A conditioning circuit and a conditioning method for improving the processing accuracy of analog signals

Abstract

The application discloses a conditioning circuit and method for improving the processing precision of analog signals, the conditioning circuit comprising an analog conditioning unit; the conditioning method comprising: parameter configuration of an analog correction device; incoming factory test of an analog processing component; initial error calculation of the analog processing component; initial error determination of the analog processing component, if the initial error is within a preset parameter range, the determination is qualified, the calculation of a correction coefficient is entered, and the correction coefficient of the analog processing component is calculated according to the qualified initial error; if the initial error exceeds the preset parameter range, the determination is unqualified, and the analog processing component is returned to the factory; the recommended correction component parameters are obtained according to the correction coefficient combined with a standard resistance table, the recommended correction component parameters are used to select corresponding correction components to be welded in the circuit.

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 analog signal processing accuracy. 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 towards intelligence. Intelligent industrial control systems can adaptively adjust control strategies and automatically optimize control processes based on real-time and historical data to predict future conditions. This places higher demands on front-end signal processing, especially analog signal processing.

[0003] The inventors have discovered that in existing analog signal processing, factors affecting analog signal processing accuracy primarily include sensors, signal transmission, power supply noise, and signal processing. The impact of sensors on accuracy can be addressed through sensor selection, signal transmission interference can be mitigated by shielding interconnects, and power supply noise can be optimized by using high-precision power supplies. However, interference in signal processing arises from the fact that analog components (such as resistors, capacitors, transistors, and operational amplifiers) used in circuits often exhibit certain parameter errors, such as resistance drift, inherent resistance error, capacitance drift, offset voltage, and temperature coefficient mismatch. These errors can impact the performance and accuracy of analog acquisition, processing, and 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 it through 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 interference in the analog signal processing link in the feedback loop, and the principle of traditional technology 2 is to use a potentiometer in the circuit to adjust the resistance in the feedback loop, thereby correcting 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 correction, the conversion process from analog to digital and from digital to analog will cause some dynamic features of the analog signal, 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 in Figure 2, the conventional potentiometer method for adjusting circuit parameters requires manual adjustment, a process that cannot be automated and requires high technical skills. This results in low production debugging efficiency and is unsuitable for mass production. Furthermore, this method is limited by the potentiometer's inherent temperature coefficient, time coefficient, and other characteristics. As a result, even if the product achieves optimal parameters after factory debugging, the performance and accuracy of the product's analog acquisition, processing, and output will deteriorate with age and temperature fluctuations. This necessitates regular product calibration to maintain designed performance and accuracy. Furthermore, since the potentiometer method only has one parameter adjustment element in the entire circuit, it cannot be applied in multi-level signal processing applications such as low-current signal acquisition. 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-speed 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 including 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 includes 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, resistor R1, resistor R2 and resistor R3 are used to form an operational amplifier circuit with the operational amplifier OP1, and resistor R1 and resistor 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 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 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 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.

[0012] In a further technical solution, 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 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, 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 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, 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 including 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 including a first-stage conditioning unit, a second-stage conditioning unit, and a third-stage conditioning unit connected in sequence; wherein, the first-stage conditioning unit includes a first-stage conditioning circuit for adjusting the amplitude of the output signal Vo1 to 1.01 times the input signal Vi1; the second-stage conditioning unit includes a second-stage 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 second-stage conditioning circuit is connected to the output signal Vo1 of the first-stage conditioning circuit; the third-stage conditioning unit includes a third-stage conditioning circuit for adjusting the amplitude of the output signal Vo3 to -0.98 to -1 times the input signal Vi2.

[0015] The present invention also provides a conditioning method for improving analog signal processing accuracy, 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, calculating the initial error of analog 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 determined to be 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 process of calculating the correction coefficient, and calculate the correction coefficient of the analog processing component based on the qualified initial error;

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

[0024] Step P6: Correct component parameters based on the correction coefficients and the standard resistance table recommendation, thereby obtaining corrected components;

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

[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 user-configured analog processing component's predetermined test points using the following formula:

[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, and eliminate analog processing components with unqualified initial performance. These analog processing components will be sent to 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 Rf2 used to compensate for the analog processing components. x Theoretical resistance parameters are calculated as follows:

[0039] Formula 8:

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

[0041] Step 6: Based on the "theoretical resistance parameters of resistors Rf1 to Rfx" obtained in step 5, recommend actual resistances of resistors Rf1 to Rfx for compensating analog processing components using a lookup table 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 conditioning circuit satisfies the requirement of increasing the comprehensive accuracy of the analog processing circuit composed of analog 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 product debugging production efficiency and the comprehensive accuracy of the analog quantity processing circuit.

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

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

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

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

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

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

[0052] Figure 6 is a circuit diagram of a first-stage conditioning unit in Example 1 of the present invention;

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

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

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

[0056] Figure 10 Schematic diagram of the software interface of the analog correction device in Example 1 of the present invention;

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

[0058] Figure 12 yes Figure 8 Another modified circuit diagram of the circuit diagram in;

[0059] Figure 13 This 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 with reference to the accompanying drawings.

[0061] Example 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 analog processing accuracy, improving the analog correction efficiency, 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 the actual analog signal. In the primary 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 resistor voltage divider method. 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 their 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 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 accuracy of analog processing voltage. The core of the present invention is the analog correction principle and correction circuit.

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

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

[0067] The analog correction device has a board-to-board interface that can be connected to a modular analog fixture. The analog fixture can be designed by the user to meet the correction requirements 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 Figure 2 shows the circuit diagram of a first-stage conditioning unit. This circuit adjusts the amplitude of the output signal Vo1 to 0.99 times the input signal Vi1. This is to accommodate situations where the analog acquisition signal amplitude is larger than the actual analog signal amplitude. Resistors R1 and R2 attenuate the input signal amplitude to a preset amplitude through resistor voltage division; resistor R3 improves analog tracking accuracy and reduces offset range. The resistance values ​​of resistors R1 and R2 depend on the ratio of their respective input signal amplitudes to their output signal amplitudes. For example, in this circuit adjusting the amplitude of the output signal Vo1 to 0.99 times the input signal Vi1, substituting 0.99 into Equation 1 yields a resistance ratio of 1:99 for resistors R1 and R2.

[0071] Formula 1:

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

[0073] If necessary Figure 6 The circuit in Figure 1 has a larger signal attenuation ratio (such as 0.98, 0.97, 0.9, etc.). You can substitute the attenuation coefficient into Equation 1 and use the same method to calculate the resistance ratio of resistors R1 and R2.

[0074] like Figure 7The figure shows the circuit diagram of a secondary conditioning unit. The input signal Vi2 of this circuit is connected to the output signal Vo1 of the primary conditioning unit. The secondary conditioning unit adjusts the amplitude of the output signal Vo2 to -1 times the input signal Vi2, preparing for signal processing by the third-stage conditioning unit. Resistors R4 and R5 form an inverting input amplifier circuit with operational amplifier OP2. The resistance values ​​of resistors R4 and R5 depend on the ratio of the input signal amplitude to the output signal amplitude (the resistance values ​​of resistors R4 and R5 are determined by the conversion amplitude of their respective input and output signals). Taking the example of this circuit adjusting the amplitude of the output signal Vo2 to -1 times the input signal Vi2, substituting -1 into Equation 2 yields a 1:1 resistance ratio between resistors R4 and R5.

[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 Figure 2 shows the circuit diagram of a three-stage conditioning unit. The input signal Vi3 of this circuit is connected to the output signal Vo2 of the second-stage conditioning unit. The second-stage conditioning unit adjusts the amplitude of the output signal Vo3 to between -1 and -1.02 times the input signal Vi2. Resistors R6, R7, Rf1 through Rfx, switches K1 and K2, and microcontroller U1 form an inverting input amplifier circuit with operational amplifier OP3. The resistance values ​​of resistors R6, R7, and Rf1 through Rfx depend on the ratio of their respective input signal amplitudes to their respective output signal amplitudes. For example, using this circuit to adjust the amplitude of the output signal Vo3 to -1 times the input signal Vi3, substituting -1 into Equation 3 yields a 1:1 resistance ratio between resistors R4 and R5, and zero resistance between resistors Rf1 through Rf1x. Taking this circuit as an example, adjusting the amplitude of the output signal Vo3 to -1.02 times the input signal Vi3, substituting -1.02 into Equation 3 yields a 1:1 resistance ratio between resistors R4 and R5, and a resistance value from resistors Rf1 to Rfx of 0.02 times the resistance of 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, switch K1 uses a microcontroller enable signal to select different channels, Rf1 through Rfx, for connection to the three-stage conditioning unit feedback loop, enabling analog correction for different gears in the multi-speed analog front end. Switch K2 uses a microcontroller enable signal to select whether to connect Rf1 through Rfx to the three-stage conditioning unit feedback loop, enabling initial testing of the analog processing circuit before correction. Switches K1 and K2 can be composed of electromechanical components capable of on-off control of electrical signals, such as relays, multiplexers, analog switches, MOSFETs, jumpers, and mechanical switches.

[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 this embodiment 2 are the same as those of embodiment 1, except that Figure 11 As shown, when the conditioning circuit is integrated into an actual circuit to perform analog processing, in the three-stage conditioning circuit, resistors R6, R7, switch K1, microcontroller U1, and resistors Rf1 through Rfx are used to form an inverting input amplifier circuit with operational amplifier OP3; where x is a positive integer greater than 1. This further reduces the size of the three-stage conditioning unit.

[0085] Example 3

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

[0087] Example 4

[0088] like Figure 13As shown, the present invention also provides a conditioning circuit for improving the processing accuracy of analog signals, the conditioning circuit including a second analog conditioning unit for improving the analog processing accuracy, improving the analog correction efficiency, and correcting the accuracy of the multi-speed analog processing circuit, the second analog conditioning unit including a first-stage conditioning unit, a second-stage conditioning unit, and a third-stage conditioning unit connected in sequence; wherein, the first-stage conditioning unit includes a first-stage conditioning circuit for adjusting the amplitude of the output signal Vo1 to 1.01 times the input signal Vi1; the second-stage conditioning unit includes a second-stage 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 second-stage conditioning circuit is connected to the output signal Vo1 of the first-stage conditioning circuit; the third-stage conditioning unit includes a third-stage conditioning circuit for adjusting the amplitude of the output signal Vo3 to -0.98 to -1 times the input signal Vi2.

[0089] Example 5

[0090] like Figure 9-10 As shown, the present invention further 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, calculating the initial error of analog 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 determined to be 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 process of calculating the correction coefficient, and calculate the correction coefficient of the analog processing component based on the qualified initial error;

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

[0099] Step P6: Correct component parameters based on the correction coefficients and the standard resistance table recommendation, thereby obtaining corrected components;

[0100] Step P7: Based on the recommended correction component (component or element) parameters, select the corresponding correction component and solder it into the above-mentioned conditioning circuit for improving the analog signal processing accuracy.

[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 user-configured analog processing component's predetermined test points using the following formula:

[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, and eliminate analog processing components with unqualified initial performance. These analog processing components will be sent to 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 Rf2 used to compensate for the analog processing components. x Theoretical resistance parameters are calculated as follows:

[0113] Formula 8:

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

[0115] Step 6: Based on the "theoretical resistance parameters of resistors Rf1 to Rfx" obtained in step 5, recommend actual resistances of resistors Rf1 to Rfx for compensating analog processing components using a lookup table method; wherein, x is a positive integer greater than 1.

[0116] The specific analysis is as follows:

[0117] like Figure 9 The figure shows a workflow diagram for a conditioning method for improving analog signal processing accuracy. Processes numbered P1 to P6 are related to analog correction equipment, while process numbered P7 is related to the actual circuit in which the analog conditioning circuit is applied. Processes P1 to P7, in order, include parameter configuration of the analog correction equipment, factory testing of analog processing components, calculation of the initial error of the analog processing components, and determination of the initial error of the analog processing components. If the initial error is within a certain range, the component is deemed qualified, and the correction coefficient calculation process continues. If the initial error exceeds a certain range, the component is deemed unqualified, and the unqualified components are returned to the factory. Based on the correction coefficient and a standard resistance table, correction component parameters are recommended. Based on the recommended correction component parameters, the corresponding materials are selected and soldered into the analog processing circuit.

[0118] like Figure 10 The figure shows a schematic diagram of the software interface of the analog correction device. In the software interface, the PCM02 micro-current amplifier module is taken as an example, and the P1 to P7 processes are carried out for the four built-in gears of the PCM02 micro-current amplifier module.

[0119] The above-described embodiments merely represent specific implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, and all such variations and improvements fall within the scope of protection of the present invention.

Claims

1. A conditioning circuit for improving analog signal processing accuracy, 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. The first-stage conditioning unit includes a first-stage conditioning circuit for adjusting the amplitude of the output signal Vo1 to 0.99 times 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; The secondary conditioning unit includes a secondary conditioning circuit for adjusting the amplitude of the output signal Vo2 to -1 times the amplitude 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, resistors R4 and R5 are used to form an inverting input amplifier circuit with the operational amplifier OP2; the resistance values ​​of resistors R4 and R5 are respectively determined by 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 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.

2. A conditioning circuit for improving analog signal processing accuracy according to claim 1, 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 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, microcontroller U1, and resistors Rf1 to Rfx are all used to form an inverting input amplification 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 their respective input signals to the amplitude of the output signals, wherein x is a positive integer greater than 1.

3. The conditioning circuit for improving analog signal processing accuracy according to claim 1, 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 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, 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.

4. A conditioning method for improving analog signal processing accuracy, 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, calculating the initial error of analog processing components; Step P4: Determine the initial error of analog processing components. If the initial error is within the preset parameter range, it is determined to be 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 process of calculating the correction coefficient, and calculate the correction coefficient of the analog processing component based on the qualified initial error; Step P52: Return unqualified analog processing components to the factory; Step P6: Correct component parameters based on the correction coefficients and the standard resistance table recommendation, thereby obtaining corrected components; Step P7: According to the recommended correction component parameters, corresponding correction components are selected and soldered into the conditioning circuit for improving the analog signal processing accuracy as described in claim 1.

5. A conditioning method for improving analog signal processing accuracy according to claim 4, 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 user-configured analog processing component's predetermined test points using the following formula: 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 user-configured initial full-scale accuracy threshold, and eliminate analog processing components with unqualified initial performance. Step 3: Calculate the "initial absolute error" of the user-configured analog processing component's predetermined test points using the following formula: 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 of the "initial absolute error" obtained in step 4, calculate the theoretical resistance parameters of resistors Rf1 to Rfx used to compensate for the analog processing components. The calculation formula is as follows: Formula 8: In formula 8, Rf A The theoretical resistance parameters of resistors Rf1 to Rfx; Step 6: Based on the theoretical resistance parameters of resistors Rf1 to Rfx obtained in step 5, use a lookup table to recommend actual resistances of resistors Rf1 to Rfx for compensating analog processing components; where x is a positive integer greater than 1.

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