects mobile charges in the presence of a magnetic field that is perpendicular to the current flowing through the Hall sensing element (e.g., Hall plate). Thus, the sensing element may be a thin sheet of semiconductor material or metal. The deflection causes charge separation, thereby generating a Hall magnetic field. This Hall magnetic field acts on the charge in a direction opposite to the Lorentz force. The two forces balance each other and produce a potential difference perpendicular to the direction of current flow. The potential difference can be measured as a Hall voltage and varies linearly with the magnetic field.

[0037] There are generally two types of Hall sensing elements, including vertical Hall sensing elements and lateral Hall sensing elements. A vertical Hall sensing element (e.g., a vertical Hall plate) is configured to be perpendicular to a chip plane defined by a main surface of a semiconductor chip. In particular, a vertical Hall sensing element can be a conductive plate having a sensor plane that extends "vertically" from the main surface of the semiconductor chip into the chip body of the semiconductor chip. The sensitivity axis of the vertical Hall sensing element is perpendicular to the sensor plane. This generally means that the vertical Hall sensing element is sensitive to magnetic field components that are parallel to the main surface of the semiconductor chip (in which the vertical Hall sensing element is integrated) or extend within the plane of the main surface. For a vertical Hall sensing element, a voltage value can be output according to the magnetic field flux density in the direction of its sensitivity axis.

[0038] On the other hand, a lateral (planar) Hall sensing element (e.g., a lateral Hall plate) is composed of a sensor plane that is parallel to a chip plane defined by a main surface of a semiconductor chip. In particular, a lateral Hall sensing element can be a conductive plate having a sensor plane that extends laterally along or parallel to the main surface of the semiconductor chip. Since the sensitivity axis of the lateral Hall sensing element is perpendicular to the sensor plane, this generally means that the lateral Hall sensing element is sensitive to magnetic fields that are perpendicular to the main surface of the semiconductor chip or out of the plane of the main surface. For a lateral Hall sensing element, a voltage value can be output according to the magnetic field flux density in the direction of its sensitivity axis.

[0039] Thus, the vertical Hall sensing element can be used to measure a magnetic field parallel to the chip plane of the magnetic sensor 108, and the lateral Hall sensing element can be used to measure a magnetic field perpendicular to the chip plane of the magnetic sensor 108. Two or more sensing elements and corresponding sensor circuit devices can be housed (e.g., integrated) in the same semiconductor chip. The sensor circuit device can be referred to as a signal processing circuit device and / or a signal conditioning circuit device, which receives one or more signals (e.g., sensor signals) in the form of raw measurement data from one or more sensing elements, and derives a measurement signal representing a magnetic field from the one or more signals. For example, the sensor circuit device can be configured to condition and amplify the sensor signal of one or more sensing elements 210 via signal processing and / or conditioning.

[0040] The above examples of sensing elements 210 are provided for illustration purposes, and in practice, the sensing elements 210 may include any type of magnetic field sensing element capable of sensing magnetic field characteristics and enabling sensor signals to be provided to the sensor circuit device. For example, in some implementations, the plurality of sensing elements 210 may include one or more magnetoresistive based sensing elements.

[0041] The ADC 220 may include an analog-to-digital converter that converts analog signals from one or more sensing elements 210 into digital signals. For example, the ADC 220 may convert analog signals received from the plurality of sensing elements 210 into digital signals (e.g., digital samples) for processing by the DSP 230. The ADC 220 may provide the digital signals to the DSP 230. In some implementations, the magnetic sensor 108 may include one or more ADCs 220. For example, different ADCs 220 may be configured to receive analog signals from different sets of sensing elements 210 in the plurality of sensing elements 210.

[0042] DSP 230 may include a digital signal processing device or a group of digital signal processing devices. In some implementations, DSP 230 may receive digital signals from ADC 220 and may process the digital signals to form output signals (e.g., to a controller), such as output signals conveying sensor data, as described elsewhere herein. In some implementations, the output signals may be referred to as measurement signals.

[0043] The memory element 240 may include a read-only memory (ROM) (e.g., EEPROM), a random access memory (RAM), and / or another type of dynamic or static storage device (e.g., flash memory, magnetic memory, optical memory, etc.) that stores information and / or instructions for use by the magnetic sensor 108. In some implementations, the memory element 240 may store information associated with processing performed by the DSP 230. Additionally or alternatively, the memory element 240 may store configuration values ​​or parameters of one or more sensing elements 210, and / or information of one or more other components of the magnetic sensor 108 (such as the ADC 220 or the interface 250).

[0044] The interface 250 may include an interface via which the magnetic sensor 108 may receive information from and / or provide information to another device in the system, such as a controller (not shown). For example, the interface 250 may provide an output signal determined or otherwise generated by the DSP 230 to the controller, and may also receive information from the controller. In some implementations, the interface 250 may be a communication interface that receives an output signal from the DSP 230 according to a communication protocol and provides the output signal as a communication signal, which may include transmitting the output signal as a communication signal or generating a communication signal based on the output signal.

[0045] As mentioned above, Figure 2 Provided as an example. Other examples can be found with Figure 2 Different from what is described. Figure 2 The number and arrangement of components shown are provided as examples. Figure 2 The magnetic sensor 108 may include more phases, fewer phases, different phases, or differently arranged phases than those shown. Figure 2 Two or more of the components shown may be implemented in a single component, or Figure 2 The single component shown may be implemented as multiple distributed components. Additionally or alternatively, a collection of components (eg, one or more components) of the magnetic sensor 108 may perform one or more functions described as being performed by another collection of components of the magnetic sensor 108 .

[0046] Figure 3is a diagram 300 illustrating examples associated with measurement resolutions achievable with the sensor system 100 described herein. Figure 3 The horizontal axis in represents the distance (in mm) between the 3D sensing pixels 110 of the magnetic sensor 108 . Figure 3 The vertical axis in represents the magnetic state separation (in mT / step).

[0047] In some implementations, as described above, each possible state of the object 102 (e.g., any of a plurality of rotational positions at any tilt position) can be represented by a different point in the 3D magnetic space, where each point is defined by a differential magnetic field strength in the x-direction, a differential magnetic field strength in the y-direction, and a differential magnetic field strength in the z-direction. Thus, each state of the object 102 can correspond to a different set of magnetic field strengths. Figure 3 The minimum separation in mT per step (mT / step) is shown for various sizes of magnets 106 (e.g., application specific shaped magnets (shaped), 2 mm×2 mm×2 mm, 3 mm×3 mm×3 mm, 4 mm×4 mm×4 mm, 5 mm×5 mm×5 mm) and various distances between 3D sensing pixels 110 (e.g., from 1 mm to 3 mm) for both a longitudinal arrangement of the magnetic sensors 108 (represented by solid lines) and a vertical arrangement of the magnetic sensors 108 (represented by dashed lines).

[0048] As an example, Figure 3As shown, the sensor system 100 achieves a minimum state separation of about 0.57 mT / step for a 5 mm×5 mm×5 mm magnet 106 and magnetic sensor 108, a 3D sensing pixel 110 with a distance of 2 mm, and a magnetic sensor 108 in a vertical arrangement. In a specific example, the magnetic sensor 108 may be capable of 0.0325 mT / least significant bit (mT / LSB). Such a magnetic sensor 108 may achieve a resolution of less than about 0.1° for tilt measurement (e.g., for a 1° tilt step, (0.57 mT / step) / (0.0325 mT / LSB)=17.5 LSB / step; (1° / step) / (17.5 LSB / step)=0.06° / LSB), and may achieve a resolution of less than about 0.3° for rotational position measurement over 360° (e.g., for a 5° rotation step, (0.57 mT / step) / (0.0325 mT / LSB)=17.5 LSB / step; (5° / step) / (17.5 LSB / step)=0.29° / LSB). As another specific example, the magnetic sensor 108 may be capable of 0.0082 mT / LSB. Such a magnetic sensor 108 can achieve a resolution of less than about 0.02° for tilt measurement (e.g., for a tilt step of 1°, (0.57mT / step) / (0.0082mT / LSB)=69.5LSB / step; (1° / step) / (69.5LSB / step)=0.014° / LSB), and can achieve a resolution of less than about 0.1° for rotational position measurement above 360° (e.g., for a rotation step of 5°, (0.57mT / step) / (0.0082mT / LSB)=69.5LSB / step; (5° / step) / (69.5LSB / step)=0.07° / LSB).

[0049] As another example, Figure 3As shown, for a 5 mm x 5 mm x 5 mm magnet 106 and magnetic sensor 108, a 3D sensing pixel 110 with a distance of 2 mm, and a magnetic sensor 108 in a longitudinal arrangement, the sensor system 100 achieves a state separation of about 0.17 mT / step. In one specific example, the magnetic sensor 108 may be capable of 0.0325 mT / LSB). Such a magnetic sensor 108 can achieve a resolution of less than about 0.2° for tilt measurement (e.g., for a 1° tilt step, (0.18mT / step) / (0.0325mT / LSB)=5.5LSB / step; (1° / step) / (5.5LSB / step)=0.18° / LSB), and can achieve a resolution of about 1.0° for rotational position measurement above 360° (e.g., for a 5° rotation step, (0.18mT / step) / (0.0325mT / LSB)=5.5LSB / step; (5° / step) / (5.5LSB / step)=0.91° / LSB). As another specific example, the magnetic sensor 108 may be capable of 0.0082mT / LSB. Such a magnetic sensor 108 can achieve a resolution of less than about 0.5° for tilt measurement (e.g., for a tilt step of 1°, (0.18mT / step) / (0.0082mT / LSB)=22.0LSB / step; (1° / step) / (22.0LSB / step)=0.045° / LSB), and can achieve a resolution of less than about 0.25° for rotational position measurement above 360° (e.g., for a rotation step of 5°, (0.18mT / step) / (0.0082mT / LSB)=22.0LSB / step; (5° / step) / (22.0LSB / step)=0.23° / LSB)). Notably, a sensor system 100 in which the object 102 is configured to rotate in less than 360° rotations will have improved resolution with respect to rotational position measurements (e.g., due to the reduced number of possible rotational positions compared to an object 102 configured to rotate 360°). In this manner, the sensor system 100 can achieve sufficient magnetic state separation to allow the state of the object 102 to be reliably determined.

[0050] like Figure 3 As shown, sensor system 100 is able to achieve sufficient magnetic state separation to reliably determine the state of object 102 .

[0051] As mentioned above, Figure 3 Provided as an example. Other examples can be found with Figure 3 Different from what is described.

[0052] The above disclosure provides illustration and description, but is not intended to be exhaustive or to limit the implementation to the precise form disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the implementation.

[0053] It is apparent that the systems and / or methods described herein may be implemented in various forms of hardware, firmware, or a combination of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods does not limit these implementations. Therefore, the operation and behavior of the systems and / or methods are described herein without reference to specific software code - it should be understood that software and hardware can be designed based on the description herein to implement these systems and / or methods.

[0054] As used herein, satisfying a threshold may refer to a value being greater than a threshold, greater than or equal to a threshold, less than a threshold, less than or equal to a threshold, equal to a threshold, not equal to a threshold, etc., depending on the context.

[0055] Even though specific combinations of features are listed in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various implementations. In fact, many of these features can be combined in ways that are not specifically listed in the claims and / or disclosed in the specification. Although each dependent claim listed below may be directly dependent on only one claim, the disclosure of various implementations includes each dependent claim combined with each other claim in the claim set. As used herein, a phrase referring to "at least one" in a list of items refers to any combination of these items, including single members. For example, "at least one of a, b, or c" is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiple identical items.

[0056] Unless explicitly stated, any element, action or instruction used in this article should not be interpreted as key or necessary. In addition, as used in this article, the article "one" and "an" are intended to include one or more projects, and can be used interchangeably with "one or more". In addition, as used in this article, the article "the" or "said" is intended to include one or more projects related to the article "the" or "said", and can be used interchangeably with "one or more". In addition, as used in this article, the term "set" is intended to include two or more projects (for example, a combination of related projects, unrelated projects or related projects and unrelated projects), and can be used interchangeably with it. If only one project is intended to be used, the phrase "only one" or similar language is used. In addition, as used in this article, the term "has", "have", "having" etc. are intended to be open terms. In addition, unless otherwise explicitly stated, the word "based on" means "at least partially based on". In addition, as used in this article, the term "or" is inclusive when used in a series, and can be used interchangeably with "and / or", unless otherwise explicitly stated (for example, if used in combination with "any one" or "only one"). Additionally, for ease of description, spatially relative terms (such as "below," "lower," "above," "upper," etc.) may be used herein to describe the relationship of one element or feature to another element or feature, as shown in the figures. Spatially relative terms are intended to encompass different orientations of the device, equipment, and / or element in use or operation in addition to the orientation shown in the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations), and the spatially relative descriptors used herein may be interpreted accordingly.

Claims

1. A sensor system comprising: object; a magnet connected to the object, the magnet connected to the object such that a center of the magnet is offset from an axis of the object; as well as A magnetic sensor comprising a first three-dimensional sensing pixel and a second three-dimensional sensing pixel, wherein the magnetic sensor is arranged such that the first three-dimensional sensing pixel and the second three-dimensional sensing pixel are at different distances from a tilt point of the object, and Wherein the magnetic sensor is arranged such that the first three-dimensional sensing pixel and the second three-dimensional sensing pixel are at different distances from the center of the magnet. 2 . The sensor system according to claim 1 , wherein the magnetic sensor is arranged so that the first three-dimensional sensing pixel and the second three-dimensional sensing pixel are aligned with a tilt direction of the object.

3. The sensor system of claim 1 , wherein the magnetic sensor is arranged such that the first three-dimensional sensing pixel and the second three-dimensional sensing pixel are aligned with the axis of the object when the object is in a non-tilted position. 4 . The sensor system of claim 1 , wherein the first 3D sensing pixel and the second 3D sensing pixel form a differential 3D sensor. 5 . The sensor system of claim 1 , wherein a distance between the first three-dimensional sensing pixel and the second three-dimensional sensing pixel is in a range of about 1 mm to about 3 mm.

6. The sensor system of claim 1, wherein the sensor system is included in a joystick.

7. The sensor system of claim 1, wherein the sensor system is included in a device capable of three degrees of freedom (3-DoF) motion.

8. A sensor system comprising: a magnet connected to an object, the magnet connected to the object such that the magnet is not centered about an axis of the object; as well as Differential 3D sensor, wherein the first 3D sensing pixel of the differential 3D sensor and the second 3D sensing pixel of the differential 3D sensor are at different distances from the tilt point of the object, and Wherein the differential three-dimensional sensor is not centered relative to the center of the magnet. 9 . The sensor system according to claim 8 , wherein the differential three-dimensional sensor is arranged so that each three-dimensional sensing pixel of the differential three-dimensional sensor is aligned with a tilt direction of the object.

10. The sensor system of claim 8, wherein the differential 3D sensor is arranged such that each 3D sensing pixel of the differential 3D sensor is aligned with the axis of the object when the object is in a non-tilted position.

11. The sensor system of claim 8, wherein a distance between a pair of 3D sensing pixels of the differential 3D sensor is in a range of about 1 mm to about 3 mm.

12. The sensor system of claim 8, wherein the sensor system is included in a joystick.

13. The sensor system of claim 8, wherein the sensor system is included in a device capable of three degrees of freedom (3-DoF) motion.

14. An apparatus comprising: Magnets, attached to objects that can be positioned with respect to multiple degrees of freedom, wherein the magnet is connected to the object such that the center of the magnet is offset from the axis of the object; as well as a magnetic sensor for determining the state of the object relative to the plurality of degrees of freedom based on a set of magnetic field strengths of the magnetic field generated by the magnet, the magnetic sensor comprising first three-dimensional sensing pixels and second three-dimensional sensing pixels, wherein a distance between the first three-dimensional sensing pixel and a tilt point of the object is different from a distance between the second three-dimensional sensing pixel and the tilt point of the object, and The distance between the first three-dimensional sensing pixel and the center of the magnet is different from the distance between the second three-dimensional sensing pixel and the center of the magnet. 15 . The device of claim 14 , wherein the first three-dimensional sensing pixel and the second three-dimensional sensing pixel are aligned with a tilt direction of the object. 16 . The apparatus of claim 14 , wherein the first 3D sensing pixel and the second 3D sensing pixel are aligned with the axis of the object when the object is in a non-tilted position.

17. The apparatus of claim 14, wherein the first three-dimensional sensing pixel and the second three-dimensional sensing pixel cause the magnetic sensor to determine a differential measurement based on the set of magnetic field strengths. 18 . The device of claim 14 , wherein a distance between the first 3D sensing pixel and the second 3D sensing pixel is in a range of about 1 mm to about 3 mm.

19. The device of claim 14, wherein the device is a joystick.

20. The apparatus of claim 14, wherein the apparatus is a device capable of three degrees of freedom (3-DoF) motion.

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