Voltage analog-to-digital conversion system based on multi-slope integral control

Abstract

The invention relates to the technical field of voltage analog-to-digital conversion systems, in particular to a voltage analog-to-digital conversion system based on multi-slope integral control, which comprises a voltage input interface, a control module, a multi-slope integral module, an analog-to-digital conversion module and a digital output interface which are in communication connection with one another, the voltage input interface is used for receiving a to-be-converted voltage signal and transmitting the to-be-converted voltage signal to the multi-slope integration module; the control module generates a plurality of time periods with variable slopes and transmits the time periods to the multi-slope integration module; the multi-slope integration module is used for integrating the voltage signal to be converted, obtaining the integrated voltage signal and transmitting the integrated voltage signal to the analog-to-digital conversion module, and the multi-slope integration module is also used for calculating a selection function of the number of operation times of the multi-slope integrator, obtaining the information of the number of operation times of the multi-slope integrator and transmitting the information to the control module; the analog-to-digital conversion module converts the integrated voltage signal into a digital signal and transmits the digital signal to the digital output interface. According to the system, the accuracy of integral operation of the multi-slope integrator can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of voltage analog-to-digital conversion systems, and in particular to a voltage analog-to-digital conversion system based on multi-slope integral control. Background Art

[0002] An analog-to-digital converter, also known as an A / D converter, or ADC for short, usually refers to an electronic component that converts analog signals into digital signals.

[0003] A traditional slope-integrating analog-to-digital converter operates by placing a charge proportional to the unknown voltage to be measured on a capacitor associated with an op-amp integrator, applying a reference voltage to discharge the integrator capacitor at a known rate and measuring the amount of discharge time, and finally calculating the unknown voltage as the ratio of the measured time to a predetermined time multiplied by the reference voltage.

[0004] Now many have been developed. After a lot of searching and reference, we found that the prior art is disclosed in US4574271A, US5321403A, and US07064694B1. These general integrators and converters integrate the input voltage signal and then convert the integrated voltage signal into a digital signal. In the actual conversion process, due to the influence of other factors during the conversion process, there will be a certain error in the conversion. Summary of the invention

[0005] The purpose of the present invention is to improve the conversion accuracy. In view of the above-mentioned shortcomings, a voltage analog-to-digital conversion system based on multi-slope integral control is proposed.

[0006] The present invention adopts the following technical solution:

[0007] A voltage analog-to-digital conversion system based on multi-slope integral control, the system comprising a voltage input interface, a control module, a multi-slope integral module, an analog-to-digital conversion module and a digital output interface that are communicatively connected to each other;

[0008] The voltage input interface is used to receive the voltage signal to be converted and transmit it to the multi-slope integration module;

[0009] The control module generates a plurality of time periods with variable slopes and transmits the generated time periods to the multi-slope integration module;

[0010] The multi-slope integration module integrates the voltage signal to be converted according to multiple time periods with variable slopes, obtains the integrated voltage signal and transmits it to the analog-to-digital conversion module, and the multi-slope integration module is also used to calculate the selection function of the number of multi-slope integrator operations, obtains the information of the number of multi-slope integrator operations and transmits it to the control module;

[0011] The analog-to-digital conversion module converts the integrated voltage signal into a digital signal and transmits it to the digital output interface;

[0012] The digital output interface is used to output digital signals;

[0013] The multi-slope integration module includes a multi-slope integrator, a multi-slope integration storage submodule, a multi-slope integration time submodule and a multi-slope integration calculation submodule which are communicatively connected to each other;

[0014] The multi-slope integrator receives a time signal with multiple slopes and a voltage signal to be converted and fits them into a linear graph. The multi-slope integrator obtains the value of the i-th slope, the time starting point of the i-th slope, the time ending point of the i-th slope and the duration of the i-th slope according to the linear graph and transmits them to the multi-slope integral calculation submodule. The multi-slope integrator integrates the voltage signal to be converted according to the time signal with multiple slopes to obtain the integrated voltage signal and transmits it to the analog-to-digital conversion module, wherein the value of the i-th slope is the slope of the i-th oblique line segment of the linear graph, the time starting point of the i-th oblique line segment is the time corresponding to the starting point of the i-th oblique line segment, and the time ending point of the i-th oblique line segment is the time corresponding to the ending point of the i-th oblique line segment;

[0015] The multi-slope integral storage submodule is used to store the information of the production year and the current year of the multi-slope integrator, and transmit it to the multi-slope integral calculation submodule;

[0016] The multi-slope integration time submodule is used to calculate the current continuous use time of the multi-slope integrator and the cumulative use time of the multi-slope integrator, and transmit them to the multi-slope integration calculation submodule, wherein the current continuous use time of the multi-slope integrator is the continuous use time of the multi-slope integrator after the last restart, and the cumulative use time is the cumulative sum of the time from the first use of the multi-slope integrator to the current use time;

[0017] The multi-slope integral calculation submodule calculates a first error coefficient according to information transmitted by the multi-slope integrator, the multi-slope integral storage submodule and the multi-slope integral time submodule, calculates a selection function of the number of multi-slope integrator operations according to the first error coefficient, and transmits information of the number of multi-slope integrator operations to the control module.

[0018] Optionally, when the multi-slope integral calculation submodule calculates the first error coefficient, the following formula is satisfied:

[0019]

[0020]

[0021]

[0022]

[0023] Among them, B is the first error coefficient, Z(K slope ) is the selection function of the slope error coefficient, I is the total number of slopes, K T1 is the usage time reference coefficient of the multi-slope integrator, α is the reference index of the multi-slope integrator, and α has the following values: α=1 or α=2. When the cumulative usage time of the multi-slope integrator is less than or equal to 10,000 hours, α=1; when the cumulative usage time of the multi-slope integrator is greater than 10,000 hours, α=2;

[0024] K slope is the slope error index, A i is the value of the i-th slope, T i is the time period of the i-th slope, is the starting value of the i-th slope, is the end point value of the i-th slope;

[0025] a1 to a m For different slope error coefficients, to are the thresholds of different slope error indices;

[0026] is the difference between the production year of the multi-slope integrator and the current year, This is the duration of the multi-slope integrator being used.

[0027] Optionally, when the multi-slope integral calculation submodule calculates the selection function of the number of multi-slope integrator operations, the following formula is satisfied:

[0028]

[0029] Where Y(B) is the selection function of the number of operations of the multi-slope integrator, d1 to d m For different multi-slope integrator operation times, b1 to b m-1 is the threshold of the first error coefficient.

[0030] Optionally, the analog-to-digital conversion module is also used to calculate a selection function of the number of operations of the analog-to-digital converter, and transmit information on the number of operations of the analog-to-digital converter to the control module.

[0031] Optionally, the analog-to-digital conversion module includes an analog-to-digital converter, an analog-to-digital conversion storage submodule, an analog-to-digital conversion time submodule, an analog-to-digital conversion calculation submodule, and a temperature monitoring submodule that are communicatively connected to each other;

[0032] The analog-to-digital converter converts the integrated voltage signal into a digital signal and transmits it to the digital output interface;

[0033] The analog-to-digital conversion storage submodule is used to store the interval reference coefficient, the number of bits of the analog-to-digital converter resolution, the maximum value of the analog-to-digital converter distinguishable signal amplitude, the clock stability reference coefficient, the production year of the analog-to-digital converter, and the current year information, and transmit it to the analog-to-digital conversion calculation submodule;

[0034] The analog-to-digital conversion time submodule is used to calculate the conversion time of the analog-to-digital converter, the current continuous use time of the analog-to-digital converter, and the time for the internal device to recover when the analog-to-digital converter is restarted, and transmit them to the analog-to-digital conversion calculation submodule;

[0035] The temperature monitoring submodule is used to monitor the ambient temperature and the operating temperature of the analog-to-digital converter, and transmit the results to the analog-to-digital conversion calculation submodule;

[0036] The analog-to-digital conversion calculation submodule calculates a second error coefficient based on information transmitted by the analog-to-digital conversion storage submodule, the analog-to-digital conversion time submodule and the temperature monitoring submodule, calculates a selection function of the number of analog-to-digital converter operations based on the second error coefficient, and transmits information on the number of analog-to-digital converter operations to the control module.

[0037] Optionally, when the analog-to-digital conversion calculation submodule calculates the second error coefficient, the following formula is satisfied:

[0038]

[0039]

[0040] K ots =ε g +T rst ;

[0041] Where E is the second error coefficient, β is the interval reference coefficient, β has the following values, β = 1 or β = 2, when the analog-to-digital converter has nonlinear characteristics, β = 2, when the analog-to-digital converter has linear characteristics, β = 1, N is the number of bits of the analog-to-digital converter resolution, μ max is the maximum value of the signal amplitude that the analog-to-digital converter can distinguish, ρ is the reference coefficient of clock stability, ρ has the following values, ρ = 1 or ρ = 2, when the clock stability is good ρ = 1, when the clock stability is poor ρ = 2, is the clock sampling frequency, T rt is the conversion time of the analog-to-digital converter, K is the time reference factor of the analog-to-digital converter. ots is the environmental error reference coefficient;

[0042] is the difference between the production year of the analog-to-digital converter and the current year, The current usage time of the analog-to-digital converter;

[0043] ε is the reference index of the ambient temperature, and ε has the following values: ε=1 or ε=2 or ε=3 or ε=4 or ε=5. When the range value of the ambient temperature is less than or equal to 25℃, ε=1; when the range value of the ambient temperature is greater than 25℃ to less than or equal to 28℃, ε=2; when the range value of the ambient temperature is greater than 28℃ to less than or equal to 31℃, ε=3; when the range value of the ambient temperature is greater than 31℃ to less than or equal to 34℃, ε=4; when the range value of the ambient temperature is greater than 34℃, ε=5. g is the reference index of the working state of the analog-to-digital converter, and g has the following values: g=1 or g=2. When the analog-to-digital converter is overheated, g=2; when the analog-to-digital converter is in normal working state, g=1. T rst is the reference index of restart time, T rst The values ​​are as follows: T rst =1 or T rst =2 or T rst =3 or T rst =4 or T rst =5, when the time range for the internal device to recover when the analog-to-digital converter is restarted is less than or equal to 30s T rst =1, when the time range of the internal device recovery when the analog-to-digital converter restarts is greater than 30s and less than or equal to 60s T rst = 2, when the time range of the internal device recovery when the analog-to-digital converter restarts is greater than 60s and less than or equal to 90s T rst =3, when the time range of the internal device recovery when the analog-to-digital converter restarts is greater than 90s and less than or equal to 120s T rst =4, when the time range of the internal device recovery when the analog-to-digital converter restarts is greater than 120s T rst =5.

[0044] Optionally, when the analog-to-digital conversion calculation submodule calculates the selection function of the number of analog-to-digital converter operations, the following formula is satisfied:

[0045]

[0046] Where X(E) is the selection function of the number of operations of the analog-to-digital converter, f1 to f m The number of operations of the analog-to-digital converter is different, e1 to e m-1 is the threshold of the second error coefficient.

[0047] The beneficial effects achieved by the present invention are:

[0048] 1. The multi-slope integral calculation submodule calculates a first error coefficient according to information transmitted by the multi-slope integrator, the multi-slope integral storage submodule and the multi-slope integral time submodule, calculates a selection function of the number of operations of the multi-slope integrator according to the first error coefficient, and transmits information of the number of operations of the multi-slope integrator to the control module to improve the accuracy of the integral operation of the multi-slope integrator;

[0049] 2. The analog-to-digital conversion calculation submodule calculates the second error coefficient based on the information transmitted by the analog-to-digital conversion storage submodule, the analog-to-digital conversion time submodule and the temperature monitoring submodule, calculates the selection function of the number of analog-to-digital converter operations based on the second error coefficient, and transmits the information of the number of analog-to-digital converter operations to the control module to improve the accuracy of the analog-to-digital converter conversion.

[0050] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0052] Figure 2 It is a structural schematic diagram of the analog-to-digital conversion module in the present invention;

[0053] Figure 3 is a linear graph fitted by the multi-slope integrator in the present invention;

[0054] Figure 4 It is a schematic diagram of the overall structure of the second embodiment of the present invention. DETAILED DESCRIPTION

[0055] The following is an explanation of the embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual dimensions. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention.

[0056] Embodiment 1: This embodiment provides a voltage analog-to-digital conversion system based on multi-slope integral control, combined with Figure 1 and Figure 2 and Figure 3 .

[0057] A voltage analog-to-digital conversion system based on multi-slope integral control, the system comprising a voltage input interface, a control module, a multi-slope integral module, an analog-to-digital conversion module and a digital output interface that are communicatively connected to each other;

[0058] The voltage input interface is used to receive the voltage signal to be converted and transmit it to the multi-slope integration module;

[0059] The control module generates a plurality of time periods with variable slopes and transmits the generated time periods to the multi-slope integration module;

[0060] The multi-slope integration module integrates the voltage signal to be converted according to multiple time periods with variable slopes, obtains the integrated voltage signal and transmits it to the analog-to-digital conversion module, and the multi-slope integration module is also used to calculate the selection function of the number of multi-slope integrator operations, obtains the information of the number of multi-slope integrator operations and transmits it to the control module;

[0061] The analog-to-digital conversion module converts the integrated voltage signal into a digital signal and transmits it to the digital output interface;

[0062] The digital output interface is used to output digital signals;

[0063] The multi-slope integration module includes a multi-slope integrator, a multi-slope integration storage submodule, a multi-slope integration time submodule and a multi-slope integration calculation submodule which are communicatively connected to each other;

[0064] The multi-slope integrator receives a time signal with multiple slopes and a voltage signal to be converted and fits it into Figure 3 The linear graph shown in the figure, the multi-slope integrator obtains the value of the i-th slope, the time starting point of the i-th slope, the time end point of the i-th slope and the duration of the i-th slope according to the linear graph and transmits them to the multi-slope integral calculation submodule, the multi-slope integrator integrates the voltage signal to be converted according to the time signal with multiple slopes, obtains the integrated voltage signal and transmits it to the analog-to-digital conversion module; specifically, the value of the i-th slope is the slope of the line segment corresponding to the i-th oblique line segment of the linear graph, the time starting point of the i-th oblique line segment is the time corresponding to the starting point of the corresponding line segment, the time end point of the i-th oblique line segment is the time corresponding to the end point of the corresponding line segment, and the duration of the i-th oblique line segment is the time difference between the time end point and the time starting point of the corresponding line segment, combined with Figure 3 Note: Taking i=1 as an example, the value of Tb minus Ta in the figure is the duration of the first slope, Ta is the time starting point of the first slope, Tb is the time end point of the first slope, and the slope of the line segment corresponding to Ta to Tb is the value of the first slope.

[0065] The multi-slope integral storage submodule is used to store the information of the production year and the current year of the multi-slope integrator, and transmit it to the multi-slope integral calculation submodule;

[0066] The multi-slope integration time submodule is used to calculate the current continuous use time of the multi-slope integrator and the cumulative use time of the multi-slope integrator, and transmit them to the multi-slope integration calculation submodule; specifically, the current continuous use time of the multi-slope integrator is the continuous use time of the multi-slope integrator after the last restart, and the cumulative use time of the multi-slope integrator is the cumulative sum of the time from the first use of the multi-slope integrator to the current use time;

[0067] The multi-slope integral calculation submodule calculates a first error coefficient according to information transmitted by the multi-slope integrator, the multi-slope integral storage submodule and the multi-slope integral time submodule, calculates a selection function of the number of multi-slope integrator operations according to the first error coefficient, and transmits information of the number of multi-slope integrator operations to the control module.

[0068] Optionally, when the multi-slope integral calculation submodule calculates the first error coefficient, the following formula is satisfied:

[0069]

[0070]

[0071]

[0072]

[0073] Among them, B is the first error coefficient, Z(K slope ) is the selection function of the slope error coefficient, I is the total number of slopes, is the usage time reference coefficient of the multi-slope integrator, α is the reference index of the multi-slope integrator, α is preset by a person skilled in the art based on experience, and α has the following values, α=1 or α=2, when the cumulative usage time of the multi-slope integrator is less than or equal to 10,000 hours, α=1, when the cumulative usage time of the multi-slope integrator is greater than 10,000 hours, α=2;

[0074] K slope is the slope error index, A i is the value of the i-th slope, T i is the time period of the i-th slope, is the starting value of the i-th slope, is the end point value of the i-th slope;

[0075] a1 to a m For different slope error coefficients, to are thresholds of different slope error indices, which are preset by those skilled in the art based on experience;

[0076] is the difference between the production year of the multi-slope integrator and the current year, This is the duration of the multi-slope integrator being used.

[0077] Optionally, when the multi-slope integral calculation submodule calculates the selection function of the number of multi-slope integrator operations, the following formula is satisfied:

[0078]

[0079] Where Y(B) is the selection function of the number of operations of the multi-slope integrator, d1 to d m For different multi-slope integrator operation times, b1 to b m-1 is the threshold of the first error coefficient, which is preset by those skilled in the art based on experience.

[0080] Optionally, the analog-to-digital conversion module is also used to calculate a selection function of the number of operations of the analog-to-digital converter, and transmit information on the number of operations of the analog-to-digital converter to the control module.

[0081] Optionally, the analog-to-digital conversion module includes an analog-to-digital converter, an analog-to-digital conversion storage submodule, an analog-to-digital conversion time submodule, an analog-to-digital conversion calculation submodule, and a temperature monitoring submodule that are communicatively connected to each other;

[0082] The analog-to-digital converter converts the integrated voltage signal into a digital signal and transmits it to the digital output interface;

[0083] The analog-to-digital conversion storage submodule is used to store the interval reference coefficient, the number of bits of the analog-to-digital converter resolution, the maximum value of the analog-to-digital converter distinguishable signal amplitude, the clock stability reference coefficient, the production year of the analog-to-digital converter, and the current year information, and transmit it to the analog-to-digital conversion calculation submodule;

[0084] The analog-to-digital conversion time submodule is used to calculate the conversion time of the analog-to-digital converter, the current continuous use time of the analog-to-digital converter, and the time for the internal device to recover when the analog-to-digital converter is restarted, and transmit them to the analog-to-digital conversion calculation submodule;

[0085] The temperature monitoring submodule is used to monitor the ambient temperature and the operating temperature of the analog-to-digital converter, and transmit the results to the analog-to-digital conversion calculation submodule;

[0086] The analog-to-digital conversion calculation submodule calculates a second error coefficient based on information transmitted by the analog-to-digital conversion storage submodule, the analog-to-digital conversion time submodule and the temperature monitoring submodule, calculates a selection function of the number of analog-to-digital converter operations based on the second error coefficient, and transmits information on the number of analog-to-digital converter operations to the control module.

[0087] Optionally, when the analog-to-digital conversion calculation submodule calculates the second error coefficient, the following formula is satisfied:

[0088]

[0089]

[0090] K ots =ε g +T rst ;

[0091] Wherein, E is the second error coefficient, β is the interval reference coefficient, which is preset by those skilled in the art based on experience, and β has the following values, β=1 or β=2, when the analog-to-digital converter has nonlinear characteristics, β=2, when the analog-to-digital converter has linear characteristics, β=1, N is the number of bits of the analog-to-digital converter resolution, μ max is the maximum value of the signal amplitude that the analog-to-digital converter can distinguish, and ρ is the reference coefficient of clock stability, which is preset by technicians in this field based on experience. ρ has the following values: ρ = 1 or ρ = 2. When the clock stability is good, ρ = 1; when the clock stability is poor, ρ = 2. is the clock sampling frequency, T rt is the conversion time of the analog-to-digital converter, K is the time reference factor of the analog-to-digital converter. ots is the environmental error reference coefficient;

[0092] is the difference between the production year of the analog-to-digital converter and the current year, The current usage time of the analog-to-digital converter;

[0093] ε is a reference index of ambient temperature, which is preset by those skilled in the art based on experience. ε has the following values: ε=1 or ε=2 or ε=3 or ε=4 or ε=5. When the range value of ambient temperature is less than or equal to 25°C, ε=1; when the range value of ambient temperature is greater than 25°C to less than or equal to 28°C, ε=2; when the range value of ambient temperature is greater than 28°C to less than or equal to 31°C, ε=3; when the range value of ambient temperature is greater than 31°C to less than or equal to 34°C, ε=4; when the range value of ambient temperature is greater than 34°C, ε=5. g is a reference index of the working state of the analog-to-digital converter, which is preset by those skilled in the art based on experience. g has the following values: g=1 or g=2. When the analog-to-digital converter is overheated, g=2; when the analog-to-digital converter is in normal working state, g=1. Those skilled in the art set different overheat temperatures according to different types of analog-to-digital converters, generally by monitoring the temperature inside the analog-to-digital converter. T rst is the reference index of restart time, T rst The values ​​are as follows: T rst=1 or T rst =2 or T rst =3 or T rst =4 or T rst =5, when the time range for the internal device to recover when the analog-to-digital converter is restarted is less than or equal to 30s T rst =1, when the time range of the internal device recovery when the analog-to-digital converter restarts is greater than 30s and less than or equal to 60s T rst = 2, when the time range of the internal device recovery when the analog-to-digital converter restarts is greater than 60s and less than or equal to 90s T rst =3, when the time range of the internal device recovery when the analog-to-digital converter restarts is greater than 90s and less than or equal to 120s T rst =4, when the time range of the internal device recovery when the analog-to-digital converter restarts is greater than 120s T rst =5.

[0094] Optionally, when the analog-to-digital conversion calculation submodule calculates the selection function of the number of analog-to-digital converter operations, the following formula is satisfied:

[0095]

[0096] Where X(E) is the selection function of the number of operations of the analog-to-digital converter, f1 to f m The number of operations of the analog-to-digital converter is different, e1 to e m-1 is the threshold of the second error coefficient.

[0097] This embodiment solves the problem of large conversion error in traditional voltage analog-to-digital conversion systems through simple circuit design. Specifically, a first error coefficient is calculated by a multi-slope integral calculation submodule based on information transmitted by a multi-slope integrator, a multi-slope integral storage submodule and a multi-slope integral time submodule, a selection function of the number of operations of the multi-slope integrator is calculated based on the first error coefficient, and the information of the number of operations of the multi-slope integrator is transmitted to a control module to improve the accuracy of the integral operation of the multi-slope integrator; in addition, a second error coefficient is calculated by an analog-to-digital conversion calculation submodule based on information transmitted by an analog-to-digital conversion storage submodule, an analog-to-digital conversion time submodule and a temperature monitoring submodule, a selection function of the number of operations of the analog-to-digital converter is calculated based on the second error coefficient, and the information of the number of operations of the analog-to-digital converter is transmitted to the control module to improve the accuracy of the conversion of the analog-to-digital converter.

[0098] Embodiment 2: This embodiment includes all the contents of embodiment 1, and provides a voltage analog-to-digital conversion system based on multi-slope integral control, combined with Figure 4 shown.

[0099] The output signal output by the digital output interface is transmitted to the control module, and the control module calculates the reference value of the output voltage and the selection function of the total number of operations.

[0100] When the control module calculates the reference value of the output voltage, the following formula is satisfied:

[0101]

[0102] W = max(Y(B), X(E));

[0103] Among them, V ref is the reference value of the output voltage, V out is the output value of the actual voltage, that is, the output signal output by the digital output interface, and W is the selection function of the total number of operations.

[0104] This embodiment solves the conversion error problem existing in the traditional voltage analog-to-digital conversion system. Specifically, the control module calculates the selection function of the total number of operations, and then sums and averages the reference values ​​of the multiple output voltages, thereby obtaining a more accurate reference value of the output voltage. This embodiment is easy to implement, has low requirements on hardware equipment, is easy to transplant, and has strong versatility.

[0105] The contents disclosed above are only preferred feasible embodiments of the present invention, and do not limit the protection scope of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention description and drawings are included in the protection scope of the present invention. In addition, the elements therein can be updated as technology develops.

Claims

1. A voltage analog-to-digital conversion system based on multi-slope integral control, characterized in that: The system includes a voltage input interface, a control module, a multi-slope integration module, an analog-to-digital conversion module and a digital output interface that are communicatively connected to each other; The voltage input interface is used to receive the voltage signal to be converted and transmit it to the multi-slope integration module; The control module generates a plurality of time periods with variable slopes and transmits the generated time periods to the multi-slope integration module; The multi-slope integration module integrates the voltage signal to be converted according to multiple time periods with variable slopes, obtains the integrated voltage signal and transmits it to the analog-to-digital conversion module, and the multi-slope integration module is also used to calculate the selection function of the number of multi-slope integrator operations, obtains the information of the number of multi-slope integrator operations and transmits it to the control module; The analog-to-digital conversion module converts the integrated voltage signal into a digital signal and transmits it to the digital output interface; The digital output interface is used to output digital signals; The multi-slope integration module includes a multi-slope integrator, a multi-slope integration storage submodule, a multi-slope integration time submodule and a multi-slope integration calculation submodule which are communicatively connected to each other; The multi-slope integrator receives a time signal with multiple slopes and a voltage signal to be converted and fits them into a linear graph. The multi-slope integrator obtains the value of the i-th slope, the time starting point of the i-th slope, the time ending point of the i-th slope and the duration of the i-th slope according to the linear graph and transmits them to the multi-slope integral calculation submodule. The multi-slope integrator integrates the voltage signal to be converted according to the time signal with multiple slopes to obtain the integrated voltage signal and transmits it to the analog-to-digital conversion module, wherein the value of the i-th slope is the slope of the i-th oblique line segment of the linear graph, the time starting point of the i-th oblique line segment is the time corresponding to the starting point of the i-th oblique line segment, and the time ending point of the i-th oblique line segment is the time corresponding to the ending point of the i-th oblique line segment; The multi-slope integral storage submodule is used to store the information of the production year and the current year of the multi-slope integrator, and transmit it to the multi-slope integral calculation submodule; The multi-slope integration time submodule is used to calculate the current continuous use time of the multi-slope integrator and the cumulative use time of the multi-slope integrator, and transmit them to the multi-slope integration calculation submodule, wherein the current continuous use time of the multi-slope integrator is the continuous use time of the multi-slope integrator after the last restart, and the cumulative use time is the cumulative sum of the time from the first use of the multi-slope integrator to the current use time; The multi-slope integral calculation submodule calculates a first error coefficient according to information transmitted by the multi-slope integrator, the multi-slope integral storage submodule and the multi-slope integral time submodule, calculates a selection function of the number of multi-slope integrator operations according to the first error coefficient, and transmits information of the number of multi-slope integrator operations to the control module.

2. A voltage analog-to-digital conversion system based on multi-slope integral control as claimed in claim 1, characterized in that: When the multi-slope integral calculation submodule calculates the first error coefficient, the following formula is satisfied: Among them, B is the first error coefficient, Z(K slope ) is the selection function of the slope error coefficient, I is the total number of slopes, is the usage time reference coefficient of the multi-slope integrator, α is the reference index of the multi-slope integrator, and α has the following values: α=1 or α=2. When the cumulative usage time of the multi-slope integrator is less than or equal to 10,000 hours, α=1; when the cumulative usage time of the multi-slope integrator is greater than 10,000 hours, α=2; K slope is the slope error index, A i is the value of the i-th slope, T i is the time period of the i-th slope, is the starting value of the i-th slope, is the end point value of the i-th slope; a1 to a m For different slope error coefficients, to are the thresholds for different slope error indices; is the difference between the production year of the multi-slope integrator and the current year, This is the duration of the multi-slope integrator being used.

3. A voltage analog-to-digital conversion system based on multi-slope integral control as claimed in claim 2, characterized in that: When the multi-slope integral calculation submodule calculates the selection function of the number of multi-slope integrator operations, the following formula is satisfied: Where Y(B) is the selection function of the number of operations of the multi-slope integrator, d1 to d m For different multi-slope integrator operation times, b1 to b m-1 is the threshold of the first error coefficient.

4. A voltage analog-to-digital conversion system based on multi-slope integral control as claimed in claim 3, characterized in that: The analog-to-digital conversion module is also used to calculate a selection function of the number of operations of the analog-to-digital converter, and transmit information on the number of operations of the analog-to-digital converter to the control module.

5. A voltage analog-to-digital conversion system based on multi-slope integral control as claimed in claim 4, characterized in that: The analog-to-digital conversion module includes an analog-to-digital converter, an analog-to-digital conversion storage submodule, an analog-to-digital conversion time submodule, an analog-to-digital conversion calculation submodule, and a temperature monitoring submodule that are interconnected and communicated with each other; The analog-to-digital converter converts the integrated voltage signal into a digital signal and transmits it to the digital output interface; The analog-to-digital conversion storage submodule is used to store the interval reference coefficient, the number of bits of the analog-to-digital converter resolution, the maximum value of the analog-to-digital converter distinguishable signal amplitude, the clock stability reference coefficient, the production year of the analog-to-digital converter, and the current year information, and transmit it to the analog-to-digital conversion calculation submodule; The analog-to-digital conversion time submodule is used to calculate the conversion time of the analog-to-digital converter, the current continuous use time of the analog-to-digital converter, and the time for the internal device to recover when the analog-to-digital converter is restarted, and transmit them to the analog-to-digital conversion calculation submodule; The temperature monitoring submodule is used to monitor the ambient temperature and the operating temperature of the analog-to-digital converter, and transmit the results to the analog-to-digital conversion calculation submodule; The analog-to-digital conversion calculation submodule calculates a second error coefficient based on information transmitted by the analog-to-digital conversion storage submodule, the analog-to-digital conversion time submodule and the temperature monitoring submodule, calculates a selection function of the number of analog-to-digital converter operations based on the second error coefficient, and transmits information on the number of analog-to-digital converter operations to the control module.

6. A voltage analog-to-digital conversion system based on multi-slope integral control as claimed in claim 5, characterized in that: When the analog-to-digital conversion calculation submodule calculates the second error coefficient, the following formula is satisfied: K ots =e g +T rst ; Where E is the second error coefficient, β is the interval reference coefficient, β has the following values, β = 1 or β = 2, when the analog-to-digital converter has nonlinear characteristics, β = 2, when the analog-to-digital converter has linear characteristics, β = 1, N is the number of bits of the analog-to-digital converter resolution, μ max is the maximum value of the signal amplitude that the analog-to-digital converter can distinguish, ρ is the reference coefficient of clock stability, ρ has the following values, ρ = 1 or ρ = 2, when the clock stability is good ρ = 1, when the clock stability is poor ρ = 2, is the clock sampling frequency, T rt is the conversion time of the analog-to-digital converter, K is the time reference factor of the analog-to-digital converter. ots is the environmental error reference coefficient; is the difference between the production year of the analog-to-digital converter and the current year, The current usage time of the analog-to-digital converter; ε is the reference index of the ambient temperature, and ε has the following values: ε=1 or ε=2 or ε=3 or ε=4 or ε=5. When the range value of the ambient temperature is less than or equal to 25℃, ε=1; when the range value of the ambient temperature is greater than 25℃ to less than or equal to 28℃, ε=2; when the range value of the ambient temperature is greater than 28℃ to less than or equal to 31℃, ε=3; when the range value of the ambient temperature is greater than 31℃ to less than or equal to 34℃, ε=4; when the range value of the ambient temperature is greater than 34℃, ε=5. g is the reference index of the working state of the analog-to-digital converter, and g has the following values: g=1 or g=2. When the analog-to-digital converter is overheated, g=2; when the analog-to-digital converter is in normal working state, g=1. T rst is the reference index of restart time, T rst The values ​​are as follows: T rst =1 or T rst =2 or T rst =3 or T rst =4 or T rst =5, when the time range for the internal device to recover when the analog-to-digital converter is restarted is less than or equal to 30s T rst =1, when the time range of the internal device recovery when the analog-to-digital converter restarts is greater than 30s and less than or equal to 60s T rst = 2, when the time range of the internal device recovery when the analog-to-digital converter restarts is greater than 60s and less than or equal to 90s T rst =3, when the time range of the internal device recovery when the analog-to-digital converter restarts is greater than 90s and less than or equal to 120s T rst =4, when the time range of the internal device recovery when the analog-to-digital converter restarts is greater than 120s T rst =5.

7. A voltage analog-to-digital conversion system based on multi-slope integral control as claimed in claim 6, characterized in that: When the analog-to-digital conversion calculation submodule calculates the selection function of the number of analog-to-digital converter operations, the following formula is satisfied: Where X(E) is the selection function of the number of operations of the analog-to-digital converter, f1 to f m The number of operations of the analog-to-digital converter is different, e1 to e m-1 is the threshold of the second error coefficient.

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