Method for detecting and diagnosing a sensor deviation using an electronic circuit

Abstract

Method (300) for detecting and diagnosing a sensor deviation and / or sensor deviations of a sensor, wherein detection and diagnosis includes falling below or exceeding a tolerance band, the method comprising at least the following steps: providing (302) an electronic circuit, measuring (304) a reference value, wherein a reference value is a reference voltage value (213) or a reference current value (142), acquiring (304.2) a number of measurements (304) of a reference value, performing an if query (304.4) to determine whether the number of acquired measurements exceeds a predefined maximum value, generating an error message (312) if a maximum value is exceeded, or step V.is performed when a maximum value is undershot, measuring (306) a specified parameter, wherein a parameter includes a voltage parameter (a voltage U (212)) or a current parameter (a current I_Shunt (140)), calculating (308) a difference value, wherein a difference value is obtained by taking the difference of a specified parameter with a reference value; and determining (310) whether a current sensor has a corresponding accuracy, wherein a corresponding accuracy is determined by maintaining a deviation value within a predetermined tolerance band.

Description

[0001] The invention relates to a method for detecting and diagnosing a sensor deviation using an electronic circuit, wherein the detection and diagnosis includes exceeding or falling below a tolerance band. The invention further relates to an electronic circuit for detecting and diagnosing a sensor deviation. State of the art

[0002] The measurement and monitoring of electrical currents plays a crucial role in electrical engineering. Current sensors are essential components for precisely detecting and controlling current flow in electrical systems. Current sensors are therefore an important tool for a wide range of applications. For this reason, current sensors are initially calibrated, for example, in the factory, to meet the necessary accuracy requirements. However, due to various external influences such as temperature, vibration, humidity, and component tolerances, they age and can therefore potentially exhibit a greater tolerance than specified, which is particularly critical for safety functions such as ASIL-C / D.

[0003] KR 20190101635 A relates to a device and a method for diagnosing a shunt current sensor connected between a first node and a second node of a main current path arranged in a high-voltage region of a battery pack. The device comprises a first and a second winding that are magnetically coupled to one another, wherein the first winding is arranged in a low-voltage region that is isolated from the high-voltage region, a transformer that is connected to the first node at one end of the second winding, a diagnostic switch that is arranged in the high-voltage region and connected between the other end of the second winding and the second node, and a first voltage converter that is arranged in the low-voltage region and connected to the first winding. The diagnostic switch is configured to be switched on in response to a switching signal.The first voltage converter is configured to convert, in response to a first control signal, an input voltage into a first output voltage required by the first control signal and apply the first output voltage to the first primary winding.

[0004] US 6,337,570 B1 relates to a 4 mA-20 mA or 0-20 mA current loop that connects an analog sensor to a detection system and carries a sensor current or a detection current. A test circuit is connected in parallel with the current loop to inject a superimposed current into the loop, which is superimposed on the sensor current or the detection current. In a first embodiment, a variable voltage generator injects the superimposed current by adding it to the detection current, making it possible to test a low-current threshold of the detection system. In a second embodiment, a variable current regulator injects the superimposed current by adding it to the sensor current, making it possible to test a high-current threshold of the detection system. The high- and low-current thresholds of the detection system are tested without opening the current loop. Disclosure of the invention

[0005] According to a first aspect of the invention, a method for detecting and diagnosing a sensor deviation and / or sensor deviations of a sensor is proposed, wherein detecting and diagnosing comprises falling below or exceeding a tolerance band, wherein the method comprises at least the following steps: I. Providing an electronic circuit, II. Measuring a reference value, where a reference value is a reference voltage value or a reference current value, III. Recording a number of measurements of a reference value, IV. Performing an if-query to determine whether the number of recorded measurements exceeds a predefined maximum value, generating an error message if a maximum value is exceeded, or performing step V. if a maximum value is undershot, V. Measuring a specified parameter, where a parameter comprises a voltage parameter (a voltage U) or a current parameter (a current I_Shunt), VI. Calculating a difference value, wherein a difference value is obtained by subtracting a specified parameter from a reference value; and VII. Determining whether a current sensor has adequate accuracy, wherein adequate accuracy is determined by maintaining a deviation value within a predetermined tolerance band.

[0006] A sensor within the meaning of the proposed invention is, for example, a current sensor that comprises an electronic device for measuring the electrical current in an electrical circuit, such as a shunt, a Hall sensor, a fluxgate sensor, or triple modular redundancy (TMR). A shunt within the meaning of the invention is an electrical resistor capable of measuring a current flow in an electrical circuit. Sensor deviation, particularly in current sensors, is understood to be the difference between the actually measured value, for example of a specific parameter, and the reference value measured by the sensor. A tolerance band within the meaning of the proposed invention is understood to be the permissible range of deviation of a current and / or voltage from its actual measured value, for example of a specific parameter.A tolerance band covers the permissible range of deviation, beyond which a sensor is considered inadequate or faulty.

[0007] In an advantageous development of the method according to the invention, it is determined according to a step VII. whether a current sensor has a corresponding accuracy, wherein in the event of a deviation from a tolerance band, a repetition of the method proposed according to the invention according to step II. for measuring a reference value is repeatedly initiated.

[0008] In an advantageous development of the method according to the invention, characterized in that the detection and diagnosis of a sensor deviation and / or sensor deviations is carried out before a cycle.

[0009] A cycle, within the meaning of the invention, is a recurring process and / or a sequence of steps that repeat at regular intervals. For example, a cycle includes a driving cycle in which a current sensor monitors the vehicle's current flow during a defined driving cycle, which includes various driving states, such as acceleration, deceleration, and driving at a constant speed.

[0010] In an advantageous development of the method according to the invention, proper operation of an application is enabled if a deviation value is determined within a predetermined tolerance band.

[0011] In an advantageous development of the method according to the invention, proper operation of an application is blocked if a deviation value is not determined within a predetermined tolerance band, wherein a step II. of the method proposed according to the invention is initiated, wherein a predetermined number of maximum measurements is increased.

[0012] According to a second aspect of the invention, an electronic circuit for detecting and diagnosing a sensor deviation and / or sensor deviations of a sensor is proposed, wherein the detection and diagnosis includes an undershoot or overshoot of a tolerance band according to the method proposed according to the invention, comprising: a. a first electronic circuit, wherein the reference value is a reference current value and the specific parameter is defined as a current value parameter (a current I_Shunt); wherein a deviation value comprises a current value and a tolerance band comprises a current tolerance, wherein the first electronic circuit comprises one or more voltage sources, one or more resistors, one or more operational amplifiers, and one or more transistors; or b. a second electronic circuit, wherein the reference value is a reference voltage value and the specific parameter is defined as a voltage parameter (a voltage U); wherein a deviation value comprises a voltage value and a tolerance band a voltage tolerance, wherein the second electronic circuit comprises a Wheatstone bridge, wherein a Wheatstone bridge, one or more voltage sources, at least four resistors, wherein at least one resistor is a resistor R_Shunt to be diagnosed and one or more switches, wherein at least one switch has a shutdown function for detecting and diagnosing the undershooting or exceeding of a tolerance band.

[0013] For example, a first electronic circuit according to the proposed electronic circuit comprises a first voltage source, wherein the first voltage source is designed, for example, as a battery, and a transistor, wherein a transistor is, for example, a metal-oxide-semiconductor field-effect transistor (MOSFET), by means of which a current flowing through the resistor R_Shunt is adjusted. According to the invention, the R_Shunt resistor is a resistor that is connected in parallel to another electrical element for measuring or controlling a current flow. For example, the first electronic circuit comprises an operational amplifier with a reference voltage, a feedback resistor, a load resistor, and a capacitor. In addition, a first electronic circuit comprises at least one measuring resistor and optionally a resistor R_power, wherein the resistor R_power serves, for example, to limit a current drop.For example, a first electronic circuit according to the proposed electronic circuit further comprises a current I_Shunt to be adjusted, wherein the current I_Shunt to be adjusted is set via the quotient of the reference voltage and the measuring resistor and corresponds, for example, to a value of 100 mA. A reference voltage and a measuring resistor are freely selectable.

[0014] For example, a second electronic circuit according to the proposed electronic circuit comprises a first voltage source, wherein the first voltage source is embodied, for example, as a battery. Furthermore, a second electronic circuit comprises at least four resistors, wherein one of the resistors, R_Shunt, is used to detect and diagnose the deviation of the current sensor. Furthermore, a second electronic circuit comprises at least two switches S1 and S2, wherein, for example, when switch S1 is open in the positive path, a second switch S2 is closed to activate a Wheatstone bridge.

[0015] By means of the second electronic circuit proposed according to the invention, a voltage change at voltage U can be diagnosed, for example, in the event of an undesired change in the resistance of R_Shunt.

[0016] In an advantageous development of the electronic circuit according to the invention, an existing voltage source comprises a battery voltage source.

[0017] As an alternative to a battery voltage source, an existing voltage source can be used by a voltage source such as switching power supplies, solar charge controllers, thermoelectric generators and inductive voltage sources.

[0018] In an advantageous development of the electronic circuit according to the invention, it comprises a sensor which detects temperature data and / or humidity data and / or vibration data, wherein the detected temperature data and / or humidity data and / or vibration data are designed to compensate for one or more environmental influences.

[0019] In an advantageous development of the electronic circuit according to the invention, a first electronic circuit comprises an analog-to-digital converter.

[0020] In an advantageous development of the electronic circuit according to the invention, at least one resistor and / or one capacitor C_fill in conjunction with an operational amplifier represent a filter function and / or a current limiting function.

[0021] In an advantageous development of the electronic circuit according to the invention, a Wheatstone bridge comprises two resistance paths; wherein a first resistance path comprises two resistors R2 and R3 connected in parallel and a second resistance path comprises two resistors R4 and R_Shunt connected in parallel.

[0022] The resistance paths according to the proposed second electronic circuit are dimensioned to be balanced against each other, so that the voltage U is 0 V without errors.

[0023] In an advantageous development of the electronic circuit according to the invention, a first resistance path is dimensioned to be high-impedance.

[0024] For example, leakage current can be minimized and / or ignored by dimensioning the first resistance path, which consists of two resistors R2 and R3 connected in parallel, with a high resistance. For example, high resistance dimensioning results in a reduced current flow through the electronic circuit, which results in a reduced influence of leakage currents. This advantageously prevents falsification of the acquired data, for example, the measurement results.

[0025] Alternatively, a Wheatstone bridge can be designed according to the invention to be low-ohmic, wherein, for example, at least one of the four resistors of a Wheatstone bridge is low-ohmic. Advantages of the invention

[0026] The solution proposed according to the invention advantageously avoids the use of a more expensive redundant current sensor. Furthermore, the solution includes cost-effective electronic circuits for diagnosing the current sensors. Furthermore, the electronic circuit can utilize existing voltage sources, such as an auxiliary voltage source and / or battery voltage.

[0027] The proposed solution minimizes the influence of disturbances such as current / voltage fluctuations and tolerances of the measuring device. Furthermore, the method works with both sporadic and permanently occurring disturbances.

[0028] The solution proposed according to the invention advantageously makes it possible to diagnose a sensor before a cycle, for example, a driving cycle, with minimal conducted interference. Furthermore, deviations in the measured values, such as exceeding or undershooting the tolerance band of the sensor, for example, the current sensor, can be detected early, thus enabling early detection of malfunctions or deterioration in sensor performance.

[0029] The inventive solution provides a precise and efficient method for detecting sensor deviations within a tolerance band. This ensures early detection of sensor deviations. This minimizes potential measurement errors or malfunctions. This allows the sensor system to be calibrated or adjusted to maintain measurement accuracy and reliability. Short description of the drawings

[0030] Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

[0031] They show: Fig. 1 a schematic representation of a first electronic circuit for detecting and diagnosing a sensor deviation and / or sensor deviations of a sensor, Fig. 2 a schematic representation of a second high-impedance electronic circuit for detecting and diagnosing a sensor deviation and / or sensor deviations of a sensor, Fig. 3 a schematic representation of a method for detecting and diagnosing a sensor deviation and / or sensor deviations of a sensor. Embodiments of the invention

[0032] In the following description of the embodiments of the invention, identical or similar elements are designated by the same reference numerals, whereby a repeated description of these elements is omitted in individual cases. The figures only schematically illustrate the subject matter of the invention.

[0033] Fig. 1 shows a schematic representation of a first electronic circuit 100 for detecting and diagnosing a sensor deviation and / or sensor deviations of a sensor, wherein the sensor 114 has, for example, a resistor R_Shunt 112.5 and an operational amplifier 106. An operational amplifier 106 is powered by a voltage source 104, wherein an operational amplifier 106 comprises a non-inverting input 106.1, an inverting input 106.2, and an output 106.3. Furthermore, an operational amplifier 106 has a reference voltage 122 at the non-inverting input 106.1, three resistance elements 112, including a feedback resistor 112.1, between the inverting input 106.2 and the output 106.3, and additionally a series-connected capacitor C_fill 110. A further resistance element 112 is connected as load resistor 112.2 to the output 106.3 of an operational amplifier 106. Fig. 1 further comprises a voltage source 104, wherein a first voltage source 104.1 is connected in series with a resistor R_Shunt 112.5. A first voltage of a first voltage source 104.1 is known and / or calculable, wherein a current I_Shunt 140 flows from a first voltage source 104.1 to a resistor R_Shunt 112.5, wherein the current I_Shunt 140 is calculable, wherein a voltage U_Shunt 126 drops across R_Shunt 112.5. A first voltage source 104.1 can comprise a battery, for example. A further resistor R_power 112.4 is connected in series between the first voltage source 104.1 and the resistor R_Shunt 112.5. The resistor R_power 112.4 serves, for example, to limit a current drop. Fig. 1 further comprises a transistor 114, wherein a transistor 114 corresponds to a MOSFET according to Fig. 1 corresponds. Fig. 1 further includes three grounds 134 and power lines 116 which interconnect the electronic components of the electronic circuit 100. Fig. 1 further includes a sensor 144. In addition, a reference current value 142 drops across the circuit when a transistor 114 is open.

[0034] By the first electronic circuit 100 according to an embodiment of Fig. 1, one or more sensor deviations can be detected and diagnosed, for example, by passing a known current value, such as a reference current value 142, through the sensor 144 (which is connected, for example, to the resistor R_Shunt 112.5). The sensor 144 measures the current and outputs a measured value. The measured value, as the reference current value 142, is then compared with the desired current parameter 140, with the desired current parameter 140 being set by the operational amplifier 106 and the transistor 114. If the comparison of the reference current value 142 and the desired current value results in a deviation, a sensor deviation is diagnosed.

[0035] For example, an existing resistor R_power 112.4 can relieve the load on transistor 114, such as a MOSFET. This resistor R_power 112.4 is chosen to be sufficiently small so that, under unfavorable conditions, the set current I_Shunt 140 is still guaranteed when transistor 114 is closed.

[0036] In the Fig. 1, protective circuits such as Zener diodes, for example for a MOSFET 114, were neglected for better illustration.

[0037] Fig. Figure 2 shows an exemplary circuit diagram of a second electronic circuit with a high-impedance Wheatstone bridge 200. In this example, this includes a voltage source 104, two circuits 200 S1 and S2, five resistors 112, R_Shunt 208, R2 206, R3 204, R4 210, and R_load 209. The four resistors 112 of a Wheatstone bridge are configured as two resistance paths, with resistors R3 204 and R2 206 forming one path and R_Shunt 208 and R4 210 forming another path. A voltage U_Shunt 214 is dropped across R_Shunt 208. Furthermore, Fig. 2 a voltage U 212, where a voltage U 212 is, for example, a sensor output voltage, where in a balanced arrangement of the resistors R_Shunt 208, R2 206, R3 204 and R4 210 a voltage U 212 is equal to 0 V. Fig. Figure 2 shows an arrangement 220 in which a switch S2 is arranged between resistors R3 204 and R4 210 to control the current flow through the Wheatstone bridge. For example, a high-impedance Wheatstone bridge is activated when switch S1 is open and switch S2 is closed. Switches 202 S1 and S2 can be mechanical, electromechanical, or semiconductor-based, for example. Fig. 2 further comprises a sensor 144. When a switch S2 is open, a reference voltage value (213) drops across R2.

[0038] For example, in the case of an unwanted change in resistance at the resistor R_Shunt 208 according to an embodiment according to Fig. 2 Voltage change at a voltage U 212 can be diagnosed. A voltage change at a voltage U 212, for example, can be used to detect and diagnose a current sensor deviation.

[0039] As from Fig.3, the illustrated embodiment of a method 300 according to the invention for detecting and diagnosing one or more sensor deviations is provided. In a first step, an electronic circuit is provided 302 according to a first or a second electronic circuit 100 and 200 according to the invention. In a second step, a reference value is measured 304, wherein a reference value has, for example, a reference voltage value 213 according to the first electronic circuit 100 or a reference current value 142 according to the second electronic circuit 200. A third step comprises detecting 304.2 a number of measurements of a reference value. A fourth step comprises performing an if-query 304.4, wherein in an if-query 304.4, the number of detected measurements 304.2 is compared with a predetermined maximum number of measurements, and if the predetermined maximum number of measurements is exceeded, an error message 312 is output. An error message 312 according to the proposed method 300 can, for example, indicate that a circuit has a faulty state. If the fifth step is not exceeded, a method 300 is initiated, which includes a measurement 306 of a specified parameter, for example a voltage value or a current value. The sixth step is then executed, which includes a calculation 308 of a difference value resulting from the difference between a specific parameter and a reference value. If the maximum number of measurements is not exceeded, a fifth method step is initiated, which includes a measurement 306 of a specified parameter, for example a voltage value or a current value.Subsequently, the sixth step is executed, which includes calculating 308 a difference value resulting from the difference between a specific parameter and a reference value. In the final, seventh step, a determination 310 of the state of a sensor 144 is performed, wherein the determination of the state is based on an accuracy check.

[0040] For example, based on the last step of the method 300 proposed according to the invention, a sensor deviation can be detected and diagnosed if a predetermined tolerance band, for example of a sensor 144, is exceeded or undershot, and thus the accuracy of the sensor 144, for example of a current sensor, is insufficient or a temporary fault is present. In this case, the second step of the method 300 can be repeated by increasing the number of maximum values ​​of the measurements. If a deviation from a tolerance band is not detected, for example, an application can be properly commissioned.

[0041] The invention is not limited to the embodiments described here and the aspects highlighted therein. Rather, numerous modifications are possible within the scope of the claims, which are within the scope of one skilled in the art. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] KR 20190101635 A

[0003] US 6 337 570 B1

[0004]

Claims

[1] Method (300) for detecting and diagnosing a sensor deviation and / or sensor deviations of a sensor (144), wherein detecting and diagnosing comprises falling below or exceeding a tolerance band, wherein the method comprises at least the following steps I. Providing (302) an electronic circuit, II. Measuring (304) a reference value, wherein a reference value is a reference voltage value (213) or a reference current value (142), III. Recording (304.2) a number of measurements (304) of a reference value, IV. Performing an if query (304.4) to determine whether the number of recorded measurements exceeds a predefined maximum value, generating an error message (312) if a maximum value is exceeded, or performing step V. if a maximum value is undershot, V. Measuring (306) a specified parameter, wherein a parameter comprises a voltage parameter (a voltage U (212)) or a current parameter (a current I_Shunt), VI. Calculating (308) a difference value, wherein a difference value is obtained by forming a difference between a specified parameter and a reference value (140, 212); and VII. Determining (310) whether a current sensor has a corresponding accuracy, wherein a corresponding accuracy is determined by maintaining a deviation value within a predetermined tolerance band. [2] Method (300) according to step VII of claim 1, wherein in the event of a deviation from a tolerance band, step II of the method (300) is repeated. [3] Method (300) according to one of the preceding claims characterized bythat the detection and diagnosis of a sensor deviation and / or sensor deviations is performed before a cycle. [4] Method (300) according to one of the preceding claims, in which proper operation of an application is blocked if a deviation value is determined within a predetermined tolerance band. [5] Method (300) according to one of the preceding claims, wherein proper operation of an application is not enabled if a deviation value outside a predetermined tolerance band is determined (310), wherein a step I. according to claim 1 is initiated, wherein a predetermined number of maximum measurements is increased. [6] Electronic circuit for detecting and diagnosing a sensor deviation and / or sensor deviations of a sensor (144), wherein the detecting and diagnosing includes an undershoot or overshoot of a tolerance band according to claim 1, comprising: a. a first electronic circuit (100), wherein the reference value is a reference current value and the specific parameter is defined as a current value parameter (a current I_Shunt (140)); wherein a deviation value comprises a current value and a tolerance band comprises a current tolerance, wherein the first electronic circuit (100) comprises one or more voltage sources (104), one or more resistors (112), one or more operational amplifiers (106), and one or more transistors (114); or b. a second electronic circuit (200), wherein the reference value is a reference voltage value and the specific parameter is defined as a voltage parameter (a voltage U (212)); wherein a deviation value comprises a voltage value and a tolerance band comprises a voltage tolerance, wherein the second electronic circuit (200) comprises a Wheatstone bridge, wherein a Wheatstone bridge, one or more voltage sources (104), at least four resistors (112), wherein at least one resistor (112) is a resistor R_Shunt (208) to be diagnosed, one or more switches (202), wherein at least one switch (202) has a shutdown function for detecting and diagnosing the undershooting or exceeding of a tolerance band. [7] The electronic circuit of claim 6, wherein an existing voltage source (104) comprises a battery voltage source. [8] Electronic circuit according to one of claims 6 or 7, wherein a sensor (144) comprises a detection of temperature data and / or humidity data and / or vibration data, wherein the detected temperature data and / or humidity data and / or vibration data are designed to compensate for one or more environmental influences. [9] Electronic circuit according to claim 6, wherein a first electronic circuit (100) comprises an analog-to-digital converter (120). [10] Electronic circuit according to claim 6 or 7, wherein at least one resistor (112) and / or one capacitor C_fill (110) in conjunction with an operational amplifier (106) represent a filter function and / or a current limiting function. [11] Electronic circuit according to one of claims 6 to 8, wherein a Wheatstone bridge (200.1) comprises two resistance paths; wherein a first resistance path comprises two resistors (112) R2 (206) and R3 (204) connected in parallel and a second resistance path comprises two resistors (112) R4 (210) and R_Shunt (208) connected in parallel. [12] Electronic circuit according to claim 11, wherein a first resistance path is dimensioned to be high-resistance (220).

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