Conditioning circuit and conditioning method for improving analog quantity signal processing precision

Abstract

The invention discloses a conditioning circuit and a conditioning method for improving analog quantity signal processing precision. The conditioning circuit comprises an analog quantity conditioning unit. The conditioning method comprises the following steps: configuring parameters of analog quantity correction equipment; testing the analog quantity processing component in a factory; calculating an initial error of the analog quantity processing component; judging an initial error of the analog quantity processing component, if the initial error is within a preset parameter range, judging that the analog quantity processing component is qualified, entering calculation of a correction coefficient, and calculating the correction coefficient of the analog quantity processing component according to the initial error which is judged to be qualified; if the initial error exceeds a preset parameter range, judging that the product is unqualified, and returning to a factory; revised component parameters are recommended according to the revised coefficients in combination with a standard resistance meter, revised components are obtained, and the corresponding revised components are selected to be welded in the circuit according to the recommended revised component parameters.

Description

Technical Field

[0001] The present invention relates to the technical field of front-end signal processing, and in particular to a conditioning circuit and a conditioning method for improving the processing accuracy of analog signals. Background Art

[0002] With the continuous application of technologies such as artificial intelligence and cloud-edge collaboration in the industrial control industry, industrial control equipment is developing in the direction of intelligence. Intelligent industrial control systems can predict future states based on real-time data and historical data, adaptively adjust control strategies, and automatically optimize control processes. Therefore, higher requirements are placed on front-end signal processing, especially analog signal processing.

[0003] The inventors have found that in the existing analog signal processing process, the factors that affect the accuracy of analog signal processing mainly include sensors, signal transmission, power supply noise, signal processing, etc. Among them, the impact of sensors on accuracy can be solved by sensor selection, signal transmission interference can be avoided by shielding on the interconnection line, and power supply noise can be optimized by using high-precision power supply, etc., while the interference in the signal processing link is due to the large number of analog devices (such as resistors, capacitors, transistors, operational amplifiers, etc.) used in the circuit. There are certain parameter errors, such as resistance drift, resistance inherent error, capacitance drift, offset voltage, temperature coefficient mismatch, etc. These errors will affect the performance and accuracy of analog acquisition, analog processing, and analog output.

[0004] like Figure 1 As shown, the interference in the analog signal processing link, the principle of traditional technology 1 is to use an analog-to-digital converter to collect the analog signal, and use a digital-to-analog converter to output the analog signal after processing by the internal algorithm of the microcontroller.

[0005] like Figure 2 As shown, the interference in the analog signal processing link, the principle of traditional technology 2 is to use a potentiometer in the circuit to adjust the resistance in the feedback loop, and then correct the performance and accuracy of analog acquisition, analog processing, and analog output.

[0006] However, if Figure 1 As shown in the figure: Although traditional technology 1 can meet the needs of analog quantity correction, the conversion process from analog to digital and from digital to analog will cause some dynamic characteristics of analog signals such as high frequency and background noise to be lost, and it cannot meet the needs of intelligent industrial control equipment for trend prediction, deep learning, and large model analysis; Figure 2As shown: The method of adjusting the circuit parameters by the potentiometer of the traditional technology 2 can only be adjusted manually, and this process cannot be automatically controlled, which requires high skills of personnel, resulting in low efficiency of production debugging and not suitable for mass production needs. In addition, the method of adjusting the circuit parameters by the potentiometer is limited by the temperature coefficient, time coefficient and other characteristics of the potentiometer itself, resulting in that even if the product reaches good parameters after factory debugging when it leaves the factory, the performance and accuracy of the analog quantity acquisition, analog quantity processing and analog quantity output of the product will deteriorate with the increase of usage time and the change of usage temperature. Therefore, it is necessary to calibrate the product regularly to maintain the design performance and accuracy of the product. In addition, the method of adjusting the circuit parameters by the potentiometer cannot meet the application fields of multi-speed signal processing such as small current signal acquisition because there is only one parameter adjustment element in the entire circuit. Summary of the invention

[0007] In response to the above problems, the present invention provides a conditioning circuit and conditioning method for improving analog signal processing accuracy, which can improve analog processing accuracy, improve analog correction efficiency, and realize multi-level analog processing circuit accuracy correction needs.

[0008] The technical solution of the present invention is: a conditioning circuit for improving the processing accuracy of analog signals, the conditioning circuit comprising an analog conditioning unit for improving the analog processing accuracy, improving the analog correction efficiency and correcting the accuracy of multi-speed analog processing circuits. In a further technical solution, the first analog conditioning unit comprises a primary conditioning unit, a secondary conditioning unit and a tertiary conditioning unit connected in sequence.

[0009] In a further technical solution, the first-stage conditioning unit includes a first-stage conditioning circuit for adjusting the amplitude of the output signal Vo1 to 0.99 times that of the input signal Vi1; in the first-stage conditioning circuit, resistors R1, R2 and R3 are used to form an operational amplifier circuit with the operational amplifier OP1, and resistors R1 and R2 are used to attenuate the amplitude of the input signal to a preset amplitude through a resistance voltage divider method, and resistor R3 improves the analog quantity tracking accuracy and reduces the offset range.

[0010] In a further technical solution, the secondary conditioning unit includes a secondary conditioning circuit for adjusting the amplitude of the output signal Vo2 to -1 times of the input signal Vi2; wherein the input signal Vi2 of the secondary conditioning circuit is connected to the output signal Vo1 of the primary conditioning circuit; in the secondary conditioning circuit, resistor R4 and resistor R5 are used to form an inverting input amplifier circuit with the operational amplifier OP2; the resistance values ​​of resistor R4 and resistor R5 depend on the ratio of the amplitude of each input signal to the amplitude of the output signal.

[0011] In a further technical solution, the three-stage conditioning unit includes a three-stage conditioning circuit for adjusting the amplitude of the output signal Vo3 to -1 to -1.02 times of the input signal Vi2; wherein, the input end signal Vi3 of the three-stage conditioning circuit is connected to the output signal Vo2 of the secondary conditioning circuit; in the three-stage conditioning circuit, resistor R6, resistor R7, switch K1, switch K2, microcontroller U1 and resistors Rf1 to Rfx are all used to form an inverting input amplifier circuit with the operational amplifier OP3; the resistance values ​​of resistor R6, resistor R7 and resistors Rf1 to Rfx depend on the ratio of the amplitude of each input signal to the amplitude of the output signal, wherein x is a positive integer greater than 1.

[0012] In a further technical solution, when the conditioning circuit is integrated into an actual circuit to be subjected to analog quantity processing, the three-stage conditioning circuit is modified as follows: the three-stage conditioning unit includes a three-stage conditioning circuit for adjusting the amplitude of the output signal Vo3 to -1 to -1.02 times of the input signal Vi2; wherein the input end signal Vi3 of the three-stage conditioning circuit is connected to the output signal Vo2 of the secondary conditioning circuit; in the three-stage conditioning circuit, resistor R6, resistor R7, switch K1, microcontroller U1 and resistors Rf1 to Rfx are all used to form an inverting input amplifier circuit with the operational amplifier OP3; the resistance values ​​of resistor R6, resistor R7 and resistors Rf1 to Rfx depend on the ratio of the input signal amplitude to the output signal amplitude, wherein x is a positive integer greater than 1.

[0013] In a further technical solution, when applicable to the analog quantity correction function of a single-speed analog front end, the three-stage conditioning circuit is modified as follows: the three-stage conditioning unit includes a three-stage conditioning circuit for adjusting the amplitude of the output signal Vo3 to -1 to -1.02 times of the input signal Vi2; wherein the input end signal Vi3 of the three-stage conditioning circuit is connected to the output signal Vo2 of the secondary conditioning circuit; in the three-stage conditioning circuit, resistor R6, resistor R7, switch K1, microcontroller U1 and resistor Rf1 are all used to form an inverting input amplifier circuit with the operational amplifier OP3; the resistance values ​​of resistor R6, resistor R7 and resistor Rf1 depend on the ratio of the amplitude of each input signal to the amplitude of the output signal.

[0014] The present invention also provides a conditioning circuit for improving the processing accuracy of analog signals, the conditioning circuit comprising a second analog conditioning unit for improving the analog processing accuracy, improving the analog correction efficiency and correcting the accuracy of a multi-speed analog processing circuit, the second analog conditioning unit comprising a primary conditioning unit, a secondary conditioning unit and a tertiary conditioning unit connected in sequence; wherein the primary conditioning unit comprises a primary conditioning circuit for adjusting the amplitude of an output signal Vo1 to 1.01 times that of an input signal Vi1; the secondary conditioning unit comprises a secondary conditioning circuit for adjusting the amplitude of an output signal Vo2 to -1 times that of an input signal Vi2; wherein the input end signal Vi2 of the secondary conditioning circuit is connected to the output signal Vo1 of the primary conditioning circuit; the tertiary conditioning unit comprises a tertiary conditioning circuit for adjusting the amplitude of an output signal Vo3 to -0.98 to -1 times that of an input signal Vi2.

[0015] The present invention also provides a conditioning method for improving the processing accuracy of analog signals, comprising the following steps:

[0016] Step P1, parameter configuration of analog correction equipment;

[0017] Step P2: Factory testing of analog processing components;

[0018] Step P3, initial error calculation of analog quantity processing components;

[0019] Step P4: Determine the initial error of analog processing components.

[0020] If the initial error is within the preset parameter range, it is judged as qualified and the process goes to step P51;

[0021] If the initial error exceeds the preset parameter range, it is judged as unqualified and the process goes to step P52;

[0022] Step P51, enter the calculation of the correction coefficient, and calculate the correction coefficient of the analog processing component according to the qualified initial error;

[0023] Step P52: Return unqualified analog processing components to the factory;

[0024] Step P6, correcting component parameters according to the correction coefficient combined with the standard resistance table recommendation, that is, obtaining the corrected components;

[0025] Step P7: According to the recommended correction component parameters, select corresponding correction components and weld them in the above-mentioned conditioning circuit for improving the processing accuracy of analog signals.

[0026] In a further technical solution, the initial error test and correction coefficient calculation of the analog correction device include the following steps:

[0027] Step 1: Calculate the "initial full-scale accuracy" of the predetermined test points of the analog processing components configured by the user. The calculation formula is as follows:

[0028] Formula 4:

[0029] In formula 4, A FS is the initial full-scale accuracy, V m is the measured value, V n is the nominal value, V FS is the full scale value;

[0030] Step 2: Compare the "initial full-scale accuracy" of each predetermined test point obtained in step 1 with the initial full-scale accuracy threshold configured by the user, remove the analog processing components with unqualified initial performance, and flow the analog processing components with unqualified initial performance into the subsequent test process;

[0031] Step 3: Calculate the "initial absolute error" of the predetermined test points of the analog processing components configured by the user. The calculation formula is as follows:

[0032] Formula 5:

[0033] In formula 5, A E is the initial absolute error;

[0034] Step 4: Calculate the "correction coefficient" of the analog processing components based on the weighted average of the "initial absolute error" of each predetermined test point obtained in step 3. The calculation formula is as follows:

[0035] Formula 6:

[0036] Formula 7:

[0037] In formula 6, is the weighted average of the initial absolute error, A E 1 is the absolute error of test point 1, A E 2 is the absolute error of test point 2, and so on to the absolute error A of the kth test point. E k, V n1 is the nominal value of test point 1, V n2 is the nominal value of test point 2, and so on to the nominal value V of the kth test point. nk , n is the total number of test points; in formula 7, is the weighted average of the initial absolute error, F C is the theoretical correction coefficient;

[0038] Step 5: Based on the weighted average of the "initial absolute error" obtained in step 4, calculate the resistors Rf1 to Rf1 used to compensate the analog processing components. x Theoretical resistance parameters, calculated as follows:

[0039] Formula 8:

[0040] In formula 8, Rf A Theoretical resistance parameters of resistors Rf1 to Rfx;

[0041] Step 6: Based on the “theoretical resistance parameters of resistor Rf1 to resistor Rfx” obtained in step 5, the actual resistances of resistors Rf1 to resistor Rfx used to compensate the analog processing components are recommended according to the table lookup method; wherein, x is a positive integer greater than 1.

[0042] The beneficial effects of the present invention are:

[0043] 1. In the present invention, the analog quantity conditioning circuit satisfies the requirement of increasing the comprehensive accuracy of the analog quantity processing circuit composed of analog quantity processing components with an initial error of ±1% to ±0.1% or even ±0.01%.

[0044] 2. The present invention improves the analog quantity processing accuracy, improves the analog quantity correction efficiency, and realizes the accuracy correction needs of multi-level analog quantity processing circuits.

[0045] 3. In the present invention, the analog quantity correction equipment, analog quantity conditioning circuit, and analog quantity conditioning method based on the hardware conditioning principle abandon the traditional manual debugging operation and potentiometer correction method, and combine with digital automatic testing to improve the product debugging production efficiency and the comprehensive accuracy of the analog quantity processing circuit.

[0046] 4. In the present invention, the analog quantity correction device, analog quantity conditioning circuit and analog quantity conditioning method based on the hardware conditioning principle comprehensively explain a method for improving the comprehensive accuracy of the product analog quantity processing circuit without sacrificing the bandwidth characteristics of the analog quantity signal from the perspective of correction method, correction device and correction application. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the analog quantity correction performed by the analog-to-digital converter in the conventional technology 1;

[0048] Figure 2 It is the schematic diagram of the potentiometer adjusting circuit parameters in the conventional technology 2;

[0049] Figure 3 is a schematic diagram of an analog correction device and a correction fixture in Example 1 of the present invention;

[0050] Figure 4It is a block diagram of the composition of the analog quantity conditioning circuit in Embodiment 1 of the present invention integrated into an actual circuit that needs to perform analog quantity processing;

[0051] Figure 5 is a principle block diagram of the analog quantity conditioning circuit in Embodiment 1 of the present invention;

[0052] Figure 6 is a circuit diagram of a primary conditioning unit in Embodiment 1 of the present invention;

[0053] Figure 7 is a circuit diagram of a secondary conditioning unit in Embodiment 1 of the present invention;

[0054] Figure 8 is a circuit diagram of a three-stage conditioning unit in Embodiment 1 of the present invention;

[0055] Fig. 9 This is a workflow diagram of a conditioning method for improving analog signal processing accuracy described in Example 1 of the present invention;

[0056] Fig.10 is a schematic diagram of the software interface of the analog correction device in Example 1 of the present invention;

[0057] Fig.11 yes Figure 8 A modified circuit diagram of the circuit diagram in FIG.

[0058] Fig.12 yes Figure 8 Another modified circuit diagram of the circuit diagram in FIG.

[0059] Fig.13 It is the reverse sequence analog quantity conditioning circuit in the present invention. DETAILED DESCRIPTION

[0060] The embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

[0061] Embodiment 1:

[0062] like Figure 3-8As shown, the present invention provides a conditioning circuit for improving the processing accuracy of analog signals, and the conditioning circuit includes an analog conditioning unit for improving the processing accuracy of analog signals, improving the efficiency of analog correction, and correcting the accuracy of multi-speed analog processing circuits. The first analog conditioning unit includes a primary conditioning unit, a secondary conditioning unit, and a tertiary conditioning unit connected in sequence. The primary conditioning unit includes a primary conditioning circuit for adjusting the amplitude of the output signal Vo1 to 0.99 times that of the input signal Vi1, to meet the situation when the amplitude of the analog acquisition signal is larger than that of the real analog signal. In the primary conditioning circuit, resistors R1, R2, and R3 are used to form an operational amplifier circuit with operational amplifier OP1, and resistors R1 and R2 are used to attenuate the amplitude of the input signal to a preset amplitude through a resistor voltage divider method, and resistor R3 is used to improve the analog tracking accuracy and reduce the offset range. The secondary conditioning unit includes a secondary conditioning circuit for adjusting the amplitude of the output signal Vo2 to -1 times the input signal Vi2; wherein the input end signal Vi2 of the secondary conditioning circuit is connected to the output signal Vo1 of the primary conditioning circuit; in the secondary conditioning circuit, resistor R4 and resistor R5 are used to form an inverting input amplifier circuit with the operational amplifier OP2; the resistance values ​​of resistor R4 and resistor R5 depend on the ratio of the amplitude of the respective input signals to the amplitude of the output signals. The three-stage conditioning unit includes a three-stage conditioning circuit for adjusting the amplitude of the output signal Vo3 to -1 to -1.02 times of the input signal Vi2; wherein, the input end signal Vi3 of the three-stage conditioning circuit is connected to the output signal Vo2 of the two-stage conditioning circuit; in the three-stage conditioning circuit, resistor R6, resistor R7, switch K1, switch K2, microcontroller U1 and resistors Rf1 to Rfx are all used to form an inverting input amplifier circuit with the operational amplifier OP3; the resistance values ​​of resistor R6, resistor R7 and resistors Rf1 to Rfx depend on the ratio of the amplitude of each input signal to the amplitude of the output signal, wherein x is a positive integer greater than 1.

[0063] The specific analysis is as follows:

[0064] The present invention relates to two sets of objects and a method (the method is shown in Example 5), both of which use the same method to achieve the purpose of improving the analog processing voltage accuracy. The core of the present invention is the analog quantity correction principle and correction circuit.

[0065] like Figure 3 As shown, it is a schematic diagram of an analog quantity correction device and a correction fixture. The actual object 1 of the present invention is an analog quantity correction device, which is used for factory testing of analog quantity processing components (such as amplifiers, acquisition modules, and output modules). The initial errors of the analog quantity processing components can be measured during the factory testing, and the correction coefficients of the analog quantity processing components and the correction component parameters can be inferred based on the initial errors, thereby providing theoretical support for the subsequent application of analog quantity conditioning circuits.

[0066] When actual circuits that require analog quantity processing are mass-produced, they can be selectively soldered and assembled according to the analog quantity correction component parameters given by the analog quantity correction equipment, thereby improving the production and debugging efficiency of the analog quantity processing circuit.

[0067] The analog correction device has a board-to-board interface inside, which can be connected to the analog fixture with modular design. The analog fixture can be designed by the user to meet the correction of analog processing components in different installation forms.

[0068] like Figure 4 As shown, the block diagram of the analog quantity conditioning circuit is integrated into the actual circuit that needs to perform analog quantity processing. The actual object 2 of the present invention is an analog quantity conditioning circuit. The correction principle is consistent with the analog quantity correction device and can be integrated into the actual circuit that needs to perform analog quantity processing.

[0069] like Figure 5 As shown in the figure, it is the principle block diagram of the analog quantity conditioning circuit. The analog quantity conditioning circuit can be divided into three levels, namely the primary conditioning unit, the secondary conditioning unit, and the tertiary conditioning unit.

[0070] like Figure 6 As shown, it is a circuit diagram of a first-stage conditioning unit. The function of the circuit is to adjust the amplitude of the output signal Vo1 to 0.99 times of the input signal Vi1. This is to meet the situation when the amplitude of the analog acquisition signal is larger than the actual analog signal. The function of resistors R1 and R2 is to attenuate the amplitude of the input signal to a preset amplitude through the resistor voltage divider method; the function of resistor R3 is to improve the analog tracking accuracy and reduce the offset range. Among them, the resistance values ​​of resistors R1 and R2 depend on the ratio of the amplitude of their respective input signals to the amplitude of the output signal. Taking the circuit that adjusts the amplitude of the output signal Vo1 to 0.99 times of the input signal Vi1 as an example, substituting 0.99 times into formula 1, it can be obtained that the resistance ratio of resistors R1 and R2 is 1:99.

[0071] Formula 1:

[0072] Wherein, r1 is the resistance value of the resistor R1; r2 is the resistance value of the resistor R2.

[0073] If necessary Figure 6 The circuit in has a larger signal attenuation ratio (such as 0.98, 0.97, 0.9, etc.). The attenuation coefficient can be substituted into Formula 1, and the resistance ratio of resistor R1 and resistor R2 can be calculated using the same method.

[0074] like Figure 7As shown, it is a circuit diagram of a secondary conditioning unit. The input signal Vi2 of the circuit is connected to the output signal Vo1 of the primary conditioning unit. The function of the secondary conditioning unit is to adjust the amplitude of the output signal Vo2 to -1 times of the input signal Vi2. It is prepared for the signal processing of the third-stage conditioning unit. The resistor R4 and the resistor R5 function together with the operational amplifier OP2 to form an inverting input amplifier circuit. Among them, the resistance values ​​of the resistor R4 and the resistor R5 depend on the ratio of the amplitude of the respective input signal to the amplitude of the output signal (the resistance values ​​of the resistor R4 and the resistor R5 are determined by the conversion amplitude of the respective input and output signals). Taking the circuit adjusting the amplitude of the output signal Vo2 to -1 times of the input signal Vi2 as an example, substituting -1 times into formula 2, it can be obtained that the resistance ratio of the resistor R4 and the resistor R5 is 1:1.

[0075] Formula 2:

[0076] Wherein, r4 is the resistance value of the resistor R4, and r5 is the resistance value of the resistor R5.

[0077] like Figure 8 As shown, it is a circuit diagram of a three-stage conditioning unit. The input signal Vi3 of the circuit is connected to the output signal Vo2 of the secondary conditioning unit. The function of the secondary conditioning unit is to adjust the amplitude of the output signal Vo3 to -1 times to -1.02 times of the input signal Vi2. The resistor R6, the resistor R7, the resistors Rf1 to Rfx, the switch K1, the switch K2, and the microcontroller U1 function to form an inverting input amplifier circuit with the operational amplifier OP3. Among them, the resistance values ​​of the resistors R6, the resistor R7, the resistors Rf1 to the resistors Rfx depend on the ratio of the amplitude of the respective input signals to the amplitude of the output signals. Taking the circuit adjusting the amplitude of the output signal Vo3 to -1 times of the input signal Vi3 as an example, substituting -1 times into formula 3, it can be obtained that the resistance ratio of the resistor R4 to the resistor R5 is 1:1, and the resistance values ​​of the resistors Rf1 to the resistors Rf1x are 0. Taking the circuit adjusting the amplitude of the output signal Vo3 to -1.02 times of the input signal Vi3 as an example, substituting -1.02 times into Formula 3, it can be obtained that the resistance ratio of the resistor R4 to the resistor R5 is 1:1, and the resistance of the resistor Rf1 to the resistor Rfx is 0.02 times the resistance of the resistor R4.

[0078] Formula 3:

[0079] Wherein, r6 is the resistance value of the resistor R6, r7 is the resistance value of the resistor R7, and rf(1-x) is the resistance value of the resistor Rf1, the resistor Rf2, the resistor Rf3, ... or the resistor Rfx.

[0080] If necessary Figure 8The circuit in has a larger signal amplification ratio (such as 1.04, 1.06, 1.2, etc.). The amplification factor can be substituted into Formula 3, and the resistance ratio of resistors R6, R7, Rf1 to Rfx can be calculated using the same method.

[0081] exist Figure 8 In the example, the switch K1 is used to select different Rf1 to Rfx to access the three-stage conditioning unit feedback loop through the microcontroller enable signal, so as to realize the analog correction function of different gears of the multi-gear analog front end. The switch K2 is used to select whether to connect Rf1 to Rfx to the three-stage conditioning unit feedback loop through the microcontroller enable signal, so as to realize the initial test function of the analog processing circuit before correction. The switches of switches K1 and K2 can be composed of electromechanical components such as relays, multiplexers, analog switches, MOS tubes, jumpers, mechanical switches, etc. that can realize the on-off control of electrical signals.

[0082] In summary, the analog quantity conditioning circuit designed in the present invention can improve the comprehensive accuracy of the analog quantity processing circuit composed of analog quantity processing components with an initial error of ±1% to ±0.1% or even ±0.01%.

[0083] Example 2

[0084] The other structures of the present embodiment 2 are the same as those of the embodiment 1, except that: Fig.11 As shown, when the conditioning circuit is integrated into the actual circuit to be processed by analog quantity, in the three-stage conditioning circuit, the resistor R6, the resistor R7, the switch K1, the microcontroller U1, and the resistors Rf1 to Rfx are used to form an inverting input amplifier circuit with the operational amplifier OP3; wherein x is a positive integer greater than 1. The volume of the three-stage conditioning unit is further reduced.

[0085] Example 3

[0086] The other structures of this embodiment 3 are the same as those of embodiment 1 or 2, except that: Fig.12 As shown, when the analog correction function of the single-gear analog front end is applied, in the three-stage conditioning circuit, the resistor R6, the resistor R7, the switch K1, the microcontroller U1 and the resistor Rf1 are used to form an inverting input amplifier circuit with the operational amplifier OP3, further reducing the volume of the three-stage conditioning unit.

[0087] Example 4

[0088] like Fig.13As shown, the present invention also provides a conditioning circuit for improving the processing accuracy of analog signals, the conditioning circuit comprising a second analog conditioning unit for improving the analog processing accuracy, improving the analog correction efficiency and correcting the accuracy of multi-speed analog processing circuits, the second analog conditioning unit comprising a primary conditioning unit, a secondary conditioning unit and a tertiary conditioning unit connected in sequence; wherein the primary conditioning unit comprises a primary conditioning circuit for adjusting the amplitude of the output signal Vo1 to 1.01 times of the input signal Vi1; the secondary conditioning unit comprises a secondary conditioning circuit for adjusting the amplitude of the output signal Vo2 to -1 times of the input signal Vi2; wherein the input end signal Vi2 of the secondary conditioning circuit is connected to the output signal Vo1 of the primary conditioning circuit; the tertiary conditioning unit comprises a tertiary conditioning circuit for adjusting the amplitude of the output signal Vo3 to -0.98 to -1 times of the input signal Vi2.

[0089] Example 5

[0090] like Figure 9-10 As shown, the present invention also provides a conditioning method for improving the processing accuracy of analog signals, based on any one of the above embodiments 1 to 3, the conditioning method comprises the following steps:

[0091] Step P1, parameter configuration of analog correction equipment;

[0092] Step P2: Factory testing of analog processing components;

[0093] Step P3, initial error calculation of analog quantity processing components;

[0094] Step P4: Determine the initial error of analog processing components.

[0095] If the initial error is within the preset parameter range, it is judged as qualified and the process goes to step P51;

[0096] If the initial error exceeds the preset parameter range, it is judged as unqualified and the process goes to step P52;

[0097] Step P51, enter the calculation of the correction coefficient, and calculate the correction coefficient of the analog processing component according to the qualified initial error;

[0098] Step P52: Return unqualified analog processing components to the factory;

[0099] Step P6, correcting component parameters according to the correction coefficient combined with the standard resistance table recommendation, that is, obtaining the corrected components;

[0100] Step P7: According to the recommended correction component (component or element) parameters, select the corresponding correction component and weld it in the above-mentioned conditioning circuit for improving the processing accuracy of analog signals.

[0101] In a further technical solution, the initial error test and correction coefficient calculation of the analog correction device include the following steps:

[0102] Step 1: Calculate the "initial full-scale accuracy" of the predetermined test points of the analog processing components configured by the user. The calculation formula is as follows:

[0103] Formula 4:

[0104] In formula 4, A FS is the initial full-scale accuracy, V m is the measured value, V n is the nominal value, V FS is the full scale value;

[0105] Step 2: Compare the "initial full-scale accuracy" of each predetermined test point obtained in step 1 with the initial full-scale accuracy threshold configured by the user, remove the analog processing components with unqualified initial performance, and flow the analog processing components with unqualified initial performance into the subsequent test process;

[0106] Step 3: Calculate the "initial absolute error" of the predetermined test points of the analog processing components configured by the user. The calculation formula is as follows:

[0107] Formula 5: In formula 5, A E is the initial absolute error;

[0108] Step 4: Calculate the "correction coefficient" of the analog processing components based on the weighted average of the "initial absolute error" of each predetermined test point obtained in step 3. The calculation formula is as follows:

[0109] Formula 6:

[0110] Formula 7:

[0111] In formula 6, is the weighted average of the initial absolute error, A E 1 is the absolute error of test point 1, A E 2 is the absolute error of test point 2, and so on to the absolute error A of the kth test point. E k, V n1 is the nominal value of test point 1, V n2 is the nominal value of test point 2, and so on to the nominal value V of the kth test point. nk, n is the total number of test points; in formula 7, is the weighted average of the initial absolute error, F C is the theoretical correction coefficient;

[0112] Step 5: Based on the weighted average of the "initial absolute error" obtained in step 4, calculate the resistors Rf1 to Rf1 used to compensate the analog processing components. x Theoretical resistance parameters, calculated as follows:

[0113] Formula 8:

[0114] In formula 8, Rf A Theoretical resistance parameters of resistors Rf1 to Rfx;

[0115] Step 6: Based on the “theoretical resistance parameters of resistor Rf1 to resistor Rfx” obtained in step 5, the actual resistances of resistors Rf1 to resistor Rfx used to compensate the analog processing components are recommended according to the table lookup method; wherein, x is a positive integer greater than 1.

[0116] The specific analysis is as follows:

[0117] like Fig. 9 As shown, a workflow diagram of a conditioning method for improving the processing accuracy of analog signals is shown. The processes numbered P1 to P6 are related to the analog correction equipment, and the process numbered P7 is related to the actual circuit that applies the analog conditioning circuit. The processes from P1 to P7 are, in order, the parameter configuration of the analog correction equipment, the factory test of the analog processing components, the initial error calculation of the analog processing components, and the initial error determination of the analog processing components. If the initial error is within a certain range, it is determined to be qualified, and then the correction coefficient calculation process is continued. If the initial error exceeds a certain range, it is determined to be unqualified, and the unqualified components are returned to the factory, and the correction component parameters are recommended according to the correction coefficient combined with the standard resistance table. According to the recommended correction component parameters, the corresponding materials are selected and welded in the analog processing circuit.

[0118] like Fig.10 As shown, it is a schematic diagram of the software interface of the analog correction device. In the software interface, taking the PCM02 microcurrent amplification module as an example, the P1 to P7 processes are carried out for the 4 built-in gears of the PCM02 microcurrent amplification module.

[0119] The above-mentioned embodiments only express the specific implementation of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A conditioning circuit for improving the processing accuracy of analog signals, characterized in that: The conditioning circuit includes a first analog quantity conditioning unit for improving analog quantity processing accuracy, improving analog quantity correction efficiency, and correcting the accuracy of a multi-speed analog quantity processing circuit. The first analog quantity conditioning unit includes a primary conditioning unit, a secondary conditioning unit, and a tertiary conditioning unit connected in sequence.

2. A conditioning circuit for improving analog signal processing accuracy according to claim 1, characterized in that: The primary conditioning unit includes a primary conditioning circuit for adjusting the amplitude of the output signal Vo1 to 0.99 times of the input signal Vi1; in the primary conditioning circuit, resistors R1, R2 and R3 are used to form an operational amplifier circuit with an operational amplifier OP1.

3. A conditioning circuit for improving analog signal processing accuracy according to claim 2, characterized in that: The secondary conditioning unit includes a secondary conditioning circuit for adjusting the amplitude of the output signal Vo2 to -1 times of the input signal Vi2; wherein, the input end signal Vi2 of the secondary conditioning circuit is connected to the output signal Vo1 of the primary conditioning circuit; in the secondary conditioning circuit, resistor R4 and resistor R5 are used to form an inverting input amplifier circuit with the operational amplifier OP2; the resistance values ​​of resistor R4 and resistor R5 depend on the ratio of their respective input signal amplitudes to the output signal amplitudes.

4. A conditioning circuit for improving analog signal processing accuracy according to claim 3, characterized in that: The three-stage conditioning unit includes a three-stage conditioning circuit for adjusting the amplitude of the output signal Vo3 to -1 to -1.02 times of the input signal Vi2; wherein, the input end signal Vi3 of the three-stage conditioning circuit is connected to the output signal Vo2 of the two-stage conditioning circuit; in the three-stage conditioning circuit, resistor R6, resistor R7, switch K1, switch K2, microcontroller U1 and resistors Rf1 to Rfx are all used to form an inverting input amplifier circuit with the operational amplifier OP3; the resistance values ​​of resistor R6, resistor R7 and resistors Rf1 to Rfx depend on the ratio of the amplitude of each input signal to the amplitude of the output signal, wherein x is a positive integer greater than 1.

5. The conditioning circuit for improving the processing accuracy of analog signals according to claim 3, characterized in that: When the conditioning circuit is integrated into an actual circuit to perform analog quantity processing, the three-stage conditioning circuit is modified as follows: the three-stage conditioning unit includes a three-stage conditioning circuit for adjusting the amplitude of the output signal Vo3 to -1 to -1.02 times of the input signal Vi2; wherein the input end signal Vi3 of the three-stage conditioning circuit is connected to the output signal Vo2 of the secondary conditioning circuit; in the three-stage conditioning circuit, resistor R6, resistor R7, switch K1, microcontroller U1 and resistors Rf1 to Rfx are all used to form an inverting input amplifier circuit with the operational amplifier OP3; the resistance values ​​of resistor R6, resistor R7 and resistors Rf1 to Rfx depend on the ratio of the amplitude of each input signal to the amplitude of the output signal, wherein x is a positive integer greater than 1.

6. A conditioning circuit for improving analog signal processing accuracy according to claim 3, characterized in that: When applicable to the analog quantity correction function of a single-speed analog front end, the three-stage conditioning circuit is modified as follows: the three-stage conditioning unit includes a three-stage conditioning circuit for adjusting the amplitude of the output signal Vo3 to -1 to -1.02 times of the input signal Vi2; wherein the input end signal Vi3 of the three-stage conditioning circuit is connected to the output signal Vo2 of the secondary conditioning circuit; in the three-stage conditioning circuit, resistor R6, resistor R7, switch K1, microcontroller U1 and resistor Rf1 are all used to form an inverting input amplification circuit with the operational amplifier OP3; the resistance values ​​of resistor R6, resistor R7 and resistor Rf1 depend on the ratio of the amplitude of each input signal to the amplitude of the output signal.

7. A conditioning circuit for improving the processing accuracy of analog signals, characterized in that: The conditioning circuit includes a second analog conditioning unit for improving the analog quantity processing accuracy, improving the analog quantity correction efficiency and correcting the accuracy of the multi-speed analog quantity processing circuit, and the second analog quantity conditioning unit includes a primary conditioning unit, a secondary conditioning unit and a tertiary conditioning unit connected in sequence; wherein, the primary conditioning unit includes a primary conditioning circuit for adjusting the amplitude of the output signal Vo1 to 1.01 times of the input signal Vi1; the secondary conditioning unit includes a secondary conditioning circuit for adjusting the amplitude of the output signal Vo2 to -1 times of the input signal Vi2; wherein, the input end signal Vi2 of the secondary conditioning circuit is connected to the output signal Vo1 of the primary conditioning circuit; the tertiary conditioning unit includes a tertiary conditioning circuit for adjusting the amplitude of the output signal Vo3 to -0.98 to -1 times of the input signal Vi2.

8. A conditioning method for improving the processing accuracy of analog signals, characterized in that: The following steps are involved: Step P1, parameter configuration of analog correction equipment; Step P2: Factory testing of analog processing components; Step P3, initial error calculation of analog quantity processing components; Step P4: Determine the initial error of analog processing components. If the initial error is within the preset parameter range, it is judged as qualified and the process goes to step P51; If the initial error exceeds the preset parameter range, it is judged as unqualified and the process goes to step P52; Step P51, enter the calculation of the correction coefficient, and calculate the correction coefficient of the analog processing component according to the qualified initial error; Step P52: Return unqualified analog processing components to the factory; Step P6, correcting component parameters according to the correction coefficient combined with the standard resistance table recommendation, that is, obtaining the corrected components; Step P7: According to the recommended correction component parameters, select corresponding correction components and weld them in a conditioning circuit for improving the processing accuracy of analog signals as described in claim 7.

9. A conditioning method for improving analog signal processing accuracy according to claim 8, characterized in that: The initial error test and correction coefficient calculation of the analog correction device include the following steps: Step 1: Calculate the "initial full-scale accuracy" of the predetermined test points of the analog processing components configured by the user. The calculation formula is as follows: Formula 4: In formula 4, A FS is the initial full-scale accuracy, V m is the measured value, V n is the nominal value, V FS is the full scale value; Step 2: Compare the "initial full-scale accuracy" of each predetermined test point obtained in step 1 with the initial full-scale accuracy threshold configured by the user, remove the analog processing components with unqualified initial performance, and flow the analog processing components with unqualified initial performance into the subsequent test process; Step 3: Calculate the "initial absolute error" of the predetermined test points of the analog processing components configured by the user. The calculation formula is as follows: Formula 5: In formula 5, A E is the initial absolute error; Step 4: Calculate the "correction coefficient" of the analog processing components based on the weighted average of the "initial absolute error" of each predetermined test point obtained in step 3. The calculation formula is as follows: Formula 6: Formula 7: In formula 6, is the weighted average of the initial absolute error, A E 1 is the absolute error of test point 1, A E 2 is the absolute error of test point 2, and so on to the absolute error A of the kth test point. E k, V n1 is the nominal value of test point 1, V n2 is the nominal value of test point 2, and so on to the nominal value V of the kth test point. nk , n is the total number of test points; in formula 7, is the weighted average of the initial absolute error, F C is the theoretical correction coefficient; Step 5: Based on the weighted average value of the "initial absolute error" obtained in step 4, calculate the theoretical resistance parameters of the resistors Rf1 to Rfx used to compensate the analog processing components. The calculation formula is as follows: Formula 8: In formula 8, Rf A Theoretical resistance parameters of resistors Rf1 to Rfx; Step 6: Based on the "theoretical resistance parameters of resistor Rf1 to resistor Rfx" obtained in step 5, the actual resistance of resistor Rf1 to resistor Rfx used to compensate the analog processing components is recommended according to the table lookup method; wherein, x is a positive integer greater than 1.

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