Safety mechanism monitoring of autocalibrated compensation parameters

Abstract

An auto-calibration system, including: a sensor component comprising at least one sensing element, wherein each of the at least one sensing element is configured to generate a sensor signal from at least one sensor signal in response to a measurement of a physical quantity; a compensation element comprising a first processing circuit arrangement configured to receive the at least one sensor signal and at least one compensation parameter and to compensate the at least one sensor signal based on the at least one compensation parameter in order to generate at least one compensated sensor signal, wherein a different compensated sensor signal is generated for each of the at least one sensor signal; an auto-calibration element comprising a second processing circuit arrangement configured to receive the at least one sensor signal or the at least one compensated sensor signal and to generate the at least one compensation parameter based on the at least one sensor signal or the at least one compensated sensor signal; and a first safety mechanism comprising a third processing circuit arrangement connected between the compensation circuit and the autocalibration element, wherein the third processing circuit arrangement is configured to compare each of the at least one compensation parameter with a respective tolerance range and, provided that each of the at least one compensation parameter is within its respective tolerance range, to transmit the at least one compensation parameter to the compensation circuit as at least one validated compensation parameter, and, provided that at least one of the at least one compensation parameter is not within its respective tolerance range, to generate a first fault detection signal. wherein the auto-calibration element is configured to generate the at least one compensation parameter by adjusting at least one current compensation parameter based on the at least one compensated sensor signal.

Description

AREA

[0001] The present disclosure relates generally to monitoring auto-calibrated compensation parameters and more specifically to monitoring auto-calibrated compensation parameters of a device. BACKGROUND

[0002] Today's vehicles have numerous safety, body, and powertrain applications that rely on magnetic position and angle sensors. A magnetic angle sensor can be used to detect the rotational position or movement of a shaft or other rotatable object. For example, in an electric power steering (EPS) system, magnetic angle sensors can be used to measure steering angle and torque for steering wheel sensing. Modern powertrain systems may rely on magnetic angle sensors for camshaft, crankshaft, and transmission applications.

[0003] In addition, functional safety of electronic systems in passenger cars is an important consideration given the increasing automation and semiconductor content of modern automobiles. It is desirable to have reliable and safe functionality for the safety-critical components used in the system.

[0004] A requirement that can often exist in such safety-critical applications is that malfunctions of a sensor component must be detectable by the system, for example, by an entity receiving signals from the sensor component. In other words, such a requirement must be possible to detect whether a sensor component delivers erroneous values, e.g., due to a fault in the sensor component.

[0005] In a broader sense, functional safety aims to prevent harm to people. Safety mechanisms (SM) monitor certain signals in a system to detect errors that could lead to hazards. Upon detection of an error, the system can enter a safe state to mitigate the risk. The accuracy and extent of this monitoring influence the achievable safety level of the system.

[0006] Additionally, compensation is the process of correcting for non-idealities in a device, such as a sensor or actuator. The parameters that determine these corrections are called compensation parameters. A common method for determining the optimal compensation parameters for a particular device is calibration, which involves comparing the device's output with the output of a more accurate reference device. This limits the applicability of calibration to situations where such a reference device is available.

[0007] Autocalibration, also called continuous calibration, is a special form of calibration that does not require such a reference device. Rather, autocalibration uses certain system properties to automatically optimize the compensation parameters. Therefore, autocalibration can correct certain non-idealities of a device directly in the application (i.e., during operation).

[0008] A magnetic angle sensor, for example, can generate signals that are sinusoidally dependent on the angle of the magnetic field with respect to a reference direction. If the magnetic field is continuously rotating, the absolute values ​​of the maxima and minima of the sensor signal should be equal due to the symmetry of the sine function. Deviations from this property could be caused, for example, by an amplifier offset in the sensor. Analyzing the sensor signal allows these deviations to be detected and the compensation parameters to be optimized accordingly, thus improving the sensor output. However, autocalibration has the potential to mask certain errors in the sensor component, such as excessive offsets that lead to signal clipping, which could cause dangerous situations.In addition, errors in generating the compensation parameters with autocalibration may not be detected, which may also lead to functional safety errors remaining undetected.

[0009] A device and method that ensures functionally safe autocalibration may be desirable to ensure that the functional benefits of autocalibration do not interfere with functional safety requirements.

[0010] Publication DE 10 2017 106 733 A1 relates to a circuit, a method, and a computer program configured to detect mechanical stress, and to a circuit, a method, and a computer program configured to monitor the safety of a system. The detection circuit is configured to monitor a mechanical stress level of a semiconductor circuit. The detection circuit comprises a stress monitoring module configured to monitor a signal comprising information about the mechanical stress level of the semiconductor circuit, a reference module for generating a reference signal, and a calibration module configured to modify at least one of the stress signal or the reference signal based on calibration information for the semiconductor circuit to obtain at least one modified signal. SUMMARY

[0011] There is a need to provide an improved concept for an autocalibration system and a method for autocalibration.

[0012] Such a need may be satisfied by the subject matter of one or more of the claims.

[0013] One or more embodiments provide an auto-calibration system comprising a sensor device comprising at least one sensing element, each of the at least one sensing element being configured to generate a sensor signal from at least one sensor signal in response to measuring a physical quantity; a compensation device comprising first processing circuitry configured to receive the at least one sensor signal and at least one compensation parameter and to compensate the at least one sensor signal based on the at least one compensation parameter to generate at least one compensated sensor signal, wherein a different compensated sensor signal is generated for each of the at least one sensor signal;an auto-calibration device comprising a second processing circuitry configured to receive the at least one sensor signal or the at least one compensated sensor signal and to generate the at least one compensation parameter based on the at least one sensor signal or the at least one compensated sensor signal;and a first safety mechanism comprising third processing circuitry connected between the compensation circuit and the auto-calibration component, the third processing circuitry being configured to compare each of the at least one compensation parameter with a respective tolerance range and, under a condition that each of the at least one compensation parameter is within its respective tolerance range, to transmit the at least one compensation parameter as at least one validated compensation parameter to the compensation circuit, and, under a condition that at least one of the at least one compensation parameter is not within its respective tolerance range, to generate a first error detection signal.

[0014] One or more embodiments provide a method for autocalibration, comprising generating at least one sensor signal in response to measuring a physical quantity; compensating, by a compensation circuit, the at least one sensor signal based on at least one compensation parameter to generate at least one compensated sensor signal, wherein a different compensated sensor signal is generated for each of the at least one sensor signals; generating, by an autocalibration device, the at least one compensation parameter based on the at least one sensor signal or on the at least one compensated sensor signal; comparing each of the at least one compensation parameter to a respective tolerance range;Under a condition that each of the at least one compensation parameter is within its respective tolerance range, transmitting the at least one compensation parameter to the compensation circuit as at least one validated compensation parameter, wherein the at least one validated compensation parameter is used to compensate the at least one sensor signal; and under a condition that at least one of the at least one compensation parameter is not within its respective tolerance range, generating a first error detection signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Embodiments are described herein with reference to the accompanying drawings. Fig. 1 is a block diagram illustrating a magnetic angle sensor according to one or more embodiments; Fig. 2A is a schematic block diagram of a magnetic angle sensor device according to one or more embodiments; Fig. 2B is a graph illustrating a vector length tolerance region according to one or more embodiments; Fig. 3 is a schematic diagram of a calibration system 300 implementing autocalibration for a sensor device, according to one or more embodiments; Fig. Figure 4 shows exemplary electrical vectors (X, Y) as a function of the angle θ for the vector length test performed in the safety mechanism SM1 (left; using uncompensated sensor signals) or the safety mechanism SM2 (right; using compensated sensor signals); and Fig. 5 shows a static offset test (left) and an adapted offset test (right) according to one or more embodiments. DETAILED DESCRIPTION

[0016] Details are set forth below to provide a more detailed explanation of the exemplary embodiments. However, it will be apparent to those skilled in the art that embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form or in a schematic view rather than in detail to avoid obscuring the embodiments. Additionally, features of the various embodiments described below may be combined with one another unless specifically stated otherwise.

[0017] Furthermore, equivalent or identical elements, or elements with equivalent or identical functionality, are denoted by equivalent or identical reference numerals in the following description. Since the corresponding or functionally equivalent elements in the figures are given the same reference numerals, a repeated description for elements provided with the same reference numerals can be omitted. Thus, descriptions provided for elements with the same or similar reference numerals are interchangeable.

[0018] It should be noted that when an element is described as being "connected" or "coupled" to another element, the element may be directly connected or coupled to the other element, or intervening elements may be present. Conversely, when an element is described as being "directly connected" or "coupled" to another element, no intervening elements are present. Other terms used to describe the relationship between elements should be interpreted similarly (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.).

[0019] In embodiments described herein or shown in the drawings, any direct electrical connection or coupling, i.e., any connection or coupling without additional intervening elements, may also be through an indirect connection or coupling, i.e., a connection or coupling with one or more additional intervening elements, or vice versa, as long as the general purpose of the connection or coupling, e.g., transmitting a particular type of signal or transmitting a particular type of information, is substantially retained. Features of different embodiments may be combined to form further embodiments. For example, variations or modifications described with respect to one of the embodiments may also be applicable to other embodiments, unless otherwise stated.

[0020] Embodiments relate to sensors and sensor systems, and obtaining information via sensors and sensor systems. A sensor may refer to a component that converts a physical quantity to be measured into an electrical signal, for example, a current signal or a voltage signal. The physical quantity may include, for example, but is not limited to, a magnetic field, an electric field, a pressure, a force, a current, or a voltage.

[0021] A magnetic field sensor, for example, includes one or more magnetic field sensing elements that measure one or more characteristics of a magnetic field (e.g., an amount of magnetic field flux density, a field strength, a field angle, a field direction, a field orientation, etc.). The magnetic field may be generated by a magnet, a current-carrying conductor (e.g., a wire), the ground, or another magnetic field source. Each magnetic field sensing element is configured to generate a sensor signal (e.g., a voltage signal) in response to one or more magnetic fields impinging on the sensing element. Thus, a sensor signal is indicative of the magnitude and / or orientation of the magnetic field impinging on the sensing element.

[0022] It should be noted that the terms "sensor" and "sensing element" may be used interchangeably throughout this description, and the terms "sensor signal" and "measurement signal" may be used interchangeably throughout this description. Magnetic sensors provided in the described embodiments may include one or more magnetoresistive sensing elements made of a magnetoresistive material (e.g., nickel-iron (NiFe)), wherein the electrical resistance of the magnetoresistive material may depend on a strength and / or a direction of the magnetic field present at the magnetoresistive material. Here, a sensing element may operate based on an anisotropic magnetoresistance (AMR) effect, a giant magnetoresistance (GMR) effect, a tunnel magnetoresistance (TMR) effect, or the like.As another example, a magnetic sensor may include one or more Hall-based sensing elements that operate based on a Hall effect. A magnetic angle sensor may include multiple sensing elements of one or more types.

[0023] As an additional example, resolver coils can be used as magnetic sensors. However, it should be understood that the induced voltages of the resolver coils must be demodulated before they can be used as x- and y-components for calculating the angle and vector length.

[0024] For example, a magnetic field component can be an x-magnetic field component (Bx), a y-magnetic field component (By), or a z-magnetic field component (Bz), where the Bx and By field components are in-plane with the chip and Bz is out-of-plane with the chip, in the examples provided. A sensing element can be sensitive to a component of the magnetic field according to its "sensitivity axis" or "sensing axis."

[0025] For example, a measured value (e.g., voltage) output by a sensing element changes according to the magnetic field strength along its sensing axis. For example, a sensing element with its sensitivity axis aligned with an x-axis is sensitive to an x-magnetic field component (Bx), whereas a sensing element with its sensitivity axis aligned with a y-axis is sensitive to a y-magnetic field component (By). Thus, two sensing elements can be configured so that their sensitivity axes are arranged orthogonally to each other.

[0026] According to one or more embodiments, both a plurality of magnetic field angle sensors and a sensor circuit arrangement may be housed (i.e., integrated) in the same chip. The sensor circuit may be referred to as a signal processing circuit and / or a signal conditioning circuit that receives one or more signals (i.e., sensor signals) from one or more magnetic field sensing elements in the form of raw measurement data and derives a measurement signal representing the magnetic field from the sensor signal.

[0027] In some cases, a measurement signal can be a differential measurement signal derived from sensor signals generated by two sensing elements sharing the same sensing axis (e.g., two sensing elements sensitive to the same magnetic field component) using differential calculus. A differential measurement signal provides robustness to homogeneous external stray magnetic fields.

[0028] Signal conditioning, as used herein, refers to the manipulation of an analog signal in such a way that the signal meets the requirements of a next stage for further processing. Signal conditioning may include analog-to-digital conversion (e.g., via an analog-to-digital converter), amplification, filtering, conversion, biasing, range adjustment, isolation, and any other processes required to make a sensor output suitable for processing after conditioning.

[0029] Thus, the sensor circuit may include an analog-to-digital converter (ADC) that converts the analog signal from the one or more sensing elements into a digital signal. The sensor circuit may also include a digital signal processor (DSP) that performs processing on the digital signal, as discussed below. Therefore, a chip, which may also be referred to as an integrated circuit (IC), may include circuitry that conditions and amplifies the small-signal signal from the one or more magnetic field sensing elements via signal processing and / or conditioning. It should also be noted that the described embodiments may be split across two or more chips.Additionally, the sensor circuit can include an optional demodulator that demodulates the x and y components when the measurement is performed using an alternating magnetic field, as is done in a resolver. Demodulation can be performed in the analog domain, before the ADC, or in the digital domain via a DSP, after the A / D conversion.

[0030] A sensor device, as used herein, may refer to a device comprising a sensor and a sensor circuit as described above.

[0031] Fig. 1 is a block diagram illustrating a magnetic angle sensor 100 according to one or more embodiments. The magnetic angle sensor 100 may include two sensing elements Sx and Sy arranged to provide output signals corresponding to two orthogonal components of a magnetic field, such as an x-component of the magnetic field and a y-component of the magnetic field. In this case, the sensing element Sx is configured to detect a sine angle component (e.g., x-component) of the magnetic field, and the sensing element Sy is configured to detect a cosine angle component (e.g., y-component) of the magnetic field. Thus, the two sensing elements Sx and Sy are configured to generate two sensor signals (e.g., a voltage signal Vx and a voltage signal Vy) that are 90° out of phase with each other.

[0032] The magnetic angle sensor 100 also includes a sensor circuit 10 that receives the sensor signals from the sensing elements Sx and Sy for processing and generating an angle output signal corresponding to an orientation of the magnetic field. The sensor circuit 10 includes two signal paths: an X signal path and a Y signal path. The X signal on the X signal path may be in the form of a sinusoidal waveform representing an angular orientation of the target object, and the Y signal on the Y signal path may be a similar waveform shifted by 90° from the X signal. That is, the Y signal is a cosinusoidal waveform representing an angular orientation of the target object.It should be noted that although the examples herein describe the sine waveform as being used as signal X and the cosine waveform as being used as signal Y, the opposite may also be true as long as the two signals are 90° out of phase with each other.

[0033] The signal paths X and Y may each comprise an ADC 1x and an ADC 1y, which convert the sensor signal Vx and Vy of the respective signal path into a digital signal for further processing by a remaining portion of the sensor circuit 10.

[0034] A DSP may comprise a digital signal processing component or a collection of digital signal processing components. The DSP may receive digital signals from ADCs 1x and 1y and may process the digital signals to form output signals intended for an external device, such as a controller (not shown). Each "block" may comprise one or more processors for processing one or more signals.

[0035] The DSP may include a temperature compensation (TC), autocalibration and filter block 2, a signal conversion algorithm block 3 and a memory element 4.

[0036] The temperature compensation (TC), autocalibration and filtering block 2 may receive the sensor signals Vx and Vy and a temperature sensor signal T, and perform one or more signal conditioning operations thereon before outputting the compensated sensor signals Vx' and Vy' to the signal conversion algorithm block 3.

[0037] In particular, the temperature compensation (TC), autocalibration, and filter block 2 is configured to receive the sensor signals Vx and Vy for further processing. For example, the temperature compensation (TC), autocalibration, and filter block 2 may comprise one or more processors and / or logic units that perform various signal conditioning functions, such as absolute signal conversion, normalization, linearization, self-testing, and so on. One or more signal conditioning functions may be performed in combination with a look-up table stored in the memory element 4. In other words, the temperature compensation (TC), autocalibration, and filter block 2 receives the sensor signals Vx and Vy from the sensing elements Sx and Sy and converts the sensor signals into compensated measurement signals (i.e.measured values) Vx' and Vy', which are to be used for further calculations, such as angle calculations and vector length calculations.

[0038] The memory element 4 may comprise a read-only memory (ROM) (e.g., an 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 temperature compensation (TC), autocalibration, and filtering block 2. In some implementations, the memory element 4 may store information associated with processing performed by the temperature compensation (TC), autocalibration, and filtering block 2. Additionally or alternatively, the memory element 4 may store configurable values ​​or parameters for the set of sensing elements Sx and Sy and / or information for one or more other elements of the angle sensor 100, such as ADCs 1x and 1y.

[0039] Thus, the temperature compensation (TC), autocalibration, and filter block 2 converts the sensor signals Vx and Vy into compensated measurement signals Vx' and Vy'. The outputs of the temperature compensation (TC), autocalibration, and filter block 2 are provided to a signal conversion algorithm block 3 configured to generate an angle signal as an output signal based on the compensated measurement signals Vx' and Vy'. The signal conversion algorithm block 3 may be a processor configured to apply an angle algorithm (e.g., θ=arctan(Vy' / Vx')), stored in a memory element 4, to determine the angle of a rotating magnetic field and generate the angle signal representing an angle value θ.

[0040] Finally, the signal conversion algorithm block 3 is configured to receive the sensor signals Vx and Vy or measurement signals derived therefrom (e.g., compensated voltage signal Vx' and compensated voltage signal Vy'). The signal conversion algorithm block 3 is configured to calculate a rotation angle (θ) of a magnet generating the magnetic field (and a rotation angle of a rotatable object to which the magnet is connected) based on the sensor signals or the measurement signals corresponding to the two orthogonal components (e.g., θ=arctan(Vy' / Vx')). One or more signal conditioning functions can be executed in combination with a look-up table stored in the memory element 4 to further improve the angle θ.

[0041] In some cases, a functional safety test may be implemented in the angle sensor 100. For example, a vector length associated with the sensor signals (e.g., a vector length (VL) equal to Vx '2 +Vy '2 ) during operation of the angle sensor as a functional safety test. In one example, safe operation of the angle sensor can be assumed if the vector length remains essentially constant during operation of the angle sensor (e.g., after calibration and / or temperature compensation). In addition to monitoring the absolute vector length, the change in the vector length can be monitored.

[0042] Fig. 2A is a schematic block diagram of a magnetic angle sensor device 200 according to one or more embodiments. The magnetic angle sensor device 200 is a system that can be integrated on one or more chips. The magnetic angle sensor device 200 includes a plurality of signal processing circuits and blocks configured to process sensor signals and measurement signals, which as a whole form a sensor circuit. It should be noted that the signal processing circuits and blocks can be combined into a single processor, microprocessor, DSP, and the like. Alternatively, the signal processing circuits and blocks can be provided in two or more processors, microprocessors, DSPs, and the like.The one or more signal processing circuits and blocks may be integrated together with the sensing elements on a sensor chip or provided in a system-level microcontroller.

[0043] Fig. Figure 2B is a graph illustrating a vector length tolerance region according to one or more embodiments. In particular, a vector length is determined according to the equation VL = Vx '2 +Vy '2 The graph represents a vector length plotted in xy coordinates (i.e., based on the two detected x and y magnetic field components), where + / - Ymax represents the extremes of a Y-ADC conversion range and + / - Xmax represents the extremes of an X-ADC conversion range. Ideally, the length vector should follow a circle, but a certain degree of tolerance is used to account for non-idealities.

[0044] The graph represents a wide vector length tolerance region 11 and a narrow vector length tolerance region 12. The graph also represents a normal length vector 13 with a changing angle and a faulty vector 14 that is "stuck" at an x-value. Since the x and y components are constantly changing with a rotating magnetic field, the faulty length vector 14 that is stuck at an x-value indicates that the sensed x-component is no longer changing. This may indicate that the sensing element Sx is faulty.

[0045] The graph shows that the changing normal length vector 13 remained within the narrow vector length tolerance region 12, indicating normal operation. In contrast, the faulty length vector 14 extends beyond the boundaries of the narrow vector length tolerance region 12, indicating faulty behavior.

[0046] Again referring to Fig. 2A, the magnetic angle sensor device 200 includes a first sensing element (Sx) 21 and a second sensing element (Sy) 22, which generate the sensor signals Vx and Vy, as described above.

[0047] The magnetic angle sensor component 200 also includes a first compensation circuit 23 and a second compensation circuit 24, which, as described above, generate measurement signals Vx' and Vy', respectively. It should be noted that the first and second compensation circuits 23 and 24 can be combined into a single compensation circuit.

[0048] Compensation circuits 23 and 24 may each include an ADC (e.g., ADC 1x or ADC 1y) and a temperature compensation (TC), autocalibration, and filter block 2. Thus, compensation circuits 23 and 24 each include one or more processors and / or logic units that perform various signal conditioning and compensation functions to derive the measured values ​​Vx' and Vy' from the sensor signals Vx and Vy for use in further calculations. Compensation circuits 23 and 24 may be a microprocessor, such as a DSP, or a portion thereof.

[0049] The magnetic angle sensor device 200 further comprises a signal conversion algorithm block 25 configured to process the measured values ​​Vx' and Vy' to generate an angle signal θ as an output angle according to an angle algorithm (e.g., θ=arctan(Vy' / Vx'). The signal conversion algorithm block 25 may be configured to generate and output an angle measurement at different sampling times.

[0050] The magnetic angle sensor component 200 further comprises a vector length calculation block 26 configured to process the measured values ​​Vx' and Vy' to generate a vector length signal as an output vector length according to a vector length algorithm (e.g., VL = Vx' 2 +Vy' 2). The vector length calculation block 26 is configured to generate and output a vector length measurement VL at different sampling times, which may coincide with the different sampling times of the angle measurements. Thus, each vector length measurement VL may also correspond to an angle measurement.

[0051] The magnetic angle sensor component 200 further comprises a vector length differentiation block 27 configured to calculate a vector length difference between at least two vector length (VL) samples.

[0052] In one implementation, the vector length differentiating block 27 is configured to receive two adjacent VL samples (i.e., two samples taken at two consecutive sampling times) and calculate a difference therebetween to generate a differential vector length (e.g., ΔVL = VL1-VL2).

[0053] In another implementation, the vector length differentiating block 27 is configured to receive two or more adjacent VL samples (i.e., two or more samples taken at consecutive sampling times), calculate a differential vector length (ΔVL) between each pair of adjacent VL samples to generate a set of differential vector length values, and further calculate an average of the differential vector lengths (ΔVL avg1 ) at its output.

[0054] In another implementation, the vector length differentiating block 27 is configured to receive two or more adjacent VL samples (i.e., two or more samples taken at consecutive sampling times), calculate a differential vector length (ΔVL) between each pair of adjacent VL samples to generate a set of differential vector length values, determine a differential vector length minimum value (ΔVLmin) from the set of differential vector length values, determine a differential vector length maximum value (ΔVLmax) from the set of differential vector length values, and output the minimum value (ΔVLmin) and the maximum value (ΔVLmax) at its output as differential vector lengths to be evaluated.

[0055] In another implementation, the vector length differentiating block 27 is configured to receive two or more adjacent VL samples (i.e., two or more samples taken at consecutive sampling times), detect minimum and maximum values ​​among the vector length samples, and calculate ΔVLmm=VLmax-VLmin as the differential vector length.

[0056] In another implementation, the vector length differentiation block 27 is configured to receive two or more adjacent VL samples (i.e., two or more samples taken at consecutive sampling times), a standard deviation (stdev) of the adjacent VL samples as the differential vector length ΔVL to be evaluated SD to calculate.

[0057] The magnetic angle sensor device 200 may further comprise an error detector 28 configured to detect the outputs from the vector length calculation block 26 (i.e., VL) and / or the vector length differentiation block 27 (e.g., ΔVL, ΔVL avg1 , ΔVLmin, ΔVLmax, ΔVLmm, and / or ΔVL SD ). Using the vector lengths VL, the error detector 28 can perform an absolute vector length analysis test based on one or more predetermined tolerance thresholds. Using the vector length differentiation outputs, the error detector 28 can perform a vector length variance analysis test on the received information based on one or more predetermined tolerance thresholds.

[0058] For example, if a measured value exceeds a predetermined tolerance threshold or tolerance range, the error detector 28 may generate a warning signal indicating a fault in the angle sensor device 200 and output the warning signal to an external device, such as an external controller.

[0059] For example, the fault detector 28 may receive the differential vector length (ΔVL) and compare the differential vector length (ΔVL) to a minimum tolerance threshold and a maximum tolerance threshold. One or both of the minimum tolerance threshold and the maximum tolerance threshold may define a tolerance range or window within which the differential vector lengths are acceptable and indicate normal functionality.

[0060] Thus, if the differential vector length (ΔVL) is less than the minimum tolerance threshold or greater than the maximum tolerance threshold, the fault detector 28 determines that the differential vector length (ΔVL) is outside the limits of the tolerance range and that a fault may exist within the magnetic angle sensor device 200.

[0061] On the other hand, if the differential vector length (ΔVL) is equal to or greater than the minimum tolerance threshold and equal to or less than the maximum tolerance threshold, the error detector 28 determines that the differential vector length (ΔVL) is within the limits of the tolerance range and that the magnetic angle sensor component 200 is operating within an acceptable error margin (i.e., the magnetic angle sensor component 200 is operating normally). If the differential vector length (ΔVL) is within the limits of the tolerance range, the error detector 28 determines that the inputs under test are valid and does not generate a warning signal.

[0062] In the event that no error is detected, the error detector 28 allows measurement signals to be output as valid output signals. For example, the error detector 28 can additionally receive compensated measurement signals Vx' and Vy' (e.g., via the vector length calculation block 26) and output the compensated measurement signals as valid output signals to be used by the signal conversion algorithm block 25 to calculate the angle measurement θ under the condition that the operations of the sensor elements 21 and 22 are verified as normal based on the described analysis tests.

[0063] The error detector 28 performs a similar evaluation for ΔVL avg1 , ΔVLmm, ΔVLmin, ΔVLmax and ΔVL SDwhere each delta value output by the vector length differentiation block 27 can be evaluated by a minimum tolerance threshold and a maximum tolerance threshold. Different minimum and maximum tolerance thresholds can be used depending on the type of delta variable being evaluated. The delta variables ΔVLmin and ΔVLmax can be evaluated according to a same set of minimum and maximum tolerance thresholds (i.e., over a tolerance range).

[0064] The vector length differencing block 27 may be configured to change the type of delta variable it calculates and outputs to the error detector 28. As a result, the error detector 28 may include a memory element storing a lookup table including different sets of minimum and maximum tolerance thresholds (i.e., different sets of tolerance ranges) mapped to different types of delta variables, and may be configured to select a set of minimum and maximum tolerance thresholds from the lookup table based on the type of the received delta variable.

[0065] Additionally, the error detector 28 can monitor the absolute vector length based on the vector length measurements VL in addition to monitoring the change in the vector length. For this purpose, the vector length calculation block 26 and the error detector 28 can be coupled such that the vector length calculation block 26 provides the vector length signal comprising vector length measurements VL to the error detector 28.

[0066] The vector length calculation block 26 and the error detector 28, in combination, may represent a type of safety mechanism (SM) used in the described embodiments. Alternatively, a safety mechanism may additionally comprise the vector length differentiation block 27. Two or more safety mechanisms may be used. For example, a safety mechanism may be provided between the sensor elements 21 and 22 and the compensation circuits 23 and 24 to evaluate the sensor signals Vx and Vy. Another safety mechanism may be provided as in Fig. 2A to evaluate sensor signals Vx' and Vy'.

[0067] Fig. 3 is a schematic diagram of a calibration system 300 implementing autocalibration for a sensor device, according to one or more embodiments. The calibration system 300 includes a sensor device 31 that generates N sensor signals S1, a first security mechanism (SM1) 32, a compensation circuit 33, an autocalibration device 34 that automatically generates and outputs M compensation parameters for the compensation circuit 33, a second security mechanism (SM2) 35, and a third security mechanism (SM3) 36. Here, N and M are integers equal to or greater than 1. The calibration system 300 may be implemented in a sensor module integrated on a single chip, or it may be split across two or more chips.

[0068] The sensor component 31 includes one or more sensor elements. For example, the sensor component 31 may include the first sensing element (Sx) 21 and the second sensing element (Sy) 22, which generate the sensor signals Vx and Vy, as described above. The M compensation parameters are optimized by the auto-calibration component 34 to achieve the optimal compensated sensor output(s). The M compensation parameters may, for example, include different types of compensation parameters, including, but not limited to, gain (amplitude) value settings, offset values, and angular offset adjustment values.

[0069] The safety mechanisms SM1 and SM2 represent two locations used to detect errors in the sensor device 31 (e.g., to detect errors in the sensor elements). Each safety mechanism comprises one or more processors or processing circuitry configured to perform a validity check on the sensor signals. In the context of Fig. 2A, for example, the safety mechanism SM1 is coupled to the output of the first sensing element (Sx) 21 and the second sensing element (Sy) 22 to receive N sensor signals S1 (i.e., sensor signals Vx and Vy). The safety mechanism SM1 is configured to perform a validity check on the uncompensated sensor signals S1 using at least a first tolerance range. For example, the safety mechanism SM1 may perform an absolute vector length analysis check based on one or more predetermined tolerance thresholds and / or a vector length variance analysis check based on one or more predetermined tolerance thresholds.

[0070] The safety mechanism SM1 additionally generates a result signal R1 indicating the result of the validity check. If an error is detected, the safety mechanism SM1 generates a warning signal or an error detection signal as the result signal R1 (i.e., an error detection signal) as safety information that can be received by a system controller (not shown) for further analysis and action. If no error is detected, the safety mechanism SM1 provides the validated N sensor signals S2 without any error detection to the compensation circuit 33, which performs similar functions as described above with respect to the compensation circuits 23 and 24. Under some circumstances, the safety mechanism SM1 can generate an "all clear" signal or an "OK" signal as the result signal R1, indicating that the validity check has been passed.

[0071] Thus, the compensation circuit 33 generates N compensated sensor signals S3 (e.g., compensated sensor signals Vx' and Vy'), one for each of the N validated sensor signals S2. The compensation circuit 33 generates the N compensated sensor signals S3 based on the M compensation parameters generated by the auto-calibration component 34. In the event that a fault is detected by the safety mechanism SM1, the safety mechanism SM1 can deactivate its output of the sensor signals S2. However, if the sensor component is part of a safety-critical function, for example, in a vehicle, the safety mechanism SM1 can continue to output the sensor signals S2 for use in the safety-critical function. Alternatively, the safety mechanism SM1 can deactivate its output of the sensor signals S2 that are invalid, while only outputting those sensor signals S2 that have been verified as valid.

[0072] In the context of Fig. 2A, the safety mechanism SM2 is coupled to the output of the compensation circuit 33 to receive the N compensated sensor signals S3 (i.e., the compensated sensor signals Vx' and Vy'). The safety mechanism SM2 is configured to perform a validity check using at least one second tolerance range. For example, the safety mechanism SM2 may perform an absolute vector length analysis check based on one or more predetermined tolerance thresholds and / or a vector length variance analysis check based on one or more predetermined tolerance thresholds.The tolerance range(s) used by safety mechanism SM2 can be chosen to be narrower than the tolerance range(s) used by safety mechanism SM1 because a higher degree of noise, offset, and error must be tolerated by safety mechanism SM1 due to its positioning upstream of compensation circuit 33. In contrast, since safety mechanism SM2 receives compensated signals, the amount of noise, offset, and error should be compensated and thus smaller. In other words, the safety limits for safety mechanism SM2 can be chosen to be narrower than for safety mechanism SM1 because compensation reduces the signal fluctuations caused by sensor non-idealities. This improves the accuracy of safety mechanism SM2 with respect to safety mechanism SM1 and can result in a safer system.Thus, the safety mechanism SM2 uses a smaller tolerance range compared to the safety mechanism SM1.

[0073] The safety mechanism SM2 additionally generates a result signal R2 indicating the result of the validity check. If an error is detected, the safety mechanism SM2 generates a warning signal or an error detection signal as the result signal R2 as safety information that can be received by a system controller (not shown) for further analysis and action. If no error is detected, the safety mechanism SM2 provides the validated N compensated sensor signals S4 as valid outputs. For example, the safety mechanism SM2 can provide the validated N compensated sensor signals S4 to another signal processor, such as the signal conversion algorithm block 25 for calculating the angle measurement θ, or to a controller.Under some circumstances, the safety mechanism SM2 may generate an "all clear" or "OK" signal as the result signal R2, indicating that the validity check has been passed. Additionally, if an error is detected by the safety mechanism SM2, the safety mechanism SM2 may deactivate its output of the sensor signals S4. However, if the sensor component is part of a safety-critical function, for example, in a vehicle, the safety mechanism SM2 may continue to output the sensor signals S4 for use in the safety-critical function. Alternatively, the safety mechanism SM2 may deactivate its output of the sensor signals S4 that are invalid, while only outputting those sensor signals S4 that have been verified as valid.

[0074] The autocalibration component 34 is configured to receive the validated N sensor signals S2 from the safety mechanism SM2 and generate M compensation parameters based thereon. The compensation circuit 33 uses the M compensation parameters to perform compensation on the validated N sensor signals S2 to generate the N compensated sensor signals S3.

[0075] Additionally or alternatively, the autocalibration component 34 is configured to receive the N compensated sensor signals S3 from the compensation circuit 33 and generate M compensation parameters based thereon. The compensation circuit 33 uses the M compensation parameters to perform a compensation on the validated N sensor signals S2 to generate the N compensated sensor signals S3.

[0076] In case of using the validated N sensor signals S2 to generate the M compensation parameters, the autocalibration component 34 is configured to generate new compensation parameters based on the validated N sensor signals S2 for use in the compensation operation.

[0077] In the case of using the N compensated sensor signals S3 to generate the M compensation parameters, the auto-calibration component 34 is configured to calculate the changes required for the currently used calibration parameters based on the N compensated sensor signals S3 and to adjust the currently used calibration parameters based on the calculated changes to generate updated or compensated calibration parameters for use in the compensation operation.

[0078] In both cases, the autocalibration performed by the compensation circuit 33 and the autocalibration component 34 can calibrate out (i.e., mask) certain errors of the sensor component 31 that become undetectable by the safety mechanism SM2. Without the safety mechanism SM3, this would result in the system being left with a less accurate safety mechanism SM1 and / or a more accurate, but partially blind, safety mechanism SM2, resulting in reduced diagnostic coverage.

[0079] Depending on the system, processing the safety mechanisms SM1 and SM2 can be quite expensive. One example of a safety mechanism for angle sensors is the vector length check described above. The vector length check monitors the magnitude of the electrical vector, whose elements are given by the cosine (X) and sine (Y) sensor channels.

[0080] For an ideal sensor, this value remains constant, since cos 2 θ+sin 2 θ=1. For example, if a sensor channel experiences a stuck fault, the magnitude changes as a function of the angle θ, which can be detected by the vector length check.

[0081] As a result of the blind spot of the safety mechanism SM2 resulting from the auto-calibration, a safety mechanism SM3 is provided between the auto-calibration component 34 and the compensation circuit 33. The safety mechanism SM3 comprises one or more processors or processing circuitry configured to perform a validity check on the compensation parameters.

[0082] More specifically, the safety mechanism SM3 is configured to receive the M compensation parameters determined by the autocalibration component 34 and to monitor the received M compensation parameters. The safety mechanism SM3 can compare each of the M compensation parameters with a tolerance range, verifying that the compensation parameters remain within certain predefined limits. The safety mechanism SM3 can also monitor the variation over time of the M compensation parameters to detect sudden changes in these parameters that could indicate the occurrence of an error. As a result, the safety mechanism SM3 can be implemented with minimal overhead. This safety mechanism SM3 effectively detects errors that would otherwise be masked by the compensation and escape detection by the safety mechanism SM2, which only monitors the N compensated signals S3.This combination provides excellent accuracy over the SM2 security mechanism, along with comprehensive coverage (SM2+SM3) and minimal cost by eliminating costly operations in the SM1 security mechanism.

[0083] The safety mechanism SM3 additionally generates a result signal R3 indicating the result of the validity check. As a result of the validity check performed by the safety mechanism SM3, the safety mechanism SM3 generates a warning signal or an error detection signal as the result signal R3 under a condition that one of the M compensation parameters exceeds its respective tolerance range. Alternatively, if no error is detected, the safety mechanism SM3 outputs validated M compensation parameters to the compensation circuit 33 to be used to compensate the validated N sensor signals S2. Additionally, if no error is detected, the safety mechanism SM3 can generate an "all clear" signal or an "OK" signal as the result signal R3, indicating that the validity check has been passed.In addition, in the case where an error is detected by the safety mechanism SM3, the safety mechanism SM3 can disable its output of the compensation parameters that are invalid, while outputting only those compensation parameters that have been verified as valid.

[0084] Several different implementations for verifying the M compensation parameters are conceivable. First, each of the M compensation parameters can be compared against a corresponding predefined static limit. Second, each of the M compensation parameters can be compared against a corresponding adjusted limit, which can be compensated by an external or environmental factor such as temperature or mechanical stress measured by a sensor 37. While the first approach is simpler, the second approach can result in better accuracy by allowing a tighter safety margin (i.e., narrower tolerance ranges).

[0085] Fig. Figure 4 shows example electrical vectors (X, Y) as a function of the angle θ for the vector length check implemented in the safety mechanism SM1 (left; using uncompensated sensor signals) or in the safety mechanism SM2 (right; using compensated sensor signals). X and Y are the components of the electrical vector given by (X, Y). Example signals are plotted as solid lines at ambient temperature (AT), cold temperature (CT), and hot temperature (HT). Safety limits are shown as shaded areas and represent a corresponding tolerance range for each safety mechanism.

[0086] For a magnetic angle sensor, the autocalibration component 34 can autocalibrate offsets and amplitudes of the sine (X) and cosine (Y) sensor channels, and additionally autocalibrate an orthogonality error between the sensor signals Vx and Vy. The offsets of the X and Y sensor channels could, for example, change significantly as a function of temperature. If the safety mechanism SM1 implements a vector length, the corresponding safety limits would need to include these offset variations (see, for example, Fig. 4 (left)). Since errors within the tolerance range cannot be detected, this leads to a fairly large region of undetected failures within the tolerance range for the vector length check. By implementing the vector length check in the SM2 safety mechanism, the safety limits can be selected to be considerably smaller (see, for example, Fig. 4 (right)). This results in a minimal region of undetected failures for the vector length check due to the narrower tolerance range. However, the vector length check in the SM2 safety mechanism is now blind to errors caused by fluctuations in the compensation parameters, including offsets, amplitudes, and orthogonality errors.

[0087] As a countermeasure, the safety mechanism SM3 is configured to check the autocalibrated compensation parameters, including amplitudes (Ax and Ay) for the sensor channels X and Y, offsets (Ox and Oy) for the sensor channels X and Y, and orthogonality errors (φ) between the sensor channels X and Y. Thus, the compensation parameters include at least one of an amplitude compensation parameter for compensating an amplitude of the sensor signal X, an offset compensation parameter for compensating an offset of the sensor signal X, an amplitude compensation parameter for compensating an amplitude of the sensor signal Y, an offset compensation parameter for compensating an offset of the sensor signal Y, and optionally even an orthogonality error compensation parameter for compensating an orthogonality error between the sensor signals X and Y.

[0088] Fig.5 shows a static offset check (left) and an adjusted offset check (right) according to one or more embodiments. In particular, sensor channel offsets (Ox, Oy) can be compared against a static tolerance range TR1 (left) that is independent of an external or environmental factor such as temperature T. If the safety mechanism SM3 detects that one of the sensor channel offsets (Ox, Oy) set by the auto-calibration component 34 is outside the static tolerance range TR1, the safety mechanism SM3 generates a warning signal W3 as a compensation parameter. Otherwise, the sensor channel offsets (Ox, Oy) are output by the safety mechanism SM3 as validated compensation parameters.

[0089] Alternatively, the sensor channel offsets (Ox, Oy) can be compared against an adjusted tolerance range TR2 (right), which depends on an external or environmental factor such as temperature T. More specifically, the safety mechanism SM3 receives a sensor signal from the sensor 37, such as a temperature signal, and adjusts the tolerance range for the sensor channel offsets (Ox, Oy) based on the temperature measurement. The safety mechanism SM3 then uses the adjusted tolerance range to validate the sensor channel offsets (Ox, Oy). If the safety mechanism SM3 detects that one of the sensor channel offsets (Ox, Oy) set by the auto-calibration component 34 is outside the adjusted tolerance range TR2, the safety mechanism SM3 generates a warning signal W3; otherwise, the sensor channel offsets (Ox, Oy) are output by the safety mechanism SM3 as validated compensation parameters.Compared to static tolerance ranges, adjusted tolerance ranges can result in more precise safety mechanisms with improved diagnostic coverage.

[0090] Each compensation parameter type can have a different tolerance range, whether static or adjusted. Whether a tolerance range is static or adjusted can be configured independently for each compensation parameter type.

[0091] If the sensor uses Hall plates to measure the x and y magnetic field components, additional stress compensation can be applied using stress sensor 38, which measures mechanical stress. Sensors 37 and 38 can be representative of a set of sensors used in combination by the safety mechanism SM3 to adjust each of the tolerance ranges for the respective compensation parameters. Here, the safety mechanism SM3 can adjust the tolerance ranges based on values ​​received from both temperature and stress sensor signals.

[0092] To further increase diagnostic coverage, the extracted correction values ​​for the offsets, gains, and temperatures can be captured over the temperature during the sensor's end-of-line test, providing an extremely narrow monitoring band for aging effects. In cases where operating time can be captured, the drift rate of each compensation parameter can also be monitored by safety mechanism 3, and a fault detection message can be issued by safety mechanism 3 if the drift rate is too high, which would indicate a defect.

[0093] In cases where the drifts of the compensation parameters depend on known physical effects, e.g., the stability of a bias magnetic field or the drift of dopants in a semiconductor, it can be exploited that the drifts must be monotonic, which can also be monitored.

[0094] Although various embodiments have been described, it will be apparent to those of ordinary skill in the art that many other embodiments and implementations are possible within the scope of the disclosure. Accordingly, the invention is not intended to be limited except in terms of the appended claims and their equivalents. With regard to the various functions performed by the above-described components or structures (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a "means") used to describe such components are intended, unless otherwise indicated, to correspond to any component or structure that performs the specified function of the described component (i.e.which is functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the function in the exemplary implementations of the invention presented herein.

[0095] Furthermore, the following claims are hereby incorporated into the Detailed Description, where each claim may stand on its own as a separate exemplary embodiment. While each claim may stand on its own as a separate exemplary embodiment, it should be noted that although a dependent claim may refer to a particular combination with one or more other claims in the claims, other examples may include a combination of the dependent claim with the subject matter of any other dependent or independent claim. Such combinations are suggested herein unless it is stated that a particular combination is not intended. Furthermore, features of a claim for any other independent claim are also intended to be included, even if that claim is not made directly dependent on the independent claim.

[0096] It should further be noted that methods disclosed in the description or in the claims may be implemented by an apparatus comprising means for performing each of the respective steps of those methods.

[0097] Furthermore, it should be understood that the disclosure of multiple steps or functions disclosed in the description or claims should not be construed as being in a particular order. Therefore, the disclosure of multiple steps or functions does not limit them to a particular order, unless these steps or functions are not interchangeable for technical reasons. Furthermore, in some embodiments, a single step may comprise multiple substeps or may be divided into multiple substeps. Such substeps may be included and be part of the disclosure of that single step unless explicitly excluded.

[0098] 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, digital signal processors (DSPs), application-specific integrated circuits (ASICs), or any other equivalent integrated or discrete logic circuitry, as well as any combination of such components. The word "processor" or "processing circuitry" may generally refer to any of the foregoing logic circuitry, either alone or in combination with other logic circuitry or any other equivalent circuitry.A control unit comprising hardware may also perform one or more of the techniques of this disclosure. Such hardware, software, or firmware may be implemented within the same device, or within separate devices, to support the various techniques described in this disclosure.

[0099] Although various exemplary embodiments have been disclosed, it will be apparent to those skilled in the art that various changes and modifications can be made that will achieve some of the advantages of the concepts disclosed herein without departing from the spirit and scope of the invention. It will be apparent to those of ordinary skill in the art that other components performing the same functions may be suitably substituted. It should be appreciated that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. It should be noted that features described with reference to a particular figure may be combined with features of other figures, even those not explicitly mentioned.Such modifications of the general inventive concept are intended to be covered by the appended claims and their legal equivalents.

[0100] Embodiment 1 is an auto-calibration system comprising: a sensor device comprising at least one sensing element, each of the at least one sensing element being configured to generate a sensor signal from at least one sensor signal in response to measuring a physical quantity; a compensation device comprising first processing circuitry configured to receive the at least one sensor signal and at least one compensation parameter and to compensate the at least one sensor signal based on the at least one compensation parameter to generate at least one compensated sensor signal, wherein a different compensated sensor signal is generated for each of the at least one sensor signal;an auto-calibration device comprising a second processing circuitry configured to receive the at least one sensor signal or the at least one compensated sensor signal and to generate the at least one compensation parameter based on the at least one sensor signal or the at least one compensated sensor signal;and a first safety mechanism comprising third processing circuitry connected between the compensation circuit and the auto-calibration component, the third processing circuitry being configured to compare each of the at least one compensation parameter with a respective tolerance range and, under a condition that each of the at least one compensation parameter is within its respective tolerance range, to transmit the at least one compensation parameter as at least one validated compensation parameter to the compensation circuit, and, under a condition that at least one of the at least one compensation parameter is not within its respective tolerance range, to generate a first error detection signal.

[0101] In Embodiment 2, the autocalibration component in the autocalibration system of Embodiment 1 is configured to regenerate the at least one compensation parameter based on the at least one sensor signal.

[0102] In embodiment 3, the autocalibration component in the autocalibration system of one of embodiments 1 or 2 is configured to generate the at least one compensation parameter by adjusting at least one current compensation parameter based on the at least one compensated sensor signal.

[0103] In embodiment 4, the sensor component in the auto-calibration system of any one of embodiments 1 to 3 is a magnetic sensor component, and the at least one sensing element comprises a first magnetic sensor configured to generate a first sensor signal of the at least one sensor signal in response to a first component of a magnetic field, and a second magnetic sensor configured to generate a second sensor signal of the at least one sensor signal in response to a second component of the magnetic field.

[0104] In Embodiment 5, the at least one compensation parameter in the auto-calibration system of Embodiment 4 includes at least one of a first amplitude compensation parameter for compensating an amplitude of the first sensor signal, a first offset compensation parameter for compensating an offset of the first sensor signal, a second amplitude compensation parameter for compensating an amplitude of the second sensor signal, a second offset compensation parameter for compensating an offset of the second sensor signal, and an orthogonality error compensation parameter for compensating an orthogonality error between the first sensor signal and the second sensor signal.

[0105] In embodiment 6, in the autocalibration system of any one of embodiments 1 to 5, the respective tolerance range for each of the at least one compensation parameter is static.

[0106] In embodiment 7, the third processing circuitry in the autocalibration system of any of embodiments 1 to 6 is configured to receive a temperature measurement and adjust the respective tolerance range for each of the at least one compensation parameter based on the temperature measurement.

[0107] In embodiment 8, the third processing circuitry in the autocalibration system of any of embodiments 1 to 7 is configured to receive a measurement of mechanical stress and to adjust the respective tolerance range for each of the at least one compensation parameter based on the measurement of mechanical stress.

[0108] In Embodiment 9, the third processing circuitry in the autocalibration system of any one of Embodiments 1 to 8 is configured to measure a drift rate for each of the at least one compensation parameter, compare the drift rate for each of the at least one compensation parameter with a respective drift rate threshold, and generate a second error detection signal under a condition that at least one drift rate exceeds its respective drift rate threshold.

[0109] In embodiment 10, the auto-calibration system of any one of embodiments 1 to 9 further comprises a second safety mechanism comprising fourth processing circuitry connected between the sensor device and the compensation circuit, wherein the fourth processing circuitry is configured to compare each of the at least one sensor signal with a first tolerance range and, under a condition that each of the at least one sensor signal is within the first tolerance range, to transmit the at least one sensor signal as at least one validated sensor signal to the compensation circuit and to the auto-calibration device and, under a condition that at least one of the at least one sensor signal is not within the first tolerance range, to generate a second error detection signal.

[0110] In Embodiment 11, the autocalibration system of Embodiment 10 further comprises a third safety mechanism comprising fifth processing circuitry connected between the compensation circuit and a system output, the fifth processing circuitry being configured to compare each of the at least one compensated sensor signals to a second tolerance range and, under a condition that each of the at least one compensated sensor signals is within the second tolerance range, to transmit the at least one compensated sensor signal as at least one validated compensated sensor signal to the system output and, under a condition that at least one of the at least one compensated sensor signals is not within the second tolerance range, to generate a third error detection signal.

[0111] In Embodiment 12, the first tolerance range in the auto-calibration system of Embodiment 11 is wider than the second tolerance range.

[0112] Embodiment 13 is a method for autocalibration, comprising generating at least one sensor signal in response to measuring a physical quantity; compensating, by a compensation circuit, the at least one sensor signal based on at least one compensation parameter to generate at least one compensated sensor signal, wherein a different compensated sensor signal is generated for each of the at least one sensor signals; generating, by an autocalibration device, the at least one compensation parameter based on the at least one sensor signal or based on the at least one compensated sensor signal; comparing each of the at least one compensation parameter to a respective tolerance range;Under a condition that each of the at least one compensation parameter is within its respective tolerance range, transmitting the at least one compensation parameter to the compensation circuit as at least one validated compensation parameter, wherein the at least one validated compensation parameter is used to compensate the at least one sensor signal; and under a condition that at least one of the at least one compensation parameter is not within its respective tolerance range, generating a first error detection signal.

[0113] In embodiment 14, generating the at least one compensation parameter in the method of embodiment 13 comprises regenerating the at least one compensation parameter based on the at least one sensor signal.

[0114] In embodiment 15, generating the at least one compensation parameter in the method of one of embodiments 13 or 14 comprises adjusting at least one current compensation parameter based on the at least one compensated sensor signal.

[0115] In embodiment 16, generating the at least one sensor signal in the method of any of embodiments 13 to 15 comprises generating a first sensor signal of the at least one sensor signal in response to a first component of a magnetic field; and generating a second sensor signal of the at least one sensor signal in response to a second component of the magnetic field.

[0116] In embodiment 17, the at least one compensation parameter in the method of embodiment 16 comprises at least one of a first amplitude compensation parameter for compensating an amplitude of the first sensor signal, a first offset compensation parameter for compensating an offset of the first sensor signal, a second amplitude compensation parameter for compensating an amplitude of the second sensor signal, a second offset compensation parameter for compensating an offset of the second sensor signal, and an orthogonality error compensation parameter for compensating an orthogonality error between the first sensor signal and the second sensor signal.

[0117] In embodiment 18, in the method of any of embodiments 13 to 17, the respective tolerance range for each of the at least one compensation parameter is static.

[0118] In embodiment 19, the method of any of embodiments 13 to 18 further comprises adjusting the respective tolerance range for each of the at least one compensation parameter based on a temperature measurement.

[0119] In embodiment 20, the method of any of embodiments 13 to 19 further comprises adjusting the respective tolerance range for each of the at least one compensation parameter based on a measurement of the mechanical stress.

[0120] In embodiment 21, the method of any of embodiments 13 to 20 further comprises measuring a drift rate for each of the at least one compensation parameter; comparing the drift rate for each of the at least one compensation parameter to a respective drift rate threshold; and generating a second error detection signal under a condition that at least one drift rate exceeds its respective drift rate threshold.

[0121] In embodiment 22, the method of any of embodiments 13 to 21 further comprises comparing each of the at least one sensor signals to a first tolerance range; under a condition that each of the at least one sensor signals is within the first tolerance range, transmitting the at least one sensor signal to the compensation circuit and the auto-calibration device as at least one validated sensor signal; and under a condition that at least one of the at least one sensor signals is not within the first tolerance range, generating a second error detection signal.

[0122] In embodiment 23, the method of embodiment 22 further comprises comparing each of the at least one compensated sensor signals to a second tolerance range; under a condition that each of the at least one compensated sensor signals is within the second tolerance range, transmitting the at least one compensated sensor signal to a system output as at least one validated compensated sensor signal; and under a condition that at least one of the at least one compensated sensor signals is not within the second tolerance range, generating a third fault detection signal.

[0123] In Embodiment 24, the first tolerance range in the method of Embodiment 23 is wider than the second tolerance range.

Claims

[1] An autocalibration system comprising: a sensor component comprising at least one sensing element, wherein each of the at least one sensing element is configured to generate a sensor signal from at least one sensor signal in response to measuring a physical quantity; a compensation component comprising first processing circuitry configured to receive the at least one sensor signal and at least one compensation parameter and to compensate the at least one sensor signal based on the at least one compensation parameter to generate at least one compensated sensor signal, wherein a different compensated sensor signal is generated for each of the at least one sensor signal; an autocalibration device comprising a second processing circuitry configured to receive the at least one sensor signal or the at least one compensated sensor signal and to generate the at least one compensation parameter based on the at least one sensor signal or the at least one compensated sensor signal; and a first safety mechanism comprising third processing circuitry connected between the compensation circuit and the autocalibration component, wherein the third processing circuitry is configured to compare each of the at least one compensation parameter with a respective tolerance range and, under a condition that each of the at least one compensation parameter is within its respective tolerance range, to transmit the at least one compensation parameter as at least one validated compensation parameter to the compensation circuit, and, under a condition that at least one of the at least one compensation parameter is not within its respective tolerance range, to generate a first error detection signal, wherein the auto-calibration component is configured to generate the at least one compensation parameter by adjusting at least one current compensation parameter based on the at least one compensated sensor signal. [2] The auto-calibration system of claim 1, wherein the auto-calibration device is configured to regenerate the at least one compensation parameter based on the at least one sensor signal. [3] The auto-calibration system according to one of claims 1 or 2, wherein the sensor component is a magnetic sensor component and the at least one sensing element comprises a first magnetic sensor configured to generate a first sensor signal of the at least one sensor signal in response to a first component of a magnetic field and a second magnetic sensor configured to generate a second sensor signal of the at least one sensor signal in response to a second component of the magnetic field. [4] The auto-calibration system according to claim 3, the at least one compensation parameter comprising at least one of a first amplitude compensation parameter for compensating an amplitude of the first sensor signal, a first offset compensation parameter for compensating an offset of the first sensor signal, a second amplitude compensation parameter for compensating an amplitude of the second sensor signal, a second offset compensation parameter for compensating an offset of the second sensor signal, and an orthogonality error compensation parameter for compensating an orthogonality error between the first sensor signal and the second sensor signal. [5] The autocalibration system according to any one of claims 1 to 4, wherein the respective tolerance range for each of the at least one compensation parameter is static. [6] The autocalibration system according to any one of claims 1 to 5, wherein: the third processing circuitry is configured to receive a temperature measurement and to adjust the respective tolerance range for each of the at least one compensation parameter based on the temperature measurement. [7] The autocalibration system according to any one of claims 1 to 6, wherein: the third processing circuitry is configured to receive a measurement of the mechanical stress and to adjust the respective tolerance range for each of the at least one compensation parameter based on the measurement of the mechanical stress. [8] The autocalibration system according to any one of claims 1 to 7, wherein: the third processing circuitry is configured to measure a drift rate for each of the at least one compensation parameter, compare the drift rate for each of the at least one compensation parameter with a respective drift rate threshold, and generate a second error detection signal under a condition that at least one drift rate exceeds its respective drift rate threshold. [9] The autocalibration system according to any one of claims 1 to 8, further comprising: a second safety mechanism comprising fourth processing circuitry connected between the sensor component and the compensation circuit, the fourth processing circuitry being configured to compare each of the at least one sensor signal with a first tolerance range and, under a condition that each of the at least one sensor signal is within the first tolerance range, to transmit the at least one sensor signal as at least one validated sensor signal to the compensation circuit and to the auto-calibration component and, under a condition that at least one of the at least one sensor signal is not within the first tolerance range, to generate a second error detection signal. [10] The autocalibration system according to claim 9, further comprising: a third safety mechanism comprising fifth processing circuitry connected between the compensation circuit and a system output, the fifth processing circuitry being configured to compare each of the at least one compensated sensor signals with a second tolerance range and, under a condition that each of the at least one compensated sensor signals is within the second tolerance range, to transmit the at least one compensated sensor signal as at least one validated compensated sensor signal to the system output and, under a condition that at least one of the at least one compensated sensor signals is not within the second tolerance range, to generate a third fault detection signal. [11] The auto-calibration system of claim 10, wherein the first tolerance range is wider than the second tolerance range. [12] A method for autocalibration, comprising: Generating at least one sensor signal in response to measuring a physical quantity; Compensating, by a compensation circuit, the at least one sensor signal based on at least one compensation parameter to generate at least one compensated sensor signal, wherein a different compensated sensor signal is generated for each of the at least one sensor signal; Generating, by an auto-calibration component, the at least one compensation parameter based on the at least one sensor signal or based on the at least one compensated sensor signal; Comparing each of the at least one compensation parameter with a respective tolerance range; under a condition that each of the at least one compensation parameter is within its respective tolerance range, transmitting the at least one compensation parameter to the compensation circuit as at least one validated compensation parameter, wherein the at least one validated compensation parameter is used to compensate the at least one sensor signal; and under a condition that at least one of the at least one compensation parameter is not within its respective tolerance range, generating a first error detection signal, wherein generating the at least one compensation parameter comprises adjusting at least one current compensation parameter based on the at least one compensated sensor signal. [13] The method of claim 12, wherein generating the at least one compensation parameter comprises regenerating the at least one compensation parameter based on the at least one sensor signal.

Images