Method for detecting and diagnosing sensor deviations by means of electronic circuit

Abstract

The invention relates to a method (300) for identifying and diagnosing one and / or more sensor deviations of a sensor, in which the identifying and diagnosing comprise a lower tolerance zone or a higher tolerance zone, the method comprising at least the following steps: providing (302) an electronic circuit; measuring (304) a reference value, where the reference value is a reference voltage value (213) or a reference current value (142); detecting (304.2) a number of measurements (304) of a reference value; a determination query (304.4) is performed in order to determine whether the number of detected measurements exceeds a predetermined maximum value, a fault report (312) being generated if the number of detected measurements exceeds the predetermined maximum value, or step V. is performed if the number of detected measurements is below the predetermined maximum value. Measuring (306) a specified parameter, where the parameter comprises a voltage parameter (voltage U (212)) or a current parameter (current IShut (140)); calculating (308) a difference value, where the difference value is obtained by subtraction of the specified parameter from the reference value; and determining (310) whether the current sensor has a corresponding accuracy, where the corresponding accuracy is determined by maintaining the deviation value within a predetermined tolerance band.

Description

Technical Field

[0001] The invention relates to a method for detecting and diagnosing a sensor deviation by means of an electronic circuit, wherein the detection and diagnosis include undershooting or exceeding a tolerance band. The invention further relates to an electronic circuit for detecting and diagnosing a sensor deviation. Background Art

[0002] The measurement and monitoring of electric currents plays a decisive role in electronics. Current sensors are important components for accurately detecting and controlling the currents flowing through electrical systems. Current sensors are therefore important tools for a wide range of applications. For this reason, current sensors are initially calibrated, for example in the factory, in order to meet the necessary accuracy requirements. However, these current sensors age due to various external influences, such as temperature, vibrations, moisture and component tolerances, and can then have tolerances that are greater than specified, which is critical in particular for safety functions, such as, for example, ASIL-C / D.

[0003] KR 20190101635 A relates to a device and a method for diagnosing a shunt-current sensor, which is 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 includes: a first winding and a second winding magnetically coupled to each other, wherein the first winding is arranged in a low voltage region isolated from the high voltage region; a transformer connected to the first node at the end of the second winding; a diagnostic switch 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 arranged in the low voltage region and connected to the first winding. The diagnostic switch is configured so that the diagnostic switch is turned on in response to a switch signal. The first voltage converter is configured so that the first voltage converter converts the input voltage into a first output voltage required by the first control signal in response to a first control signal, and applies the first output voltage to the first primary winding.

[0004] US 6337570 B1 relates to a current loop of the 4-20 mA type or of the 0-20 mA type, which connects an analog sensor to a detection system and conducts a sensor current or a detection current. A test circuit is connected in parallel with the current loop so as to feed a superimposed current into the loop, which superimposed current is superimposed on the sensor current or the detection current. In a first embodiment, a variable voltage generator feeds the superimposed current in such a way that it adds the superimposed current to the detection current, thereby enabling a check of the threshold value for the low current of the detection system. In a second embodiment, a variable voltage generator feeds the superimposed current in such a way that it adds the superimposed current to the sensor current, thereby enabling a check of the high current threshold of the detection system. The high and low current thresholds of the detection system are tested without disconnecting the current loop. Summary of the invention

[0005] According to a first aspect of the invention, a method for identifying and diagnosing a deviation of one and / or more sensors of a sensor is proposed, wherein the identification and diagnosis includes undershooting or exceeding a tolerance band, wherein the method comprises at least the following steps:

[0006] I. Provide electronic circuits;

[0007] II. Measuring a reference value, wherein the reference value is a reference voltage value or a reference current value;

[0008] III. Detecting the number of measurements against a reference value;

[0009] IV. Performing a decision query (If-Abfrage) to determine whether the number of detected measurements exceeds a predetermined maximum value, wherein if the maximum value is exceeded, a fault report is generated, or if it is below the maximum value, step V is executed;

[0010] V. measuring a specified parameter, wherein the parameter includes a voltage parameter (voltage U) or a current parameter (current I_Shunt);

[0011] VI. Calculating a difference, wherein the difference is obtained by subtracting a specified parameter from a reference value; and

[0012] VII. Determining whether the current sensor has a corresponding accuracy, wherein the corresponding accuracy is determined by maintaining the deviation value within a predetermined tolerance band.

[0013] In the sense of the proposed invention, a sensor is, for example, a current sensor, which comprises an electronic device for measuring the current in a current loop, such as, for example, a shunt, a Hall sensor, a fluxgate sensor or a triple modular redundancy (TMR). In the sense of the present invention, a shunt is a resistor, which is able to measure the current passing through a current loop. In particular, in the case of a current sensor, a "sensor deviation" is understood to be the difference between, for example, the actual measured value of a specified parameter and a reference value measured by the sensor. In the sense of the proposed invention, a "tolerance band" is understood to be the permissible range of deviations of a current and / or voltage (for example a specified parameter) from its actual measured value. The tolerance band comprises a permissible range of deviations, beyond which the sensor is considered to be insufficient or faulty.

[0014] In an advantageous development of the method according to the invention, it is determined according to step VII. whether the current sensor has a corresponding accuracy, wherein, in the event of a deviation from the tolerance, a repetition of the method according to the invention is initiated according to step II. to repeat the measurement of the reference value.

[0015] An advantageous development of the method according to the invention is characterized in that the detection and diagnosis of one or more sensor deviations is carried out before the cycle.

[0016] In the sense of the present invention, a "cycle" is a repetitive process and / or a series of steps that are repeated at regular intervals. A cycle includes, for example, a driving cycle, wherein a current sensor monitors the current flowing through the vehicle during a defined driving cycle, which includes different driving states, such as, for example, acceleration, braking, and driving at a constant speed.

[0017] In an advantageous development of the method according to the invention, the correct operation of the application is initiated if it is determined that the deviation value lies within a predefined tolerance band.

[0018] In an advantageous development of the method according to the invention, if it is determined that the deviation value is not within a predefined tolerance band, proper operation of the application is prevented, wherein step II. of the proposed method according to the invention is initiated, wherein a predefined maximum number of measurements is increased.

[0019] According to a second aspect of the invention, an electronic circuit for detecting and diagnosing a sensor deviation and / or a plurality of sensors is proposed, wherein the detection and diagnosis includes undershooting or exceeding of a tolerance band according to the proposed method according to the invention, the electronic circuit comprising:

[0020] a. a first electronic circuit, wherein the reference value is a reference current value, and the specified parameter is determined as a current value parameter (current I_Shunt); wherein the deviation value includes the current value, and the tolerance band includes the current tolerance, wherein the first electronic circuit includes one or more voltage sources, one or more resistors, one or more operational amplifiers, and one or more transistors; or

[0021] b. A second electronic circuit, wherein the reference value is a reference voltage value and the specified parameter is determined as a voltage parameter (voltage U); wherein the deviation value is a voltage value and the tolerance band includes a voltage tolerance, wherein the second electronic circuit includes a Wheatstone bridge, wherein the Wheatstone bridge includes: one or more voltage sources, at least four resistors and one or more switches, wherein at least one resistor is a resistor R_Shunt to be diagnosed, wherein at least one switch has a shutdown function for identifying and diagnosing a value below or above the tolerance band.

[0022] The first electronic circuit according to the proposed electronic circuit comprises, for example: a first voltage source, wherein the first voltage source is configured as a battery, for example; a transistor, wherein the transistor is, for example, a metal oxide semiconductor field effect transistor (MOSFET), by which the current flowing through the resistor R_Shunt is set. According to the invention, the R_Shunt resistor is a resistor for connecting in parallel with other electrical components to measure or control the current passing through. The first electronic circuit comprises, for example, an operational amplifier having a reference voltage, a feedback resistor, a load resistor and a capacitor. In addition, the first electronic circuit comprises at least one measuring resistor and optionally a resistor R_power, wherein the resistor R_power is used, for example, to limit the current drop. The first electronic circuit according to the proposed electronic circuit further comprises, for example, a current I_Shunt to be set, wherein the current I_Shunt to be set is set by a quotient formed by a reference voltage and a measuring resistor and corresponds, for example, to a value of 100 mA. The reference voltage and the measuring resistor can be set freely selectably.

[0023] The second electronic circuit according to the proposed electronic circuit comprises, for example, a first voltage source, wherein the first voltage source is designed, for example, as a battery. In addition, the second electronic circuit comprises at least four resistors, wherein the detection and diagnosis of a deviation of the current sensor is performed at one of the resistors R_Shunt. In addition, the second electronic circuit comprises at least two switches S1 and S2, wherein, for example, when the switch S1 is opened in the positive path (positiven Pfad), the second switch S2 is closed in order to activate the Wheatstone bridge.

[0024] By means of the second electronic circuit proposed according to the invention, a voltage change at the voltage U can be diagnosed, for example, in the case of an undesired resistance change of R_Shunt.

[0025] In an advantageous development of the electronic circuit according to the invention, the available voltage source comprises a battery voltage source.

[0026] As an alternative to a battery voltage source, an existing voltage source can be used by way of a voltage source such as, for example, a switching power supply, a solar charge regulator, a thermoelectric generator and an inductive voltage source.

[0027] In an advantageous development of the electronic circuit according to the invention, the electronic circuit 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.

[0028] In an advantageous development of the electronic circuit according to the invention, the first electronic circuit comprises an analog-to-digital converter.

[0029] In an advantageous development of the electronic circuit according to the invention, at least one resistor and / or capacitor C_fill in conjunction with the operational amplifier exhibits a filtering function and / or a current limiting function.

[0030] In an advantageous development of the electronic circuit according to the invention, the Wheatstone bridge comprises two resistance paths; the first resistance path comprises two resistors R2 and R3 connected in parallel, and the second resistance path comprises two resistors R4 and R_Shunt connected in parallel.

[0031] The resistance paths of the proposed second electronic circuit are designed to compensate for one another, so that the voltage U is 0 V in the absence of errors.

[0032] In an advantageous development of the electronic circuit according to the invention, the first resistance path is designed to be high-impedance.

[0033] By designing the first resistance path, which is formed by two resistors R2 and R3 connected in parallel, with a high impedance, it is possible, for example, to minimize and / or negligibly reduce the leakage current. By designing the first resistance path, which is formed by two resistors R2 and R3 connected in parallel ... reduce the flow current through the electronic circuit, which leads to a reduction in the effect of the leakage current. This advantageously prevents the detected data, for example the data of the measurement result, from being distorted.

[0034] Alternatively, the Wheatstone bridge according to the invention can be designed to be low-impedance, wherein, for example, at least one of the four resistors of the Wheatstone bridge is low-impedance.

[0035] Advantages of the present invention

[0036] The proposed solution according to the invention advantageously allows the avoidance of more expensive redundant current sensors. In addition, the solution includes a cost-effective electronic circuit for diagnosing the current sensor. Furthermore, the electronic circuit can use an already existing voltage source, such as, for example, an auxiliary voltage source and / or a battery voltage.

[0037] The proposed solution according to the invention minimizes the influence of disturbance variables such as, for example, current / voltage fluctuations, tolerances of the measuring device. Furthermore, the method functions properly both in the case of occasional disturbances and in the case of permanent disturbances.

[0038] The proposed solution according to the invention advantageously allows the diagnosis of the sensor to be carried out before a cycle, for example a driving cycle, in which the number of conducted disturbance variables is low. Furthermore, deviations in the measured values, such as falling below or exceeding the tolerance band of a sensor, for example a current sensor, can be detected in advance, thereby enabling early detection of malfunctions or degradation of the sensor performance.

[0039] The solution according to the invention provides a precise and efficient method for identifying sensor deviations within the tolerance band. This ensures that sensor deviations are identified in advance. This allows possible erroneous measurements or malfunctions to be minimized. This allows the sensor system to be calibrated or adapted in order to maintain the accuracy and reliability of the measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Embodiments of the invention are explained in more detail with reference to the drawings and the following description.

[0041] in:

[0042] Figure 1 shows a schematic diagram of a first electronic circuit for identifying and diagnosing a sensor and / or sensor deviation,

[0043] Figure 2 shows a schematic diagram of a second electronic circuit designed with high impedance for detecting and diagnosing deviations of one and / or more sensors of the sensor,

[0044] Figure 3 A schematic diagram of a method for identifying and diagnosing sensor deviations of a sensor and / or sensors is shown. DETAILED DESCRIPTION

[0045] In the following description of embodiments of the invention, identical or similar elements are denoted by the same reference numerals, wherein a repeated description of these elements is omitted in individual cases. The figures merely schematically illustrate the subject matter of the invention.

[0046] Figure 1 A schematic diagram of a first electronic circuit 100 for detecting and diagnosing one or more sensor deviations of a sensor is shown, wherein a sensor 114, for example, has a resistor R_Shunt 112.5, an operational amplifier 106. The operational amplifier 106 is fed by a voltage source 104, wherein the operational amplifier 106 comprises a non-inverted input 106.1, an inverted input 106.2, and an output 106.3. In addition, the operational amplifier 106 has: a reference voltage 122 at the non-inverted input 106.1, three resistor elements 112 (the resistor elements comprising a feedback resistor 112.1) between the inverted input 106.2 and the output 106.3, and an additional capacitor C_fill 110 connected in series. A further resistor element 112 is connected as a load resistor 112.2 to the output 106.3 of the operational amplifier 106. Figure 1 Furthermore, a voltage source 104 is included, wherein a first voltage source 104.1 is connected in series with a resistor R_Shunt 112.5. A first voltage of the first voltage source 104.1 is known and / or calculable, wherein a current I_Shunt 140 flows from the first voltage source 104.1 to the resistor R_Shunt 112.5, wherein the current I_Shunt 140 can be calculated, wherein a voltage U_Shunt 126 drops across R_Shunt 112.5. The first voltage source 104.1 can include, for example, a battery. 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 is used, for example, to limit the current drop. Figure 1 Furthermore, a transistor 114 is included, wherein the transistor 114 is configured in accordance with Figure 1 Corresponds to metal oxide semiconductor field effect transistor. Figure 1 Furthermore, three ground connections 134 and current-carrying lines 116 are included, which connect the electronic components of the electronic circuit 100 to one another. Figure 1 Furthermore, a sensor 144 is included. Furthermore, when the transistor 114 is switched off, the reference current value 142 at the circuit drops.

[0047] By following the Figure 1The first electronic circuit 100 of an exemplary embodiment of the present invention is capable of identifying and diagnosing one or more sensor deviations by, for example, conducting a known current value, such as a reference current value 142, through a sensor 144 (which is connected, for example, to a resistor R_Shunt 112.5). The sensor 144 measures the current and outputs the measured value. The measured value is then compared as a reference current value 142 with a desired current parameter 140, wherein the desired current parameter 140 is set by the operational amplifier 106 and the transistor 114. If a deviation results from the comparison of the reference current value 142 with the target current value, a sensor deviation is diagnosed.

[0048] The existing resistor R_power 112.4 can, for example, relieve the transistor 114, such as a metal oxide semiconductor field effect transistor, and is selected to be small enough so that when the transistor 114 is closed, the current I_Shunt 140 to be set is still ensured under unfavorable conditions.

[0049] exist Figure 1 In the figure, protective wiring structures such as, for example, a Zener diode for the metal oxide semiconductor field effect transistor 114 are omitted for the sake of a better illustration.

[0050] Figure 2 An exemplary circuit diagram of a second electronic circuit with a high-impedance Wheatstone bridge 200 is shown. In this example, the Wheatstone bridge includes a voltage source 104, two circuits 200S1 and S2, and five resistors 112 (R_Shunt 208, R2206, R3204, R4210, and R_load 209). The four resistors 112 of the Wheatstone bridge are configured as two resistance paths, wherein the resistors R3204 and R2206 are configured as one path, and R_Shunt 208 and R4210 are configured as another path. Via R_Shunt 208, the voltage U_Shunt 214 drops. In addition, Figure 2 The voltage U212 is included, wherein the voltage U212 is, for example, a sensor output voltage, wherein in the case of a balanced arrangement of the resistors R_Shunt 208 , R2 206 , R3 204 , and R4 210 , the voltage U 212 is equal to 0 V. Figure 2 An arrangement 220 is shown in which a switch S2 is arranged between resistors R3 204 and R4 210 in order to control the through-current through the Wheatstone bridge. If the switch S1 is open and the switch S2 is closed, for example, a high-impedance Wheatstone bridge is activated. The switches 202 S1 and S2 can be mechanical, electromechanical or based on semiconductors, for example. Figure 2 Also included is a sensor 144. When the switch S2 is opened, the reference voltage value (213) at R2 decreases.

[0051] According to Figure 2 In an exemplary embodiment, in the case of an undesired resistance change at the resistor R_Shunt 208 , for example, a voltage change at the voltage U 212 can be diagnosed. In this case, for example, a current sensor deviation can be identified and diagnosed via the voltage change of the voltage U 212 .

[0052] If Figure 3 It can be seen that the exemplary embodiment shown includes a method 300 according to the present invention for identifying and diagnosing one or more sensor deviations. In a first step, an electronic circuit according to the first or second electronic circuit 100 and 200 according to the present invention is provided 302. In a second step, a reference value is measured 304, wherein the 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 includes detecting 304.2 the number of measurements of the reference value. A fourth step includes performing a decision query 304.4, wherein in the decision query 304.4 the number of detected measurements 304.2 is compared with a predetermined maximum number of the measurements, and a fault message 312 is output if the predetermined maximum number of the measurements is exceeded. The fault message 312 according to the proposed method 300 can, for example, indicate that the switching circuit has a fault state. In the fifth step, if it is not exceeded, the method 300 is started, which includes measuring 306 a specified parameter, for example a voltage value or a current value. A sixth step is then carried out, which includes calculating 308 a difference value resulting from the subtraction of the specified parameter from the reference value. In the case of a maximum number of measurements being below, a fifth method step is initiated, which includes measuring 306 a specified parameter, such as a voltage value or a current value. A sixth step is then carried out, which includes calculating 308 a difference value resulting from the subtraction of the specified parameter from the reference value. In a final seventh step, a determination 310 of the state of the sensor 144 is performed, wherein said determination of the state is based on an accuracy check.

[0053] If, for example, a predefined tolerance band of sensor 144 is undershot or exceeded and therefore the accuracy of sensor 144, for example a current sensor, is insufficient or a temporary fault may exist, then, for example, a sensor deviation can be detected and diagnosed based on the last step of method 300 proposed according to the present invention. In this case, the second step of method 300 can be repeated by increasing the number of measured maximum values. In the case of undetected deviations of the tolerance band, for example, the application can be operated as intended.

[0054] The invention is not limited to the exemplary embodiments described here and the aspects highlighted therein. Rather, numerous variants are possible within the scope of the claims within the scope of the professional practice.

Claims

1. A method (300) for identifying and diagnosing a sensor and / or sensor deviation of a sensor (144), wherein: The identification and diagnosis includes undershooting or overshooting of 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 the reference value is a reference voltage value (213) or a reference current value (142); III. Detection (304.2) of the number of measurements (304) of the reference value; IV. Execute a decision query (304.4) to determine whether the number of detected measurements exceeds a predetermined maximum value, wherein, if it exceeds the maximum value, a fault report (312) is generated, or if it is below the maximum value, step V is executed; V. measuring (306) a specified parameter, wherein the parameter includes a voltage parameter (voltage U (212)) or a current parameter (current I_Shunt); VI. Calculating (308) a difference value, wherein the difference value is obtained by subtracting the specified parameter from the reference value (140, 212); and VII. Determining ( 310 ) whether the current sensor has a corresponding accuracy, wherein the corresponding accuracy is determined by maintaining the deviation value within a predetermined tolerance band.

2. The method (300) according to step VII. of claim 1, wherein: In the event of a deviation from the tolerance band, step II. of the method ( 300 ) is repeated.

3. The method (300) according to any one of the preceding claims, characterized in that Identification and diagnosis of sensor and / or sensor deviations are performed prior to the cycle.

4. The method (300) according to any one of the preceding claims, wherein: If it is determined that the deviation value lies within a predefined tolerance range, proper operation of the application is prevented.

5. The method (300) according to any one of the preceding claims, wherein: If it is determined (310) that the deviation value lies outside a predefined tolerance band, proper operation of the application is not initiated, wherein step I. according to claim 1 is initiated, wherein a predefined maximum number of measurements is increased.

6. An electronic circuit for identifying and diagnosing a sensor and / or sensor deviation of a sensor (144), wherein: The identification and diagnosis includes undershooting or overshooting of a tolerance band according to claim 1, the electronic circuit comprising: a. A first electronic circuit (100), wherein the reference value is a reference current value and the specified parameter is determined as a current value parameter (current I_Shunt (140)); wherein the deviation value includes the current value and the tolerance band includes the current tolerance, wherein the first electronic circuit (100) includes 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 specified parameter is determined as a voltage parameter (voltage U (212)); wherein the deviation value comprises a voltage value and the tolerance band comprises a voltage tolerance, wherein the second electronic circuit (200) comprises a Wheatstone bridge, wherein the Wheatstone bridge comprises one or more voltage sources (104), at least four resistors (112), and one or more switches (202), wherein at least one resistor (112) is a resistor R_Shunt (208) to be diagnosed, and wherein at least one switch (202) has a shutdown function for identifying and diagnosing a fall below or a fall above the tolerance band.

7. The electronic circuit according to claim 6, wherein: The existing voltage source (104) includes a battery voltage source.

8. The electronic circuit according to any one of claims 6 or 7, wherein: The sensor (144) comprises the 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. The electronic circuit according to claim 6, wherein: The first electronic circuit (100) comprises an analog-to-digital converter (120).

10. The electronic circuit according to claim 6 or 7, wherein: At least one resistor (112) and / or capacitor C_fill (110) exhibits a filtering function and / or a current limiting function in conjunction with the operational amplifier (106).

11. The electronic circuit according to any one of claims 6 to 8, wherein: The Wheatstone bridge (200.1) includes two resistance paths; wherein the first resistance path includes two resistors (112) R2 (206) and R3 (204) connected in parallel, and the second resistance path includes two resistors (112) R4 (210) and R_Shunt (208) connected in parallel.

12. The electronic circuit according to claim 11, wherein The first resistance path (220) is designed with high impedance.

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