Vibration Compliant Monitor for Speed ​​Sensors

Abstract

Embodiments of the present disclosure relate to a vibration-compatible monitor for a velocity sensor. The sensor device includes: at least one first sensor element generating a first sensor signal based on sensing a changing magnetic field; at least one second sensor element generating a second sensor signal based on sensing a changing magnetic field; a signal tracking circuit generating a trigger signal and extracting vibration-related information using the first sensor signal and the second sensor signal, the trigger signal having a trigger pulse generated based on the crossing of the first sensor signal with an adaptive threshold; an output controller generating an output signal having an output pulse triggered by the trigger pulse during a non-vibration event and suppressing the output pulse during the entire duration of a vibration event; a vibration detection circuit detecting a vibration event based on the extracted vibration-related information and indicating the vibration event to the output controller.

Description

Technical Field

[0001] Various embodiments of the present disclosure are directed to a vibration-compliant monitor for a velocity sensor. Background Art

[0002] Magnetic speed sensors are used for speed sensing in many applications across many industries, including wheel speed, engine speed, and transmission speed in the automotive industry. In the field of speed sensing, a sinusoidal signal can be generated by a magnetic sensor in response to the rotation of a target object such as a wheel, camshaft, crankshaft, etc. The sinusoidal signal can be converted into pulses, which are further converted into motion detection or speed output.

[0003] One purpose of a transmission speed sensor or wheel sensor is to evaluate the rotational speed of a target object (e.g., a gear or wheel). Information from the speed sensor can generate a speed signal representing the speed of the target object and a direction signal representing the rotational direction of movement of the target object. Thus, the speed sensor can generate a speed signal and a direction signal. Based on these signals, an additional output signal (e.g., a pulsed output signal) is generated, which provides the sensor information to a microcontroller or electronic control unit (ECU). Mechanical vibrations at the speed sensor can affect the speed signal and / or the direction signal by causing erroneous or unwanted sinusoidal oscillations in the signal, resulting in incorrect information being output at the output signal.

[0004] With the trend towards miniaturization and the continued development of autonomous driving, the requirements for vibration suppression and 0 Hz capability are needed today not only in transmission applications, but also in anti-lock braking system (ABS) sensors. The zero Hz functionality provides high sensor sensitivity for smaller rotational movements, which are used for start / stop detection and hill hold system detection (i.e., slope slip detection). The higher the sensor sensitivity, the higher the resolution for detecting smaller movements. On the other hand, using an overly aggressive vibration suppression algorithm (i.e., using too high a sensitivity for the sensor) can lead to sensor deadlock, resulting in no output switching. Magnetic particles, sudden air gap jumps, and large temperature drifts can all lead to such deadlock situations in speed sensors. However, the requirements for vibration suppression and 0 Hz functionality in terms of sensor sensitivity are contradictory.

[0005] Furthermore, there is a conflict between the requirement to suppress vibrations and the ability to recover to normal operation after large signal changes due to particles or significant air gap changes. In both cases, the amplitude-related hysteresis of extreme value, direction, and speed detection may be too large to track the significantly reduced signal. While the output signal needs to be suppressed during vibrations, the loss of the output signal after a large air gap change can cause the sensor to deadlock. To avoid deadlock, the sensor can automatically reset after a timeout in the absence of events at the output signal. The disadvantage of this solution is reduced vibration suppression and loss of functionality for signal frequencies close to 0 Hz required for start / stop detection and hill-hold system detection.

[0006] A compromise must be made between the ability to dampen vibrations and the potential for deadlock. The need for a compromise has been a long-standing problem in speed sensing in the presence of vibrations and particles in applications, particularly in transmission applications.

[0007] Therefore, there may be a need for an improved speed sensor that can suppress vibration, prevent deadlock, and allow 0 Hz functionality. Summary of the invention

[0008] Embodiments are directed to speed sensors capable of suppressing vibrations, preventing deadlock, and / or achieving 0 Hz functionality.

[0009] One or more embodiments are directed to a sensor device, the sensor device comprising: at least one first sensor element, configured to generate a first sensor signal based on sensing a changing magnetic field; at least one second sensor element, configured to generate a second sensor signal based on sensing a changing magnetic field; a signal tracking circuit, configured to generate a trigger signal having a trigger pulse, the trigger pulse being generated based on a first crossing of the first sensor signal with at least one of at least one adaptive threshold, wherein the signal tracking circuit also uses the first sensor signal and the second sensor signal to extract vibration-related information; an output controller, configured to generate an output signal having an output pulse triggered by the trigger pulse during a non-vibration event, and further configured to suppress the output pulse during the entire duration of a vibration event; and a vibration detection circuit, which is configured to receive the extracted vibration-related information, detect a vibration event based on the received extracted vibration-related information, and indicate the detected vibration event to the output controller.

[0010] One or more embodiments are directed to an output pulse suppression method implemented in a velocity sensor. The method includes: generating a first sensor signal by at least one first sensor element based on sensing a changing magnetic field; generating a second sensor signal by at least one second sensor element based on sensing a changing magnetic field; generating a trigger signal having a trigger pulse by a sensor circuit, the trigger pulse being generated based on a first crossing of the first sensor signal with at least one of at least one adaptive threshold; extracting vibration-related information by the sensor circuit using the first sensor signal and the second sensor signal; generating an output signal having an output pulse by the sensor circuit, the output pulse being triggered by the trigger pulse during a non-vibration event; detecting a vibration event by the sensor circuit based on the extracted vibration-related information; and suppressing the output pulse by the sensor circuit during the entire duration of the vibration event. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Embodiments are described herein with reference to the accompanying drawings.

[0012] Figure 1A-Figure 1C A schematic diagram of magnetic field sensing using a first type of magnetic encoder according to one or more embodiments is illustrated.

[0013] Figure 1D illustrates a schematic diagram of magnetic field sensing using a second type of magnetic encoder according to one or more embodiments;

[0014] Figure 2 is a schematic block diagram of a magnetic sensor according to one or more embodiments;

[0015] Figure 3 illustrates an example of a sensor signal generated by a sensor element along with a hysteresis threshold set according to one or more embodiments;

[0016] Figure 4 is a schematic block diagram of another magnetic sensor according to one or more embodiments;

[0017] Figure 5 illustrates an example of speed and direction sensor signals generated by two sensor elements along with two hysteresis threshold sets in accordance with one or more embodiments;

[0018] Fig. 6A illustrates a signal diagram according to a conventional speed magnetic sensor using no pulse blanking; and

[0019] Figure 6B Signal diagrams according to one or more embodiments using pulse blanking are illustrated. DETAILED DESCRIPTION

[0020] Hereinafter, details are set forth to provide a more thorough explanation of the exemplary embodiments. However, it will be apparent to those skilled in the art that the embodiments may be practiced without these specific details. In other cases, well-known structures and devices are shown in block diagram form or schematic diagrams rather than in detail to avoid confusing the embodiments. In addition, unless otherwise specifically stated, the features of the different embodiments described below may be combined with each other. It should also be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope defined by the claims. Therefore, the following detailed description should not be considered as limiting.

[0021] In addition, in the following description, equivalent or identical elements or elements having equivalent or identical functions are represented by equivalent or identical reference numerals. Since identical or functionally equivalent elements are given the same reference numerals in the figures, repeated descriptions of elements having the same reference numerals may be omitted. Therefore, descriptions provided for elements having the same or similar reference numerals are interchangeable.

[0022] Directional terms, such as "top," "bottom," "above," "below," "front," "rear," "after," "leading," "trailing," "above," "below," etc., may be used with reference to the orientation of the figures and / or elements being described. Because embodiments may be positioned in a number of different orientations, the directional terms are used for illustrative purposes and are not limiting. In some cases, directional terms may be interchanged with equivalent directional terms based on the orientation of the embodiments as long as the overall directional relationship between elements and their overall purpose is maintained.

[0023] In the present disclosure, expressions including ordinal numbers such as "first", "second", etc. can modify various elements. However, such elements are not limited by the above expressions. For example, the above expressions do not limit the order and / or importance of the elements. The above expressions are only used to distinguish elements from other elements. For example, the first box and the second box indicate different boxes, but they are both boxes. For another example, without departing from the scope of the present disclosure, the first element can be referred to as the second element, and similarly, the second element can also be referred to as the first element.

[0024] It should be understood that when an element is referred to as being "connected" or "coupled" to another element, it may be directly connected or coupled to the other element, or there may be intervening elements. Conversely, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intervening elements. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.).

[0025] In the embodiments described herein or shown in the accompanying drawings, any direct electrical connection or coupling, i.e., any connection or coupling without additional intermediate elements, may also be achieved by an indirect connection or coupling, i.e., connection or coupling using one or more additional intermediate elements, or vice versa, as long as the overall purpose of the connection or coupling (e.g., transmitting a certain signal or transmitting certain information) remains substantially unchanged. Features from different embodiments may be combined to form further embodiments. For example, changes or modifications described with respect to one embodiment in the embodiments may also apply to other embodiments unless otherwise stated.

[0026] According to certain implementation requirements, the storage medium may include RAM, ROM, PROM, EPROM, EEPROM, FLASH memory or any other medium on which electronically readable control signals are stored, and the electronically readable control signals cooperate (or can cooperate) with the programmable computer system so that the corresponding method is executed. Therefore, the storage medium can be considered as a computer-readable non-transitory storage medium.

[0027] In addition, the instructions can be executed by one or more processors, such as one or more central processing units (CPUs), digital signal processors (DSPs), general-purpose microprocessors, application-specific integrated circuits (ASICs), field programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuit devices. Therefore, the term "processor" used in this article refers to any of the aforementioned structures or any other structure suitable for implementing the technology described herein. In addition, in some aspects, the functions described herein can be provided in dedicated hardware and / or software modules. In addition, these technologies can be fully implemented in one or more circuits or logic elements. A "controller" including one or more processors can use electrical signals and digital algorithms to perform its reception, analysis and control functions, which can also include correction functions.

[0028] A sensor may refer to a component that converts a physical quantity to be measured into an electrical signal (e.g., a current signal or a voltage signal). Physical quantities may include, for example, magnetic fields, electric fields, pressure, force, temperature, current, or voltage, but are not limited thereto. As described herein, a sensor device may be a voltage sensor, a current sensor, a temperature sensor, a magnetic sensor, and the like.

[0029] The magnetic field sensor includes, for example, one or more magnetic field sensor elements that measure one or more characteristics of the magnetic field (e.g., the amount of magnetic field flux density, field strength, field angle, field direction, field orientation, etc.). The magnetic field can be generated by a magnet, a current-carrying conductor (e.g., a wire), the earth, or other magnetic field sources. Each magnetic field sensor element is configured to generate a sensor signal (e.g., a voltage signal) in response to one or more magnetic fields impinging on the sensor element. Therefore, the sensor signal indicates the magnitude and / or orientation of the magnetic field impinging on the sensor element.

[0030] Magnetic sensors include, for example, magnetoresistive sensors, inductive sensors, and Hall effect sensors (Hall sensors), and can be interchanged in the embodiments provided herein. According to one or more embodiments, both multiple magnetic field sensors and sensor circuit devices can be accommodated (i.e., integrated) in the same chip. The sensor circuit can be referred to as a signal processing circuit and / or a signal conditioning circuit, which receives one or more signals (i.e., sensor signals) from one or more magnetic field sensor elements in the form of raw measurement data and derives a measurement signal representing a magnetic field from the sensor signal.

[0031] In some cases, the measurement signal can be a differential measurement signal derived from sensor signals generated by two sensor elements having the same sensing axis (e.g., two sensor elements sensitive to the same magnetic field component) using differential calculations. The differential measurement signal provides robustness to uniform external stray magnetic fields.

[0032] As used herein, signal conditioning refers to manipulating an analog signal so that the signal meets the requirements of the next stage for further processing. Signal conditioning may include conversion from analog to digital (e.g., via an analog-to-digital converter), amplification, filtering, conversion, biasing, range matching, isolation, and any other process required to make the sensor output suitable for processing after conditioning.

[0033] Thus, the sensor circuit may include an analog-to-digital converter (ADC) that converts analog signals from one or more sensor elements into digital signals. The sensor circuit may also include a digital signal processor (DSP) that performs some processing on the digital signals, as discussed below. Thus, a chip, which may also be referred to as an integrated circuit (IC), may include circuits that condition and amplify small signals of one or more magnetic field sensor elements via signal processing and / or conditioning.

[0034] The sensor device used herein may refer to a device including a sensor and a sensor circuit as described above. The sensor device may be integrated on a single semiconductor die (e.g., a silicon die or chip). Therefore, the sensor and the sensor circuit are arranged on the same semiconductor die.

[0035] The magnetic field sensors provided herein can be configured for speed measurement and rotation direction measurement of a rotating magnetic encoder, such as a wheel or camshaft, referred to as a target object or target wheel.

[0036] One type of magnetic encoder may be a ferromagnetic encoder, which may be a gear or toothed disc of ferromagnetic material with a hole or notch through the front of the magnetic field sensor. The magnetic field may be generated by a back-bias magnet coupled to the back side of the magnetic field sensor. Thus, the strength of the magnetic field generated by the back-bias magnet is changed by the teeth and notches of the rotating magnetic encoder.

[0037] For example, the sensor module is positioned near a gear, wherein the distance between the sensor module and the gear is defined by an air gap. As a tooth or notch passes the sensor module, the air gap changes. Due to this changing air gap, the magnetic field (flux) generated by the reverse bias magnet expands or contracts in time with the approaching tooth or receding notch. This fluctuation in the magnetic field is measured by the sensor module, in particular, by one or more sensor elements of the sensor module.

[0038] The second type of magnetic encoder is an encoder consisting of alternating magnets that are magnetized in opposite directions (e.g., alternating south and north pole magnets) and arranged along the circumference of the encoder. In this case, a speed sensor is placed in front of the encoder and detects whether the measured magnetic field changes its polarity. In this case, the speed sensor generates an output signal indicating the passage of a magnetic pole.

[0039] Figure 1A-Figure 1C The magnetic field sensing principle of a gear 1 having alternating teeth 2 and notches 3 using a first type magnetic encoder according to one or more embodiments is illustrated. Specifically, the gear 1 may be made of a ferromagnetic material (e.g., iron) that attracts a magnetic field. In addition, a sensor device 4 is configured to sense a magnetic field generated by a reverse bias magnet 5, wherein the sensor device 4 and the reverse bias magnet 5 include a sensor module 6. The sensor device 4 may generally be referred to herein as a sensor 4 and may also include a sensor circuit (not shown) and may be provided in a sensor package.

[0040] Figure 1A and Figure 1B The teeth 2 and the notches 3 of the wheel 1 are shown passing through the sensor module 6. Figure 1AIn the case of , the magnetic field lines of the bias magnetic field generated by the reverse bias magnet 5 are pulled in the z direction towards the tooth 2. As a result, the magnetic field lines are pulled away from the x-axis and the y-axis (i.e., the sensor plane of the sensor device 4) and the magnetic field strength sensed in the x- and y-directions is reduced, so that a minimum field strength is detected at the center of the tooth 2. This may be different in actual applications, where the minimum value may not occur exactly at the center due to assembly tolerances, but the minimum field strength should be detected substantially at the center of the tooth 2.

[0041] On the contrary, Figure 1B In the case of , the magnetic field lines of the bias magnetic field generated by the back bias magnet 5 are not pulled (or pulled less) in the z direction toward the notch 3. Therefore, the magnetic field lines remain more concentrated with respect to the x and y axes (i.e., the sensor plane of the sensor device 4), and the magnetic field strength sensed in the x and y directions is maximum at the center of the notch 3. This may be different in actual applications, where the maximum value may not occur exactly at the center, but the maximum field strength should be detected substantially at the center of the notch 3.

[0042] Figure 1C A schematic diagram of a sensor module 6 close to a gear 1 is illustrated. The sensor module 6 includes a sensor device 4 having a sensor circuit (not shown) and two magnetic field sensor elements H1 and H2, and a reverse bias magnet 5 coupled to the sensor device 4. The two magnetic field sensor elements H1 and H2 may be referred to herein as differential sensor elements and are linearly aligned in the rotation direction of the gear 1. The sensor signal of each differential sensor element H1 and H2 is provided to the sensor circuit, which calculates a differential measurement signal using a differential calculation, which can be used to cancel uniform stray fields in the direction of the sensor plane.

[0043] In addition, the differential sensor elements H1 and H2 can be arranged at a distance of about half the tooth pitch of the gear 1 to generate a differential measurement signal with a high signal-to-noise ratio. The pitch is the distance along the pitch circle between two adjacent teeth of the gear. Finally, the leads 7 provide an electrical path for various input and output signals (e.g., power, command and output signals) to and from the sensor device 4.

[0044] As the wheel 1 rotates, the teeth 2 and the notches 3 alternately pass the sensor module 6 and the sensor elements within the sensor device 4 sense changes in the x-axis and y-axis magnetic field strengths, which vary as a sinusoidal waveform (i.e., as a signal modulation) whose frequency corresponds to the rotation speed of the wheel and also corresponds to the rotation speed of the drive shaft (e.g., a camshaft) that drives the wheel to rotate.

[0045] Thus, the sensor circuit of the sensor device 4 receives signals (i.e., sensor signals) from the magnetic field sensor elements H1 and H2 and derives a differential measurement signal from the sensor signal, the differential measurement signal representing the magnetic field as a signal modulation. The differential measurement signal can then be output as an output signal to an external controller, control unit or processor (e.g., ECU), or used internally by the sensor circuit for further processing (e.g., to generate a pulse output signal) before output to an external device. For example, the external device can count the pulses of the pulse output signal and calculate the wheel speed therefrom.

[0046] Alternatively, Figure 1C and Figure 1D As shown, the two magnetic field sensor elements H1 and H2 can be spaced laterally apart by a lateral distance in the sensing direction, and one sensor element can be used to generate a speed sensor signal, while the other sensor element can be used to generate a phase-shifted direction sensor signal. Therefore, the two Hall sensor elements H1 and H2 can respectively generate sensor signals Sx1 and Sx2 that are phase-shifted relative to each other, wherein the phase shift is proportional to the lateral distance. The phase shift can be used to sense the direction of rotation of the rotating magnetic field by analyzing the direction of the phase shift, and more specifically, sense the direction of rotation of the target object.

[0047] Figure 1D The magnetic field sensing principle using a second type of magnetic encoder, a magnetized encoder wheel, according to one or more embodiments is illustrated. The sensor module 6 comprises a sensor device 4 having a sensor circuit (not shown) and two differential magnetic field sensor elements H1 and H2. The sensor signal of each differential sensor element H1 and H2 is provided to the sensor circuit, which calculates a differential measurement signal using a differential calculation, which can be used to cancel uniform stray fields in the direction of the sensor plane.

[0048] In addition, the differential sensor elements H1 and H2 can be arranged at about half the distance of the magnetic pole pitch of the magnetized encoder wheel 11 to generate a differential measurement signal with a high signal-to-noise ratio. The pitch is the distance between two like-polarity magnetic poles of the magnetized encoder wheel (i.e., between two adjacent positive poles or between two adjacent negative poles) along the pitch circle.

[0049] The magnetized encoder wheel 11 comprises alternating north pole segments 12 and south pole segments 13. Thus, the north pole segments 12 and south pole segments 13 represent the teeth and notches of the tooth and notch wheel 1 described above. Figure 1C The sensor elements H1 and H2 of the described sensor device 4 are sensitive to the magnetic field influenced by the north pole segment 12 and the south pole segment 13 of the wheel 11. Here, since the magnetic field is actively generated by the wheel 11, the back bias magnet can be omitted. Figure 1CThe change of the alternating magnetic field is detected in a similar manner as described, and the sensor output corresponds to the rotation speed of the magnetized encoder wheel 11. Therefore, the sensor circuit of the sensor device 4 generates a sensor output to be output by one of the leads 7.

[0050] In some cases, the sensor device 4 may be a two-dimensional (2D) sensor including a first sensor element and a second sensor element. "2D" means that the sensor is configured to sense a magnetic field in two sensing directions. The two sensor elements may be xMR sensor elements, inductive sensor elements, Hall sensor elements, or any other magnetic sensor elements that generate sensor signals in response to a magnetic field. Specifically, the first sensor element may be an x ​​sensor having a sensitivity axis aligned in the x direction (i.e., its sensitivity direction) and generating a sensor signal Sx in response to the x component Bx of the magnetic field. In contrast, the second sensor element may be a y sensor having a sensitivity axis aligned in the y direction (i.e., its sensitivity direction) and generating a sensor signal Sy in response to the y component By of the magnetic field. Therefore, the sensitivity axes of the first sensor element and the second sensor element are orthogonal to each other. As a result, the sensor signals generated by the sensor elements are offset by 90° relative to each other. Similarly, by monitoring the phase shift direction (e.g., positive or negative), the sensor circuit can determine the direction of rotation of the magnetic field, thereby determining the direction of rotation of the target object.

[0051] For example, the sensor signal generated by the first sensor element may be sinusoidal, and the sensor signal generated by the second sensor element may be cosine relative to the sensor signal generated by the first sensor element. The sensor elements together sense changes in x-axis and y-axis magnetic field strengths, which vary in a sinusoidal waveform (i.e., as a signal modulation) having a frequency corresponding to the rotational speed of a rotating target object (such as a wheel or drive shaft).

[0052] In addition, it should be understood that the first sensor element and the second sensor element may each include one or more sensing elements. For example, in the case where the first sensor element and the second sensor element include two or more sensing elements, the sensing elements of each corresponding sensor element may be arranged in a differential configuration and / or a bridge configuration.

[0053] In view of the above, an embodiment provides a magnetic sensor that maintains high vibration suppression while preventing sensor deadlock. To this end, a signal event or a time watchdog event is monitored and detected, and pulse transmission of the sensor output signal is suppressed in response to the event detection until the magnetic sensor determines whether there is vibration (i.e., whether the detected event is caused by vibration). Therefore, pulse suppression during vibration is provided, and deadlock after air gap jump can be avoided.

[0054] Figure 2 is a schematic block diagram of a magnetic sensor 100 according to one or more embodiments. The magnetic sensor 100 includes at least two magnetic sensor elements 21 and 22 that generate analog sensor signals 31 and 32, respectively. The sensor signal 31 may be a speed sensor signal transmitted along a speed signal path to a sensor circuit of the magnetic sensor 100, the sensor circuit including the remaining components of the sensor 100. The sensor signal 32 may be a direction sensor signal transmitted along a direction signal path to the sensor circuit. According to the above sensor device, the sensor signal 32 is phase-shifted relative to the sensor signal 31. For example, the sensor signal 31 generated by the sensor element 21 may be sinusoidal, and the sensor signal 32 generated by the sensor element 22 may be cosine relative to the sensor signal 31 generated by the sensor element 21. Therefore, the sensor signal 31 may correspond to the signal Sx and the sensor signal 32 may correspond to the above signal Sy, or the sensor signal 31 may correspond to the signal Sx1 and the sensor signal 32 may correspond to the above signal Sx2.

[0055] The sensor circuit includes a signal tracking processing circuit 23 that analyzes speed and direction sensor data from sensor signals 31 and 32 to extract amplitude information, offset information, and phase information from each of the sensor signals 31 and 32. Specifically, the signal tracking processing circuit 23 may include a comparator that sends a pulse trigger as the trigger signal 33 if the amplitude of the input signal has crossed a threshold. For example, the signal tracking processing circuit 23 may compare the amplitude of the sensor signal 31 with one or more switching thresholds and generate a trigger pulse based on the amplitude crossing the one or more switching thresholds. It should be understood that although the speed sensor signal 31 is described in the following embodiments as being used to trigger certain events or pulses, the direction sensor signal 32 may be used in addition or alternatively.

[0056] The sensor output control circuit 24 or protocol generator is configured to receive a trigger signal 33 from the signal tracking processing circuit 23 and generate an output pulse as a sensor output signal 34 based on the trigger signal 33. The sensor output signal 34 can be a modulated current. The programmed switching protocol or rule set specifies the length and time of the output pulse. In addition to the triggered output pulse, the protocol generator also issues safety-related output signals. For example, an activity pulse, a warning pulse, a startup and high-speed pulse, or an error state.

[0057] The output current (i.e., sensor output signal 34) can be switched between two current values ​​by the sensor output control circuit 24 to generate current pulses. The frequency of the current pulses is directly related to the rotation speed of the target object. Therefore, the sensor output signal 34 can be a pulse (digital) signal converted from the speed sensor signal 31 by the signal tracking processing circuit 23 and the sensor output control circuit 24 (protocol generator and current modulator).

[0058] The sensor output control circuit 24 is configured to receive a trigger signal 33 from the signal tracking processing circuit 23, and to enable or disable output pulses of the sensor output signal 34 based on vibration detection and other monitoring parameters. Specifically, the sensor output control circuit 24 can send an output pulse based on the trigger signal 33 received from the signal tracking processing circuit 23, or ignore the trigger signal 33 and suppress the output pulse corresponding to the trigger pulse according to the additional input signals 35, 37 and 41. The output pulse needs to be suppressed to avoid sending an erroneous output pulse during a vibration event, otherwise an output pulse that does not correspond to the rotation speed will be generated. In normal operation, the behavior of suppressing the output pulse is triggered by the vibration detection circuit 25 based on the phase shift between the input signals 31 and 32 and based on the amplitude of the input signals 31 and 32. In this regard, any trigger pulse received via the trigger signal 33 is ignored and therefore suppressed by the sensor output control circuit 24. This pulse suppression can also be referred to as pulse blanking because no output pulse is output via the output signal 34 when the output pulse is disabled.

[0059] The signal tracking processing circuit 23 also determines phase information from the sensor signals 31 and 32, including whether the phase shift between the two signals is positive or negative, and indicates whether there is a direction change in the phase shift that indicates a change in the rotational direction of the target object (e.g., from clockwise to counterclockwise or vice versa). The signal tracking processing circuit 23 generates a phase signal 36 that provides the phase information (e.g., a direction change signal) to the vibration detection circuit 25. The signal tracking processing circuit 23 also provides an amplitude 39 of the direction signal 32 in a direction amplitude signal.

[0060] In the presence of vibration, changes in direction are more common, which can cause the phase shift between the sensor signals 31 and 32 to change frequently. When vibration occurs, the phase shift between the sensor signals 31 and 32 can oscillate between positive and negative values, can be zero / 180°, or leave a visible signal in only one of the two speed / direction signal channels. The vibration detection circuit 25 monitors all of these behaviors to detect vibration. In addition, if the direction amplitude signal 39 is too small (e.g., below a predetermined threshold), the vibration is detected and a signal is sent to the sensor output control circuit 24 via the vibration detection signal 37.

[0061] The phase information (e.g., direction change) and the direction amplitude are processed by the vibration detection circuit 25, which outputs the vibration detection via the vibration detection signal 37. In the case of different indicators programmable by the EEPROM, vibration is detected by analyzing the history of the detected rotation direction (e.g., a rotation direction pattern of forward, forward, backward can indicate vibration and / or an alternating rotation direction pattern of forward, backward, forward, backward can indicate vibration). In addition, if the direction amplitude signal 39 is too small (e.g., below a predetermined threshold), vibration is detected.

[0062] The vibration detection circuit 25 transmits a vibration detection signal 37 to the sensor output control circuit 24, which signals the detected vibration event. In response to being notified of the detected vibration event, the sensor output control circuit 24 disables the output pulses of the output signal 34.

[0063] Additional functional integration of sensor circuits Figure 3 Give a description. Figure 3 An example of a sensor signal generated by a sensor element together with a set of hysteresis thresholds according to one or more embodiments is illustrated. The signal tracking processing circuit 23 implements a programmed current switching protocol based on the adaptive hysteresis thresholds 15 and 16. Specifically, the sensor signal can be a speed sensor signal 31. A set of hysteresis thresholds includes a first switching threshold 15 and a second switching threshold 16. The signal tracking processing circuit 23 is configured to compare the sensor signal 31 with one or both of the switching thresholds 15, 16 to generate a trigger pulse transmitted as a pulse trigger signal 33. The switching threshold is a switching point at which the signal tracking processing circuit 23 switches the output signal from one state to another state (i.e., low to high or high to low) to generate a pulse when the sensor signal 31 is detected to cross the switching point.

[0064] The output signal may be pulsed when the speed sensor signal 31 crosses the switching threshold 15 or 16 from one direction (e.g., at a rising edge of the sensor signal). However, the signal tracking processing circuit 23 may be configured such that the output signal is pulsed when the speed sensor signal 31 crosses the switching threshold from either direction (e.g., at a rising edge or a falling edge). Alternatively, the output may switch from a logic low to a high on the first rising edge of the speed sensor signal 31 and from a logic high to a low on the first falling edge of the speed sensor signal 31, or vice versa, where the rising and falling edges occur at the same switching threshold crossing. Thus, the pulses in the output signal 34 may be triggered in a variety of ways.

[0065] The first switching threshold 15 and the second switching threshold 16 can be adjusted (i.e., adapted) based on the history of the sensor signal 31. For example, the switching thresholds 15 and 16 stored in the memory are located between the minimum value (min) and the maximum value (max) of the magnetic field B. The signal tracking processing circuit 23 can use the update algorithm stored in the processor to periodically and autonomously (re)calculate the switching thresholds 15 and 16 (i.e., their offsets), and self-calibrate the switching points implemented by the signal tracking processing circuit 23. As will be discussed, the switching thresholds 15 and 16 can be initialized or reset to the corresponding minimum values ​​and adjusted based on the update threshold algorithm implemented by the signal tracking processing circuit 23.

[0066] In order to make the correct pulse delivery more robust to noise and small vibrations, the hysteresis level of the switching thresholds 15 and 16 is set adaptively according to the amplitude of the speed signal 31. By adapting one or more switching points on a continuous basis, the accuracy of the switching points is kept within the desired region in accordance with rapid changes in the sensor signal and ensures that additional pulses are not sent and good jitter performance is achieved.

[0067] The calibration of the hysteresis level can be based on an average of one or more minimum values ​​and one or more maximum values ​​of the measured magnetic field of the sensor signal 31. For example, the switching thresholds 15 and 16 can be calculated as an average value depending on the most recent minimum and maximum values ​​of the speed sensor signal 31, and adjusted accordingly. For example, the switching thresholds 15 and 16 can be set to a predetermined percentage (e.g., 90%) of the peak-to-peak average value of the sensor signal 31. The most recent minimum and maximum values ​​can be used based on the period of the most recent speed sensor signal 31. Specifically, the signal tracking processing circuit 23 can be configured to perform an update after the first signal period and perform an update once per signal period thereafter. Once a complete signal period occurs, the signal tracking processing circuit 23 can use the speed sensor signal 31 in the above-described manner during the signal period to perform an update of the switching thresholds 15 and 16.

[0068] Sudden air gap jumps may be caused by, for example, a mechanical shock. The larger the air gap between the magnetic sensor 100 and the target object, the smaller the sensor signals 31 and 32. Therefore, when a large air gap jump occurs, the sensor signal 31 may no longer meet or cross the switching thresholds 15 and 16 and its extreme values ​​(maximum and minimum) are limited to the region between them. When this happens, switching (i.e., pulse generation) at the output signal 34 should not occur until it is confirmed that the vibration is no longer present.

[0069] For example, vibrations can cause the amplitude of the speed sensor signal to jump, becoming larger when the vibrations begin. This causes the switching thresholds 15 and 16 to be abnormally high through calibration. However, when the vibrations stop, the sensor 100 may no longer react to smaller signals due to the increased values ​​of the switching thresholds 15 and 16. In other words, vibrations may cause the switching thresholds 15 and 16 to be set outside the boundaries of the speed sensor signal 31 when the vibrations are absent, causing the sensor to deadlock. Alternatively, if the gear is installed, the wheel may be displaced relative to the sensor. Alternatively, there may be metal particles between the wheel and the sensor, which can increase or decrease the speed sensor signal 31. In any of these cases, the extreme values ​​of the speed sensor signal 31 may be lower than the hysteresis level defined by the switching thresholds 15 and 16, and the sensor circuit may no longer be able to detect the crossing of the thresholds 15 and 16.

[0070] To prevent sensor deadlock, two options are provided. Either a time monitor circuit 26a implementing a timeout is used, or a signal monitor circuit 26b implementing a second set of hysteresis thresholds 17 and 18 is used (see e.g. Figure 5 ).from Figure 2 These two options will be addressed in turn, starting with the time monitor circuit 26a shown, followed by Figure 4 Signal monitor circuit 26b is shown.

[0071] Return to Figure 2 The signal tracking processing circuit 23 implements an event generation protocol using the sensor signal 31 based on the adaptive hysteresis thresholds 15 and 16 to generate a signal event 38 (e.g., an event pulse). If the sensor signal 31 is correctly tracked, the signal tracking processing circuit 23 signals at least one event to the time monitor circuit 26a operating as a time monitor via the event signal 38 in each signal cycle.

[0072] For example, the signal tracking processing circuit 23 may generate an event signal 38 (e.g., an event pulse 38) each time the sensor signal 31 crosses one or both of the switching thresholds 15 and / or 16 in a particular rising direction or falling direction. In this case, the event pulse is triggered each time the sensor signal 31 crosses the switching threshold 15 on a rising edge. Alternatively, the signal tracking processing circuit 23 may detect a situation where the sensor signal 31 is at a maximum or minimum peak amplitude, and generate an event pulse 38 at each maximum or minimum peak amplitude. The event trigger point 38p is at Figure 3 The event signal 38 is sent to the time monitor circuit 26a for monitoring.

[0073] The time monitor circuit 26a has a counter 51 that increments a count based on a clock signal generated by a clock (CLK) signal generator 52. The clock signal is received at the CLK input of the counter 51 and the counter 51 counts clock pulses until an event signal 38 indicating a crossing event of one of the switching thresholds 15 and / or 16 is received. Specifically, the event signal 38 is provided to the reset (RST) input and an event pulse from the event signal 38 triggers the counter 51 to be reset to zero. On the other hand, if the counter 51 reaches a predefined timeout threshold (e.g., 500 ms) due to the absence of such an event pulse from the event signal 38, the counter 51 triggers one or more set signals. Specifically, the counter 51 generates an inhibit signal 41 and a reset signal 42 corresponding to the set signal in response to the counter value of the counter 51 reaching or exceeding the predefined timeout threshold corresponding to the preset timeout time.

[0074] Inhibit signal 41 instructs sensor output control circuit 24 to inhibit output pulses of output signal 34 until confidence signal 35 indicates a high confidence level after the recalibration phase (ie, until confidence signal 35 is set to a value corresponding to high confidence).

[0075] The reset signal 42 resets the thresholds 15 and 16 at the signal tracking processing circuit 23 to predefined minimum values ​​(e.g., the threshold 15 is set to a first minimum value and the threshold 16 is set to a second minimum value), so that the threshold calibration of the thresholds 15 and 16 restarts. The reset signal 42 also resets the confidence signal 35 to a low confidence value (i.e., a value corresponding to low confidence).

[0076] The signal tracking processing circuit 23 determines the confidence level of the extracted information obtained from the analysis of the speed and direction sensor data, and generates a confidence signal 35 indicating the confidence level (e.g., low or high) of the extracted information. In this regard, the confidence signal 35 can be binary, but intermediate signal levels between low and high are also possible. If more cycles of the sensor signals 31 and 32 have been recorded, and, for example, offset correction or amplitude-related thresholds are applied in the signal processing, the confidence level of the extracted information increases. The confidence level can also increase with an increase in the number of signal crossings relative to the switching thresholds 15 and 16. The confidence is signaled by the confidence signal 35 to the sensor output control circuit 24.

[0077] After resetting the confidence level signal 35 to low in response to the reset signal, the signal tracking processing circuit 23 may switch the value of the confidence signal 35 to correspond to a high confidence level only after certain conditions are met. For example, the signal tracking processing circuit 23 may monitor the speed signal 31 or the direction signal 32 over the entire signal cycle (i.e., at least one signal cycle) after the thresholds 15 and 16 are reset, and when at least one signal cycle is detected, switch the value of the confidence signal 35 to correspond to a high confidence level. The high confidence level indicates that the uncertainty associated with the vibration event has ended, and the output pulses correctly associated with the rotation of the target object can be recovered with high confidence.

[0078] In another example, offset correction (i.e., threshold calibration) of the thresholds 15 and 16 should occur after being reset to their minimum values. Once the offset correction is performed on the thresholds 15 and 16, the signal tracking processing circuit 23 monitors the occurrence of a predetermined signal period or a portion thereof relative to the speed signal 31 or the direction signal 32, and switches the value of the confidence signal 35 to correspond to a high confidence level when the predetermined signal period length occurs and has been detected.

[0079] For example, in Figure 3 In the example shown, one signal period of the speed sensor signal 31 is marked by two threshold crossings of the signal 31 relative to the threshold 15. Figure 5 In another example shown, one signal cycle of the speed sensor signal 31 is marked by three threshold crossings of the signal 31 relative to the thresholds 15 and 16 (e.g., two crossings of the threshold 15 and one crossing of the threshold 16, or two crossings of the threshold 16 and one crossing of the threshold 15). Of course, one signal cycle of the speed sensor signal 31 may be marked by five threshold crossings of the signal 31 relative to the thresholds 15 and 16.

[0080] Thus, to switch confidence signal 35 to correspond to a high confidence level, for example, after resetting signal 42, two or more threshold crossings 15 and / or 16 may be detected via signal 31 or 32 to indicate a predetermined signal period length for triggering a high confidence level.

[0081] After receiving the inhibit signal 41 , the sensor output control circuit 24 is configured to re-enable pulse generation at the output signal 34 only upon receiving the confidence signal 35 indicating a high confidence level.

[0082] Figure 4 2 is a schematic block diagram of a magnetic sensor 200 according to one or more embodiments. Specifically, the magnetic sensor 200 includes a signal monitor circuit 26b that implements event detection to prevent sensor deadlock.

[0083] Figure 5An example of a speed and direction sensor signal generated by two sensor elements along with two hysteresis threshold sets according to one or more embodiments is illustrated. The magnetic sensor 200 uses these two hysteresis threshold sets to prevent sensor deadlock. Thus, Figure 5 The signal diagrams shown in Figure 4 The magnetic sensor 200 is shown for reading.

[0084] It should also be noted that vibration detection based on signals 36 and 39 is performed as described above for magnetic sensor 100. Similarly, the functions performed by signal tracking processing circuit 23 in response to receiving reset signal 42 and the functions performed by sensor output control circuit 24 in response to receiving inhibit signal 41 are performed as described above for magnetic sensor 100. In addition, event signals 43 and 44 generated by signal tracking processing circuit 23 are now generated using similar principles used to generate event signal 38 in the previous embodiment. Therefore, unless otherwise stated, it should be assumed that the functionality between sensors 100 and 200 is the same or similar.

[0085] In order to prevent sensor deadlock according to the magnetic sensor 200, a second hysteresis threshold set is provided, which includes a first minimum hysteresis threshold 17 and a second minimum hysteresis threshold 18. The magnitude of thresholds 17 and 18 is equal to or less than the magnitude of thresholds 15 and 16, and defines a threshold range that is smaller than the threshold range of its larger counterpart. Thresholds 15-18 can be initialized or reset to a predefined minimum value (for example, thresholds 15 and 17 are both equal to the first minimum value and thresholds 16 and 18 are both equal to the second minimum value), and then thresholds 15 and 16 can be dynamically increased after analyzing one or more cycles of the sensor signal 31 for threshold calibration. In this way, thresholds 17 and 18 are located at the limits of thresholds 15 and 16 or are completely within the limits of thresholds 15 and 16. Typically, once the threshold calibration of the speed sensor signal 31 above the predefined minimum value is detected, thresholds 15 and 16 are separated from thresholds 17 and 18 so that thresholds 17 and 18 are completely within the limits of thresholds 15 and 16.

[0086] The minimum hysteresis thresholds 17 and 18 may be fixed or may depend on a predetermined percentage (e.g., 33%) of the peak-to-peak average value of the sensor signal 31, being regularly adapted in a similar manner as described with reference to the adaptation of thresholds 15 and 16. The predefined percentage used for adapting thresholds 17 and 18 is significantly smaller than the predefined percentage used for adapting thresholds 15 and 16. Alternatively, the minimum hysteresis thresholds 17 and 18 may be set to a predetermined factor that is smaller than thresholds 15 and 16. Thus, when thresholds 15 and 16 change, thresholds 17 and 18 change based on the predetermined factor.

[0087] In addition to comparing the sensor signal 31 and the direction signal 32 with the switching thresholds 15 and 16, the sensitive signal tracking circuit 27 is configured to compare the sensor signal 31 with the minimum hysteresis thresholds 17 and 18 and generate a minimum event signal 45, which is generated using similar principles as used to generate the event signal 38 in the previous embodiment.

[0088] As described above, a sudden air gap jump may be caused by, for example, a mechanical shock. The larger the air gap between the magnetic sensor 100 and the target object, the smaller the sensor signals 31 and 32. Therefore, when a large air gap jump occurs, the sensor signals 31 and 32 no longer meet or cross the switching thresholds 15 and 16, and their extreme values ​​(maximum and minimum) are limited to the region between them. When this happens, switching (i.e., pulse generation) at the output signal 34 should not occur until it is confirmed that the vibration is no longer present.

[0089] However, in order to prevent sensor deadlock, the minimum hysteresis thresholds 17 and 18 are provided so that despite the increase in the air gap, the sensor signal 31 can still be monitored via the minimum hysteresis thresholds 17 and 18. In other words, despite the increase in the air gap, the sensor signal 31 continues to cross the minimum hysteresis thresholds 17 and 18. Therefore, the minimum hysteresis thresholds 17 and 18 should be set to be higher than the noise floor of the magnetic sensor 200, but low enough to enable the sensor signal 31 to be monitored by the sensitive signal tracking circuit 27 in the case of an increase in the air gap.

[0090] As described above, the signal tracking processing circuit 23 implements the event generation protocol based on the adaptive hysteresis thresholds 15 and 16. In this embodiment, the signal tracking processing circuit 23 uses both the sensor signals 31 and 32 to generate a speed signal event 43 (e.g., a speed event pulse) and a direction signal event 44 (e.g., a direction event pulse), respectively. Each corresponding event pulse 43 and 44 is generated by detecting a signal that crosses one or both switching thresholds 15 or 16 or detecting a situation when the sensor signals 31 and 32 are at a maximum or minimum peak amplitude. In other words, similar to the event signal 38, the event pulse for the event signal 43 is generated based on the sensor signal 31 and the trigger indicator, and the event pulse for the event signal 44 is generated based on the sensor signal 32 and the trigger indicator. The same or different trigger indicators can be used to generate event pulses for the event signal 43 and the event signal 44.

[0091] Event trigger points 43p and 44p are Figure 5, and can be set according to any type of rule set. For example, when the speed signal 31 crosses the hysteresis threshold 15 (going upward or in an ascending direction) and / or crosses the hysteresis threshold 16 (going downward or in a descending direction), a speed signal event 43 (i.e., a pulse) is generated by the signal tracking circuit 23. When the direction signal 32 crosses the hysteresis threshold 15 (going upward or in an ascending direction) and / or crosses the hysteresis threshold 16 (going downward or in a descending direction), a direction signal event 44 (i.e., a pulse) is generated by the signal tracking circuit 23. If the sensor signal 31 and the direction signal 32 are tracked correctly, then in each signal cycle, the signal tracking processing circuit 23 sends a signal to the signal monitor circuit 26b with at least one speed signal event 43 and at least one direction signal event 44.

[0092] The sensitive signal tracking circuit 27 implements an event generation protocol based on the minimum hysteresis thresholds 17 and 18. In this embodiment, the sensitive signal tracking circuit 27 generates a minimum signal event 45 (e.g., a minimum event pulse) using the sensor signal 31 by detecting a signal crossing of the sensor signal 31 across one or both of the minimum hysteresis thresholds 17 and 18. For example, the sensitive signal tracking circuit 27 generates a minimum signal event 45 (i.e., a pulse) when the speed signal 31 crosses the hysteresis threshold 17 (traveling downward or in a falling direction) and / or crosses the hysteresis threshold 18 (traveling upward or in a rising direction). The example event trigger point 45p is at Figure 5 The minimum event pulse is provided to the signal monitor circuit 26b via the minimum event signal 45 and is used as a clock signal for the monitor counters 53 and 54 to count the corresponding counter values.

[0093] Specifically, the counter value of the counter 53 is increased for each minimum event pulse received by the minimum event signal 45 and is compared with a predetermined counter threshold value (e.g., 10). In addition, the speed event signal 43 is provided to the reset (RST) input of the counter 53 and each event pulse from the speed event signal 43 triggers the counter value of the counter 53 to be reset to zero. Therefore, if the counter value of the counter 53 reaches the predetermined counter threshold value due to the absence of such event pulses from the event signal 43 (e.g., caused by a vibration event), the counter 53 triggers one or more set signals. Specifically, the counter 53 generates the inhibit signal 41 and the reset signal 42 corresponding to the set signal in response to the counter value of the counter 53 reaching or exceeding the predetermined counter threshold value corresponding to the preset signal timeout.

[0094] Similarly, the counter value of the counter 54 is incremented for each minimum event pulse received by the minimum event signal 45 and compared to a predetermined counter threshold value (e.g., 10). In addition, the direction event signal 44 is provided to the reset (RST) input of the counter 54 and each event pulse from the direction event signal 44 triggers the counter value of the counter 54 to be reset to zero. Therefore, if the counter value of the counter 54 reaches the predetermined counter threshold value due to the absence of such event pulses from the event signal 55 (e.g., caused by a vibration event), the counter 54 triggers one or more set signals. Specifically, the counter 54 generates the inhibit signal 41 and the reset signal 42 corresponding to the set signal in response to the counter value of the counter 54 reaching or exceeding the predetermined counter threshold value corresponding to the preset signal timeout period.

[0095] Therefore, the inhibit signal 41 and the reset signal 42 can be triggered by any one of the counters 53 and 54. In this way, the signal monitor circuit 26b must regularly receive event pulses from both event signals 43 and 44 (i.e., within a preset signal timeout period) to ensure that sensor deadlock has not occurred. If any one of the counters 53 and 54 times out, the signal monitor circuit 26b determines that a potential sensor deadlock has occurred, and generates the inhibit signal 41 and the reset signal 42 to resolve the sensor deadlock.

[0096] Inhibit signal 41 instructs sensor output control circuit 24 to inhibit output pulses of output signal 34 until confidence signal 35 indicates a high confidence level after the recalibration phase (ie, until confidence signal 35 is set to a value corresponding to high confidence).

[0097] The reset signal 42 resets the thresholds 15 and 16 at the signal tracking processing circuit 23 to predefined minimum values ​​(e.g., threshold 15 is set to a first minimum value and threshold 16 is set to a second minimum value), so that the threshold calibration of thresholds 15 and 16 restarts. For example, threshold 15 can be reset to coincide with threshold 17, and threshold 16 can be reset to coincide with threshold 18. Thresholds 17 and 18 may have been fixed at their respective minimum thresholds, or if they are adjusted via automatic calibration during operation, they may also be reset to the minimum thresholds. The reset signal 42 also resets the confidence signal 35 to a low confidence value (i.e., a value corresponding to low confidence).

[0098] Fig. 6AThe signal diagram according to a conventional speed magnetic sensor with a signal monitor and without pulse blanking is illustrated. Specifically, the signal diagram includes a speed sensor signal 31, a direction sensor signal 32, and an output signal 34. It can be seen that during a vibration event occurring between two rotation intervals of the target object, pulses are still output at the output signal 34. Therefore, incorrect pulses are transmitted at the output, resulting in incorrect information being interpreted by a microcontroller, ECU, etc.

[0099] Figure 6B A signal diagram is illustrated according to one or more embodiments using pulse blanking. Specifically, the signals and counter values ​​shown in the signal diagram correspond to those signals generated in the magnetic sensor 200. It can be seen that the output pulse at the output signal 34 is completely suppressed during the vibration event and restored after the vibration detection history has terminated. By looking at the internal signals (45, 44, 42) during the vibration, the detection of the monitor event can still be seen (e.g., when the counter 54 reaches 10), but because the confidence signal 35 is low, no erroneous output pulse is sent.

[0100] Although various embodiments have been disclosed, it is obvious to those skilled in the art that various changes and modifications may be made to achieve some advantages of the concepts disclosed herein without departing from the spirit and scope of the present invention. It is obvious to those of ordinary skill in the art that other components performing the same function may be appropriately replaced. It should be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. It should be noted that features explained with reference to a particular figure may be combined with features of other figures, even if not explicitly mentioned. Such modifications to the overall inventive concept are intended to be covered by the appended claims and their legal equivalents.

[0101] In addition, the appended claims are hereby incorporated into the detailed description, where each claim can stand on its own as a separate exemplary embodiment. Although each claim can stand on its own as a separate exemplary embodiment, it should be noted that although a dependent claim may refer to a specific combination with one or more other claims in a claim, other exemplary embodiments may also include combinations of dependent claims with the subject matter of each other's dependent or independent claims. Unless it is stated that a specific combination is not intended, such combinations are suggested herein. In addition, even if the claim is not directly dependent on the independent claim, it is intended to include the features of any other independent claim.

[0102] It is also noted that the methods disclosed in the specification or claims may be implemented by a device having components for performing each of the corresponding actions of these methods. For example, the techniques described in this disclosure may be implemented at least in part in hardware, software, firmware, or any combination thereof. For example, various aspects of the described techniques may be implemented within one or more processors, including one or more microprocessors, DSPs, ASICs, or any other equivalent integrated or discrete logic circuit devices, as well as any combination of these components.

[0103] In addition, it should be understood that the disclosure of multiple actions or functions disclosed in the specification or claims may not be interpreted as being in a specific order. Therefore, unless multiple actions or functions are not interchangeable for technical reasons, the disclosure of these actions or functions will not limit these to a specific order. In addition, in some embodiments, a single action may include or may be decomposed into multiple sub-actions. Unless explicitly excluded, such sub-actions may be included and are part of the disclosure of the single action.

Claims

1. A sensor device, comprising: at least one first sensor element configured to generate a first sensor signal based on sensing a changing magnetic field; at least one second sensor element configured to generate a second sensor signal based on sensing a changing magnetic field; a signal tracking circuit configured to generate a trigger signal having a trigger pulse, the trigger pulse being generated based on a first crossing of the first sensor signal with at least one of at least one adaptive threshold, wherein the signal tracking circuit further uses the first sensor signal and the second sensor signal to extract vibration-related information; an output controller configured to generate an output signal having an output pulse triggered by the trigger pulse during a non-vibration event and further configured to suppress the output pulse during the entire duration of the vibration event; a vibration detection circuit configured to receive the extracted vibration-related information, detect the vibration event based on the received extracted vibration-related information, and indicate the detected vibration event to the output controller, wherein the signal tracking circuit is configured to generate a first event signal having a first event pulse, the first event pulse being generated based on a second crossing of the first sensor signal by at least one of the at least one adaptive threshold; as well as a monitor circuit configured to monitor the first event signal for the first event pulse, detect an absence of the first event pulse, and transmit an inhibit signal to the output controller in response to detecting the absence of the first event pulse, wherein the output controller is configured to inhibit the output pulse in response to receiving the inhibit signal until a confidence signal is received from the signal tracking circuit indicating a high confidence level, the high confidence level indicating that uncertainty associated with the vibration event has ceased. 2 . The sensor device of claim 1 , wherein the signal tracking circuit is configured to adjust the at least one adaptive threshold based on an amplitude of the first sensor signal and an updated threshold algorithm. 3 . The sensor device of claim 2 , wherein each of the at least one adaptive threshold is an adaptive hysteresis threshold.

4. The sensor device according to claim 1, wherein the signal tracking circuit is configured to generate the confidence signal indicating the high confidence when the signal tracking circuit detects at least one signal cycle of the first sensor signal after the triggering of the suppression signal.

5. The sensor device according to claim 1, wherein: The monitor circuit is configured to transmit a reset signal to the signal tracking circuit in response to detecting an absence of the first event pulse, and The signal tracking circuit is configured to reset each of the at least one adaptive threshold to a corresponding minimum threshold in response to the reset signal.

6. The sensor device according to claim 5, wherein after resetting each of the at least one adaptive threshold, the signal tracking circuit is configured to: perform calibration of the at least one adaptive threshold by adjusting the at least one adaptive threshold based on the amplitude of the first sensor signal and the update threshold algorithm, so that each of the at least one adaptive threshold is away from the corresponding minimum threshold.

7. The sensor device according to claim 6, wherein the signal tracking circuit is configured to generate a confidence signal indicating a high confidence level when the signal tracking circuit detects at least one signal period of the first sensor signal after calibration of the at least one adaptive threshold.

8. The sensor device of claim 1, wherein: The monitor circuit is configured to transmit a reset signal to the signal tracking circuit in response to detecting an absence of the first event pulse, and The signal tracking circuit is configured to reset the confidence signal to indicate low confidence in response to the reset signal.

9. The sensor device of claim 1, wherein: The monitor circuit is a time monitor circuit, the time monitor circuit comprising a counter and a comparator, the comparator comparing a counter value of the counter with a predetermined timeout threshold, The counter is configured to increase the counter value according to a clock signal and reset the counter value at each of the first event pulses, and The monitor circuit is configured to generate the inhibit signal in response to the counter value being equal to the predetermined timeout threshold.

10. The sensor device according to claim 9, wherein: The monitor circuit is configured to transmit a reset signal to the signal tracking circuit in response to the counter value being equal to the predetermined timeout threshold, and The signal tracking circuit is configured to reset each of the at least one adaptive threshold to a corresponding minimum threshold in response to the reset signal. 11 . The sensor device of claim 10 , wherein the signal tracking circuit is configured to reset the confidence signal to indicate low confidence in response to the reset signal.

12. The sensor device according to claim 1, further comprising: a sensitive signal tracking circuit configured to generate a minimum event signal having a minimum event pulse, the minimum event pulse being generated based on a crossing of the first sensor signal by at least one of at least one minimum threshold, wherein the signal tracking circuit is configured to generate a second event signal having a second event pulse, the second event pulse being generated based on a crossing of the second sensor signal by at least one of the at least one adaptive threshold, wherein the monitor circuit is a signal monitor circuit comprising a first counter and a second counter, wherein the first counter is configured to increment a first counter value according to the minimum event pulse, to reset the first counter value at each first event pulse of the first event pulses, and to compare the first counter value to a first predetermined counter threshold value, wherein the second counter is configured to increment a second counter value according to the minimum event pulse, to reset the second counter value at each second event pulse of the second event pulses, and to compare the second counter value to a second predetermined counter threshold value, The monitor circuit is configured to generate the inhibit signal in response to either the first counter value being equal to the first predetermined counter threshold or the second counter value being equal to the second predetermined counter threshold.

13. The sensor device of claim 12, wherein: The monitor circuit is configured to transmit a reset signal to the signal tracking circuit in response to either the first counter value being equal to the first predetermined counter threshold or the second counter value being equal to the second predetermined counter threshold, and The signal tracking circuit is configured to reset each of the at least one adaptive threshold to a corresponding minimum threshold in response to the reset signal. 14 . The sensor device of claim 13 , wherein the signal tracking circuit is configured to reset the confidence signal to indicate a low confidence in response to the reset signal.

15. The sensor device according to claim 14, wherein the signal tracking circuit is configured to generate the confidence signal indicating the high confidence when the signal tracking circuit detects at least one signal cycle of the first sensor signal after triggering of the reset signal.

16. The sensor device of claim 1, wherein: The extracted vibration-related information includes at least one of phase information and amplitude signal information, wherein the phase information corresponds to a phase shift between the first sensor signal and the second sensor signal, and wherein the amplitude signal information corresponds to an amplitude value of the second sensor signal; and The vibration detection circuit is configured to receive at least one of phase information and amplitude signal information, and detect the vibration event based on the received at least one of the phase information and amplitude signal information.

17. An output pulse suppression method implemented in a speed sensor, the method comprising: generating, by at least one first sensor element, a first sensor signal based on sensing a changing magnetic field; generating, by at least one second sensor element, a second sensor signal based on sensing the changing magnetic field; generating, by the sensor circuit, a trigger signal having a trigger pulse, the trigger pulse being generated based on a first crossing of the first sensor signal and at least one of the at least one adaptive threshold; extracting vibration related information by the sensor circuit using the first sensor signal and the second sensor signal; generating, by the sensor circuit, an output signal having an output pulse, the output pulse being triggered by the trigger pulse during a non-vibration event; detecting, by the sensor circuit, a vibration event based on the extracted vibration-related information; suppressing, by the sensor circuit, the output pulses during the entire duration of the vibration event; generating, by the sensor circuit, a first event signal having a first event pulse, the first event pulse being generated based on a second crossing of the first sensor signal by at least one of the at least one adaptive threshold; monitoring, by the sensor circuit, the first event pulse of the first event signal; detecting, by the sensor circuit, an absence of the first event pulse; as well as The output pulses are inhibited by the sensor circuit in response to the inhibit signal until, with a high confidence indicated by a confidence signal, the vibration event has terminated.

18. The output pulse suppression method according to claim 17, further comprising: The confidence signal indicating the high confidence level is generated by the sensor circuit when the at least one signal period of the first sensor signal is detected after triggering of the inhibition signal.

19. The output pulse suppression method according to claim 17, further comprising: generating, by the sensor circuit, a reset signal in response to detecting an absence of the first event pulse; as well as Each of the at least one adaptive threshold is reset to a corresponding minimum threshold by the sensor circuit in response to the reset signal.

20. The output pulse suppression method according to claim 19, further comprising: The at least one adaptive threshold is adjusted by the sensor circuit based on the amplitude of the first sensor signal and an updated threshold algorithm such that each of the at least one adaptive threshold is away from a corresponding minimum threshold.

21. The output pulse suppression method according to claim 17, further comprising: generating, by the sensor circuit, a reset signal in response to detecting an absence of the first event pulse; as well as The confidence signal is reset, by the sensor circuit in response to the reset signal, to indicate a low confidence.

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