Method and device for determining target working temperature of gas sensor and medium

Abstract

The invention discloses a method and device for determining the target working temperature of a gas sensor and a medium, and the gas sensor comprises a first oxygen pumping unit, a second oxygen pumping unit and a heating device. The method for determining the target working temperature of the gas sensor comprises the following steps: heating a heating device, and acquiring the temperature of the heating device as a heating temperature; in the heating process of the heating device, when the heating temperature is larger than or equal to the first preset temperature, the first impedance of the first oxygen pumping unit and the second impedance of the second oxygen pumping unit are obtained; wherein the impedance phase angle of the first impedance and the second impedance is 0; and determining a target working temperature interval of the gas sensor according to the first impedance and the second impedance. According to the technical scheme, the setting accuracy of the target working temperature of the gas sensor is improved, the measurement precision of the gas sensor is further improved, and meanwhile the service life of the gas sensor can be prolonged.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a method, device and medium for determining a target operating temperature of a gas sensor. Background Art

[0002] The NOx sensor needs to operate at high temperatures to activate its own pump oxygen unit and achieve accurate measurement of the gas concentration in the vehicle exhaust. Whether the target operating temperature setting of the NOx sensor is reasonable has a great impact on its performance. When the target operating temperature of the NOx sensor is too low, it will affect the measurement accuracy of the NOx sensor. On the contrary, when the target operating temperature of the NOx sensor is too high, thermal stress will accumulate in the heating device for a long time, which will affect its service life. Due to differences in the materials, structures and / or quality of the heating devices of NOx sensors from different manufacturers, the relationship between them and temperature presents different functional characteristics, so that the optimal operating temperature of the NOx sensor is different.

[0003] There is a gas sensor in the prior art that measures impedance through high-frequency voltage to reduce the impact of electrode impedance on the target operating temperature, but it does not specify how to set a suitable target resistance, does not consider the combined impact of other impedances, and does not consider how to quickly and accurately achieve a reasonable setting of the target operating temperature during the driving process. Summary of the invention

[0004] The present invention provides a method, device and medium for determining the target operating temperature of a gas sensor, so as to solve the defects of the prior art, improve the setting accuracy of the target operating temperature of the gas sensor, thereby improving the measurement accuracy of the gas sensor, and at the same time, can extend the service life of the gas sensor.

[0005] In a first aspect, the present invention provides a method for determining a target operating temperature of a gas sensor, wherein the gas sensor comprises a first oxygen pumping unit, a second oxygen pumping unit, and a heating device; the method for determining the target operating temperature of the gas sensor comprises:

[0006] heating the heating device and obtaining the temperature of the heating device as a heating temperature;

[0007] In the process of heating the heating device, when the heating temperature is greater than or equal to a first preset temperature, obtaining a first impedance of the first oxygen pumping unit and a second impedance of the second oxygen pumping unit; wherein an impedance phase angle between the first impedance and the second impedance is 0;

[0008] A target operating temperature range of the gas sensor is determined according to the first impedance and the second impedance.

[0009] Optionally, obtaining the temperature of the heating device includes:

[0010] Applying a heating excitation signal to the heating device so that the heating device generates a heating feedback signal;

[0011] determining a heating impedance of the heating device according to the heating excitation signal and the heating feedback signal;

[0012] Based on the heating impedance, the temperature of the heating device is determined.

[0013] Optionally, heating the heating device and obtaining the temperature of the heating device as the heating temperature includes:

[0014] Applying a first pulse width modulation signal to the heating device to quickly heat the heating device until the heating temperature reaches a first target heating temperature; wherein the first target heating temperature is less than or equal to the first preset temperature;

[0015] The target heating temperature is adjusted with a preset step size, and the temperature of the heating device is controlled by a PID regulation method.

[0016] Optionally, adjusting the target heating temperature with a preset step size and controlling the temperature of the heating device by a PID adjustment method includes:

[0017] increasing the target heating temperature by a first preset step length until the heating temperature reaches the first preset temperature;

[0018] Increasing the target heating temperature with a second preset step length until a difference between the first impedance at a current moment and the first impedance at a previous moment is greater than or equal to a first preset value;

[0019] Increasing the target heating temperature with a third preset step size until a difference between the first impedance at a current moment and the first impedance at a previous moment is less than or equal to a second preset value;

[0020] The target heating temperature is reduced with a fourth preset step size until the difference between the second impedance at the current moment and the second impedance at the previous moment is greater than or equal to a third preset value; wherein the first preset step size ≥ the second preset step size ≥ the third preset step size ≥ the fourth preset step size.

[0021] Optionally, obtaining a first impedance of the first oxygen pumping unit and a second impedance of the second oxygen pumping unit includes:

[0022] applying a first excitation signal to the first oxygen pumping unit so that the first oxygen pumping unit generates a first feedback signal;

[0023] determining the first impedance of the first oxygen pumping unit according to the first excitation signal and the first feedback signal; and;

[0024] applying a second excitation signal to the second oxygen pumping unit so that the second oxygen pumping unit generates a second feedback signal;

[0025] The second impedance of the second oxygen pumping unit is determined according to the second excitation signal and the second feedback signal.

[0026] Optionally, the second excitation signal and / or the second excitation signal is a direct current excitation signal.

[0027] Optionally, determining a target operating temperature range of the gas sensor according to the first impedance and the second impedance includes:

[0028] determining a target operating temperature upper limit value of the gas sensor according to the first impedance; and determining a target operating temperature lower limit value of the gas sensor according to the second impedance;

[0029] The interval determined by the target operating temperature lower limit value and the target operating temperature upper limit value is determined as the target operating temperature interval.

[0030] Optionally, determining an upper limit value of a target operating temperature of the gas sensor according to the first impedance; and determining a lower limit value of a target operating temperature of the gas sensor according to the second impedance; comprising:

[0031] Calculating a difference between the first impedance obtained at a current moment and the first impedance obtained at a previous moment, and recording the difference as a first difference;

[0032] When the first difference is less than or equal to a second preset value, determining that the temperature corresponding to the first impedance acquired at the current moment is the upper limit value of the target operating temperature of the gas sensor; and,

[0033] Calculating a difference between the second impedance obtained at the current moment and the second impedance obtained at the previous moment, and recording the difference as a second difference;

[0034] When the second difference is greater than or equal to a third preset value, it is determined that the temperature corresponding to the second impedance acquired at the current moment is the lower limit of the target operating temperature of the gas sensor.

[0035] In a second aspect, the present invention provides a device for determining a target operating temperature of a gas sensor, wherein the gas sensor comprises a first oxygen pumping unit, a second oxygen pumping unit, and a heating device; the device for determining the target operating temperature of the gas sensor comprises:

[0036] A heating module, used for heating the heating device and obtaining the temperature of the heating device as a heating temperature;

[0037] an impedance acquisition module, used for acquiring a first impedance of the first oxygen pumping unit and a second impedance of the second oxygen pumping unit when the heating temperature is greater than or equal to a first preset temperature during the heating of the heating device; wherein an impedance phase angle between the first impedance and the second impedance is 0;

[0038] A determination module is used to determine a target operating temperature range of the gas sensor according to the first impedance and the second impedance.

[0039] In a third aspect, the present invention provides a computer-readable storage medium, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to implement the method for determining the target operating temperature of the gas sensor described in any one of the above items when executed by a processor.

[0040] The technical solution of the present invention is to heat the heating device of the gas sensor and obtain the temperature of the heating device as the heating temperature. In the process of heating the heating device, when the heating temperature is greater than or equal to the first preset temperature, the first impedance of the first pump oxygen unit of the gas sensor and the second impedance of the second pump oxygen unit of the gas sensor are obtained. Since the temperature of the first pump oxygen unit is related to the first impedance and the temperature of the second pump oxygen unit is related to the second impedance, the target operating temperature range of the gas sensor can be determined according to the first impedance and the second impedance. In this way, the reasonable target operating temperature can be determined for the characteristics of different gas sensor probes, and the influence of the electrode impedance on the target operating temperature of the gas sensor can be reduced, thereby improving the setting accuracy of the target operating temperature of the gas sensor, and then improving the measurement accuracy of the gas sensor, and at the same time, the service life of the gas sensor can be extended.

[0041] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1A flow chart of a method for determining a target operating temperature of a gas sensor provided in Embodiment 1 of the present invention;

[0044] Figure 2 A structural block diagram of a gas sensor provided by an embodiment of the present invention;

[0045] Figure 3 A schematic diagram of the structure of a device for measuring the target operating temperature of a gas sensor provided by an embodiment of the present invention;

[0046] Figure 4 A flow chart of a method for determining a target operating temperature of a gas sensor provided in Embodiment 2 of the present invention;

[0047] Figure 5 This is a schematic diagram of the structure of a device for determining a target operating temperature of a gas sensor provided in Embodiment 3 of the present invention. DETAILED DESCRIPTION

[0048] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first", "second", "target", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0050] Embodiment 1

[0051] Figure 1 This is a flow chart of a method for determining a target operating temperature of a gas sensor provided in Embodiment 1 of the present invention. This embodiment is applicable to the case of determining a target operating temperature of a gas sensor. The method can be executed by a device for determining a target operating temperature of a gas sensor. The device can be implemented in the form of hardware and / or software and can be configured in a processor. Figure 1 As shown, the method includes:

[0052] S110, heating the heating device, and acquiring the temperature of the heating device as the heating temperature.

[0053] The gas sensor may include, but is not limited to, a nitrogen oxygen sensor or a carbon oxygen sensor, etc. As long as the gas sensor needs to activate its own oxygen pump unit at a specific temperature, it is within the scope disclosed in this embodiment. Figure 2 For a structural block diagram of a gas sensor provided by an embodiment of the present invention, refer to Figure 2 As shown, the gas sensor includes a probe 11 and a controller 10, wherein the probe 11 and the controller 10 are connected by a wiring harness. The controller 10 includes a power supply, an operation and storage module, a first power supply, a first impedance measuring unit, a second power supply, a second impedance measuring unit, a heating power supply and a heating impedance measuring unit. The probe 11 includes a first pump oxygen unit, a second pump oxygen unit and a heating device. The first power supply and the first impedance measuring unit are respectively electrically connected to the first pump oxygen unit, and the first power supply is used to provide a first excitation signal to the first pump oxygen unit so that the first impedance measuring unit obtains the first impedance of the first pump oxygen unit; the second power supply and the second impedance measuring unit are respectively electrically connected to the second pump oxygen unit, and the second power supply is used to provide a second excitation signal to the second pump oxygen unit so that the second impedance measuring unit obtains the second impedance of the second pump oxygen unit; the heating power supply and the heating impedance measuring unit are respectively electrically connected to the heating device, and the heating power supply is used to provide a heating excitation signal to the heating device so that the heating impedance measuring unit obtains the heating impedance of the heating device.

[0054] The heating device may include, but is not limited to, a heating wire. The heating device may have a positive temperature coefficient or a negative temperature coefficient. For ease of description, a positive temperature coefficient heating device is used as an example for description below. In an optional embodiment, the heating device is driven by a PWM wave for heating, and the PWM wave includes a valid drive signal and an invalid drive signal; under a valid drive signal, the heating device is heated, and under an invalid drive signal, the heating device stops being heated.

[0055] Acquiring the temperature of the heating device may include, but is not limited to, acquiring the temperature of the heating device using a temperature sensor or determining the temperature of the heating device according to the heating impedance of the heating device, etc. This embodiment does not make any specific limitation on this.

[0056] S120. During the process of heating the heating device, when the heating temperature is greater than or equal to the first preset temperature, obtaining a first impedance of the first oxygen pumping unit and a second impedance of the second oxygen pumping unit.

[0057] The impedance phase angle between the first impedance and the second impedance is 0.

[0058] The first preset temperature can be determined according to the material, process and structure of the heating device. At the first preset temperature, the impedance corresponding to the first oxygen pump unit is greater than or equal to the impedance corresponding to the normal working stage. In an optional embodiment, the preset temperature is determined by calibration.

[0059] The first impedance of the first oxygen pump unit can be obtained by the first impedance measuring unit, and the second impedance of the second oxygen pump unit can be obtained by the second impedance measuring unit. Specifically, the first impedance measuring unit provides a first excitation signal to the first oxygen pump unit, so that the first oxygen pump unit generates a first feedback signal, so that the first impedance measuring unit determines the impedance of the first oxygen pump unit according to the first excitation signal and the first feedback signal. Similarly, the second impedance measuring unit provides a second excitation signal to the second oxygen pump unit, so that the second oxygen pump unit generates a second feedback signal, so that the second impedance measuring unit determines the impedance of the second oxygen pump unit according to the second excitation signal and the second feedback signal. In an optional embodiment, the first excitation signal and the second excitation signal are both DC excitation signals.

[0060] The impedance phase angle of the first impedance and the second impedance is 0. It can be understood that when the first excitation signal and the second excitation signal are DC signals, at the moment when the first excitation signal acts on the first oxygen pump unit, and at the moment when the second excitation signal acts on the second oxygen pump unit, the first impedance and the second impedance have a large phase angle. At this time, the first impedance and the second impedance obtained cannot represent the real impedance of the first oxygen pump unit and the second oxygen pump unit. By making the impedance phase angle of the obtained first impedance and the second impedance 0, the accuracy of the obtained first impedance and the second impedance can be guaranteed.

[0061] S130: Determine a target operating temperature range of the gas sensor according to the first impedance and the second impedance.

[0062] The target operating temperature range of the gas sensor can be understood as the optimal operating temperature of the gas sensor. When the gas sensor operates in the target operating temperature range, the gas sensor measures the corresponding gas content more accurately, and can protect the gas sensor and extend the life of the gas sensor.

[0063] It should be noted that Figure 3 A schematic diagram of a gas sensor target operating temperature measuring environment device provided by an embodiment of the present invention, referring to Figure 3 As shown, the environment measuring device includes a gas source 21, a gas pipeline 14 and an environment temperature sensor 22. The gas source 21 is connected to the gas pipeline 14, and the environment temperature sensor 22 and the gas sensor 23 are arranged in the gas pipeline 14. The gas source 21 is used to provide a constant concentration gas component with a certain flow rate, so that when the target operating temperature of the gas sensor 23 is measured, the gas component around the gas sensor 23 is constant.

[0064] It is understandable that the constant concentration gas component may be a gas component with a constant oxygen concentration and a constant nitrogen and oxygen concentration. In an optional embodiment, the constant concentration gas component may be air, thereby simplifying the conditions for determining the target operating temperature of the gas sensor and reducing costs.

[0065] The ambient temperature sensor is used to measure the gas temperature in the gas pipeline at the heating starting point of the gas sensor to determine the impedance deviation caused by the temperature deviation at the heating starting point, so as to make the heating impedance of the heating device at the heating starting point more accurate. For example, if the ambient temperature is 20°C, the heating impedance of the heating device in the gas sensor is 1.3Ω, and the gas temperature at the heating starting point measured by the ambient temperature sensor is 25°C, then the heating impedance of the heating device at the heating starting point should take into account the heating impedance deviation caused by the 5°C temperature deviation.

[0066] In this embodiment, the heating device of the gas sensor is heated and the temperature of the heating device is obtained as the heating temperature. During the heating of the heating device, when the heating temperature is greater than or equal to the first preset temperature, the first impedance of the first oxygen pump unit of the gas sensor and the second impedance of the second oxygen pump unit of the gas sensor are obtained. Since the temperature of the first oxygen pump unit is related to the first impedance and the temperature of the second oxygen pump unit is related to the second impedance, the target operating temperature range of the gas sensor can be determined according to the first impedance and the second impedance. In this way, a reasonable target operating temperature can be determined for different characteristics of the gas sensor probe, and the influence of the electrode impedance on the target operating temperature of the gas sensor can be reduced, thereby improving the accuracy of setting the target operating temperature of the gas sensor, and further improving the measurement accuracy of the gas sensor, and at the same time, the service life of the gas sensor can be extended.

[0067] Embodiment 2

[0068] Figure 4 This is a flow chart of a method for determining the target operating temperature of a gas sensor provided in the second embodiment of the present invention. Based on the above embodiment, this embodiment further adds steps of how to heat the heating device, how to obtain the temperature of the heating device, how to obtain the first impedance and the second impedance, and how to determine the target operating stable range of the gas sensor based on the first impedance and the second impedance. Figure 4 As shown, the method specifically includes:

[0069] S210: Apply a first pulse width modulation signal to the heating device to quickly heat the heating device until the heating temperature reaches a first target heating temperature.

[0070] The first target heating temperature is less than or equal to the first preset temperature. The first target heating temperature is the stop temperature of rapid heating and can be set according to actual needs. In an exemplary embodiment, the first target heating temperature is 500°C.

[0071] It should be noted that, in the rapid heating stage, the effective driving signal of the first pulse width modulation signal accounts for a relatively large proportion, so that the heating device can be heated rapidly.

[0072] It should also be noted that when the heating device is rapidly heated, the temperature of the heating device may be controlled by open-loop control or closed-loop control, which is not specifically limited in this embodiment.

[0073] In an optional embodiment, when a dew point signal is received, rapid heating of the heating device is started.

[0074] In an optional embodiment, obtaining the temperature of the heating device includes: applying a heating excitation signal to the heating device so that the heating device generates a heating feedback signal; determining the heating impedance of the heating device based on the heating excitation signal and the heating feedback signal; and determining the temperature of the heating device based on the heating impedance.

[0075] The heating excitation signal may be a current signal or a voltage signal, etc. The heating impedance of the heating device is the complex impedance generated by the heating device under the heating excitation signal.

[0076] In an exemplary embodiment, the heating excitation signal is a DC voltage signal, and by applying the DC voltage signal to the heating device, the heating device generates a corresponding feedback current signal, ie, a heating feedback signal.

[0077] Specifically, by applying a heating excitation signal to the heating device, the heating device generates a heating feedback signal, and then the heating impedance of the heating device can be obtained according to the heating excitation signal and the heating feedback signal. Since the complex impedance of the heating device has a corresponding relationship with the temperature of the heating device, for example, when the heating device has a positive temperature coefficient, the complex impedance of the heating device is positively correlated with the temperature of the heating device, so the temperature of the heating device can be determined according to the heating impedance.

[0078] In an optional embodiment, the step of obtaining the temperature of the heating device occurs during the invalid drive signal phase of the PWM wave and before the valid drive signal phase of the current cycle, so that the PWM wave of the next cycle can be controlled according to the temperature of the current cycle.

[0079] S220, adjusting the target heating temperature with a preset step size, and controlling the temperature of the heating device by using a PID adjustment method.

[0080] The preset step size can be set according to actual requirements. When the preset step size is larger, the cycle of obtaining the temperature of the heating device and the cycle of obtaining the first impedance and the second impedance are longer, so that the accuracy of the target operating temperature range of the gas sensor finally determined is lower, but the time taken to determine the target operating temperature range of the gas sensor is shorter, which is conducive to improving efficiency; on the contrary, when the preset step size is larger, the accuracy of the target operating temperature range of the gas sensor finally determined is improved, but the time taken is longer and the efficiency is lower.

[0081] It should be noted that the step sizes in the preset step size may be equal or unequal, and may be set according to actual needs.

[0082] The target heating temperature can be understood as the target temperature for heating the heating device.

[0083] The PID adjustment method includes PID closed-loop control, which controls the temperature of the heating device by taking the heating impedance of the heating device as the output and outputting the voltage negative feedback. In an optional embodiment, the PID adjustment includes at least a proportional parameter and an integral parameter. The proportional parameter should be set with an upper limit value, which is determined in a calibrated manner. In an exemplary embodiment, in the high temperature zone (temperature greater than 700°C), the upper limit value of the proportional parameter should make the temperature of the heating device not exceed the set maximum value, that is, the maximum overtemperature value at the target temperature.

[0084] In an optional embodiment, S220 includes:

[0085] S221. Increase the target heating temperature with a first preset step length until the heating temperature reaches the first preset temperature.

[0086] S222, increasing the target heating temperature with a second preset step size until the difference between the first impedance at the current moment and the first impedance at the previous moment is greater than or equal to the first preset value.

[0087] The first preset value can be determined based on the error range between the acquired first impedance and the actual first impedance, and the error range between the actual first excitation signal and the preset first excitation signal. Ideally, the second preset value is greater than 0. Specifically, the target heating temperature is increased with a second preset step size until the difference between the first impedance at the current moment and the first impedance at the previous moment, that is, the first difference is greater than 0, that is, a step appears in the first impedance.

[0088] S223, increasing the target heating temperature with a third preset step size until the difference between the first impedance at the current moment and the first impedance at the previous moment is less than or equal to the second preset value.

[0089] The second preset value can be determined according to the error range between the acquired first impedance and the actual first impedance, and the error range between the actual first excitation signal and the preset first excitation signal. In an ideal case, the second preset value is 0, that is, the first difference is equal to 0, that is, the target heating temperature is increased by the third preset step until the first impedance no longer changes.

[0090] S224, reducing the target heating temperature with a fourth preset step size until the difference between the second impedance at the current moment and the second impedance at the previous moment is greater than or equal to the third preset value.

[0091] Among them, the first preset step length ≥ the second preset step length ≥ the third preset step length ≥ the fourth preset step length.

[0092] The third preset value can be determined according to the error range between the acquired first impedance and the actual first impedance, and the error range between the actual first excitation signal and the preset first excitation signal. Ideally, the third preset value is greater than 0, that is, the second difference is greater than 0, that is, the target heating temperature is reduced by the fourth step until a step appears in the second impedance.

[0093] It can be understood that as the temperature of the heating device increases, the first impedance and the second impedance successively appear steps, and then the first impedance and the second impedance reach the platform area, and the second impedance reaches the platform area before the first impedance, so that when the second difference is greater than or equal to the third preset value, it is determined that the temperature corresponding to the second impedance obtained at the current moment is the lower limit value of the target operating temperature of the gas sensor, and when the first difference is less than or equal to the second preset value, it is determined that the temperature corresponding to the first impedance obtained at the current moment is the upper limit value of the target operating temperature of the gas sensor.

[0094] S230, applying a first excitation signal to the first oxygen pumping unit so that the first oxygen pumping unit generates a first feedback signal; applying a second excitation signal to the second oxygen pumping unit so that the second oxygen pumping unit generates a second feedback signal.

[0095] The first excitation signal may be a current signal or a voltage signal, etc. The second excitation signal may be a current signal or a voltage signal, etc. In an exemplary embodiment, the first excitation signal and the second excitation signal are both direct current signals. By applying a direct current signal to the first oxygen pumping unit and the second oxygen pumping unit, the first oxygen pumping unit and the second oxygen pumping unit generate corresponding feedback voltage signals, i.e., the first feedback signal and the second feedback signal.

[0096] S240, determining a first impedance of the first oxygen pumping unit according to the first excitation signal and the first feedback signal; and determining a second impedance of the second oxygen pumping unit according to the second excitation signal and the second feedback signal.

[0097] Specifically, by applying a first excitation signal to the first oxygen pump unit, the first oxygen pump unit generates a first feedback signal, and then the first impedance of the first oxygen pump unit can be obtained according to the first excitation signal and the first feedback signal. Similarly, by applying a second excitation signal to the second oxygen pump unit, the second oxygen pump unit generates a second feedback signal, and then the second impedance of the second oxygen pump unit can be obtained according to the second excitation signal and the second feedback signal.

[0098] In an optional embodiment, the acquisition of the first impedance, the second impedance and the heating impedance is implemented in the same cycle, and further, the first impedance and the second impedance are phase-delayed relative to the measurement of the heating impedance.

[0099] In an optional embodiment, the acquisition frequency of the heating impedance is less than or equal to the acquisition frequency of the first impedance and the second impedance. Preferably, the acquisition frequencies of the heating impedance, the first impedance and the second impedance are the same.

[0100] In an optional embodiment, the step of obtaining the first impedance and the second impedance occurs in the invalid drive signal stage of the PWM wave and after the valid drive signal stage of the current cycle, so that the first impedance and the second impedance obtained at the current moment are the impedances after heating in the current cycle.

[0101] S250. Determine an upper limit value of the target operating temperature of the gas sensor according to the first impedance; and determine a lower limit value of the target operating temperature of the gas sensor according to the second impedance.

[0102] Specifically, as the temperature of the heating device increases, the first impedance and the second impedance change in a certain regularity, and the second impedance reaches the platform area before the first impedance. Therefore, according to the change of the first impedance, the target operating temperature upper limit of the gas sensor is determined, and according to the change of the second impedance, the target operating stability lower limit of the gas sensor is determined.

[0103] In an optional embodiment, determining the target upper limit of the operating temperature of the gas sensor based on the first impedance includes: calculating the difference between the first impedance obtained at the current moment and the first impedance obtained at the previous moment, and recording it as the first difference; when the first difference is less than or equal to the second preset value, determining that the temperature corresponding to the first impedance obtained at the current moment is the target upper limit of the operating temperature of the gas sensor.

[0104] In an optional embodiment, determining the lower limit value of the target operating temperature of the gas sensor based on the second impedance includes: calculating the difference between the second impedance obtained at the current moment and the second impedance obtained at the previous moment, and recording it as the second difference; when the second difference is less than or equal to the third preset value, determining that the temperature corresponding to the second impedance obtained at the current moment is the lower limit value of the target operating temperature of the gas sensor.

[0105] S260: Determine the interval determined by the target operating temperature lower limit value and the target operating temperature upper limit value as the target operating temperature interval.

[0106] In this embodiment, by setting different heating speeds according to the temperature of the heating device, the efficiency can be improved under the premise of ensuring that the target operating temperature range of the gas sensor is finally determined with high accuracy. In addition, by applying a first excitation signal to the first pump oxygen unit and applying a second excitation signal to the second pump oxygen unit, the first impedance and the second impedance obtained are more accurate, thereby making the lower limit value and the upper limit value of the target working stability of the gas sensor determined more accurate.

[0107] Embodiment 3

[0108] This embodiment provides a device for determining a target operating temperature of a gas sensor. The device may be implemented in the form of hardware and / or software and may be integrated into a processor. Figure 5 This is a schematic diagram of the structure of a device for determining the target operating temperature of a gas sensor provided in Embodiment 3 of the present invention. Figure 5 As shown, the determining device includes:

[0109] The heating module 310 is used to heat the heating device and obtain the temperature of the heating device as the heating temperature.

[0110] The impedance acquisition module 320 is used to acquire the first impedance of the first oxygen pumping unit and the second impedance of the second oxygen pumping unit when the heating temperature is greater than or equal to the first preset temperature during the heating process of the heating device; wherein the impedance phase angle between the first impedance and the second impedance is 0.

[0111] The determination module 330 is used to determine a target operating temperature range of the gas sensor according to the first impedance and the second impedance.

[0112] The device for determining the target operating temperature of a gas sensor provided in an embodiment of the present invention can execute the method for determining the target operating temperature of a gas sensor provided in any embodiment of the present invention, and has functional modules and beneficial effects corresponding to the execution method. The similarities can be referred to the above description.

[0113] Embodiment 4

[0114] Based on the same concept, an embodiment of the present invention further provides a computer-readable storage medium, which stores computer instructions, and the computer instructions are used to enable a processor to implement the control method provided by any of the above embodiments when executed.

[0115] In the context of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in combination with an instruction execution system, device or equipment. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices or equipment, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0116] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining a target operating temperature of a gas sensor, characterized in that: The gas sensor includes a first oxygen pump unit, a second oxygen pump unit and a heating device; the method for determining the target operating temperature of the gas sensor includes: heating the heating device and obtaining the temperature of the heating device as a heating temperature; In the process of heating the heating device, when the heating temperature is greater than or equal to a first preset temperature, obtaining a first impedance of the first oxygen pumping unit and a second impedance of the second oxygen pumping unit; wherein an impedance phase angle between the first impedance and the second impedance is 0; A target operating temperature range of the gas sensor is determined according to the first impedance and the second impedance.

2. The method for determining the target operating temperature of a gas sensor according to claim 1, characterized in that: Obtaining the temperature of the heating device includes: Applying a heating excitation signal to the heating device so that the heating device generates a heating feedback signal; determining a heating impedance of the heating device according to the heating excitation signal and the heating feedback signal; Based on the heating impedance, the temperature of the heating device is determined.

3. The method for determining the target operating temperature of a gas sensor according to claim 1 or 2, characterized in that: Heating the heating device and obtaining the temperature of the heating device as a heating temperature includes: Applying a first pulse width modulation signal to the heating device to quickly heat the heating device until the heating temperature reaches a first target heating temperature; wherein the first target heating temperature is less than or equal to the first preset temperature; The target heating temperature is adjusted with a preset step size, and the temperature of the heating device is controlled by a PID regulation method.

4. The method for determining the target operating temperature of a gas sensor according to claim 3, characterized in that: The target heating temperature is adjusted with a preset step size, and the temperature of the heating device is controlled by a PID adjustment method, including: increasing the target heating temperature by a first preset step length until the heating temperature reaches the first preset temperature; Increasing the target heating temperature with a second preset step length until a difference between the first impedance at a current moment and the first impedance at a previous moment is greater than or equal to a first preset value; Increasing the target heating temperature with a third preset step size until a difference between the first impedance at a current moment and the first impedance at a previous moment is less than or equal to a second preset value; The target heating temperature is reduced with a fourth preset step size until the difference between the second impedance at the current moment and the second impedance at the previous moment is greater than or equal to a third preset value; wherein the first preset step size ≥ the second preset step size ≥ the third preset step size ≥ the fourth preset step size.

5. The method for determining the target operating temperature of a gas sensor according to claim 1, characterized in that: Acquiring a first impedance of the first oxygen pumping unit and a second impedance of the second oxygen pumping unit includes: applying a first excitation signal to the first oxygen pumping unit so that the first oxygen pumping unit generates a first feedback signal; determining the first impedance of the first oxygen pumping unit according to the first excitation signal and the first feedback signal; and; applying a second excitation signal to the second oxygen pumping unit so that the second oxygen pumping unit generates a second feedback signal; The second impedance of the second oxygen pumping unit is determined according to the second excitation signal and the second feedback signal.

6. The method for determining the target operating temperature of a gas sensor according to claim 5, characterized in that: The second excitation signal and / or the second excitation signal is a direct current excitation signal.

7. The method for determining the target operating temperature of a gas sensor according to claim 1, characterized in that: Determining a target operating temperature range of the gas sensor according to the first impedance and the second impedance includes: determining a target operating temperature upper limit value of the gas sensor according to the first impedance; and determining a target operating temperature lower limit value of the gas sensor according to the second impedance; The interval determined by the target operating temperature lower limit value and the target operating temperature upper limit value is determined as the target operating temperature interval.

8. The method for determining the target operating temperature of a gas sensor according to claim 7, characterized in that: determining a target operating temperature upper limit value of the gas sensor according to the first impedance; And, determining a lower limit value of a target operating temperature of the gas sensor according to the second impedance; comprising: Calculating a difference between the first impedance obtained at a current moment and the first impedance obtained at a previous moment, and recording the difference as a first difference; When the first difference is less than or equal to a second preset value, determining that the temperature corresponding to the first impedance acquired at the current moment is the upper limit value of the target operating temperature of the gas sensor; and, Calculating a difference between the second impedance obtained at the current moment and the second impedance obtained at the previous moment, and recording the difference as a second difference; When the second difference is greater than or equal to a third preset value, it is determined that the temperature corresponding to the second impedance acquired at the current moment is the lower limit of the target operating temperature of the gas sensor.

9. A device for determining a target operating temperature of a gas sensor, characterized in that: The gas sensor comprises a first oxygen pumping unit, a second oxygen pumping unit and a heating device; the device for determining the target operating temperature of the gas sensor comprises: A heating module, used for heating the heating device and obtaining the temperature of the heating device as a heating temperature; an impedance acquisition module, used for acquiring a first impedance of the first oxygen pumping unit and a second impedance of the second oxygen pumping unit when the heating temperature is greater than or equal to a first preset temperature during the heating of the heating device; wherein an impedance phase angle between the first impedance and the second impedance is 0; A determination module is used to determine a target operating temperature range of the gas sensor according to the first impedance and the second impedance.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, which are used to enable a processor to implement the method for determining the target operating temperature of the gas sensor according to any one of claims 1 to 8 when the computer-readable storage medium executes the computer instructions.

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