Robust signal path plausibility check for functional safety of sensors

Abstract

Embodiments of the present disclosure relate to functionally safe robust signal path plausibility checks for sensors. A monitoring device of a sensor can acquire a first signal at a point on a first branch of a signal path of the sensor. The monitoring device can acquire a second signal at a point on a second branch of the signal path of the sensor and can monitor the first signal for a first characteristic indicated by the first signal. The monitoring device can monitor the second signal for a second characteristic indicated by the second signal. The monitoring device can determine whether a quantity of the first characteristic indicated by the first signal without a certain quantity of the second characteristic indicated by the second signal reaches a threshold quantity of the first characteristic. The monitoring device can assess a function of the signal path based on whether the quantity of the first characteristic indicated by the first signal without the certain quantity of the second characteristic indicated by the second signal reaches the threshold quantity of the first characteristic.

Description

Technical Field

[0001] The embodiments of this disclosure relate to robust signal path rationality checks for the functional safety of sensors. Background Technology

[0002] Magnetic sensors can sense magnetic fields generated or twisted by rotating target wheels (such as gears, encoder wheels, etc.). Based on the sensed magnetic field, magnetic sensors can output signals to identify the rotation direction, rotation speed, and rotation angle of the target wheel. Summary of the Invention

[0003] In some implementations, a method includes: acquiring a first signal at a point on a first branch of the sensor's signal path by a monitoring device of the sensor; acquiring a second signal at a point on a second branch of the sensor's signal path by the monitoring device; monitoring the first signal for a first characteristic indicated by the first signal by the monitoring device; monitoring the second signal for a second characteristic indicated by the second signal by the monitoring device; determining, based on the monitoring of the first signal for the first characteristic and the monitoring of the second signal for the second characteristic, whether the number of first characteristics indicated by the first signal reaches a threshold number of the first characteristic in the absence of a specific number of second characteristics indicated by the second signal; and evaluating the functionality of the signal path by the monitoring device based on whether the number of first characteristics indicated by the first signal reaches a threshold number of the first characteristic in the absence of a specific number of second characteristics indicated by the second signal.

[0004] In some implementations, a sensor includes: a signal path including a first branch and a second branch; and a monitoring device for: acquiring a first signal at a point on the first branch of the signal path; acquiring a second signal at a point on the second branch of the signal path; monitoring the first signal for a first characteristic indicated by the first signal; monitoring the second signal for a second characteristic indicated by the second signal; determining, based on the monitoring of the first signal for the first characteristic and the monitoring of the second signal for the second characteristic, whether the number of first characteristics indicated by the first signal reaches a threshold number of the first characteristic in the absence of a specific number of second characteristics indicated by the second signal; and evaluating the functionality of the signal path based on whether the number of first characteristics indicated by the first signal reaches a threshold number of the first characteristic in the absence of a specific number of second characteristics indicated by the second signal.

[0005] In some implementations, a monitoring device includes: one or more components for: monitoring an analog signal for analog characteristics indicated by an analog signal, the analog signal being associated with an analog branch of a signal path of a sensor; monitoring a digital signal for digital characteristics indicated by a digital signal, the digital signal being associated with a digital branch of a signal path of a sensor and being a digital representation of the analog signal; and evaluating the functionality of a signal path based on the monitoring of the analog signal and the monitoring of the digital signal, the evaluation of the functionality being based on at least one of: determining whether the number of analog characteristics indicated by the analog signal reaches a threshold number of analog characteristics in the absence of a specific number of digital characteristics indicated by the digital signal, or determining whether the number of digital characteristics indicated by the digital signal reaches a threshold number of digital characteristics in the absence of a specific number of analog characteristics indicated by the analog signal. Attached Figure Description

[0006] Figure 1A and 1B This is a diagram illustrating an example implementation of robust signal path rationality checks for the functional safety of sensors;

[0007] Figure 2A and 2B It is a diagram of an example environment in which the systems and / or methods described in this article can be implemented;

[0008] Figure 3 yes Figure 2A A diagram of example sensor elements included in a 2B example environment; and

[0009] Figure 4 This is a flowchart of an example process related to robust signal path rationality checks for the functional safety of sensors, as described in this article. Detailed Implementation

[0010] The following detailed description of the example implementation is provided with reference to the accompanying drawings. The same reference numerals in different drawings may identify the same or similar elements.

[0011] As mentioned above, magnetic sensors can be designed to sense magnetic fields and output signals to identify the rotation direction, speed, and angle of a target wheel. In some applications, it may be necessary to ensure the functional safety of the magnetic sensor. Generally, functional safety can be defined as the absence of unreasonable risks (e.g., to the system, to the environment, to humans) caused by the malfunctioning behavior of the magnetic sensor (e.g., system failure, random magnetic sensor failure, etc.).

[0012] In the automotive context, the Automotive Safety Integrity Level (ASIL) scheme can be used to specify functional safety requirements for magnetic sensors. The ASIL scheme is a risk classification scheme defined by the International Organization for Standardization (ISO) standard 26262 (titled "Functional Safety for Road Vehicles"), which provides a standard for the functional safety of electrical and / or electronic systems in mass-produced vehicles. ASIL classifications define the safety requirements required to comply with the ISO 26262 standard. ASILs are established through risk analysis of potential hazards by examining the severity, exposure, and controllability of the vehicle's operating scenarios. The safety objectives for these hazards incorporate ASIL requirements. The standard identifies four ASILs: ASIL A, ASIL B, ASIL C, and ASIL D. ASIL D specifies the highest integrity requirement, while ASIL A specifies the lowest integrity requirement. Hazards with low risk (and therefore do not require safety measures according to ISO 26262) are identified as Quality Management (QM). In some cases, magnetic sensors designed to sense magnetic fields and output signals to identify the rotational direction, speed, and / or angle of a target wheel may require specific ASILs, such as ASIL B. To ensure functional safety in such magnetic sensors, a safety mechanism should be implemented to allow identification and signaling of sensor malfunction.

[0013] One possible technique for providing functional safety in magnetic sensors is to replicate the functional elements of the magnetic sensor, enabling the provision of fully redundant signal paths (which allows comparison of outputs from redundant signal paths to identify errors). However, providing full redundancy of signal paths is expensive, for example, due to the additional chip area and overhead complexity required, and may not be necessary in any case. Furthermore, the overall usability of the magnetic sensor is reduced due to the increased possibility of signal path errors caused by including two signal paths in the magnetic sensor.

[0014] Another possible technique is to implement a monitoring mechanism to monitor the signal path in the magnetic sensor. One such monitoring mechanism is a timeout monitor. If no output is generated within a specified time period, the timeout monitor will operate to reset the magnetic sensor. However, using such a timeout monitor, the ability to stop the target wheel (i.e., zero-hertz (Hz) capability) is unattainable because the stoppage of the target wheel would lead to false alarms and erroneous detections. Therefore, the timeout monitor needs to be coupled to an external safety mechanism (e.g., at the electronic control unit (ECU)) to accurately detect sensor chip failures.

[0015] Another monitoring mechanism for monitoring signal paths is a signal monitor. One implementation of the signal monitor acquires a first signal and a second signal from different points along the same signal path, where the second signal is related to the first signal, such as being a processed version of the first signal. Here, the signal monitor identifies a first characteristic (e.g., zero crossing) in the first signal and then checks whether a corresponding second characteristic consistent with the first characteristic exists in the second signal. That is, the signal monitor assesses whether the expected relationship between the first and second signals can be confirmed by evaluating whether a characteristic of the first signal (e.g., the slope of the rising edge at the zero crossing of the first signal) can be represented in the second signal. If the signal monitor does not find the second characteristic in the second signal (i.e., the first characteristic is not represented in the second signal), the signal monitor signals a warning or fault associated with the signal path.

[0016] Another implementation of the signal monitor cross-checks information received on different signal paths of the magnetic sensor, such as the speed signal path of the magnetic sensor (e.g., a signal path providing a signal that can be used to determine the rotational speed) and the orientation signal path of the magnetic sensor (e.g., a signal path providing a signal that can be used to determine the rotational direction). Here, it is expected that the speed signal and the orientation signal have a predefined relationship with each other, such as a 90-degree (°) phase difference. The monitoring mechanism acquires the speed signal and the orientation signal and determines whether a predefined relationship exists between the signals acquired from the different signal paths. If the monitoring mechanism finds a violation of the predefined relationship based on the comparison of the speed signal and the orientation signal, the monitoring mechanism signals a warning or fault to indicate that the speed signal and / or the orientation signal is unreliable.

[0017] It is worth noting that the above-described implementation of the signal monitor performs acceptablely in applications where the rotational direction does not change abruptly and the target wheel experiences little or no vibration. However, these signal monitors perform poorly when sudden changes in rotational direction occur and are not robust to vibration. Vibration can be common in certain applications, such as transmission applications (e.g., when the target wheel is not locked into a gear). Vibration in this context includes angular vibration (e.g., rapidly occurring repetitive changes in the rotational direction of the target wheel) and / or air gap vibration (e.g., rapidly occurring repetitive changes in the size of the air gap between the target wheel and the sensor chip). Vibration can significantly affect one or more characteristics of the sensor signal. For example, when a magnetic sensor includes a velocity signal path and a direction signal path, angular vibration can cause phase shifts in the velocity and direction signals, and as a result of these phase shifts, it can also cause changes in the amplitude of the velocity and direction signals. Here, air gap vibration causes changes in the amplitude of the velocity signal and / or the direction signal. The extent to which a given signal is affected depends on the angular position of the target wheel during the vibration. For example, vibrations occurring near the extremes (e.g., maximum or minimum) of the velocity signal and the zero-crossing of the direction signal may cause a phase shift, resulting in a relatively small amplitude for the velocity signal and a relatively large amplitude for the direction signal. As another example, vibrations occurring near the extremes of the direction signal and the zero-crossing of the velocity signal may cause a phase shift, resulting in a relatively large amplitude for the velocity signal and a relatively small amplitude for the direction signal.

[0018] Under such vibration conditions, the aforementioned signal monitor implementation is likely to send false alarms along the signal path. These false alarms result in reduced availability of the magnetic sensor, which is unacceptable, especially in applications where vibration is frequent (e.g., transmission applications).

[0019] Some aspects described herein provide techniques and apparatus for robust signal path rationality checks to ensure the functional safety of magnetic sensors. In some implementations, a monitoring device for a sensor can acquire a first signal at a point on a first branch of the signal path and can acquire a second signal at a point on a second branch of the signal path. The monitoring device can monitor the first signal for a first characteristic indicated by the first signal and can monitor the second signal for a second characteristic indicated by the second signal. Based on the monitoring of the first signal for the first characteristic and the monitoring of the second signal for the second characteristic, the monitoring device can determine whether the number of first characteristics indicated by the first signal reaches a threshold number for the first characteristic in the absence of a specific number of second characteristics (e.g., one or more second characteristics) indicated by the second signal. The monitoring device can then evaluate the functionality of the signal path based on whether the number of first characteristics indicated by the first signal reaches a threshold number for the first characteristic in the absence of a specific number of second characteristics indicated by the second signal. Further details are provided below.

[0020] In some implementations, the techniques and apparatus described herein significantly improve functional safety by leveraging the inherent redundancy in a single signal path of the magnetic sensor without adding costly redundant features. As a result, the functionality of the magnetic sensor can be evaluated, and because the signal is associated with the same signal path, the assessment of the magnetic sensor's functional safety will be independent of signal frequency and external vibration. Notably, the techniques and apparatus described herein provide significant coverage of the signal path (e.g., a portion of the signal path following the analog bridge, which can be approximately 75% of the signal path). Furthermore, the techniques and apparatus described herein are compatible with static functionality, meaning that the magnetic sensor does not need to be coupled to external safety mechanisms relevant to the functional safety assessment. Additionally, the techniques and apparatus described herein are robust to vibration, meaning that the possibility of false alarms or erroneous indications is reduced or eliminated, thereby increasing the usability of the magnetic sensor (e.g., compared to sensors configured with any of the aforementioned signal monitors). In general, the techniques and apparatus described herein improve the functional safety of magnetic sensors without compromising their functionality using relatively few and inexpensive additional circuitry.

[0021] Figure 1A and 1B This is a diagram illustrating an example implementation of robust signal path rationality checks for the functional safety of sensors. Figure 1A and 1B In this embodiment, sensor 100 (e.g., a magnetic sensor) includes a signal path 101 and a monitoring device 110. In some implementations, sensor 100 may be a speed sensor, for example, for outputting a speed signal (e.g., a signal indicating the rotational speed of a target wheel) and / or a direction signal (e.g., a signal indicating the rotational direction of the target wheel). Therefore, signal path 101 may be a speed path of sensor 100, a direction path of sensor 100, or another type of signal path of sensor 100. As described herein, monitoring device 110 is a device of sensor 100 used to evaluate the functionality of signal path 101.

[0022] like Figure 1A and 1B As shown, signal path 101 is defined by the signal processing flow associated with the generation and provision of output signals by sensor 100. For example... Figure 1A and 1B As shown, signal path 101 may include a sensor bridge section and an analog signal section. The sensor bridge section is connected to one or more sensing elements (e.g., one or more sensing elements 310 of a magnetic sensor 215, as described below) for sensing impacts. Figure 3A portion of the signal path 101 associated with the magnetic field described in section 2. The analog signal portion includes a portion of the signal path 101 associated with generating and processing an analog signal in response to the magnetic field of one or more sensing elements of the impact sensor bridge portion. As shown, after the analog signal portion, the signal path 101 may include two or more branches. That is, the signal path 101 may be divided into two or more signal path branches. For example, as Figure 1A and 1B As shown, signal path 101 may include branch 102a, branch 102p and branch 104d.

[0023] In signal path 101, branch 102a is an analog signal path. That is, branch 102a is a branch of signal path 101 that provides an analog signal (e.g., an analog signal generated by the analog signal portion of signal path 101). In some implementations, the analog path is a low-jitter portion of signal path 101 (e.g., because the analog signal does not include noise generated by the digitization of the analog signal). The signal on or provided by branch 102a is referred to herein as analog signal a.

[0024] In signal path 101, branch 102p is a processed signal path. That is, branch 102p is a branch of signal path 101 that provides a processed signal. In some implementations, the processed signal is a processed version of an analog signal generated by the analog signal portion of signal path 101 (as in sensor 100). In some implementations, the processed signal is a processed version of a digital signal generated by the digital signal portion of signal path 101. In some implementations, the processing of the signal performed on branch 102p results in a delay of the signal on branch 102p. Therefore, when the processed signal is a processed analog signal, the signal on branch 102p can be delayed (or otherwise processed) compared to the analog signal on branch 102a. Similarly, when the processed signal is a processed digital signal, the signal on branch 102p can be delayed (or otherwise processed) compared to the digital signal on branch 102d. In some implementations, the amount of delay imparted by branch 102p can be predetermined (i.e., the delay imparted by branch 102p can be selected through the design of branch 102p). The processed signal can be generated, for example, by applying a delay to the analog or digital signal, applying a filter to the analog or digital signal, amplifying the analog or digital signal, and / or otherwise processing the analog or digital signal. In some implementations, as shown, branch 102p can originate from a point on the analog signal path along branch 102a. In some implementations, branch 102p can originate from a point on the digital signal path along branch 102d. The signal on or provided by branch 102p is referred to herein as the processed signal p.

[0025] In signal path 101, branch 104d is a digital signal path. That is, branch 104d is a branch of signal path 101 that provides a digital signal (e.g., a signal as a digital representation of an analog signal generated by the analog signal portion of signal path 101). As shown, branch 104d may include an analog-to-digital converter (ADC) portion (e.g., a portion that performs analog-to-digital conversion) and a digital information portion (e.g., a portion that performs digital signal processing). In some implementations, branch 104d is a branch associated with providing a digitally sampled signal that can be used for, for example, amplitude evaluation, offset evaluation, zero-crossing evaluation, etc. The signal on or provided by branch 104d is referred to herein as digital signal d.

[0026] In some implementations, monitoring device 110 can evaluate the functionality of signal path 101 using signals acquired at two different branches of signal path 101 (e.g., at two different points in signal path 101, such as a point on branch 102a and a point on branch 102d, a point on branch 102a and a point on branch 102p, or a point on branch 102d and a point on branch 120p). For example, monitoring device 110 can acquire a first signal at a point on a first branch of signal path 101 and a second signal at a point on a second branch of signal path 101. Monitoring device 110 can monitor the first signal for a first characteristic indicated by the first signal and can monitor the second signal for a second characteristic indicated by the second signal. Based on the monitoring of the first signal for the first characteristic and the monitoring of the second signal for the second characteristic, monitoring device 110 can determine whether the number of first characteristics indicated by the first signal reaches a threshold number for the first characteristic in the absence of a specific number of second characteristics (e.g., one or more second characteristics) indicated by the second signal. The monitoring device 110 can then evaluate the functionality of the signal path 101 based on whether the number of first characteristics indicated by the first signal reaches a threshold number for the first characteristic in the absence of a specific number of second characteristics indicated by the second signal. As described below, the monitoring device 110 evaluates the functionality of the signal path 101 in a manner robust to vibrations and sudden changes in the rotational direction of the target wheel associated with the sensor 100. Specific examples of this functionality evaluation are described below.

[0027] In some implementations, monitoring device 110 evaluates the functionality of signal path 101 based on digital signal d and analog signal a. Figure 1AA first example is shown of a monitoring device 110 evaluating the functionality of a signal path 101 based on a digital signal d and an analog signal a. As shown by reference numeral 151, the monitoring device 110 can acquire the digital signal d (e.g., from a point on a branch 104d of the signal path 101), and as shown by reference numeral 152, a magnetic sensor can acquire the analog signal a (e.g., from a point on a branch 102a of the signal path 101).

[0028] As shown by reference numeral 153 in the figure, in a first example of evaluating the function of signal path 101, monitoring device 110 monitors digital signal d for digital characteristics and analog signal a for analog characteristics.

[0029] A digital characteristic is a characteristic indicated by a digital signal d. For example, a digital characteristic could be a threshold crossing (e.g., a zero crossing) of the digital signal d. As another example, a digital characteristic could be an event associated with the digital signal (e.g., a switching event). In some implementations, monitoring device 110 can use a digital comparator of sensor 100 (e.g., a comparator in the digital domain of sensor 100) to monitor the digital signal d for a digital characteristic. For example, in operation, the digital comparator can switch its output voltage at each zero crossing of the digital signal d. That is, the digital comparator can switch the output voltage from a first level to a second level at a first zero crossing of the digital signal d, then switch the output voltage back from the second level to the first level at a second zero crossing, then switch the output voltage back from the first level to the second level at a third zero crossing, and so on. In some implementations, the digital comparator can utilize a so-called hidden hysteresis technique. According to the hidden hysteresis technique, a digital signal d crossing a first hysteresis level (e.g., a lower voltage level) or a second hysteresis level (e.g., a higher voltage level) prepares the digital comparator to switch the output voltage at the next zero crossing. Furthermore, according to the hidden hysteresis technique, if the digital signal d crosses one hysteresis level, preparing the digital comparator to switch the output voltage at the next zero-crossing, and the digital signal d crosses the same hysteresis level (e.g., does not cross another hysteresis level, as expected after the next zero-crossing), then a second crossing of the hysteresis level triggers the digital comparator to switch the output level. In some implementations, the hidden hysteresis level is fixed (e.g., unfitted). In some implementations, the use of hidden hysteresis reduces the likelihood of lost pulses in the digital signal d.

[0030] In some implementations, monitoring device 110 may monitor digital signal d for digital characteristics based on the output of a digital comparator. For example, monitoring device 110 may identify each change in the voltage level of the output of the digital comparator as a digital characteristic. In some implementations, monitoring device 110 may maintain a count of the number of digital characteristics indicated by digital signal d in association with monitoring digital characteristics for digital characteristics.

[0031] Analog characteristics are characteristics indicated by analog signal a. For example, an analog characteristic could be a threshold crossing of analog signal a (e.g., a hysteresis crossing). As another example, an analog characteristic could be an event associated with an analog signal (e.g., a switching event). In some implementations, monitoring device 110 can use an analog comparator of sensor 100 (e.g., a comparator in the analog domain of sensor 100) to monitor analog signal a for analog characteristics. For example, in operation, the analog comparator can switch its output voltage at each downward sloping crossing of analog signal a with a lower hysteresis level and at each upward sloping crossing of analog signal a with a higher hysteresis level. That is, the analog comparator can switch the output voltage from a first level to a second level at a first downward sloping crossing of analog signal a with a lower hysteresis level, then switch the output voltage back from the second level to the first level at a first upward sloping crossing of analog signal a with a higher hysteresis level, then switch the output voltage back from the first level to the second level at a second downward sloping crossing of analog signal a with a lower hysteresis level, and so on. In some implementations, the analog comparator can utilize so-called visible hysteresis techniques. In some implementations, the lower and higher hysteresis levels used in visible hysteresis techniques can be adapted based on the extrema (e.g., maximum and minimum) of the analog signal a. For example, the hysteresis levels can be adapted such that the lower and higher hysteresis levels are 50% of the difference between the extrema of the analog signal a.

[0032] In some implementations, monitoring device 110 may monitor analog signal a for analog characteristics based on the output of an analog comparator. For example, monitoring device 110 may identify each change in the voltage level of the analog comparator's output as an analog characteristic. In some implementations, monitoring device 110 may maintain a count of the number of analog characteristics indicated by analog signal a in association with monitoring analog characteristics for analog characteristics.

[0033] As indicated by reference numeral 154 in the accompanying drawings, the next step in a first example of evaluating the function of signal path 101 includes determining whether the number of digital characteristics indicated by digital signal d reaches a threshold number of digital characteristics in the absence of a specific number of analog characteristics (e.g., one or more analog characteristics) indicated by analog signal a. For example, monitoring device 110 may determine whether the number of digital characteristics indicated by digital signal d reaches a threshold number of digital characteristics in the absence of a specific number of analog characteristics indicated by analog signal a based on monitoring of digital signal d for digital characteristics and monitoring of analog signal a for analog characteristics.

[0034] The threshold number of digital characteristics can indicate, for example, the maximum number of digital characteristics that can occur without detecting a specific number of analog characteristics. As a specific example, the threshold number of digital characteristics can indicate up to 15 digital characteristics that can be indicated by digital signal d without any analog characteristics indicated by analog signal a. In some implementations, the threshold number of digital characteristics is chosen to provide a first example functional assessment of robustness to false alarm detection. For example, in the event of vibration or a sudden change in the rotational direction of the target wheel, a period of time may be needed to allow adjustment of one or more parameters of analog signal a and / or digital signal d (e.g., offset, hysteresis level, etc.) to ensure accurate operation of the analog comparator and digital comparator respectively (e.g., so that no pulses are lost). Here, the threshold number of digital characteristics can be chosen to allow adjustment of one or more parameters of analog signal a before a fault indication associated with analog signal a is triggered.

[0035] As indicated by reference numeral 155 in the accompanying drawings, the next step in the first example of evaluating the function of signal path 101 includes evaluating the function of signal path 101 based on whether the number of digital features indicated by digital signal d in the absence of a specific number of analog features indicated by analog signal a reaches a threshold number of digital features. Here, if the number of digital features in the absence of a specific number of analog features reaches the threshold number of digital features (e.g., if 15 digital features are detected when no analog feature is detected), the monitoring device 110 can determine that signal path 101 has failed the first example function evaluation (e.g., there is an error in a portion of signal path 101 associated with analog signal a). Conversely, if the number of digital features in the absence of a specific number of analog features does not reach the threshold number of digital features (e.g., if less than 15 digital features are detected when no analog feature is detected), the monitoring device 110 can determine that signal path 101 has passed the first example function evaluation. The monitoring device 110 can continue to perform the first example function evaluation in the manner described above (e.g., periodically).

[0036] Figure 1B A second example of a monitoring device 110 for evaluating the function of a signal path 101 based on a digital signal d and an analog signal a is shown. As indicated by reference numeral 161, the monitoring device 110 can acquire the digital signal d (e.g., from a point on a branch 104d of the signal path 101), and as indicated by reference numeral 162, a magnetic sensor can acquire the analog signal a (e.g., from a point on a branch 102a of the signal path 101).

[0037] As indicated by reference numeral 163 in the accompanying drawings, in a second example of evaluating the function of signal path 101, monitoring device 110 monitors digital signal d for digital characteristics and analog signal a for analog characteristics. In some implementations, in the manner described above in relation to the first example function check, monitoring device 110 may monitor digital signal d for digital characteristics and analog signal a for analog characteristics.

[0038] As indicated by reference numeral 164 in the attached figure, the next step in a second example of evaluating the function of signal path 101 includes determining whether the number of analog characteristics indicated by analog signal a reaches a threshold number of analog characteristics in the absence of a specific number of digital characteristics (e.g., one or more digital characteristics) indicated by digital signal d. For example, monitoring device 110 may determine whether the number of analog characteristics indicated by analog signal a reaches a threshold number of analog characteristics in the absence of a specific number of digital characteristics indicated by digital signal d based on monitoring of the digital characteristics of digital signal d and monitoring of the analog characteristics of analog signal a.

[0039] The threshold number of analog characteristics can indicate, for example, the maximum number of analog characteristics that can occur without detecting a specific number of digital characteristics. As a specific example, the threshold number of analog characteristics can indicate up to six analog characteristics that can be indicated by analog signal a without any digital characteristics indicated by digital signal d. In some implementations, the threshold number of analog characteristics is chosen to provide a second example of functional evaluation for robustness to false alarm detection. For example, in the event of vibration or a sudden change in the rotation direction of the target wheel, a period of time may be needed to allow adjustment of one or more parameters of analog signal a and / or digital signal d (e.g., offset, hysteresis level, etc.) to ensure accurate operation of the analog comparator and digital comparator respectively (e.g., so that no pulses are lost). Here, the threshold number of analog characteristics can be chosen to allow adjustment of one or more parameters of digital signal d before a fault indication associated with digital signal d is triggered.

[0040] As indicated by reference numeral 165 in the attached figure, the next step in the second example of evaluating the function of signal path 101 includes: evaluating the function of signal path 101 based on whether the number of analog features indicated by analog signal a reaches a threshold number of analog features in the absence of a specific number of digital features indicated by digital signal d. Here, if the number of analog features reaches the threshold number of analog features in the absence of a specific number of digital features (e.g., if 6 analog features are detected when no digital feature is detected), the monitoring device 110 can determine that signal path 101 has failed the second example function evaluation (e.g., there is an error in a portion of signal path 101 associated with digital signal d). Conversely, if the number of analog features does not reach the threshold number of analog features in the absence of a specific number of digital features (e.g., if less than 6 analog features are detected when no digital feature is detected), the monitoring device 110 can determine that signal path 101 has passed the second example function evaluation. The monitoring device 110 can continue to perform the second example function evaluation in the manner described above (e.g., periodically).

[0041] In some implementations, monitoring device 110 evaluates the functionality of signal path 101 based on analog signal a and a processed signal p, which is a processed version of analog signal a. A third example of monitoring device 110 evaluating the functionality of signal path 101 based on analog signal a and processed signal p is described below. In one example, monitoring device 110 may acquire analog signal a (e.g., on branch 102a of signal path 101) and may acquire processed signal p (e.g., on branch 102p of signal path 101). Here, monitoring device 110 may identify the analog characteristic indicated by analog signal a (e.g., in the manner described above). Then, monitoring device 110 may determine whether the next characteristic following the analog characteristic indicated by analog signal a is the characteristic indicated by analog signal a or the characteristic indicated by processed signal p. That is, monitoring device 110 determines whether the detected next characteristic (in the time domain) is the characteristic indicated by analog signal a or the characteristic indicated by processed signal p. The monitoring device 110 then evaluates the functionality of the signal path 101 based on whether the next characteristic is indicated by the analog signal a or by the processed signal p. Here, because the processed signal p is delayed relative to the analog signal a, the characteristics of the two signals are expected to alternate between the analog signal a and the processed signal p. Therefore, if two characteristics are detected consecutively on the analog signal a (i.e., no characteristic of the processed signal p is detected between two characteristics of the analog signal a), a fault may exist on the signal path 101. Thus, for example, if the monitoring device 110 determines that the next characteristic after the characteristic of the analog signal a is indicated by the analog signal a, the monitoring device 110 can determine that the signal path 101 has not passed the functional evaluation. Conversely, if the monitoring device 110 determines that the next characteristic after the characteristic of the analog signal a is indicated by the processed signal p, the monitoring device 110 can determine that the signal path 101 has passed the third functional evaluation. The monitoring device 110 can continue to perform the third example functional evaluation in the manner described above (e.g., periodically).

[0042] In some implementations, monitoring device 110 evaluates the functionality of signal path 101 based on digital signal d and a processed signal p, which is a processed version of digital signal d. A fourth example of monitoring device 110 evaluating the functionality of signal path 101 based on digital signal d and processed signal p is described below. In one example, monitoring device 110 may acquire digital signal d (e.g., on branch 102d of signal path 101) and may acquire processed signal p (e.g., on branch 102p of signal path 101). Here, monitoring device 110 may identify the digital characteristic indicated by digital signal d (e.g., in the manner described above). Then, monitoring device 110 may determine whether the next characteristic following the digital characteristic indicated by digital signal d is the characteristic indicated by digital signal d or the characteristic indicated by processed signal p. That is, monitoring device 110 determines whether the detected next characteristic (in the time domain) is the characteristic indicated by digital signal d or the characteristic indicated by processed signal p. The monitoring device 110 then evaluates the functionality of the signal path 101 based on whether the next characteristic is indicated by the digital signal d or by the processed signal p. Here, because the processed signal p is delayed relative to the digital signal d, it is expected that the characteristics of the two signals alternate between the digital signal d and the processed signal p. Therefore, if two characteristics are detected consecutively on the digital signal d (i.e., no characteristic of the processed signal p is detected between two characteristics of the digital signal d), a fault may exist on the signal path 101. Thus, for example, if the monitoring device 110 determines that the next characteristic after the characteristic of the digital signal d is indicated by the digital signal d, the monitoring device 110 can determine that the signal path 101 has failed the functional evaluation. Conversely, if the monitoring device 110 determines that the next characteristic after the characteristic of the digital signal d is indicated by the processed signal p, the monitoring device 110 can determine that the signal path 101 has passed the fourth functional evaluation. The monitoring device 110 can continue to perform the fourth example functional evaluation in the manner described above (e.g., periodically).

[0043] In some implementations, the execution of a given functional check can be triggered based on, for example, a timer, communication from another device (e.g., an ECU), etc. In some implementations, the magnetic sensor can perform one or more of the functional checks described above. For example, the magnetic sensor can perform each of the three functional checks mentioned above. In some implementations, the order in which the magnetic sensor performs two or more functional checks can be predefined, randomized, priority-based, rotational, etc.

[0044] In some implementations, when monitoring device 110 determines that signal path 101 has failed a functional evaluation (e.g., when the result of the functional evaluation indicates an error associated with signal path 101), monitoring device 110 may signal (e.g., to an ECU or another device) the error associated with signal path 101. In some implementations, monitoring device 110 may provide an indication of the results of one or more functional evaluations associated with signal path 101. For example, monitoring device 110 may provide (e.g., to an ECU or another device) an indication of whether signal path 101 has passed one or more functional evaluations. In some implementations, the indication may include information identifying whether signal path 101 has passed or failed a functional evaluation and / or information indicating the portion of signal path 101 on which an error was detected. In some implementations, the indication may include another type of information, such as information indicating the number of characteristics indicated by one or more signals associated with a functional check, information indicating the degree to which signal path 101 has passed or failed a functional check, or other types of information.

[0045] In some implementations, monitoring device 110 may provide an indication (e.g., signaling an error in signal path 101) only if one or more conditions are met. That is, in some implementations, monitoring device 110 may suppress (e.g., avoid providing) an indication when one or more conditions are not met.

[0046] In some implementations, one or more conditions may include determining that the vibration of sensor 100 does not exceed a vibration threshold. For example, monitoring device 110 may include one or more components configured to detect whether the vibration of sensor 100 exceeds a vibration threshold (e.g., a threshold above which the operation of sensor 100 may be adversely affected). Here, if monitoring device 110 determines that the vibration of sensor 100 does not exceed the vibration threshold, monitoring device 110 may provide an indication (e.g., causing monitoring device 110 to signal a detected error). Conversely, if monitoring device 110 determines that the vibration of sensor 100 exceeds the vibration threshold, monitoring device 110 may suppress the indication (e.g., causing monitoring device 110 not to signal a detected error), and instead may signal that vibration has been detected. In this way, monitoring device 110 may be configured with an exemption from detecting the vibration of sensor 100. In some implementations, during vibration, monitoring device 110 may avoid performing any functional evaluation and / or ignore the results of any functional evaluation.

[0047] As another example, monitoring device 110 may include one or more components configured to detect when the air gap in sensor 100 exceeds the permissible air gap. Here, if monitoring device 110 determines that the air gap does not exceed the permissible air gap limit, monitoring device 110 may provide an indication (e.g., causing monitoring device 110 to signal a detected error). Conversely, if monitoring device 110 determines that the air gap exceeds the permissible air gap limit, monitoring device 110 may suppress the indication (e.g., causing monitoring device 110 not to signal a detected error).

[0048] As another example, monitoring device 110 may include one or more components configured to detect when an offset to be applied to signal path 101 exceeds (e.g., is above or below) a permissible offset range. Here, if monitoring device 110 determines that the offset does not exceed the permissible offset range, monitoring device 110 may provide an indication. Conversely, if monitoring device 110 determines that the offset exceeds the permissible offset range, monitoring device 110 may suppress the indication.

[0049] In some implementations, one or more conditions are required to prevent the monitoring device 110 from indicating an error detected by one or more functional assessments when the signal path 101 may not actually experience an error. That is, one or more conditions can prevent the indication of an error associated with the signal path 101 when there may not actually be an error or when another type of error associated with the sensor (e.g., a system-level error rather than an error on the signal path 101) may exist.

[0050] As mentioned above, Figure 1A and 1B This is provided as an example. Other examples may be provided related to... Figure 1A and 1B The descriptions are different. Figure 1A and 1B The number and arrangement of the components shown are provided as an example. In practice, with Figure 1A and 1B Compared to what is shown, there can be more parts, fewer parts, different parts, or parts arranged differently. Furthermore, Figure 1A and 1B The two or more components shown can be implemented within a single component, or Figure 1A and 1B The single component shown can be implemented as multiple, distributed components. Alternatively, Figure 1A and 1B The set of components shown (e.g., one or more components) can perform what is described as being made by Figure 1A and 1B The other set of components shown performs one or more functions.

[0051] Figure 2A and 2B These are diagrams of example environments 200 and 250 in which the systems and / or methods described herein can be implemented. (See diagrams for examples.) Figure 2A As shown, the environment 200 may include a gear 205, a magnet 210, a magnetic sensor 215, and an ECU 220.

[0052] Gear 205 includes a wheel with a set of teeth. In some implementations, gear 205 can twist the magnetic field of magnet 210 during rotation, such that magnetic sensor 215 can sense the twisted magnetic field associated with magnet 210. In some implementations, gear 205 may include a ferromagnetic material. In some implementations, gear 205 may be attached to or coupled to an object whose rotational speed, direction of rotation, and / or angular position will be measured, such as a cylindrical structure (e.g., crankshaft, camshaft, rotating cylinder, drive shaft, etc.), a wheel structure (e.g., associated with a tire), an axle (e.g., vehicle axle), etc.

[0053] In some implementations, such as in a crankshaft environment, gear 205 may include a symmetrical gear, wherein the teeth of gear 205 have the same width and the backlash of gear 205 has the same width. In some implementations, gear 205 may include a reference region (e.g., relatively long teeth or backlash) between a pair of teeth of gear 205. In some implementations, such as in a camshaft context, gear 205 may include an asymmetrical gear, wherein the teeth of gear 205 have different widths and / or the backlash of gear 205 has different widths.

[0054] Magnet 210 includes a magnet that generates a magnetic field that can be sensed by magnetic sensor 215. In some implementations, magnet 210 may be positioned such that the magnetic field generated by magnet 210 is distorted by gear 205. Additionally or alternatively, magnet 210 may include a reverse bias magnet, and / or may be located near, included in, and / or attached to magnetic sensor 215.

[0055] Magnetic sensor 215 includes a module having one or more components (referred to herein as "sensor components") of sensors such as magnetoresistive (MR) sensors, Hall effect sensors, variable magnetoresistive (VRS) sensors, fluxgate sensors, etc. In some implementations, as described herein, magnetic sensor 215 may include signal path 101 and may include monitoring device 110 capable of performing one or more functional evaluations associated with signal path 101. In some implementations, magnetic sensor 215 may be connected to ECU 220 such that magnetic sensor 215 can transmit to ECU 220 information associated with a magnetic wheel (e.g., gear 205, encoder wheel 225) and / or information associated with a sensor system (e.g., a magnetic circuit including gear 205, magnet 210, and magnetic sensor 215). Information associated with the magnetic wheel may include, for example, information associated with the rotational speed of the magnetic wheel, the direction of rotation of the magnetic wheel, the angular position of the magnetic wheel, etc. In some implementations, the magnetic sensor 215 may provide such information to the ECU 220 via one or more transmission interfaces (e.g., voltage interfaces, current interfaces, etc.) and / or via one or more output terminals. In some implementations, the magnetic sensor 215 may include a three-wire sensor (e.g., including one output terminal), a four-wire sensor (e.g., including two output terminals), etc. Additional details regarding the magnetic sensor 215 are provided below. Figure 3 Describe it.

[0056] ECU 220 includes one or more circuits associated with: determining the rotational speed and / or direction of a magnetic wheel (i.e., a rotatable object connected to gear 205 or encoder wheel 225), determining information associated with errors in a sensor system, and / or providing such information in connection with controlling one or more electrical systems and / or electrical subsystems. In some implementations, ECU 220 may be connected to magnetic sensor 215, such that ECU 220 can receive information (e.g., one or more signals) from magnetic sensor 215 via one or more transmission interfaces and / or via one or more output terminals.

[0057] In some implementations, ECU 220 can calibrate, control, and regulate one or more electrical systems and / or electrical subsystems based on information transmitted by magnetic sensor 215. In some implementations, ECU 220 may include an electronic / engine control module (ECM), a powertrain control module (PCM), a transmission control module (TCM), a brake control module (BCM or EBCM), a central control module (CCM), a central timing module (CTM), a general electronic module (GEM), a body control module (BCM), a suspension control module (SCM), etc.

[0058] like Figure 2BAs shown, example environment 250 may include magnetic sensor 215, ECU 220, and encoder wheel 225 (e.g., instead of gear 205 and magnet 210). Encoder wheel 225 includes a magnetic pole wheel with at least two alternating poles (such as north and south poles). In some implementations, encoder wheel 225 may include a reference region (e.g., a portion with relatively long poles). In some implementations, encoder wheel 225 may generate a magnetic field. In some implementations, encoder wheel 225 may be attached to or coupled to an object whose rotational speed, direction of rotation, and / or position will be measured, such as a cylindrical structure (e.g., crankshaft, camshaft, rotating cylinder, etc.), a wheel structure (e.g., associated with a tire), an axle (e.g., vehicle axle), etc. In some implementations, encoder wheel 225 and / or gear 205 may be referred to as the "target wheel".

[0059] Figure 2A and 2B The number and arrangement of the devices shown are provided as examples. In practice, with Figure 2A and 2B Compared to what is shown, there can be more devices, fewer devices, different devices, or devices arranged differently. For example, although Figure 2A and 2B Specific arrangements of the apparatus in example environments 200 and 250 are shown respectively, but in some implementations, magnet 210 and / or magnetic sensor 215 may be arranged in a so-called "top read" arrangement, wherein magnet 210 and / or magnetic sensor 215 are positioned above gear 205 / encoder wheel 225 (e.g., instead of as shown). Figure 2A and 2B (As shown below gear 205 / encoder wheel 225). Furthermore... Figure 2A and 2B The two or more devices shown can be implemented within a single device, or Figure 2A The single device shown in 2B and / or 2B can be implemented as multiple distributed devices. Alternatively or alternatively, Figure 2A and 2B A set of devices (e.g., one or more devices) can perform what is described as being performed by Figure 2A One or more functions performed by another set of devices in 2B.

[0060] Figure 3 yes Figure 2A Example environment 200 and / or Figure 2B A diagram of example elements of a magnetic sensor 215 included in example environment 250. As shown, the magnetic sensor 215 may include at least one sensing element 310, an ADC 320, a digital signal processor (DSP) 330, an optional memory element 340, and a digital interface 350.

[0061] Sensing element 310 includes elements for sensing the magnetic field at magnetic sensor 215. For example, sensing element 310 may include a magnetoresistive (MR) based sensing element, the elements of which are made of a magnetoresistive material (e.g., nickel-iron (NiFe)), wherein the resistance of the magnetoresistive material may depend on the strength and / or direction of the magnetic field present at the magnetoresistive material. Here, sensing element 310 may operate based on anisotropic magnetoresistive (AMR) effect, giant magnetoresistive (GMR) effect, tunneling magnetoresistive (TMR) effect, etc. As another example, sensing element 310 may include a Hall-based sensing element operating based on the Hall effect. As an additional example, sensing element 310 may include a variable magnetoresistive (VR) based sensing element operating based on induction. In some implementations, sensing element 310 may provide an analog signal corresponding to the magnetic field to ADC 320.

[0062] ADC 320 includes an analog-to-digital converter that converts analog signals from sensing elements 310 into digital signals. For example, ADC 320 can convert analog signals received from a set of sensing elements 310 and / or physical parameter sensors 315 into digital signals for processing by DSP 330. ADC 320 can provide digital signals to DSP 330. In some implementations, magnetic sensor 215 may include one or more ADCs 320.

[0063] The DSP 330 includes a digital signal processing device or a collection of digital signal processing devices. In some implementations, the DSP 330 can receive digital signals from the ADC 320 and can process the digital signals to form a signal (e.g., a signal destined for...). Figure 2A and 2B The ECU 220 shown herein may contain signals such as those associated with the rotational speed of gear 205 / encoder wheel 225 and / or the rotational direction of gear 205 / encoder wheel 225. In some implementations, the monitoring device 110 described herein may be configured on another component of the DSP 330 and / or magnetic sensor 215.

[0064] Optional memory element 340 includes read-only memory (ROM) (e.g., EEPROM), random access memory (RAM), and / or another type of dynamic or static storage device (e.g., flash memory, magnetic memory, optical memory, etc.) for storing information and / or instructions used by the magnetic sensor 215. In some implementations, optional memory element 340 may store information associated with processing performed by DSP 330. Additionally or alternatively, optional memory element 340 may store configuration values ​​or parameters of a set of sensing elements 310, physical parameters of sensor 315, and / or information of one or more other elements of magnetic sensor 215 (such as ADC 320 or digital interface 350).

[0065] Digital interface 350 includes an interface through which magnetic sensor 215 can be connected from another device (such as ECU 220, see...) Figure 2A and 2B It receives information and / or provides information to another device. For example, as described elsewhere herein, digital interface 350 can provide ECU 220 with signals determined by DSP 330 (i.e., output signals) and can further receive information from ECU 220. In some implementations, digital interface 350 allows magnetic sensor 215 to provide one or more signals to ECU 220.

[0066] Figure 3 The number and arrangement of the components shown are provided as an example. In fact, with... Figure 3 Compared to the examples shown, the magnetic sensor 215 may include more elements, fewer elements, different elements, or elements arranged differently. For example, the magnetic sensor 215 may include analog signal processing equipment or a collection of analog signal processing equipment (e.g., for receiving and processing analog signals from the sensing element 310), an analog current interface, etc., whose output can be stopped or suppressed via controls in the DSP 330. Additionally or alternatively, a set of elements (e.g., one or more elements) of the magnetic sensor 215 may perform one or more functions described as being performed by another set of elements of the magnetic sensor 215.

[0067] Figure 4 This is a flowchart of an example process 400 related to robust signal path rationality checks for functional safety of sensors, as described in this document. In some implementations, Figure 4 One or more process frames may be executed by a monitoring device (e.g., monitoring device 110) included in a sensor (e.g., sensor 100, magnetic sensor 215, etc.).

[0068] like Figure 4As shown, process 400 may include acquiring a first signal at a point on a first branch of the sensor's signal path (block 410). For example, as described above, the monitoring device may acquire a first signal at a point on a first branch of the sensor's signal path.

[0069] like Figure 4 As further shown, process 400 may include acquiring a second signal at a point on a second branch of the sensor's signal path (block 420). For example, as described above, the monitoring device may acquire a second signal at a point on a second branch of the sensor's signal path.

[0070] like Figure 4 As further shown, process 400 may include monitoring the first signal for a first characteristic indicated by the first signal (block 430). For example, as described above, the monitoring device may monitor the first signal for a first characteristic indicated by the first signal.

[0071] like Figure 4 As further shown, process 400 may include monitoring the second signal for a second characteristic indicated by the second signal (block 440). For example, as described above, the monitoring device may monitor the second signal for a second characteristic indicated by the second signal.

[0072] like Figure 4 As further shown, process 400 may include determining, based on monitoring of a first signal for a first characteristic and monitoring of a second signal for a second characteristic, whether the number of first characteristics indicated by the first signal reaches a threshold number for the first characteristic in the absence of a specific number of second characteristics indicated by the second signal (box 450). For example, as described above, the monitoring device may determine, based on monitoring of the first signal for a first characteristic and monitoring of the second signal for a second characteristic, whether the number of first characteristics indicated by the first signal reaches a threshold number for the first characteristic in the absence of a specific number of second characteristics (e.g., one or more second characteristics) indicated by the second signal.

[0073] like Figure 4 As further shown, process 400 may include evaluating the functionality of the signal path based on whether the number of first characteristics indicated by the first signal reaches a threshold number of the first characteristic in the absence of a specific number of second characteristics indicated by the second signal (block 460). For example, as described above, the monitoring device may evaluate the functionality of the signal path based on whether the number of first characteristics indicated by the first signal reaches a threshold number of the first characteristic in the absence of a specific number of second characteristics indicated by the second signal.

[0074] like Figure 4As further shown, process 400 may optionally include providing an indication of the results of an evaluation of the functionality of signal path 101 (block 470). For example, as described above, the monitoring device may provide an indication of the results of an evaluation of the functionality of the signal path.

[0075] Process 400 may include additional implementations, such as any single implementation or any combination of implementations of one or more other processes described below and / or elsewhere herein.

[0076] In a first implementation, process 400 includes determining, based on monitoring of a first signal for a first characteristic and monitoring of a second signal for a second characteristic, whether the number of second characteristics indicated by the second signal reaches a threshold number of the second characteristic in the absence of a specific number of first characteristics (e.g., one or more first characteristics) indicated by the first signal, and evaluating the functionality of the signal path based on whether the number of second characteristics indicated by the second signal reaches the threshold number of the second characteristic in the absence of a specific number of first characteristics indicated by the first signal, is sufficient.

[0077] In the second implementation, either alone or in combination with the first implementation, the first signal is an analog signal, and the second signal is a digital representation of the analog signal.

[0078] In the third implementation, either alone or in combination with one or more of the first and second implementations, the first signal is a digital representation of an analog signal, and the second signal is an analog signal.

[0079] In the fourth implementation, either alone or in combination with one or more of the first to third implementations, process 400 includes providing an indication of the results of an evaluation of the functionality of the signal path.

[0080] In the fifth implementation, either alone or in combination with one or more of the first to fourth implementations, the indication of the result is provided based on at least one of the following: determining that the vibration of the sensor does not exceed a vibration threshold, determining that the air gap in the sensor does not exceed an allowable air gap, or determining that the offset to be applied to the signal path does not exceed an allowable offset range.

[0081] In the sixth implementation, either alone or in combination with one or more of the first through fifth implementations, process 400 includes an indication of the result of an evaluation of the function of suppressing the signal path.

[0082] In the seventh implementation, either alone or in combination with one or more of the first to sixth implementations, the indication of the result is suppressed based on at least one of the following: detecting that the vibration of the sensor exceeds a vibration threshold, determining that the air gap in the sensor exceeds the allowable air gap, or determining that the offset to be applied to the signal path exceeds the allowable offset range.

[0083] In the eighth implementation, either alone or in combination with one or more of the first through seventh implementations, process 400 includes signaling an error when the result of an evaluation of the functionality of the signal path indicates an error on the signal path.

[0084] In the ninth implementation, either alone or in combination with one or more of the first to eighth implementations, the sensor is a speed sensor, and the signal path is either a speed signal path or a direction signal path.

[0085] Although Figure 4 The example box for process 400 is shown, but in some implementations, it is different. Figure 4 Compared to the examples shown, process 400 may include more boxes, fewer boxes, different boxes, or boxes arranged differently. Alternatively, two or more boxes of process 400 may be executed in parallel.

[0086] The foregoing disclosure provides illustrations and descriptions, but is not intended to be exhaustive or to limit implementations to the precise forms disclosed. Modifications and variations can be made based on the foregoing disclosure, and can also be derived from practical implementations.

[0087] As used herein, the term “component” is intended to be interpreted broadly as hardware, firmware, and / or a combination of hardware and software.

[0088] It is evident that the systems and / or methods described herein can be implemented in various forms of hardware, firmware, or combinations of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods is not limited in its implementation. Therefore, the operation and behavior of the systems and / or methods described herein do not refer to any specific software code—it should be understood that software and hardware can be designed to implement systems and / or methods based on those described herein.

[0089] As used in this article, depending on the context, satisfying the threshold can mean that the value is greater than the threshold, more than the threshold, higher than the threshold, greater than or equal to the threshold, less than the threshold, less than the threshold, lower than the threshold, less than or equal to the threshold, equal to the threshold, etc., depending on the context.

[0090] Although specific combinations of features are recited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various implementations. In fact, many of these features can be combined in ways not specifically recited in the claims and / or not disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of various implementations includes combinations of each dependent claim with each other claim in the claim set.

[0091] Unless explicitly stated otherwise, no element, action, or instruction used herein should be construed as critical or necessary. Furthermore, as used herein, the articles “a” and “an” are intended to include one or more items and are interchangeable with “one or more.” Furthermore, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and is interchangeable with “the one or more.” Furthermore, as used herein, the term “collection” is intended to include one or more items (e.g., related items, unrelated items, a combination of related and unrelated items, etc.) and is interchangeable with “one or more.” If only one item is intended, the phrase “only one” or similar language is used. Furthermore, as used herein, the terms “has,” “have,” “having,” etc., are intended to be open-ended terms. Furthermore, unless explicitly stated otherwise, the phrase “based on” is intended to mean “based, at least in part, on.” Furthermore, as used herein, unless otherwise expressly stated (e.g., when used in conjunction with "either" or "only one of"), the term "or" is intended to be inclusive in a series of uses and can be used interchangeably with "and / or". Additionally, for ease of description, spatially relative terms such as "below," "lower," "above," "higher," etc., may be used herein to describe the relationship of one element or feature to another element or feature(s), as illustrated in the figures. Besides the orientations depicted in the figures, spatially relative terms are intended to cover different orientations of devices, apparatuses, and / or elements in use or operation. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptive terms used herein shall be interpreted accordingly.

Claims

1. A method for monitoring, comprising: The first signal is acquired by the sensor's monitoring device at a point on the first branch of the sensor's signal path; The monitoring device acquires a second signal at a point on the second branch of the signal path of the sensor; The monitoring device monitors the first signal in response to a first characteristic indicated by the first signal; The monitoring device monitors the second signal in response to the second characteristic indicated by the second signal; The monitoring device, based on monitoring of the first signal for the first characteristic and monitoring of the second signal for the second characteristic, determines whether the number of the first characteristic indicated by the first signal reaches a threshold number for the first characteristic in the absence of a specific number of the second characteristic indicated by the second signal. as well as The monitoring device evaluates the functionality of the signal path based on whether the number of the first characteristic indicated by the first signal reaches a threshold number of the first characteristic in the absence of a specific number of the second characteristic indicated by the second signal.

2. The method according to claim 1, wherein at least one of the first feature or the second feature is a switch event or a threshold crossing.

3. The method according to claim 1, further comprising: Based on the monitoring of the first signal for the first characteristic and the monitoring of the second signal for the second characteristic, it is determined whether the number of the second characteristic indicated by the second signal reaches a threshold number for the second characteristic when there is no specific number of the first characteristic indicated by the first signal. as well as The functionality of the signal path is evaluated based on whether the number of the second characteristic indicated by the second signal reaches a threshold number of the second characteristic when there is no specific number of the first characteristic indicated by the first signal.

4. The method of claim 1, wherein the first signal is an analog signal, and the second signal is a digital representation of the analog signal.

5. The method of claim 1, wherein the first signal is a digital representation of an analog signal, and the second signal is the analog signal.

6. The method of claim 1, further comprising providing an indication of the result of the evaluation of the functionality of the signal path.

7. The method of claim 6, wherein the indication of the result is provided based on at least one of the following: It is determined that the vibration of the sensor does not exceed the vibration threshold. Determine that the air gap in the sensor does not exceed the allowable air gap, or It was determined that the offset to be applied to the signal path did not exceed the allowable offset range.

8. The method of claim 1, further comprising suppressing an indication of the result of the evaluation of the function of the signal path.

9. The method of claim 8, wherein the indication of the result is suppressed based on at least one of the following: The vibration detected by the sensor exceeded the vibration threshold. Determine that the air gap in the sensor exceeds the allowable air gap, or It was determined that the offset to be applied to the signal path exceeded the allowable offset range.

10. The method of claim 1, further comprising signaling an error when the result of the evaluation of the function of the signal path indicates an error on the signal path.

11. The method of claim 1, wherein the sensor is a speed sensor, and the signal path is a speed signal path or a direction signal path.

12. A sensor, comprising: The signal path includes a first branch and a second branch; as well as Monitoring equipment, used for: Acquire the first signal at a point on the first branch of the signal path; Acquire the second signal at a point on the second branch of the signal path; The first signal is monitored in response to a first characteristic indicated by the first signal; The second signal is monitored in response to the second characteristic indicated by the second signal; Based on the monitoring of the first signal for the first characteristic and the monitoring of the second signal for the second characteristic, it is determined whether the number of the first characteristic indicated by the first signal reaches a threshold number of the first characteristic in the absence of a specific number of the second characteristic indicated by the second signal. as well as The functionality of the signal path is evaluated based on whether the number of the first characteristics indicated by the first signal reaches a threshold number of the first characteristics in the absence of a specific number of second characteristics indicated by the second signal.

13. The sensor according to claim 12, wherein the monitoring device is further configured to: Based on the monitoring of the first signal for the first characteristic and the monitoring of the second signal for the second characteristic, it is determined whether the number of second characteristics indicated by the second signal in the absence of a specific number of first characteristics indicated by the first signal reaches a threshold number for the second characteristic; and The functionality of the signal path is evaluated based on whether the number of the second characteristic indicated by the second signal reaches a threshold number of the second characteristic when there is no specific number of the first characteristic indicated by the first signal.

14. The sensor of claim 12, wherein the first signal is an analog signal, and the second signal is a digital representation of the analog signal.

15. The sensor of claim 12, wherein the first signal is a digital representation of an analog signal, and the second signal is the analog signal.

16. The sensor of claim 12, wherein the monitoring device further provides an indication of the result of the evaluation of the function of the signal path.

17. The sensor of claim 16, wherein the indication of the result is provided based on at least one of the following: It is determined that the vibration of the sensor does not exceed the vibration threshold. Determine that the air gap in the sensor does not exceed the allowable air gap, or It was determined that the offset to be applied to the signal path did not exceed the allowable offset range.

18. The sensor of claim 12, wherein the monitoring device is further configured to suppress indication of the results of the evaluation of the function of the signal path.

19. The sensor of claim 18, wherein the indication of the result is suppressed based on at least one of the following: The vibration detected by the sensor exceeded the vibration threshold. Determine that the air gap in the sensor exceeds the allowable air gap, or It was determined that the offset to be applied to the signal path exceeded the allowable offset range.

20. A monitoring device, comprising: One or more components, used for: The analog signal is monitored in relation to analog characteristics indicated by the analog signal, and the analog signal is associated with an analog branch of the sensor's signal path; The digital signal is monitored in relation to digital characteristics indicated by the digital signal, the digital signal being associated with a digital branch of the signal path of the sensor and being a digital representation of the analog signal; as well as The function of the signal path is evaluated based on monitoring of the analog signal and monitoring of the digital signal, and the evaluation of the function is based on at least one of the following: Determine whether the number of analog characteristics indicated by the analog signal, in the absence of a specific number of digital characteristics indicated by the digital signal, reaches a threshold number of analog characteristics, or Determine whether the number of digital characteristics indicated by the digital signal in the absence of a specific number of analog characteristics indicated by the analog signal reaches a threshold number of digital characteristics.

Images