Accurate on-resistance measurement method based on humidity fuzzy feedback

Abstract

The invention provides an accurate on-resistance measurement method based on humidity fuzzy feedback. A measurement system is formed by a high-precision nominal resistor with known resistance values, a direct-current voltage source, three voltmeters, a PLC programmable relay set with three switches, a humidity sensor and a to-be-measured on-circuit. 6 typical humidity environments are selected, voltmeter data are read through a computer control switch, the humidity drift coefficient of typical humidity is solved, and then a fuzzy system between the humidity and the humidity drift coefficient is established; controlling switching of a switch through a computer program, reading data of a voltmeter through multiple times of sampling, solving voltage ratio data of a to-be-measured resistor, designing a nonlinear digital filter to solve filtering data, and further solving an accurate value of the on resistance of the to-be-measured circuit under the real-time humidity; and the resistance value of the on-resistor to be measured under the reference humidity is solved according to the fuzzy system, and a resistance value calculation method of the on-resistor to be measured under the predicted humidity is given, so that resistance value prediction under different humidity is realized.

Description

Technical Field

[0001] The invention relates to the field of on-resistance measurement and circuit inverse analysis of complex electronic circuits, and in particular to an accurate on-resistance measurement method based on humidity fuzzy feedback. Background Art

[0002] The resistance of general materials decreases with the increase of temperature and humidity. In contrast, surface resistance is sensitive to environmental humidity, while bulk resistance is more sensitive to temperature. In some special systems, the precise value of the on-resistance of the circuit is very sensitive, such as pyrotechnics systems, fuse circuit systems, etc. The precise measurement and sensitive fluctuation of the above resistance will affect whether the entire system can be triggered and work normally. Therefore, its precise measurement plays an important role in the maintenance and guarantee of the entire system and the prediction and forecast of faults of the entire system. However, the environment in which the above systems are distributed is relatively harsh, with low temperature or high humidity. Therefore, the impact of environmental humidity factors must be considered for its accurate measurement. Based on the above background reasons, the present invention proposes a method of using a high-precision known resistor and a voltmeter voltage source to form a measurement circuit, and then establishing a fuzzy system through data from a typical humidity environment to achieve a special method for accurate measurement of the on-resistance of the circuit to be measured and fuzzy compensation and forecast of humidity. It is particularly useful for scenes where the measurement and prediction of resistance in an environment with relatively harsh environmental humidity are required, and thus has high engineering practical value.

[0003] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present invention, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the invention

[0004] The purpose of the present invention is to provide an accurate on-resistance measurement method based on humidity fuzzy feedback, thereby overcoming the problem of insufficient measurement accuracy of resistance affected by ambient humidity caused by traditional measurement methods.

[0005] According to one aspect of the present invention, a method for accurately measuring on-resistance based on humidity fuzzy feedback is provided, comprising the following six steps:

[0006] Step S10, select 4 high-precision 100-ohm resistors, 1 DC voltage source, 1 high-precision humidity-sensitive resistor of the same material as the resistor to be measured, 3 high-precision digital voltmeters, the on-resistance of the circuit to be measured, a PLC programmable relay group with at least 3 switches, an environmental humidity sensor, and a computer to build a measurement circuit.

[0007] Step S20, select 6 typical humidity environments, control the switch through the computer, read the voltage meter data, and solve the environmental humidity as the typical humidity t n Humidity drift coefficient.

[0008] Step S30, controlling the switch switching and multiple sampling to read the data of three voltmeters through a computer program, and solving the resistance-voltage ratio data of the circuit to be measured.

[0009] Step S40, designing a nonlinear digital filter for the resistance-to-voltage ratio data to be measured, filtering the resistance-to-voltage ratio data to be measured, and further solving the precise value of the on-resistance of the circuit to be measured under real-time humidity.

[0010] Step S50, establishing a humidity fuzzy system between the ambient humidity and the humidity drift coefficient according to the humidity drift coefficient under the typical humidity;

[0011] Step S60, according to the real-time humidity value and the humidity fuzzy system, solve the resistance value of the on-resistance of the circuit to be tested under the reference humidity; at the same time, according to the predicted humidity, run the humidity fuzzy system to solve the approximate humidity drift coefficient of the predicted humidity, and further solve the on-resistance value of the circuit to be tested under the predicted humidity.

[0012] In an exemplary embodiment of the present invention, four high-precision 100-ohm resistors are selected, as well as a DC voltage source, a high-precision humidity-sensitive resistor made of the same material as the resistor to be measured, three high-precision digital voltmeters, the on-resistance of the circuit to be measured, a PLC programmable relay group containing at least three switches, and an environmental humidity sensor, and a computer is used to build a measurement circuit, which includes: selecting four high-precision 100-ohm resistors, a DC voltage source, a high-precision humidity-sensitive resistor made of the same material as the on-resistance of the circuit to be measured, three high-precision digital voltmeters, the on-resistance of the circuit to be measured, a PLC programmable relay group containing at least three switches, and an environmental humidity sensor, a computer program controls the closure of the switches to form a measurement circuit, and a computer connects the digital voltmeter to read and process data; wherein the four 100-ohm resistors are respectively denoted as R1, R2, R3, and R5; the three switches of the PLC programmable relay group are respectively denoted as K1, K2, and K3, and the high-precision humidity-sensitive The resistor of the same material as the on-resistance of the circuit to be measured is recorded as Rs, and the on-resistance of the circuit to be measured is recorded as R; the measuring circuit is constructed as follows: the positive electrode of the current source is connected to one end of the switches K1, K2, and K3; and the other ends of the switches K1, K2, and K3 are respectively connected to the other ends of the resistors R1, R3, and R5; the other end of R1 is connected to the positive end of the first voltmeter and to one end of R2, the other end of R3 is connected to the positive end of the second voltmeter and to one end of the resistor Rs, and the other end of R5 is connected to the positive end of the third voltmeter and to one end of the on-resistance R of the measuring circuit; the negative electrode of the voltage source is grounded and connected to the other ends of R2, Rs and R respectively, and the negative electrodes of the three voltmeters are connected to the other ends of R2, Rs and R and to ground; and the three digital voltmeters, the environmental humidity sensor, and the PLC programmable relay group containing 3-way switches are connected to the program-controlled computer to realize the reading and storage of voltage and humidity data and switch control, thereby completing the construction of the entire measuring circuit system.

[0013] In an exemplary embodiment of the present invention, six typical humidity environments are selected, the switch is controlled by a computer, the voltage meter data is read, and the environmental humidity is solved as the typical humidity t n The humidity drift coefficient includes: select 6 typical humidity environments, record the environmental humidity as s1, s2...s6, where s1=1%, s2=20%, s3=40%, s4=60%, s5=80%, s6=99%; take the first typical humidity s1 as an example: first send instructions through the computer program to control switches K1 and K2 to be in a closed state and K3 to be in an open state, and use the computer to record the first voltmeter data as U 11 , the second voltmeter data is U 21; Then divide the two to get the humidity drift reference voltage ratio of typical humidity s1; Then, according to the humidity drift reference voltage ratio, solve the measured value of the humidity sensitive resistor of typical humidity s1; Then, according to the reference resistance value of the temperature sensitive resistor under the reference humidity, calculate the humidity drift coefficient of typical humidity s1; Then, use the same method to solve the ambient humidity for typical humidity s n The humidity drift reference voltage ratio, humidity sensitive resistance measured value, and humidity drift coefficient are as follows:

[0014]

[0015] Among them U 11 The first voltmeter data recorded by the computer when switches K1 and K2 are in the closed state and K3 is in the open state under the humidity s1 environment; U 21 The second voltmeter data recorded by the computer when the control switches K1 and K2 are in the closed state and K3 is in the open state under the humidity s1 environment; K1 is the humidity drift reference voltage ratio of the typical humidity s1; R t1 is the measured value of the humidity sensor resistance at typical humidity s1; R b The reference humidity b = 50% humidity sensor reference resistance; d1 is the humidity drift coefficient of typical humidity s1; U 1n Humidity n When the control switches K1 and K2 are in the closed state and K3 is in the open state, the first voltmeter data recorded by the computer is used; U 2n Humidity n When the control switches K1 and K2 are in the closed state and K3 is in the open state, the second voltmeter data recorded by the computer is used; K n Typical humidity n Humidity drift reference voltage ratio; R tn Typical humidity n The measured value of humidity sensitive resistance; d n Typical humidity n Humidity drift coefficient.

[0016] In an exemplary embodiment of the present invention, the switch switching and multiple sampling of three voltmeter data are controlled by a computer program to solve the resistance-voltage ratio data of the measured circuit to be measured, which includes: sending instructions through the computer program to control switches K1 and K3 to be in a closed state and K2 to be in an open state, and using a computer to record the first voltmeter data as U a1 (1); Record the third voltmeter data as U a3 (1); Then repeat the above operation m times, m>1500, and record 2m voltmeter data U at the same time a1 (i) U a3(i), 1≤i≤m, and then divide the two to obtain the resistance-voltage ratio data to be measured, as follows:

[0017]

[0018] Where K a1 (i) is the resistance-voltage ratio data to be measured.

[0019] In an exemplary embodiment of the present invention, a nonlinear digital filter is designed for the measured resistance voltage ratio data, the measured resistance voltage ratio filtering data, and further solving the accurate value of the on-resistance of the measured circuit under real-time humidity, including: setting the initial value of the measured resistance voltage ratio filtering data to K d1 (1) With K a1 (1) is the same; feedback comparison is then used to solve the voltage ratio filter error data of the resistance to be measured; fractional nonlinear transformation is then performed to obtain the voltage ratio filter error nonlinear transformation data; then integral iteration is performed to obtain the voltage ratio filter data of the resistance to be measured; then according to the voltage ratio filter data of the resistance to be measured, the average value of the data is first solved to obtain the voltage ratio filter mean data of the resistance to be measured; then the precise value of the on-resistance of the circuit to be measured under real-time humidity is solved according to the formula as follows:

[0020] e 1k (n) = K d1 (n)-K a1 (n);

[0021]

[0022] K d1 (n+1)=K d1 (n)+Te 1b (n);

[0023]

[0024] Among them, l1, l2, l3 are constant filtering parameters; e 1k (n) is the resistance-voltage ratio filtering error data to be measured; e 1b (n) is the voltage ratio filtering error nonlinear transformation data; K d1 (n) is the resistance-voltage ratio filtering data to be measured; T is the constant integral iteration parameter; K 1e is the filtered mean value data of the resistance voltage ratio to be measured; R e It is the precise value of the on-resistance of the circuit to be tested under real-time humidity.

[0025] In an exemplary embodiment of the present invention, according to the humidity drift coefficient under the typical humidity, establishing a humidity fuzzy system between the ambient humidity and the humidity drift coefficient includes: firstly defining five fuzzy concepts of the fuzzy system input humidity variable s, namely

[0026] s={HBMSO},

[0027] Among them, H means that the input humidity variable s is very large, B means that the input humidity variable s is large, M means that the input humidity variable s is medium, S means that the input humidity variable s is small, and O means that the input humidity variable s is very small; the details are as follows:

[0028] When 80%≤s<100%, the humidity s is considered to be very large;

[0029] When 60%≤s<80%, the humidity s is considered to be large;

[0030] When 40%≤s<60%, the humidity s is considered to be medium;

[0031] When 20%≤s<40%, the humidity s is considered to be small;

[0032] When 0≤s<20%, ​​the humidity s is considered to be very small;

[0033] Secondly, the fuzzy concept of the humidity drift coefficient d of the fuzzy system output is defined, which is also divided into the following five fuzzy concepts, namely

[0034] d(s)={H′B′M′S′O′}

[0035] Among them, H' indicates that the humidity drift coefficient d is very large, B' indicates that the humidity drift coefficient d is large, M' indicates that the humidity drift coefficient d is medium, S' indicates that the humidity drift coefficient d is small, and O' indicates that the humidity drift coefficient d is very small. The specific ones are selected in the design:

[0036] When d5<d(s)<d6, the humidity drift coefficient d is considered to be large;

[0037] When d4<d(s)<d5, the humidity drift coefficient d is considered to be large;

[0038] When d3<d(s)<d4, the humidity drift coefficient d is considered to be medium;

[0039] When d2<d(s)<d3, the humidity drift coefficient d is considered to be small;

[0040] When d1<d(s)<d2, the humidity drift coefficient d is considered to be very small;

[0041] Finally, five fuzzy rules are established for the above fuzzy system as follows:

[0042] When the input humidity variable s is very large, it is considered that the system output humidity drift coefficient d is also very large;

[0043] When the input humidity variable s is generally large, it is believed that the system output humidity drift coefficient d is also large;

[0044] When the input humidity variable s is medium, it is considered that the system output humidity drift coefficient d is also medium;

[0045] When the input humidity variable s is small, it is considered that the system output humidity drift coefficient d is also small;

[0046] When the input humidity variable s is very small, it is considered that the system output humidity drift coefficient d is also very small;

[0047] The membership function of the above fuzzy concepts, the generation of fuzzy rules and the defuzzification method are automatically generated using the default function form of the Matlab fuzzy toolbox.

[0048] In an exemplary embodiment of the present invention, according to the real-time humidity value and the humidity fuzzy system, the resistance value of the on-resistance of the circuit to be tested under the reference humidity is solved; at the same time, according to the predicted humidity, the humidity fuzzy system is operated to solve the approximate humidity drift coefficient of the predicted humidity, and further solving the resistance value of the on-resistance of the circuit to be tested under the predicted humidity includes: according to the current humidity s measured by the ambient humidity sensor a , and then run the fuzzy system to get the approximate humidity drift coefficient d of the current humidity a ; The precise value of the on-resistance of the circuit to be tested under real-time humidity, and the resistance value of the on-resistance of the circuit to be tested under reference humidity are reversed; at the same time, according to the predicted humidity s p , run the fuzzy system and solve the predicted humidity s p Approximate humidity drift coefficient d p Then, the predicted humidity s is solved according to the resistance value of the circuit under test at the reference humidity. p The on-resistance of the circuit under test is as follows:

[0049]

[0050] R pp =R bb d p ;

[0051] where d a is the current humidity s a Approximate humidity drift coefficient; d p To predict humidity s p The approximate humidity drift coefficient of bb The reference humidity of the on-resistance of the circuit to be tested is s b The resistance value under R pp To predict humidity s p The on-resistance value of the circuit under test.

[0052] Beneficial Effects

[0053] The present invention provides an accurate on-resistance measurement method based on humidity fuzzy feedback, and its main innovations are as follows. The first point is to propose a measurement circuit construction method composed of three voltmeters and a DC voltage source, a programmable relay group of three switches, an environmental humidity sensor, a high-precision resistor, and a computer. The circuit measurement system can introduce the environmental humidity factor into the calibration compensation of the measurement result. The second point is to establish a fuzzy system between the environmental humidity and the resistance humidity drift coefficient through the measurement data of a typical humidity environment, which can automatically convert the resistance drift coefficient under different humidity conditions; thereby realizing the prediction and forecast of the on-resistance value under standard humidity and other humidity environments, so as to facilitate the system operators to make timely and reasonable predictions and precautions.

[0054] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The accompanying drawings herein are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present invention, and together with the specification are used to explain the principles of the present invention. Obviously, the accompanying drawings described below are only some embodiments of the present invention, and for those of ordinary skill in the art, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0056] Figure 1 It is a flow chart of an accurate on-resistance measurement method based on humidity fuzzy feedback provided by the present invention;

[0057] Figure 2 is a schematic diagram of a measurement circuit principle of a method provided by an embodiment of the present invention;

[0058] Figure 3 is a resistance-to-voltage ratio filtering data curve (without unit) of the method provided in the embodiment of the present invention;

[0059] Figure 4 It is a fuzzy membership function graph of the input humidity variable s of the method provided in the embodiment of the present invention. DETAILED DESCRIPTION

[0060] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as being limited to the examples set forth herein; on the contrary, these embodiments are provided so that the present invention will be more comprehensive and complete, and the concept of the example embodiments will be fully conveyed to those skilled in the art. The described features, structures, or characteristics may be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present invention. However, those skilled in the art will appreciate that the technical solutions of the present invention may be practiced while omitting one or more of the specific details, or other methods, components, devices, steps, etc. may be adopted. In other cases, known technical solutions are not shown or described in detail to avoid blurring out various aspects of the present invention.

[0061] The invention provides an accurate on-resistance measurement method based on humidity fuzzy feedback. The method comprises a measuring system composed of a nominal resistor with known high-precision resistance, a direct current voltage source, three voltmeters, a PLC programmable relay group of a 3-way switch, a humidity sensor and an on-circuit to be measured. Firstly, six typical humidity environments are selected, and voltmeter data is read by a computer-controlled switch to solve the humidity drift coefficient of the typical humidity, and then a fuzzy system between the humidity and the humidity drift coefficient is established. Then, the computer program is used to control the switch switching and multiple sampling to read the voltmeter data, solve the voltage ratio data of the resistance to be measured of the circuit to be measured, design a nonlinear digital filter, filter the voltage ratio data of the resistance to be measured, and further solve the accurate value of the on-resistance of the circuit to be measured under the real-time humidity. Then, the temperature drift coefficient of the real-time humidity is solved according to the fuzzy system, and the resistance value of the on-resistance to be measured under the reference humidity is further solved, and a resistance value calculation method of the on-resistance to be measured under the predicted humidity is given, so as to realize the resistance value prediction under different humidity.

[0062] Next, we will combine the attached Figure 1 The present invention provides a method for accurately measuring on-resistance based on humidity fuzzy feedback, which is further explained and illustrated. Figure 1 As shown, the accurate on-resistance measurement method based on humidity fuzzy feedback includes the following steps:

[0063] Step S10 can be specifically divided into the following three steps.

[0064] The first step, such as Figure 2As shown, four high-precision 100-ohm resistors, a DC voltage source, a high-precision humidity-sensitive resistor made of the same material as the on-resistance of the circuit to be measured, three high-precision digital voltmeters, the on-resistance of the circuit to be measured, a PLC programmable relay group containing at least three switches, and an environmental humidity sensor are selected. The switch closure is controlled by a computer program to form a measuring circuit, and the computer is connected to the digital voltmeter to read and process data.

[0065] The second step is, Figure 2 As shown, the components are marked and numbered. The four 100 ohm resistors are marked as R1, R2, R3, and R5 respectively; the three switches of the PLC programmable relay group are marked as K1, K2, and K3 respectively; the high-precision humidity-sensitive resistor made of the same material as the on-resistance of the circuit to be tested is marked as Rs, and the on-resistance of the circuit to be tested is marked as R.

[0066] The third step is Figure 2 The circuit connections shown in the measurement principle diagram constitute the measurement circuit as follows: the positive electrode of the current source is connected to one end of the switches K1, K2, and K3; and the other ends of the switches K1, K2, and K3 are respectively connected to the other ends of the resistors R1, R3, and R5; the other end of R1 is connected to the positive end of the first voltmeter and to one end of R2, the other end of R3 is connected to the positive end of the second voltmeter and to one end of the resistor Rs, the other end of R5 is connected to the positive end of the third voltmeter and to one end of the on-resistance R of the measuring circuit; the negative electrode of the voltage source is grounded and connected to the other ends of R2, Rs and R respectively, and the negative electrodes of the three voltmeters are connected to the other ends of R2, Rs and R and to ground; and the three digital voltmeters, the environmental humidity sensor, and the PLC programmable relay group containing 3-way switches are connected to the program-controlled computer to realize the reading and storage of voltage and humidity data and switch control, thereby completing the construction of the entire measurement circuit system.

[0067] Step S20 can be specifically divided into the following six steps: Step 1, select 6 typical humidity environments and record the environmental humidity as s1, s2...s6, where s1 = 1%, s2 = 20%, s3 = 40%, s4 = 60%, s5 = 80%, s6 = 99%.

[0068] In the second step, taking the first typical humidity s1 as an example, first send instructions through the computer program to control switches K1 and K2 to be in a closed state and K3 to be in an open state, and use the computer to record the first voltmeter data as U 11 , the second voltmeter data is U 21 .

[0069] The third step is to divide the two to obtain the humidity drift reference voltage ratio of the typical humidity s1 as follows:

[0070]

[0071] Among them U 11 The first voltmeter data recorded by the computer when switches K1 and K2 are in the closed state and K3 is in the open state under the humidity s1 environment; U 21 The second voltmeter data recorded by the computer when the switches K1 and K2 are in a closed state and K3 is in an open state under the humidity s1 environment; K1 is the humidity drift reference voltage ratio of the typical humidity s1.

[0072] Step 4: Based on the humidity drift reference voltage ratio, the measured value of the humidity sensor resistance at typical humidity s1 is solved as follows:

[0073]

[0074] Where R t1 is the measured value of the humidity sensor at typical humidity s1.

[0075] Step 5. According to the reference resistance of thermistor under reference humidity, calculate the humidity drift coefficient of typical humidity s1 as follows:

[0076]

[0077] Where d1 is the humidity drift coefficient of the typical humidity s1; R b The reference humidity b =50% humidity sensor reference resistance.

[0078] Step 6: Use the same method to solve the ambient humidity as the typical humidity s n The humidity drift reference voltage ratio, humidity sensitive resistance measured value, and humidity drift coefficient are as follows:

[0079]

[0080] Among them U 1n Humidity n When the control switches K1 and K2 are in the closed state and K3 is in the open state, the first voltmeter data recorded by the computer is used; U 2n Humidity n When the control switches K1 and K2 are in the closed state and K3 is in the open state, the second voltmeter data recorded by the computer is used; K n Typical humidity n Humidity drift reference voltage ratio; R tn Typical humidity n The measured value of humidity sensitive resistance; d n Typical humidity nHumidity drift coefficient, n=1,2,3,4,5,6.

[0081] Step S30, specifically, can be decomposed into the following three steps. The first step is to send instructions through a computer program to control switches K1 and K3 to be in a closed state and K2 to be in an open state, and to use a computer to record the first voltage meter data as U a1 (1); Record the third voltmeter data as U a3 (1).

[0082] Step 2: Repeat the above operation m times, mω1500, and record 2m voltmeter data U at the same time. a1 (i) U a3 (i), 1≤i≤m.

[0083] The third step is to divide the 2m voltmeter data to obtain the resistance-to-voltage ratio data to be measured, as follows:

[0084]

[0085] Where K a1 (i) is the resistance-voltage ratio data to be measured.

[0086] Step S40, specifically, can be decomposed into the following six steps. The first step is to set the initial value of the measured resistance voltage ratio filter data to K d1 (1) With K a1 (1) The same.

[0087] In the second step, feedback comparison is used to solve the measured resistance voltage ratio filtering error data as follows:

[0088] e 1k (n) = K d1 (n)-K a1 (n);

[0089] where e 1k (n) is the resistance-voltage ratio filtering error data to be measured.

[0090] The third step is to perform fractional nonlinear transformation to obtain the voltage ratio filter error nonlinear transformation data as follows:

[0091]

[0092] where e 1b (n) is the voltage ratio filter error combination data, where l1, l2, and l3 are constant filter parameters.

[0093] The fourth step is to perform integration iteration to obtain the resistance-voltage ratio filtering data to be measured as follows:

[0094] K d1 (n+1)=Kd1 (n)+Te 1b (n);

[0095] Where K d1 (n) is the resistance-voltage ratio filtering data to be measured; T is the constant integral iteration parameter.

[0096] The fifth step is to first solve the average value of the data according to the measured resistance voltage ratio filtering data to obtain the measured resistance voltage ratio filtering mean data as follows:

[0097]

[0098] Where K 1e It is the filtered mean data of the resistance voltage ratio to be measured.

[0099] Step 6: Use the formula to solve the precise value of the on-resistance of the circuit to be tested under real-time humidity as follows:

[0100]

[0101] Where R e It is the precise value of the on-resistance of the circuit to be tested under real-time humidity.

[0102] In the present invention, m=3000, l1=2.5, l2=1.5, l3=1.5, T=0.001 are selected, and finally the measured resistance voltage ratio filtering data is obtained as follows: Figure 3 As shown, K is finally obtained 1e =2.862, R e =21.1685 ohms.

[0103] Step S50 can be specifically divided into the following four steps. The first step is to define five fuzzy concepts of the fuzzy system input humidity variable s, namely

[0104] s={HBMSO},

[0105] Among them, H means that the input humidity variable s is very large, B means that the input humidity variable s is large, M means that the input humidity variable s is medium, S means that the input humidity variable s is small, and O means that the input humidity variable s is very small; the details are as follows:

[0106] When 80%≤s<100%, the humidity s is considered to be very large;

[0107] When 60%≤s<80%, the humidity s is considered to be large;

[0108] When 40%≤s<60%, the humidity s is considered to be medium;

[0109] When 20%≤s<40%, the humidity s is considered to be small;

[0110] When 0≤s<20%, ​​the humidity s is considered to be very small.

[0111] The second step is to define the fuzzy concept of the humidity drift coefficient d of the fuzzy system output, which is also divided into the following five fuzzy concepts, namely

[0112] d(s)={H′B′M′S′O′}

[0113] Among them, H' indicates that the humidity drift coefficient d is very large, B' indicates that the humidity drift coefficient d is large, M' indicates that the humidity drift coefficient d is medium, S' indicates that the humidity drift coefficient d is small, and O' indicates that the humidity drift coefficient d is very small. The specific ones are selected in the design:

[0114] When d5<d(s)<d6, the humidity drift coefficient d is considered to be large;

[0115] When d4<d(s)<d5, the humidity drift coefficient d is considered to be large;

[0116] When d3<d(s)<d4, the humidity drift coefficient d is considered to be medium;

[0117] When d2<d(s)<d3, the humidity drift coefficient d is considered to be small;

[0118] When d1<d(s)<d2, the humidity drift coefficient d is considered to be very small.

[0119] The third step is to establish five fuzzy rules for the above fuzzy system as follows:

[0120] When the input humidity variable s is very large, it is considered that the system output humidity drift coefficient d is also very large;

[0121] When the input humidity variable s is generally large, it is believed that the system output humidity drift coefficient d is also large;

[0122] When the input humidity variable s is medium, it is considered that the system output humidity drift coefficient d is also medium;

[0123] When the input humidity variable s is small, it is considered that the system output humidity drift coefficient d is also small;

[0124] When the input humidity variable s is very small, it is considered that the system output humidity drift coefficient d is also very small.

[0125] The fourth step is to automatically generate the membership function of the above fuzzy concepts, the generation of fuzzy rules and the defuzzification method using the default function form of the Matlab fuzzy toolbox.

[0126] In the present invention, the fuzzy membership function graph of the input humidity variable s is as follows: Figure 4 shown.

[0127] Step S60 can be specifically divided into the following four steps: Step 1: According to the current humidity s measured by the ambient humidity sensor a , and then run the fuzzy system to get the approximate humidity drift coefficient d of the current humidity a .

[0128] The second step is to reversely calculate the resistance value of the on-resistance of the circuit to be tested under the reference humidity based on the precise value of the on-resistance of the circuit to be tested under the real-time humidity as follows:

[0129]

[0130] where d a is the current humidity s a The approximate humidity drift coefficient of bb The reference humidity of the on-resistance of the circuit to be tested is s b The resistance value below.

[0131] The third step is to calculate the predicted humidity s p , run the fuzzy system and solve the predicted humidity s p Approximate humidity drift coefficient d p .

[0132] Step 4: Calculate the predicted humidity s based on the resistance value of the circuit under test at the reference humidity. p The on-resistance of the circuit under test is as follows:

[0133] R pp =R bb d p ;

[0134] where d p To predict humidity s p The approximate humidity drift coefficient of pp To predict humidity s p The on-resistance value of the circuit under test.

[0135] In this case, the real-time humidity s = 42% degrees, and the reference humidity s of the on-resistance of the circuit to be tested is obtained. b =50% resistance R bb =21.0872; at the same time, select the predicted humidity t p =73, the on-resistance value of the circuit to be tested is calculated as R pp =20.6342 ohms. This case shows that the method provided by the present invention is completely feasible and is particularly suitable for complex systems that are sensitive to humidity or require accurate resistance measurement that takes humidity into consideration. It is a special environmental humidity compensation and prediction accurate resistance measurement method with a simple structure and convenient implementation, and has high engineering practical value.

Claims

1. A precise on-resistance measurement method based on humidity fuzzy feedback, characterized in that: The following steps are involved: Step S10, select 4 high-precision 100-ohm resistors, 1 DC voltage source, 1 high-precision humidity-sensitive resistor made of the same material as the on-resistance of the circuit to be measured, 3 high-precision digital voltmeters, the on-resistance of the circuit to be measured, a PLC programmable relay group containing at least 3 switches, and an environmental humidity sensor, and control the switch closure by a computer program to form a measurement circuit, and connect the digital voltmeter by a computer to read and process data; wherein the 4 100-ohm resistors are respectively denoted as R1, R2, R3, and R5; the 3-way switches of the PLC programmable relay group are respectively denoted as K1, K2, and K3, the high-precision humidity-sensitive resistor made of the same material as the on-resistance of the circuit to be measured is denoted as Rs, and the on-resistance of the circuit to be measured is denoted as R; the measurement circuit is constructed as follows: the positive pole of the current source is connected to switches K1, K2, and K3 one end of the switch; and the other ends of the switches K1, K2, and K3 are connected to the other ends of the resistors R1, R3, and R5 respectively; the other end of R1 is connected to the positive end of the first voltmeter and to one end of R2, the other end of R3 is connected to the positive end of the second voltmeter and to one end of the resistor Rs at the same time, the other end of R5 is connected to the positive end of the third voltmeter and to one end of the on-resistance R of the measuring circuit; the negative pole of the voltage source is grounded and connected to the other ends of R2, Rs and R respectively, and the negative poles of the three voltmeters are connected to the other ends of R2, Rs and R and grounded; and the three digital voltmeters, the environmental humidity sensor, and the PLC programmable relay group containing 3-way switches are connected to the program-controlled computer to realize the reading and storage of voltage and humidity data and the switch control, thereby completing the construction of the entire measurement circuit system; Step S20, select 6 typical humidity environments, record the environmental humidity as s1, s2...s6, where s1=1%, s2=20%, s3=40%, s4=60%, s5=80%, s6=99%; take the first typical humidity s1 as an example: first send instructions through the computer program to control switches K1 and K2 to be in a closed state and K3 to be in an open state, and use the computer to record the first voltmeter data as U 11 , the second voltmeter data is U 21 ; Then divide the two to get the humidity drift reference voltage ratio of typical humidity s1; Then, according to the humidity drift reference voltage ratio, solve the measured value of the humidity sensitive resistor of typical humidity s1; Then, according to the reference resistance value of the temperature sensitive resistor under the reference humidity, calculate the humidity drift coefficient of typical humidity s1; Then, use the same method to solve the ambient humidity for typical humidity s n The humidity drift reference voltage ratio, humidity sensitive resistance measured value, and humidity drift coefficient are as follows: Among them U 11 The first voltmeter data recorded by the computer when switches K1 and K2 are in the closed state and K3 is in the open state under the humidity s1 environment; U 21 The second voltmeter data recorded by the computer when the control switches K1 and K2 are in the closed state and K3 is in the open state under the humidity s1 environment; K1 is the humidity drift reference voltage ratio of the typical humidity s1; R t1 is the measured value of the humidity sensor resistance at typical humidity s1; R b The reference humidity b = 50% humidity sensor reference resistance; d1 is the humidity drift coefficient of typical humidity s1; U 1n Humidity n When the control switches K1 and K2 are in the closed state and K3 is in the open state, the first voltmeter data recorded by the computer is used; U 2n Humidity n When the control switches K1 and K2 are in the closed state and K3 is in the open state, the second voltmeter data recorded by the computer is used; K n Typical humidity n Humidity drift reference voltage ratio; R tn Typical humidity n The measured value of humidity sensitive resistance; d n Typical humidity n Humidity drift coefficient; Step S30, sending instructions through the computer program to control switches K1 and K3 to be in a closed state and K2 to be in an open state, and using the computer to record the first voltage meter data as U a1 (1); Record the third voltmeter data as U a3 (1); Then repeat the above operation m times, m>1500, and record 2m voltmeter data U at the same time a1 (i) U a3 (i), 1≤i≤m, and then divide the two to obtain the resistance-voltage ratio data to be measured, as follows: Where K a1 (i) is the resistance-voltage ratio data to be measured; Step S40, designing a nonlinear digital filter for the resistance-to-voltage ratio data to be measured; first setting the initial value of the resistance-to-voltage ratio filter data to be measured to K d1 (1) With K a1 (1) are the same; feedback comparison is then used to solve the measured resistance voltage ratio filtering error data; Then, fractional nonlinear transformation is performed to obtain nonlinear transformation data of voltage ratio filtering error; Then, an integral iteration is performed to obtain the resistance-voltage ratio filtering data to be measured; then, according to the resistance-voltage ratio filtering data to be measured, the average value of the data is first solved to obtain the resistance-voltage ratio filtering mean data to be measured; then, the precise value of the on-resistance of the circuit to be measured under real-time humidity is solved according to the formula as follows: e 1k (n)=K d1 (n)-K a1 (n); K d1 (n+1)=K d1 (n)+You 1b (n); Among them, l1, l2, l3 are constant filtering parameters; e 1k (n) is the resistance-voltage ratio filtering error data to be measured; e 1b (n) is the voltage ratio filtering error nonlinear transformation data; K d1 (n) is the resistance-voltage ratio filtering data to be measured; T is the constant integral iteration parameter; K 1e is the filtered mean value data of the resistance voltage ratio to be measured; R e It is the precise value of the on-resistance of the circuit to be tested under real-time humidity; Step S50, according to the typical humidity s n To model the humidity drift coefficient of the fuzzy system, we first define five fuzzy concepts of the fuzzy system input humidity variable s, namely: s={HBMSO}, Among them, H means that the input humidity variable s is very large, B means that the input humidity variable s is large, M means that the input humidity variable s is medium, S means that the input humidity variable s is small, and O means that the input humidity variable s is very small; the details are as follows: When 80%≤s<100%, the humidity s is considered to be very large; When 60%≤s<80%, the humidity s is considered to be large; When 40%≤s<60%, the humidity s is considered to be medium; When 20%≤s<40%, the humidity s is considered to be small; When 0≤s<20%, ​​the humidity s is considered to be very small; Secondly, the fuzzy concept of the humidity drift coefficient d of the fuzzy system output is defined, which is also divided into the following five fuzzy concepts, namely d(s)={H′B′M′S′O′} Among them, H' indicates that the humidity drift coefficient d is very large, B' indicates that the humidity drift coefficient d is large, M' indicates that the humidity drift coefficient d is medium, S' indicates that the humidity drift coefficient d is small, and O' indicates that the humidity drift coefficient d is very small. The specific ones are selected in the design: When d5<d(s)<d6, the humidity drift coefficient d is considered to be large; When d4<d(s)<d5, the humidity drift coefficient d is considered to be large; When d3<d(s)<d4, the humidity drift coefficient d is considered to be medium; When d2<d(s)<d3, the humidity drift coefficient d is considered to be small; When d1<d(s)<d2, the humidity drift coefficient d is considered to be very small; Finally, five fuzzy rules are established for the above fuzzy system as follows: When the input humidity variable s is very large, it is considered that the system output humidity drift coefficient d is also very large; When the input humidity variable s is generally large, it is believed that the system output humidity drift coefficient d is also large; When the input humidity variable s is medium, it is considered that the system output humidity drift coefficient d is also medium; When the input humidity variable s is small, it is considered that the system output humidity drift coefficient d is also small; When the input humidity variable s is very small, it is considered that the system output humidity drift coefficient d is also very small; Step S60: The current humidity s is measured by the ambient humidity sensor. a , and then run the fuzzy system to get the approximate humidity drift coefficient d of the current humidity a ; The precise value of the on-resistance of the circuit to be tested under real-time humidity, and the resistance value of the on-resistance of the circuit to be tested under reference humidity are reversed; at the same time, according to the predicted humidity s p , run the fuzzy system and solve the predicted humidity s p Approximate humidity drift coefficient d p Then, the predicted humidity s is solved according to the resistance value of the circuit under test at the reference humidity. p The on-resistance of the circuit under test is as follows: R pp =R bb d p ; where d a is the current humidity s a Approximate humidity drift coefficient; d p To predict humidity s p The approximate humidity drift coefficient of bb The reference humidity of the on-resistance of the circuit to be tested is s b The resistance value under R pp To predict humidity s p The on-resistance value of the circuit under test.

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