Wireless temperature measurement method and wireless temperature measurement sensor

Abstract

The invention relates to the technical field of intelligent sensors, in particular to a wireless temperature measurement method and a wireless temperature measurement sensor, and the method comprises the steps: obtaining the temperature data measured by the wireless temperature measurement sensor, the current data of a power supply circuit in the measurement process of the wireless temperature measurement sensor, and the voltage data of two ends of a thermistor; the temperature data, the current data and the voltage data are analyzed, the self-heating effect expression degree of the temperature value at each measurement moment in the measurement process is determined, then the self-heating effect temperature flow proportionality coefficient is determined, the temperature data are corrected according to the self-heating effect expression degree, the self-heating effect temperature flow proportionality coefficient and the current data, and the self-heating effect temperature flow proportionality coefficient is obtained. And the corrected temperature data in the measurement process is obtained. According to the invention, the temperature deviation caused by the self-heating effect of the wireless temperature measurement sensor is corrected, so that the accuracy of temperature measurement is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent sensors, and in particular to a wireless temperature measurement method and a wireless temperature measurement sensor. Background Art

[0002] With the rapid development of industrial automation and intelligence, the types of power equipment are becoming more and more diverse, and there are more and more high-precision equipment. The requirements for real-time, accuracy and flexibility of temperature monitoring are constantly increasing. Traditional wired temperature measurement methods are limited by wiring complexity and environmental adaptability, and it is difficult to meet the needs in special scenarios. Wireless temperature measurement technology collects temperature data through wireless sensors and transmits it to the receiving terminal, avoiding wiring restrictions. It has the advantages of easy installation, low cost and strong adaptability. Wireless temperature sensors are usually based on technologies such as thermistors and combined with wireless communication modules (such as Bluetooth, Wi-Fi, ZigBee) to achieve data transmission.

[0003] In the prior art, wireless temperature measurement methods use the characteristics of thermistors that their resistance varies with the external temperature and Ohm's theorem to convert temperature changes into voltage changes at both ends of the thermistor, and calculate the temperature value based on the relationship between voltage and temperature. However, the self-heating effect of wireless temperature sensors can cause deviations in the measured temperature, that is, during the operation of wireless temperature sensors, the temperature of the sensors rises due to internal current flow or resistance heating, making the temperature of the sensors higher than the ambient temperature. This is particularly evident in high current or low heat dissipation environments, which may cause the measured values ​​to be continuously high, thereby affecting the accuracy of temperature measurement and failing to meet the temperature measurement requirements for mechanical equipment with high temperature measurement accuracy, such as transformer contacts. Summary of the invention

[0004] In order to solve the above technical problems, the purpose of the present invention is to provide a wireless temperature measurement method and a wireless temperature measurement sensor. The technical solutions adopted are as follows:

[0005] In a first aspect, the present invention provides a wireless temperature measurement method, comprising the following steps:

[0006] Obtain temperature data measured by the wireless temperature sensor, current data of the power supply circuit during the measurement process of the wireless temperature sensor, and voltage data across the sensor thermistor;

[0007] According to the relationship between the change trends of temperature data and voltage data, and the local change of temperature data, the self-heating effect expression degree of the temperature value at each measuring moment in the measurement process is determined;

[0008] According to the self-heating effect performance degree, each target measurement time in the measurement process is determined, and according to the change correlation between the self-heating effect performance degree and the current data at each target measurement time, the self-heating effect temperature-flow proportionality coefficient is determined;

[0009] The temperature data is corrected according to the self-heating effect performance, the self-heating effect temperature-flow proportionality coefficient and the current data to obtain the corrected temperature data of the measurement process.

[0010] In combination with the first aspect above, in some possible implementations, determining the self-heating effect expression degree of the temperature value at each measurement moment during the measurement process includes:

[0011] Analyze the relationship between the changing trends of temperature data and voltage data to determine the temperature deviation at each measuring moment during the measurement process;

[0012] Analyze the local fluctuation of temperature data and determine the background interference at each measurement moment during the measurement process;

[0013] The self-heating effect expression degree of the temperature value at each measuring moment in the measurement process is determined according to the background interference degree at each measuring moment in the measurement process and the temperature deviation degree of all measuring moments within the neighborhood time range of each measuring moment.

[0014] In combination with the first aspect above, in some possible implementations, determining the temperature deviation at each measurement moment during the measurement process includes:

[0015] During the measurement process, between all two adjacent measurement moments, a first temperature-pressure change relationship index is determined according to a difference between a first ratio of a voltage value to a temperature value at a later measurement moment and a second ratio of a voltage value to a temperature value at a previous measurement moment;

[0016] Determine the second temperature-pressure change relationship index at each measurement moment in the measurement process according to the difference between the third ratio of the voltage value to the temperature value at the latter measurement moment and the fourth ratio of the voltage value to the temperature value at the previous measurement moment between all two adjacent measurement moments in the neighborhood time range of each measurement moment in the measurement process;

[0017] The temperature deviation degree at each moment in the measurement process is determined according to the difference between the second temperature-pressure change relationship index and the first temperature-pressure change relationship index.

[0018] In combination with the first aspect above, in some possible implementations, the process of determining the first temperature-pressure change relationship index and the second temperature-pressure change relationship index includes:

[0019] determining an absolute value of a difference between the first ratio and the second ratio to obtain a first ratio difference;

[0020] Performing negative correlation normalization processing on the mean of all first ratio differences between all two adjacent measurement moments during the measurement process to obtain a first temperature-pressure change relationship index;

[0021] determining an absolute value of a difference between the third ratio and the fourth ratio to obtain a second ratio difference;

[0022] The mean of all second ratio differences between all two adjacent measurement moments within the neighborhood time range of each measurement moment in the measurement process is subjected to negative correlation normalization processing to obtain the second temperature-pressure change relationship index.

[0023] In combination with the first aspect, in some possible implementations, determining the background interference level at each measurement moment during the measurement process includes:

[0024] Determine the temperature mean and temperature variance of the temperature values ​​of all measurement moments within the neighborhood time range of each measurement moment during the measurement process;

[0025] The background interference degree at each measuring moment in the measurement process is determined by determining the difference between the temperature value at each measuring moment in the measurement process and the temperature mean value, and the temperature variance.

[0026] In combination with the first aspect above, in some possible implementations, determining the self-heating effect expression degree of the temperature value at each measurement moment during the measurement process includes:

[0027] Determine the average temperature deviation of all temperature deviations between two adjacent measurement moments within the neighborhood time range of each measurement moment during the measurement process;

[0028] Perform negative correlation normalization processing on the background interference degree to obtain the processing result;

[0029] The product of the average temperature deviation at each measuring moment in the measuring process and the processing result is determined, thereby obtaining the self-heating effect expression degree of the temperature value at each measuring moment in the measuring process.

[0030] In combination with the first aspect above, in some possible implementations, determining each target measurement time in the measurement process according to the self-heating effect performance degree includes:

[0031] The self-heating effect performance degree at each measurement moment in the measurement process is compared with a set threshold, and the measurement moment in the measurement process when the self-heating effect performance degree is greater than the set threshold is used as the target measurement moment in the measurement process.

[0032] In combination with the first aspect above, in some possible implementations, determining the temperature flow proportional coefficient of the self-heating effect includes:

[0033] Determine a fifth ratio of a first difference value of two self-heating effect manifestations and a second difference value of two current values ​​at each two adjacent target measurement moments during the measurement process to obtain a sub-self-heating effect temperature-flow proportionality coefficient;

[0034] The self-heating effect temperature flow proportional coefficient is determined according to the overall distribution level of the sub-self-heating effect temperature flow proportional coefficient corresponding to all two adjacent target measurement moments during the measurement process.

[0035] In combination with the first aspect above, in some possible implementations, the temperature data is corrected according to the current data and the temperature-flow proportional coefficient of the self-heating effect to obtain the corrected temperature data of the measurement process, including:

[0036] According to the temperature value and self-heating effect performance at each target measurement moment, as well as the temperature-current proportionality coefficient of the self-heating effect and the average current value at all measurement moments during the measurement process;

[0037] Determine the difference between the temperature value at each target measurement moment and the temperature deviation value of the self-heating effect, and obtain the corrected temperature value at each target measurement moment;

[0038] The corrected temperature value at each target measurement moment and the temperature data at other measurement moments except for each target measurement moment during the measurement process together constitute the corrected temperature data of the measurement process.

[0039] In a second aspect, the present invention also provides a wireless temperature measurement sensor, comprising a wireless temperature measurement sensor body, a microprocessor installed in the wireless temperature measurement sensor body, a current sensor installed in the power supply circuit of the wireless temperature measurement sensor body, and a voltage sensor installed at both ends of the thermistor of the wireless temperature measurement sensor body. The microprocessor is communicatively connected to the current sensor and the voltage sensor, a computer program is stored in the microprocessor, and the microprocessor executes the computer program to implement the above-mentioned first aspect or a wireless temperature measurement method in any possible implementation method of the first aspect.

[0040] In a third aspect, the present invention further provides a wireless temperature measurement system, comprising a memory and a processor. The memory is used to store executable program code, and the processor is used to call and run the executable program code from the memory, so that the system executes a wireless temperature measurement method in the first aspect or any possible implementation of the first aspect.

[0041] In a fourth aspect, the present invention further provides a computer program product, which includes: a computer program code, which, when executed on a computer, enables the computer to execute a wireless temperature measurement method in the above-mentioned first aspect or any possible implementation of the first aspect.

[0042] In a fifth aspect, the present invention also provides a computer-readable storage medium, which stores a computer program code. When the computer program code runs on a computer, the computer executes a wireless temperature measurement method in the above-mentioned first aspect or any possible implementation of the first aspect.

[0043] The present invention has the following beneficial effects: the present invention obtains temperature data measured by a wireless temperature measuring sensor, current data of a power supply circuit during measurement by the wireless temperature measuring sensor, and voltage data at both ends of a thermistor of the sensor; because the voltage of the thermistor in the wireless temperature measuring sensor changes according to an expected rule as the temperature changes under normal working conditions, and when the relationship between the temperature data collected by the wireless temperature measuring sensor and the voltage data at both ends of the thermistor does not conform to the expected rule, it indicates that the temperature data collected by the wireless temperature measuring sensor has an abnormal deviation, and when the abnormal deviation in the temperature data collected by the wireless temperature measuring sensor is caused by the self-heating effect of the sensor, the local fluctuation of the temperature data is often small and presents a more regular change, therefore, according to the relationship between the changing trends of the temperature data and the voltage data, and the local changes of temperature data, determine the self-heating effect expression degree of the temperature value at each measuring moment in the measurement process, the self-heating effect expression degree reflects the degree to which the temperature deviation of the temperature data is caused by the interference of the self-heating effect of the sensor; according to the self-heating effect expression degree, determine each target measurement moment in the measurement process, the temperature deviation caused by the self-heating effect of the sensor and the current show a certain correlation, according to the change correlation between the self-heating effect expression degree and the current data at each target measurement moment, determine the self-heating effect temperature flow proportional coefficient, the self-heating effect temperature flow proportional coefficient reflects the sensitivity of the temperature deviation caused by the self-heating effect to the current change; finally, according to the self-heating effect expression degree, the self-heating effect temperature flow proportional coefficient and the current data, correct the temperature data to obtain the corrected temperature data of the measurement process. The present invention corrects the temperature data measured by the sensor according to the data change characteristics caused by the self-heating effect of the wireless temperature measuring sensor to eliminate the temperature deviation caused by the self-heating effect, so that the corrected temperature data can be obtained, which effectively improves the accuracy of temperature measurement. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings required for use in the embodiments or the prior art descriptions are briefly introduced below. 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 paying creative work.

[0045] Figure 1 A flowchart of a wireless temperature measurement method according to an embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram of the structure of a wireless temperature measurement sensor according to an embodiment of the present invention;

[0047] Figure 3 The figure is a schematic diagram of the structure of a wireless temperature measurement system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0048] In order to clearly illustrate the technical features of the present invention, the present invention is described in detail below through specific implementation methods in conjunction with the accompanying drawings.

[0049] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0050] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0051] The term "including" and its variations used herein are open inclusions, i.e., "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments". The relevant definitions of other terms will be given in the following description.

[0052] It should be noted that the concepts such as "first" and "second" mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0053] Although operations or steps are described in a specific order in the drawings in the embodiments of the present invention, it should not be understood that it is required to perform these operations or steps in the specific order shown or in a serial order, or that all the operations or steps shown must be performed to obtain the desired results. In the embodiments of the present invention, these operations or steps may be performed in series; these operations or steps may also be performed in parallel; or some of these operations or steps may be performed.

[0054] At the same time, it is understood that the data involved in the technical solution of the present invention (including but not limited to the data itself, the acquisition or use of the data) shall comply with the requirements of the relevant laws, regulations and relevant provisions. Unless otherwise defined, all technical and scientific terms used in the present invention have the same meanings as those generally understood by technicians in the technical field of the present invention, and all parameters or indicators in the formulas involved in the present invention are normalized values ​​that eliminate the influence of dimensions.

[0055] In order to solve the problem in the prior art that the accuracy of temperature measurement decreases due to the self-heating effect of the wireless temperature measurement sensor, an embodiment of the present invention provides a wireless temperature measurement method and a wireless temperature measurement sensor. By compensating for the temperature deviation caused by the self-heating effect of the wireless temperature measurement sensor, more accurate wireless temperature measurement data is obtained, thereby effectively improving the accuracy of temperature measurement by the wireless temperature measurement sensor.

[0056] A wireless temperature measurement method and a wireless temperature measurement sensor provided by an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0057] Figure 1 A basic flow chart of a wireless temperature measurement method provided by an embodiment of the present invention is shown as follows: Figure 1 As shown, the method specifically comprises the following steps:

[0058] Step S100: Acquire temperature data measured by the wireless temperature measuring sensor, current data of the power supply circuit during the measurement process of the wireless temperature measuring sensor, and voltage data across the thermistor of the sensor.

[0059] Specifically, with the continuous improvement of science and technology, the types of power equipment are becoming more and more abundant, there are more and more high-precision equipment, and the temperature requirements are becoming higher and higher. Different temperatures have a great impact on the equipment. For example, for transformer contacts, wireless temperature measurement methods are needed to achieve real-time temperature monitoring of the equipment.

[0060] Since wireless temperature sensors usually need to pass current through the sensor's thermistor to measure temperature during operation, the current passing through the resistor will generate heat, which will cause the temperature of the sensor to rise. This has nothing to do with the actual change in the temperature of the actual sensor monitoring device, but is caused by the self-heating effect generated by the current and resistance inside the sensor. Therefore, identifying how the self-heating effect of wireless temperature sensors causes temperature measurement errors, analyzing the impact of the self-heating effect on temperature measurement, and reducing this error can effectively improve the accuracy of temperature measurement data.

[0061] Therefore, in order to analyze the impact of the self-heating effect of the wireless temperature sensor on temperature measurement, a current sensor is installed in the power supply circuit of the existing wireless temperature sensor, such as at the power input end of the power supply circuit, to monitor the real-time current consumption of the wireless temperature sensor during operation; a voltage sensor is installed at both ends of the thermistor of the wireless temperature sensor to monitor the voltage change during operation of the wireless temperature sensor. The current sensor and the voltage sensor collect data at a set sampling frequency (such as 10Hz) to ensure that the dynamic changes of current and voltage during the operation of the sensor can be captured, and the collected current and voltage signals are converted into digital data through an analog-to-digital converter (ADC). The temperature data measured by the existing wireless temperature sensor and the converted current and voltage data are transmitted to a microprocessor (such as STM32). At the same time, a timestamp is used to record the sampling time of each data value in the three data, so as to obtain the measurement time of the temperature, current and voltage data, and a microprocessor (such as STM32) is used to preprocess the temperature, current and voltage data, such as using a low-pass filter (such as a moving average filter) to filter the data to remove high-frequency noise, and interpolate to fill in missing values, and then normalize the current, voltage and temperature data. The normalization method can be reasonably selected according to needs, for example, the maximum and minimum value normalization method can be used for normalization.

[0062] According to the above method, the temperature data measured by the wireless temperature sensor during each measurement process, the current data of the power supply circuit and the voltage data across the sensor thermistor during the measurement process, as well as the measurement time corresponding to each data value in these temperature data, current data and voltage data can be obtained. The subsequent microprocessor analyzes these temperature data, current data and voltage data, and corrects the collected temperature data according to the self-heating effect characteristics of the wireless temperature sensor to eliminate the temperature deviation caused by the self-heating effect, thereby finally obtaining the corrected accurate temperature data.

[0063] Step S200: determining the self-heating effect expression degree of the temperature value at each measuring moment in the measurement process according to the relationship between the change trends of the temperature data and the voltage data and the local change of the temperature data.

[0064] Specifically, in the process of wireless temperature measurement using a wireless temperature sensor, under normal working conditions, the voltage and resistance of the thermistor in the wireless temperature sensor will change according to the expected law as the temperature changes. This is determined based on the design principle of the sensor and is expressed as a fixed pattern under specific conditions. By comparing the voltage and temperature data collected in real time with the normal change relationship expected by the sensor, when the change of the real-time data does not meet expectations, such as the change of temperature does not match the change of voltage, it means that the real-time temperature data currently collected has an abnormal deviation. At the same time, the reason for the abnormal deviation of the real-time temperature data collected by the wireless temperature sensor during wireless temperature measurement may come from the influence of external environmental factors (such as electromagnetic interference, changes in ambient temperature and humidity, etc.) where the sensor is located, or it may be caused by the self-heating effect caused by the heat generated by the flow of current inside the sensor. The two sources are different, resulting in different temperature data deviation laws. The temperature deviation caused by external environmental factors is often disordered and fluctuates greatly, while the self-heating effect is always related to the current passing through the sensor, and often has small local fluctuations and presents a more regular change.

[0065] Therefore, based on the relationship between the changing trends of temperature data and voltage data, the abnormal deviation of the real-time temperature data collected by the wireless temperature sensor can be analyzed. At the same time, combined with the local changes in the real-time temperature data collected by the wireless temperature sensor, it is analyzed whether the abnormal deviation is caused by the interference of the self-heating effect of the sensor itself, so as to determine the self-heating effect expression degree of the real-time temperature data collected by the wireless temperature sensor. The self-heating effect expression degree reflects the degree to which the temperature deviation of the temperature data is caused by the interference of the self-heating effect of the sensor.

[0066] Furthermore, the self-heating effect performance degree of the temperature value at each measuring moment in the above-mentioned determination process is implemented by the following steps:

[0067] Analyze the relationship between the changing trends of temperature data and voltage data to determine the temperature deviation at each measuring moment during the measurement process;

[0068] Analyze the local fluctuation of temperature data and determine the background interference at each measurement moment during the measurement process;

[0069] The self-heating effect expression degree of the temperature value at each measuring moment in the measurement process is determined according to the background interference degree at each measuring moment in the measurement process and the temperature deviation degree of all measuring moments within the neighborhood time range of each measuring moment.

[0070] Specifically, on the one hand, the wireless temperature sensor uses a thermistor to measure temperature, and uses the characteristic that different resistance values ​​caused by different external temperatures of the sensor and Ohm's theorem to convert temperature changes into changes in voltage across the resistor. Therefore, based on the relationship between the overall change trends of temperature data and voltage data, the temperature-pressure change relationship index under normal circumstances can be determined to reflect the change relationship between temperature data and voltage data under normal circumstances; at the same time, based on the relationship between the change trends of temperature data and voltage data in a local time period, the temperature-pressure change relationship index of the temperature value at each measurement moment in the temperature data can be determined, and the temperature-pressure change relationship index is compared with the temperature-pressure change relationship index under normal circumstances, so that the temperature deviation of the temperature value at each measurement moment can be determined.

[0071] Furthermore, the above-mentioned determination of the temperature deviation at each moment in the measurement process includes: between all adjacent measurement moments in the measurement process, according to the difference between the first ratio of the voltage value and the temperature value at the latter measurement moment and the second ratio of the voltage value and the temperature value at the previous measurement moment, determining the first temperature-pressure change relationship index; between all adjacent measurement moments in the neighborhood time range of each measurement moment in the measurement process, according to the difference between the third ratio of the voltage value and the temperature value at the latter measurement moment and the fourth ratio of the voltage value and the temperature value at the previous measurement moment, determining the second temperature-pressure change relationship index at each measurement moment in the measurement process; according to the difference between the second temperature-pressure change relationship index and the first temperature-pressure change relationship index, determining the temperature deviation at each moment in the measurement process.

[0072] In some possible implementations, the first temperature-pressure change relationship index is determined according to the following formula:

[0073]

[0074] Where: G represents the first temperature-pressure change relationship index; N represents the total number of measurement moments during the measurement process of the wireless temperature sensor; E n and E n+1 They represent the voltage values ​​at the nth measurement time and the n+1th measurement time during the measurement process of the wireless temperature sensor respectively; W n and W n+1 They respectively represent the temperature values ​​at the nth measurement moment and the n+1th measurement moment in the measurement process of the wireless temperature sensor; exp represents an exponential function with a natural constant as the base.

[0075] In the above formula, It represents the average value of the ratio difference between the voltage value and the temperature value between all two adjacent measurement moments in the measurement process of the wireless temperature sensor. The average value of the ratio difference is used to characterize the corresponding change relationship between the voltage and temperature data under normal circumstances. The smaller the average difference, the more consistent the corresponding changes of the voltage and temperature data.

[0076] When the wireless temperature sensor is performing wireless temperature measurement, the resistance will generate heat when the current passes through the sensor, resulting in the internal temperature of the sensor being often higher than the actual temperature of the device to be measured due to the heating effect of the current, resulting in a self-heating effect that causes temperature deviation. The self-heating effect of the wireless temperature sensor increases the internal temperature of the sensor, thereby affecting the resistance and voltage response of the sensor, and changing the original corresponding change relationship between voltage and temperature. The change in resistance value caused by the external environment is different from the change in resistance value caused by the internal current, and its corresponding relationship with the voltage will also change. According to the corresponding change relationship between the voltage and temperature data of the wireless temperature sensor, combined with the corresponding change relationship between the voltage and temperature obtained locally, the temperature deviation can be obtained by comparison.

[0077] Therefore, for each measurement moment in the measurement process, the neighborhood time range of the measurement moment is obtained. For example, the measurement moment and the 9 measurement moments in the left and right neighborhoods can be used as the neighborhood time range of the measurement moment. Based on the voltage values ​​and temperature values ​​of all measurement moments in the neighborhood time range, the second temperature-pressure change relationship index can be determined in the same manner as the first temperature-pressure change relationship index. The temperature deviation corresponding to the measurement moment can be determined by comparing the second temperature-pressure change relationship index with the first temperature-pressure change relationship index.

[0078] In some possible implementations, the temperature deviation at each moment in the measurement process is determined by the following formula:

[0079] T i =|G i -G|;

[0080] Where: T i Indicates the temperature deviation at the i-th measurement moment during the measurement process; G i represents the second temperature-pressure change relationship index at the i-th measurement moment in the measurement process; G represents the first temperature-pressure change relationship index.

[0081] In the above formula, |G i -G| reflects the difference between the corresponding change relationship between the voltage and temperature data of the wireless temperature sensor at the i-th measurement moment during the measurement process and the corresponding change relationship between the voltage and temperature data under normal circumstances. The larger the difference value, the higher the degree of temperature deviation caused by the interference to the temperature sensor at this time.

[0082] On the other hand, in order to determine whether the temperature deviation of the wireless temperature sensor is caused by the influence of the self-heating effect of the wireless temperature sensor on the temperature measurement, rather than the influence of the external environmental factors (such as electromagnetic interference, changes in ambient temperature and humidity, etc.) in which the sensor is located, the local changes in the temperature data are analyzed to determine the background interference degree of the temperature data, which is used to reflect the degree to which the temperature deviation of the sensor is caused by the influence of external environmental factors. The greater the local change fluctuation of the temperature data, the higher the degree to which the temperature deviation of the sensor is caused by the influence of external environmental factors, rather than the degree caused by the influence of the self-heating effect on the temperature measurement.

[0083] Furthermore, the above-mentioned steps of determining the background interference degree at each moment in the measurement process include:

[0084] Determine the temperature mean and temperature variance of the temperature values ​​of all measurement moments within the neighborhood time range of each measurement moment during the measurement process;

[0085] The background interference degree at each measuring moment in the measurement process is determined by determining the difference between the temperature value at each measuring moment in the measurement process and the temperature mean value, and the temperature variance.

[0086] In some possible implementations, the background interference level at each moment in the measurement process is determined by the following formula:

[0087]

[0088] Where: B i represents the background interference degree at the i-th measurement moment during the measurement process; W i Indicates the temperature value at the i-th measurement moment during the measurement process; V represents the temperature mean of all the temperature values ​​at the measurement moments within the neighborhood time range of the i-th measurement moment in the measurement process, that is, the average value of the temperature values ​​at all the measurement moments. The neighborhood time range consists of the i-th measurement moment and its left and right neighborhoods, a total of 9 measurement moments; i It represents the temperature variance of the temperature values ​​at all measurement moments within the neighborhood time range of the i-th measurement moment in the measurement process, that is, the variance of the temperature values ​​at all measurement moments.

[0089] In the above formula, It represents the difference between the temperature value at the i-th measurement moment and the mean temperature in the neighborhood time range of the i-th measurement moment during the measurement process. The temperature deviation caused by the self-heating effect has a certain regularity. When the difference is larger and the temperature variance in the neighborhood time range is larger, it means that the temperature fluctuation at the i-th measurement moment is larger, and the degree to which the temperature deviation at the i-th measurement moment is caused by background interference is higher, and the corresponding background interference degree at the i-th measurement moment is larger.

[0090] Since the temperature data deviation caused by the self-heating effect of the wireless temperature sensor is usually associated with other sensor data, when the original data relationship is broken, but a certain change pattern is retained at the same time, that is, the corresponding change relationship between the local voltage and temperature data is different from the corresponding change relationship between the voltage and temperature data in general, but the local voltage data has a certain regularity, it means that the difference is caused by the interference of the sensor self-heating effect. Therefore, based on the temperature deviation obtained from the change of the voltage-temperature relationship, combined with the background interference, the self-heating effect expression of the temperature data can be obtained.

[0091] Furthermore, the self-heating effect performance degree of the temperature value at each measuring moment in the above-mentioned determination process is implemented by the following steps:

[0092] Determine the average temperature deviation of all temperature deviations between two adjacent measurement moments within the neighborhood time range of each measurement moment during the measurement process;

[0093] Perform negative correlation normalization processing on the background interference degree to obtain the processing result;

[0094] The product of the average temperature deviation at each measuring moment in the measuring process and the processing result is determined, thereby obtaining the self-heating effect expression degree of the temperature value at each measuring moment in the measuring process.

[0095] In some possible implementations, the self-heating effect performance at each measurement moment during the measurement process is determined by the following formula:

[0096]

[0097] Where: L i Indicates the degree of self-heating effect at the i-th measurement moment during the measurement process; B represents the average temperature deviation of all measurement moments in the neighborhood time range of the i-th measurement moment during the measurement process. The neighborhood time range consists of the i-th measurement moment and its left and right neighborhoods, a total of 9 measurement moments; i It represents the background interference degree at the i-th measurement moment in the measurement process; exp represents an exponential function with a natural constant as the base.

[0098] In the above formula, the smaller the background interference value is, the higher the degree to which the temperature difference is caused by the interference of the sensor's self-heating effect is. Therefore, an exponential function is used to perform negative correlation normalization processing on the background interference, and the processing result is multiplied by the average temperature deviation to correct the average temperature deviation, thereby obtaining the self-heating effect performance at each moment in the measurement process.

[0099] Step S300: determining each target measurement time in the measurement process according to the self-heating effect performance degree, and determining the self-heating effect temperature-flow proportionality coefficient according to the change correlation between the self-heating effect performance degree and the current data at each target measurement time.

[0100] Specifically, during the operation of the wireless temperature sensor, the current generates heat through the resistor, causing the temperature of the sensor to rise, thereby making the measured temperature higher. The high-power sensor and wireless communication module will aggravate the self-heating effect, causing the internal temperature to exceed the temperature of the actual device to be measured. The temperature deviation caused by the self-heating effect shows a certain correlation with the current. According to the correlation between the self-heating effect expression of the temperature data at the corresponding moment and the change in the current data, the self-heating effect temperature-flow proportional coefficient can be determined to reflect the correspondence between the deviation temperature caused by the self-heating effect of the sensor and the current data.

[0101] In order to analyze the correspondence between the deviation temperature and current data caused by the self-heating effect of the sensor, considering that the self-heating effect performance reflects the degree to which the temperature deviation of the temperature data is caused by the interference of the self-heating effect of the sensor, in some possible implementations, a set threshold can be set in advance, such as setting the set threshold value to 0.5, and then the self-heating effect performance at each measurement moment in the measurement process is compared with the set threshold, and the measurement moment in the measurement process when the self-heating effect performance is greater than the set threshold is used as the target measurement moment in the measurement process. In some other possible implementations, the Otsu threshold method can also be used to determine an adaptive threshold based on the self-heating effect performance at all measurement moments in the measurement process, and the measurement moment in the measurement process when the self-heating effect performance is greater than the adaptive threshold is used as the target measurement moment.

[0102] Furthermore, the above-mentioned steps of determining the temperature flow proportional coefficient of the self-heating effect according to the performance degree of the self-heating effect include:

[0103] Determine a fifth ratio of a first difference value of two self-heating effect manifestations and a second difference value of two current values ​​at each two adjacent target measurement moments during the measurement process to obtain a sub-self-heating effect temperature-flow proportionality coefficient;

[0104] The self-heating effect temperature flow proportional coefficient is determined according to the overall distribution level of the sub-self-heating effect temperature flow proportional coefficient corresponding to all two adjacent target measurement moments during the measurement process.

[0105] In some possible implementations, the self-heating effect temperature flow proportionality coefficient is determined by the following formula:

[0106]

[0107] Where: Q represents the temperature-current proportionality coefficient of the self-heating effect, that is, the proportionality coefficient of the temperature and current data measured when the self-heating effect of the wireless temperature sensor occurs; M represents the total number of all target measurement moments in the measurement process; L m and L m+1 I represents the self-heating effect performance at the mth and m+1th target measurement moments in the measurement process respectively; m and I m+1 They respectively represent the current values ​​at the mth and m+1th target measurement moments in the measurement process.

[0108] In the above formula, the first difference value is obtained by calculating the absolute value of the difference between the two self-heating effect manifestations at each adjacent target measurement moment in the measurement process, and the second difference value is obtained by calculating the absolute value of the difference between the corresponding two current values. The ratio of the first difference value to the second difference value is used as a sub-self-heating effect temperature flow proportional coefficient, and the average value of all sub-self-heating effect temperature flow proportional coefficients is used as the self-heating effect temperature flow proportional coefficient. The self-heating effect temperature flow proportional coefficient reflects the sensitivity of the temperature deviation generated by the self-heating effect to the current change.

[0109] Step S400: Correcting the temperature data according to the current data and the temperature-flow proportionality coefficient of the self-heating effect to obtain the corrected temperature data of the measurement process.

[0110] Specifically, when the wireless temperature sensor is affected by the current and produces self-heating effect, there is a certain correlation between the current data and the temperature deviation. When there is a temperature deviation caused by the self-heating effect, the self-heating effect temperature flow proportional coefficient reflects the sensitivity of the temperature deviation caused by the self-heating effect to the current change. At this time, based on the self-heating effect performance, the self-heating effect temperature flow proportional coefficient and the current data, and combined with the temperature data, the self-heating effect deviation value of the temperature data can be determined. The self-heating effect deviation value is used for temperature compensation, and the measured temperature data is corrected to eliminate the deviation caused by the self-heating effect, so that more accurate temperature data can be obtained after correction.

[0111] Furthermore, the temperature data is corrected according to the self-heating effect performance, the self-heating effect temperature-flow ratio coefficient and the current data to obtain the corrected temperature data of the measurement process, and the implementation steps include:

[0112] Determine the self-heating effect temperature deviation value at each target measurement moment according to the temperature value and self-heating effect performance degree at each target measurement moment, as well as the self-heating effect temperature-flow proportionality coefficient and the average current value at all measurement moments during the measurement process;

[0113] Determine the difference between the temperature value at each target measurement moment and the temperature deviation value of the self-heating effect, and obtain the corrected temperature value at each target measurement moment;

[0114] The corrected temperature value at each target measurement moment and the temperature data at other measurement moments except for each target measurement moment during the measurement process together constitute the corrected temperature data of the measurement process.

[0115] In some possible implementations, for a target measurement moment in the measurement process of the wireless temperature sensor, the self-heating effect temperature deviation value at each target measurement moment is determined by the following formula based on the temperature value and self-heating effect performance degree at each target measurement moment, the self-heating effect temperature-current proportionality coefficient, and the average current value at all measurement moments during the measurement process:

[0116]

[0117] In the formula: ΔW j W represents the temperature deviation value of the self-heating effect at the jth target measurement moment in the measurement process; j Indicates the temperature value at the jth target measurement moment in the measurement process; L j It represents the performance degree of the self-heating effect at the jth target measurement moment during the measurement process; Q represents the temperature flow proportional coefficient of the self-heating effect; Indicates the average current value at all measurement moments during the measurement process.

[0118] In the above formula, since the measured temperature under the influence of the self-heating effect will be higher than the actual temperature, in order to calculate the self-heating effect temperature deviation value, the self-heating effect expression degree at the target measurement moment is calculated and compared with the fitted self-heating effect expression degree at all measurement moments in the measurement process obtained by the self-heating effect temperature flow proportional coefficient. When the self-heating effect expression degree at the target measurement moment is higher than the fitted self-heating effect expression degree level, it means that more heat is generated at the target moment, resulting in a higher temperature, and the self-heating effect temperature deviation value is also relatively high. At the same time, the relative temperature measurement value of the sensor is offset. Combined with the influence weight of the temperature measurement value reflecting the temperature itself, that is, the self-heating effect will be more obvious at high temperature, then the actual temperature deviation value is higher, and the final self-heating effect temperature deviation value can be determined.

[0119] Since the temperature data measured by the wireless temperature sensor is often higher than the actual temperature of the monitored device after being affected by the self-heating effect, the self-heating effect temperature deviation value at each target measurement time is obtained through the above analysis. The temperature data at each target measurement time is temperature compensated by the following formula, and the measured value is corrected to eliminate the temperature deviation caused by the self-heating effect:

[0120] W′ j =W j -ΔW j ;

[0121] Where: W′ jrepresents the corrected temperature value at the jth target measurement time in the measurement process; W j Indicates the temperature value at the jth target measurement time in the measurement process; ΔW j Indicates the self-heating effect temperature deviation value at the jth target measurement moment in the measurement process.

[0122] According to the above method, the corrected temperature values ​​of all target measurement moments in the measurement process of the wireless temperature measurement sensor can be determined. These corrected temperature values ​​and the temperature data of other measurement moments except the target measurement moments in the measurement process together constitute the corrected temperature data of the measurement process.

[0123] After the microprocessor inside the wireless temperature sensor corrects the temperature data measured by the sensor and eliminates the temperature deviation caused by the self-heating effect of the sensor, the corrected accurate temperature data is stored in the local database, or transmitted to the cloud platform through a wireless communication module (such as Wi-Fi) to ensure the integrity and accuracy of the temperature measurement data. At the same time, the specific sampling time of each temperature value in the temperature data is recorded by using a timestamp to record and track the data for a long time, which is convenient for subsequent data analysis and management, and ensures that historical data can be retrieved at any time for review and comparison during the entire life cycle of the monitored equipment. In addition, the corrected accurate temperature data is displayed in real time through the user interface or monitoring platform, and the current status and historical trend information of the monitored equipment are intuitively presented in the form of temperature curves or charts. Through temperature data, trend analysis can be performed on the temperature changes of the monitored equipment, thereby predicting the operating status of the equipment and discovering potential problems. The combination of real-time monitoring and trend analysis not only improves the efficiency of equipment management, but also provides a scientific basis for predictive maintenance and decision support, thereby greatly reducing the failure rate and maintenance costs.

[0124] Based on the same inventive concept, the embodiment of the present invention also provides a wireless temperature measurement sensor, such as Figure 2 As shown, it includes a wireless temperature measuring sensor body, which refers to an existing wireless temperature measuring sensor. A microprocessor is installed in the wireless temperature measuring sensor body, a current sensor is installed in the power supply circuit of the wireless temperature measuring sensor body, and a voltage sensor is installed at both ends of the thermistor of the wireless temperature measuring sensor body. The microprocessor communicates and connects the current sensor and the voltage sensor. A computer program is stored in the microprocessor. When the microprocessor executes the computer program, any one of the wireless temperature measurement methods introduced above is implemented.

[0125] Based on the same inventive concept, the embodiment of the present invention also provides a wireless temperature measurement system, such as Figure 3As shown, the temperature measurement system includes: a memory 301, a processor 302, and a computer program 303 stored in the memory 301 and running on the processor 302, wherein when the processor 302 executes the computer program 303, the system can execute any one of the wireless temperature measurement methods introduced above.

[0126] The embodiment of the present invention can divide the system into functional modules according to the above method example. For example, each functional module can be corresponded to, or two or more functions can be integrated into one processing module. The above integrated module can be implemented in the form of hardware. It should be noted that the division of modules in this embodiment is schematic and is only a logical function division. There may be other division methods in actual implementation.

[0127] Based on the same inventive concept, an embodiment of the present invention further provides a computer program product, which includes: a computer program code, when the computer program code runs on a computer, the computer executes any one of the wireless temperature measurement methods introduced above.

[0128] Based on the same inventive concept, an embodiment of the present invention further provides a computer-readable storage medium, which stores a computer program code. When the computer program code runs on a computer, the computer executes any one of the wireless temperature measurement methods described above.

[0129] It should be noted that the above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and should all be included in the protection scope of the present invention.

Claims

1. A wireless temperature measurement method, characterized in that: The following steps are involved: Obtain temperature data measured by the wireless temperature sensor, current data of the power supply circuit during the measurement process of the wireless temperature sensor, and voltage data across the sensor thermistor; According to the relationship between the change trends of temperature data and voltage data, and the local change of temperature data, the self-heating effect expression degree of the temperature value at each measuring moment in the measurement process is determined; According to the self-heating effect performance degree, each target measurement time in the measurement process is determined, and according to the change correlation between the self-heating effect performance degree and the current data at each target measurement time, the self-heating effect temperature-flow proportionality coefficient is determined; The temperature data is corrected according to the self-heating effect performance, the self-heating effect temperature-flow proportionality coefficient and the current data to obtain the corrected temperature data of the measurement process.

2. A wireless temperature measurement method according to claim 1, characterized in that: Determine the self-heating effect representation of the temperature value at each measurement moment during the measurement process, including: Analyze the relationship between the changing trends of temperature data and voltage data to determine the temperature deviation at each measuring moment during the measurement process; Analyze the local fluctuation of temperature data and determine the background interference at each measurement moment during the measurement process; The self-heating effect expression degree of the temperature value at each measuring moment in the measurement process is determined according to the background interference degree at each measuring moment in the measurement process and the temperature deviation degree of all measuring moments within the neighborhood time range of each measuring moment.

3. A wireless temperature measurement method according to claim 2, characterized in that: Determine the temperature deviation at each measurement moment during the measurement process, including: During the measurement process, between all two adjacent measurement moments, a first temperature-pressure change relationship index is determined according to a difference between a first ratio of a voltage value to a temperature value at a later measurement moment and a second ratio of a voltage value to a temperature value at a previous measurement moment; Determine the second temperature-pressure change relationship index at each measurement moment in the measurement process according to the difference between the third ratio of the voltage value to the temperature value at the latter measurement moment and the fourth ratio of the voltage value to the temperature value at the previous measurement moment between all two adjacent measurement moments in the neighborhood time range of each measurement moment in the measurement process; The temperature deviation degree at each moment in the measurement process is determined according to the difference between the second temperature-pressure change relationship index and the first temperature-pressure change relationship index.

4. A wireless temperature measurement method according to claim 3, characterized in that: The process of determining the first temperature-pressure change relationship index and the second temperature-pressure change relationship index includes: determining an absolute value of a difference between the first ratio and the second ratio to obtain a first ratio difference; Performing negative correlation normalization processing on the mean of all first ratio differences between all two adjacent measurement moments during the measurement process to obtain a first temperature-pressure change relationship index; determining an absolute value of a difference between the third ratio and the fourth ratio to obtain a second ratio difference; The mean of all second ratio differences between all two adjacent measurement moments within the neighborhood time range of each measurement moment in the measurement process is subjected to negative correlation normalization processing to obtain the second temperature-pressure change relationship index.

5. A wireless temperature measurement method according to claim 2, characterized in that: Determine the background interference level at each measurement moment during the measurement process, including: Determine the temperature mean and temperature variance of the temperature values ​​of all measurement moments within the neighborhood time range of each measurement moment during the measurement process; The background interference degree at each measuring moment in the measurement process is determined by determining the difference between the temperature value at each measuring moment in the measurement process and the temperature mean value, and the temperature variance.

6. A wireless temperature measurement method according to claim 2, characterized in that: Determine the self-heating effect representation of the temperature value at each measurement moment during the measurement process, including: Determine the average temperature deviation of all temperature deviations between two adjacent measurement moments within the neighborhood time range of each measurement moment during the measurement process; Perform negative correlation normalization processing on the background interference degree to obtain the processing result; The product of the average temperature deviation at each measuring moment in the measuring process and the processing result is determined, thereby obtaining the self-heating effect expression degree of the temperature value at each measuring moment in the measuring process.

7. A wireless temperature measurement method according to claim 1, characterized in that: According to the self-heating effect performance, each target measurement time in the measurement process is determined, including: The self-heating effect performance degree at each measurement moment in the measurement process is compared with a set threshold, and the measurement moment in the measurement process when the self-heating effect performance degree is greater than the set threshold is used as the target measurement moment in the measurement process.

8. A wireless temperature measurement method according to claim 1, characterized in that: Determine the temperature flow proportionality coefficient of the self-heating effect, including: Determine a fifth ratio of a first difference value of two self-heating effect manifestations and a second difference value of two current values ​​at each two adjacent target measurement moments during the measurement process to obtain a sub-self-heating effect temperature-flow proportionality coefficient; The self-heating effect temperature flow proportional coefficient is determined according to the overall distribution level of the sub-self-heating effect temperature flow proportional coefficient corresponding to all two adjacent target measurement moments during the measurement process.

9. A wireless temperature measurement method according to claim 1, characterized in that: According to the current data and the temperature-flow ratio coefficient of the self-heating effect, the temperature data is corrected to obtain the corrected temperature data of the measurement process, including: According to the temperature value and self-heating effect performance at each target measurement moment, as well as the temperature-current proportionality coefficient of the self-heating effect and the average current value at all measurement moments during the measurement process; Determine the difference between the temperature value at each target measurement moment and the temperature deviation value of the self-heating effect, and obtain the corrected temperature value at each target measurement moment; The corrected temperature value at each target measurement moment and the temperature data at other measurement moments except for each target measurement moment during the measurement process together constitute the corrected temperature data of the measurement process.

10. A wireless temperature sensor, characterized in that: The wireless temperature measurement sensor includes a wireless temperature measurement sensor body, a microprocessor is installed in the wireless temperature measurement sensor body, a current sensor is installed in the power supply circuit of the wireless temperature measurement sensor body, a voltage sensor is installed at both ends of the thermistor of the wireless temperature measurement sensor body, the microprocessor is communicatively connected to the current sensor and the voltage sensor, a computer program is stored in the microprocessor, and the microprocessor executes the computer program to implement a wireless temperature measurement method as described in any one of claims 1 to 9.

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