Dynamic weighing filter circuit and dynamic weighing filter method

Abstract

The invention relates to the technical field of weighing, in particular to a dynamic weighing filtering circuit and a dynamic weighing filtering method.The dynamic weighing filtering circuit comprises a weighing sensor, a signal processing module, a filtering module and a phase shifting module, and the dynamic weighing filtering circuit is obtained by collecting an electric signal output by the weighing sensor and conducting amplification, filtering and phase processing on the electric signal. The interference processing burden of the subsequent software side is reduced, so that a high-quality digital signal source is output in the dynamic weighing process, the overall detection precision is improved, and the MCU operation pressure is relieved.

Description

Technical Field

[0001] This application relates to the technical field of weighing, and in particular to a dynamic weighing filter circuit and a dynamic weighing filtering method. Background Art

[0002] Currently, dynamic weighing technology is widely used in scenarios such as logistics sorting, industrial packaging, and in-line material transportation, for quickly collecting and processing weight information of an object when it is in a short-term static or moving state, to meet the requirements of automatic sorting and quality determination under high-speed beats. Dynamic weighing devices usually collect weight change data in real time through weighing sensors, and combine data filtering, signal processing, and state recognition logic to output effective weighing results.

[0003] In existing dynamic weighing systems, in order to improve weighing accuracy, it often relies on the MCU to perform high-frequency sampling on the original weighing signal at the software end, and completes data correction and weight extraction through a series of calculation processes such as moving average, digital filtering, and steady-state judgment. Although this approach can improve detection accuracy, it will significantly increase the real-time operation pressure of the MCU. Especially in high-frequency weighing or multi-channel parallel application scenarios, it is extremely easy to cause processing delays or resource bottlenecks. In addition, although some solutions attempt to introduce a filter circuit at the circuit end, the filter parameters lack targeted design, and the phase shift introduced by the filter delay in turn increases the compensation pressure at the software layer, resulting in insufficient software-hardware cooperation efficiency and limited overall system performance. Therefore, there is room for improvement. Summary of the Invention

[0004] This application provides a dynamic weighing filter circuit and a dynamic weighing filtering method, which can achieve high-stability processing of weighing electrical signals during dynamic weighing, thereby effectively improving weighing accuracy while significantly reducing the calculation burden of the MCU.

[0005] The first aspect of this application provides a dynamic weighing filter circuit, including:

[0006] A weighing sensor, configured to convert the weight of the measured item into an electrical signal;

[0007] A signal processing module, connected to the weighing sensor, configured to generate an amplified electrical signal according to the electrical signal;

[0008] A filtering module, connected to the signal processing module, configured to perform filtering processing on the amplified electrical signal to obtain a filtered electrical signal;

[0009] A phase-shifting module, connected to the filtering module, configured to perform phase processing on the filtered electrical signal and output a weighing electrical signal.

[0010] By adopting the above technical solution, the weight of the measured object is converted into an electrical signal by a weighing sensor, which can realize the real-time conversion of physical weight into a processable electrical signal. Then, the signal processing module generates an amplified electrical signal according to the electrical signal, which can enhance the amplitude and signal-to-noise ratio of the original signal, avoid the analog-to-digital conversion error caused by too low signal amplitude. Furthermore, the filtering module filters the amplified electrical signal, which can remove high-frequency noise and instantaneous disturbances, improve the stability and reliability of the final weighing data. The phase-shifting module processes the phase of the filtered electrical signal and outputs a weighing electrical signal, which can compensate for the delay error introduced by the filter bank, thus enhancing the timing synchronization and sampling matching degree of signal output, so as to achieve high-stability signal output during the dynamic weighing process, improve the weighing accuracy and reduce the processing pressure at the backend.

[0011] Optionally, the signal processing module includes a first operational amplifier U1, a second operational amplifier U2, a third operational amplifier U3, a first resistor R1, a second resistor R2 and a third resistor R3. The non-inverting input terminal of the first operational amplifier U1 is connected to the first output terminal of the weighing sensor. The output terminal of the first operational amplifier U1 is connected to one end of the second resistor R2. The other end of the second resistor R2 is connected to the inverting input terminal of the third operational amplifier U3. The inverting input terminal of the first operational amplifier U1 is connected to one end of the first resistor R1. The other end of the first resistor R1 is connected to the inverting input terminal of the second operational amplifier U2. The non-inverting input terminal of the second operational amplifier U2 is connected to the second output terminal of the weighing sensor. The output terminal of the second operational amplifier U2 is connected to one end of the third resistor R3. The other end of the third resistor R3 is connected to the non-inverting input terminal of the third operational amplifier U3. The output terminal of the third operational amplifier U3 is connected to the input terminal of the filtering module.

[0012] By adopting the above technical solution, a differential amplification structure is formed by the first operational amplifier, the second operational amplifier and multiple resistors, which can perform common-mode suppression and high-gain amplification on the differential signal output by the weighing sensor, thereby enhancing the anti-interference ability of the signal.

[0013] Optionally, the signal processing module further includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. The connection between the first operational amplifier U1 and the first resistor R1 is connected to one end of the fourth resistor R4, the connection between the first operational amplifier U1 and the second resistor R2 is connected to the other end of the fourth resistor R4, the connection between the second operational amplifier U2 and the first resistor R1 is connected to one end of the fifth resistor R5, the connection between the second operational amplifier U2 and the third resistor R3 is connected to the other end of the fifth resistor R5, the connection between the third operational amplifier U3 and the second resistor R2 is connected to one end of the sixth resistor R6, the connection between the third operational amplifier U3 and the filter module is connected to the other end of the sixth resistor R6, the connection between the third resistor R3 and the third operational amplifier U3 is connected to one end of the seventh resistor R7, and the other end of the seventh resistor R7 is grounded.

[0014] By adopting the above technical solution, multiple voltage-dividing and compensating resistors are further introduced into the signal processing module, which can further stabilize the input level of the operational amplifier and suppress low-frequency drift, thereby improving the linearity and reliability in the signal amplification process.

[0015] Optionally, the filter module includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a first capacitor C1, a second capacitor C2, and a fourth operational amplifier U4. One end of the eighth resistor R8 is connected to the output terminal of the third operational amplifier U3, the other end of the eighth resistor R8 is connected to one end of the ninth resistor R9, the other end of the ninth resistor R9 is connected to the inverting input terminal of the fourth operational amplifier U4, the non-inverting input terminal of the fourth operational amplifier U4 is connected to one end of the tenth resistor R10, the other end of the tenth resistor R10 is grounded, the output terminal of the fourth operational amplifier U4 is connected to the input terminal of the phase-shifting module, the connection between the eighth resistor R8 and the ninth resistor R9 is connected to one end of the first capacitor C1, the other end of the first capacitor C1 is connected to the output terminal of the fourth operational amplifier U4, the connection between the fourth operational amplifier U4 and the tenth resistor R10 is connected to one end of the eleventh resistor R11, the other end of the eleventh resistor R11 is connected to the output terminal of the fourth operational amplifier U4, the connection between the fourth operational amplifier U4 and the ninth resistor R9 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded.

[0016] By adopting the above technical solution, the active low-pass filter structure constructed by a resistor-capacitor network and an operational amplifier can effectively weaken the high-frequency components in the input signal, thereby enhancing the signal smoothness and reducing the influence of noise interference on the weighing judgment, so as to complete the filtering operation at the analog end in advance and reduce the calculation pressure on the MCU side.

[0017] Optionally, the phase shift module includes a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a third capacitor C3, a fourth capacitor C4 and a fifth operational amplifier U5. One end of the twelfth resistor R12 is connected to the output end of the fourth operational amplifier U4, the other end of the twelfth resistor R12 is connected to one end of the third capacitor C3, the other end of the third capacitor C3 is connected to the inverting input end of the fifth operational amplifier U5, the connection between the twelfth resistor R12 and the fourth operational amplifier U4 is connected to one end of the fourteenth resistor R14, the other end of the fourteenth resistor R14 is connected to the non-inverting input end of the fifth operational amplifier U5, the connection between the twelfth resistor R12 and the third capacitor C3 is connected to one end of the fourth capacitor C4, the other end of the fourth capacitor C4 is connected to the output end of the fifth operational amplifier U5, one end of the thirteenth resistor R13 is connected to the fourth capacitor C4, the connection between the third capacitor C3 and the fifth operational amplifier U5 is connected to the other end of the thirteenth resistor R13, the connection between the fourteenth resistor R14 and the fifth operational amplifier U5 is connected to one end of the fifteenth resistor R15, and the other end of the fifteenth resistor R15 is grounded.

[0018] By adopting the above technical solution, the all-pass filter structure composed of resistors, capacitors and operational amplifiers can adjust the phase response of the signal without changing the amplitude characteristics, thereby compensating for the time drift caused by the filtering delay, enhancing the sensitivity of the weighing signal response, and effectively reducing the data delay in the case of dynamic measurement.

[0019] Optionally, the weighing sensor includes a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18 and a nineteenth resistor R19. One end of the sixteenth resistor R16 is connected to one end of the seventeenth resistor R17, the other end of the seventeenth resistor R17 is connected to one end of the eighteenth resistor R18, the other end of the eighteenth resistor R18 is connected to one end of the nineteenth resistor R19, the other end of the nineteenth resistor R19 is connected to the other end of the sixteenth resistor R16, and the connection between the sixteenth resistor R16 and the nineteenth resistor R19 is connected to the DC input signal source.

[0020] By adopting the above technical solution, a bridge structure composed of four resistors can stably output a voltage signal linearly related to the load change, thereby achieving high-precision weight sensing and improving the accuracy and consistency of the weighing signal.

[0021] Optionally, the dynamic weighing filter circuit further includes an analog-to-digital conversion module, which is connected to the phase shift processing module and is used to perform analog-to-digital conversion processing on the weighing electrical signal and output a digital coding value.

[0022] By adopting the above technical solution, by adding an analog-to-digital conversion module after the phase shift module, the processed analog weighing signal can be converted into a digital coding value in real time, thereby providing a digital signal input with a unified standard for subsequent data acquisition, analysis, and control processes, facilitating compatibility with digital processing devices, and thus improving the speed and accuracy of data processing.

[0023] The second aspect of the present application provides a dynamic weighing filtering method, which is applied to the dynamic weighing filter circuit in the first aspect and includes:

[0024] Collect the electrical signal output by the weighing sensor;

[0025] Perform signal amplification and filtering processing on the electrical signal and then output a filtered electrical signal, and analyze the phase response characteristic information of the filtered electrical signal according to the filtered electrical signal;

[0026] Judge whether to perform phase shift compensation processing through the phase response characteristic information and output a weighing electrical signal, and perform analog-to-digital conversion processing on the weighing electrical signal to output a digital coding value.

[0027] By adopting the above technical solution, by collecting the electrical signal output by the weighing sensor, it is possible to ensure real-time data collection when effectively triggered, thereby avoiding resource waste caused by invalid sampling. By performing analog-to-digital conversion after amplifying, filtering, and phase processing the electrical signal, the signal quality can be optimized before entering the digital domain, thereby improving the stability and accuracy of the digital coding value, reducing the interference processing burden on the subsequent software side, and thus outputting a high-quality digital signal source during the dynamic weighing process, which helps to improve the overall detection accuracy and reduce the MCU operation pressure.

[0028] Optionally, the dynamic weighing filtering method further includes:

[0029] Sample the measured item according to a preset time period to obtain the sampled weighing data of the measured item, and construct a sampled data window according to the sampled weighing data;

[0030] Obtain the sampling information of adjacent sample points within the sampled data window, and calculate the average change amount of the sampled data window according to the sampling information;

[0031] If the average change amount is less than a preset weighing steady state threshold value, it is determined that the weighing state of the measured item is in a stable state, the average weight value of the sampling data window is calculated, and the average weight value is output as the weight value of the measured item.

[0032] By adopting the above technical solution, by continuously sampling the obtained digital coding values and constructing a sliding data window, the data change trend can be dynamically judged based on local time series information, thereby avoiding the misjudgment problem caused by single-point judgment. By calculating the average change amount within the sampling window and comparing it with the steady state threshold value, the real-time identification of whether the weighing state is stable can be realized, so that the data within the window can be averaged and processed to output the final weighing result in a stable state, which can reduce the influence of fluctuation interference on the final value, thereby improving the credibility of data output and the practical use stability, and further reducing the dependence of the MCU on complex algorithms.

[0033] Optionally, the weighing data is converted from the digital coding value through a calibration conversion formula, and the calibration conversion formula is expressed as:

[0034]

[0035] In the formula, W(t) is the weighing data at time t, k is the proportionality coefficient, V(t) is the digital coding value at time t, and b is the offset.

[0036] By adopting the above technical solution, by converting the digital coding value into actual weight data through the calibration conversion formula, the accurate mapping of digital signals to real physical quantities can be realized, so as to ensure that the weight value can be stably output in real time even in a fast weighing scenario, taking into account the accuracy and real-time performance of the system.

[0037] In summary, the present application includes at least one of the following beneficial technical effects:

[0038] 1. By converting the weight of the measured item into an electrical signal through a weighing sensor, the real-time conversion of physical weight into a processable electrical signal can be realized, so that the signal processing module can generate an amplified electrical signal according to the electrical signal, which can increase the amplitude and signal-to-noise ratio of the original signal, avoid the analog-to-digital conversion error caused by too low signal amplitude, and then through the filtering module to filter the amplified electrical signal, the high-frequency noise and instantaneous disturbance can be removed, improving the stability and reliability of the final weighing data. By performing phase processing on the filtered electrical signal through the phase shift module and outputting the weighing electrical signal, the delay error introduced by the filter bank can be compensated, thereby improving the timing synchronization and sampling matching degree of signal output, so as to achieve high-stability signal output during the dynamic weighing process, improving the weighing accuracy while reducing the back-end processing pressure;

[0039] 2. By collecting the electrical signals output by the weighing sensor, it is possible to ensure real-time data collection upon effective triggering, thereby avoiding waste of resources caused by invalid sampling. After amplifying, filtering, and phase-processing the electrical signals and then performing analog-to-digital conversion, it is possible to optimize the signal quality before entering the digital domain, thereby improving the stability and accuracy of the digital coding value, reducing the interference processing burden on the subsequent software side, and thus outputting a high-quality digital signal source during the dynamic weighing process, which helps to improve the overall detection accuracy and reduce the MCU operation pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic structural diagram of a dynamic weighing filter circuit provided by an embodiment of the present application;

[0041] Figure 2 is a schematic structural diagram of a signal processing module provided by an embodiment of the present application:

[0042] Figure 3 is a schematic structural diagram of a filter module provided by an embodiment of the present application:

[0043] Figure 4 is a schematic structural diagram of a phase-shifting module provided by an embodiment of the present application:

[0044] Figure 5 is a schematic structural diagram of a weighing sensor provided by an embodiment of the present application:

[0045] Figure 6 is a schematic flowchart of a dynamic weighing filtering method provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0046] The terms used in the following embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. As used in the specification and appended claims of the present application, the singular forms "a", "an", "the", "above", "said", "this" are also intended to include the plural forms, unless the context clearly dictates otherwise. It should also be understood that the term "and / or" used in the present application refers to and includes any or all possible combinations of one or more of the listed items.

[0047] Hereinafter, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as implying or indicating relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present application, unless otherwise stated, the meaning of "a plurality" is two or more. The present application will be further described in detail below with reference to the accompanying drawings.

[0048] Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of a dynamic weighing filter circuit provided by an embodiment of the present application. The dynamic weighing filter circuit includes a weighing sensor, a signal processing module, a filtering module, and a phase shifting module. Among them, the signal processing module is connected to the weighing sensor, the filtering module is connected to the signal processing module, and the phase shifting module is connected to the filtering module.

[0049] The weighing sensor is used to convert the weight of the measured item into an electrical signal;

[0050] The signal processing module is connected to the weighing sensor and is used to generate an amplified electrical signal according to the electrical signal;

[0051] The filtering module is connected to the signal processing module and is used to perform filtering processing on the amplified electrical signal to obtain a filtered electrical signal;

[0052] The phase shifting module is connected to the filtering module and is used to perform phase processing on the filtered electrical signal and output a weighing electrical signal.

[0053] Among them, the weighing sensor converts the weight of the measured item into an electrical signal. The signal processing module is connected to the weighing sensor and is used to further amplify the weak electrical signal output by the weighing sensor to generate an amplified electrical signal. The filtering module is connected to the signal processing module and is used to perform filtering processing on the amplified electrical signal to filter out high-frequency noise.

[0054] Specifically, by placing the measured item on the sensing area of the weighing sensor, the bridge structure inside the weighing sensor generates a resistance change due to the force, and then outputs an electrical signal in analog form. Since the electrical signal is usually at the millivolt level before being processed and its amplitude is linearly related to the measured weight, the electrical signal output by the weighing sensor is processed. The signal processing module amplifies the electrical signal in terms of gain to obtain an amplified signal of analog weighing with sufficient amplitude, and then inputs it into the filtering module to remove high-frequency disturbance components, thereby obtaining a filtered electrical signal after filtering processing. Then, phase shifting processing is performed on the filtered electrical signal, which can effectively avoid the phenomenon of inaccurate rejection of defective products caused by the delay of the filtering module, thereby achieving the real-time performance of signal processing, effectively reducing the dependence on software processing while ensuring the weighing accuracy, and reducing the computing requirements for the controller.

[0055] Based on the above embodiment, as an optional embodiment, as Figure 2 shown, Figure 2The structural schematic diagram of a signal processing module is shown. The signal processing module includes a first operational amplifier U1, a second operational amplifier U2, a third operational amplifier U3, a first resistor R1, a second resistor R2, and a third resistor R3. The non-inverting input terminal of the first operational amplifier U1 is connected to the first output terminal of the weighing sensor. The output terminal of the first operational amplifier U1 is connected to one end of the second resistor R2. The other end of the second resistor R2 is connected to the inverting input terminal of the third operational amplifier U3. The inverting input terminal of the first operational amplifier U1 is connected to one end of the first resistor R1. The other end of the first resistor R1 is connected to the inverting input terminal of the second operational amplifier U2. The non-inverting input terminal of the second operational amplifier U2 is connected to the second output terminal of the weighing sensor. The output terminal of the second operational amplifier U2 is connected to one end of the third resistor R3. The other end of the third resistor R3 is connected to the non-inverting input terminal of the third operational amplifier U3. The output terminal of the third operational amplifier U3 is connected to the input terminal of the filtering module.

[0056] Specifically, since the amplitude of the electrical signal output by the weighing sensor is in the millivolt order of magnitude and changes linearly with the applied weight, subsequent amplification and processing are required for subsequent digital sampling and analysis. Therefore, the signal processing module is used for signal amplification processing. By means of the first operational amplifier U1, the second operational amplifier U2, and the third operational amplifier U3, a low-drift differential amplifier is formed. The first operational amplifier U1 is used to buffer the first electrical signal L1 at the first output terminal of the weighing sensor. The second operational amplifier U2 is used to buffer the second electrical signal L2 at the second output terminal of the weighing sensor. The third operational amplifier U3 serves as a differential amplifier to calculate the difference of the electrical signals output by the first two operational amplifiers and set the gain for output. Thus, the third operational amplifier U3 outputs an amplified electrical signal D1.

[0057] More specifically, the first resistor R1 connects the inverting input terminals of the first operational amplifier U1 and the second operational amplifier U2 to form a feedback path. The second resistor R2 and the third resistor R3 are respectively arranged between the output channels of the first operational amplifier U1 and the second operational amplifier U2 and the input terminal of the third operational amplifier U3 to control the differential amplification factor. When there is common-mode interference in the electrical signals L1 and L2 at the two output terminals of the weighing sensor, it can be effectively cancelled through the differential structure. Therefore, the weak electrical signal output by the weighing sensor can be amplified by the signal processing module, and thus the amplified electrical signal D1 is obtained.

[0058] Based on the above embodiments, as an alternative embodiment, the signal processing module further includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7; the connection between the first operational amplifier U1 and the first resistor R1 is connected to one end of the fourth resistor R4, the connection between the first operational amplifier U1 and the second resistor R2 is connected to the other end of the fourth resistor R4, the connection between the second operational amplifier U2 and the first resistor R1 is connected to one end of the fifth resistor R5, the connection between the second operational amplifier U2 and the third resistor R3 is connected to the other end of the fifth resistor R5, the connection between the third operational amplifier U3 and the second resistor R2 is connected to one end of the sixth resistor R6, the connection between the third operational amplifier U3 and the filtering module is connected to the other end of the sixth resistor R6, the connection between the third resistor R3 and the third operational amplifier U3 is connected to one end of the seventh resistor R7, and the other end of the seventh resistor R7 is grounded.

[0059] Specifically, to further improve the processing accuracy and response consistency of the signal processing module, a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6 are introduced on the basis of the low-drift differential amplifier formed by the first operational amplifier U1, the second operational amplifier U2, and the third operational amplifier U3 to form a symmetric feedback adjustment structure. The fourth resistor R4 connects the inverting input terminal of the first operational amplifier U1 to form a compensation path between the first resistor R1 and the second resistor R2. The fifth resistor R5 is connected between the output terminal of the second operational amplifier U2 and the first resistor R1 and the third resistor R3 to balance the inverting channel of the second operational amplifier U2. The output terminal of the third operational amplifier U3 is connected to the inverting input terminal of the third operational amplifier U3 and the filtering module through the sixth resistor R6 to form a buffer feedback. The seventh resistor R7 connects the non-inverting input terminal of the third operational amplifier U3 to the ground to form an impedance matching structure, thereby improving the common-mode rejection ratio of the circuit and maintaining channel symmetry.

[0060] Based on the above embodiments, as an alternative embodiment, as Figure 3 shown Figure 3A structural schematic diagram of a filtering module is shown. The filtering module includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a first capacitor C1, a second capacitor C2, and a fourth operational amplifier U4. One end of the eighth resistor R8 is connected to the output terminal of the third operational amplifier U3, the other end of the eighth resistor R8 is connected to one end of the ninth resistor R9, the other end of the ninth resistor R9 is connected to the inverting input terminal of the fourth operational amplifier U4, the non-inverting input terminal of the fourth operational amplifier U4 is connected to one end of the tenth resistor R10, the other end of the tenth resistor R10 is grounded, the output terminal of the fourth operational amplifier U4 is connected to the input terminal of the phase-shifting module, the connection between the eighth resistor R8 and the ninth resistor R9 is connected to one end of the first capacitor C1, the other end of the first capacitor C1 is connected to the output terminal of the fourth operational amplifier U4, the connection between the fourth operational amplifier U4 and the tenth resistor R10 is connected to one end of the eleventh resistor R11, the other end of the eleventh resistor R11 is connected to the output terminal of the fourth operational amplifier U4, the connection between the fourth operational amplifier U4 and the ninth resistor R9 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is grounded.

[0061] Specifically, due to the existence of a large amount of high-frequency interference in the dynamic weighing scenario, such as motor noise, electromagnetic interference, etc., directly sampling the unfiltered signal will cause the weighing result to fluctuate unstably. Therefore, a second-order active low-pass filtering structure is constructed using the eighth resistor R8, the ninth resistor R9, the tenth resistor R10, the eleventh resistor R11, the first capacitor C1, the second capacitor C2, and the fourth operational amplifier U4, which can effectively filter the amplified electrical signal D1, thereby suppressing the invalid high-frequency components and extracting the main component of the signal trend.

[0062] More specifically, the eighth resistor R8 is connected to the output terminal of the third operational amplifier U3 to serve as a filtering input channel, the ninth resistor R9 is connected to the inverting input terminal of the fourth operational amplifier U4, the tenth resistor R10 is the bias impedance of the non-inverting input of the fourth operational amplifier U4 and is connected to the ground, the eleventh resistor R11 serves as a negative feedback channel, connecting the output terminal and the non-inverting input terminal of the fourth operational amplifier U4, the first capacitor C1, the eighth resistor R8, and the ninth resistor R9 form an input RC filtering network to determine the first-stage filtering characteristics, the second capacitor C2 is connected between the inverting input of the fourth operational amplifier U4 and the ground to form a second-stage integration response, the fourth operational amplifier U4 realizes the functions of impedance isolation and filtering gain control, and the response frequency of the filtering module can be flexibly configured by selecting the values of the resistor R and the capacitor C, so as to match the fluctuation characteristics and the desired response speed of the electrical signal output by the weighing sensor in the dynamic state.

[0063] Based on the above embodiments, as an optional embodiment, as Figure 4 shown, Figure 4The structural schematic diagram of a phase shift module is shown. The phase shift module includes a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a third capacitor C3, a fourth capacitor C4, and a fifth operational amplifier U5. One end of the twelfth resistor R12 is connected to the output end of the fourth operational amplifier U4, the other end of the twelfth resistor R12 is connected to one end of the third capacitor C3, the other end of the third capacitor C3 is connected to the inverting input end of the fifth operational amplifier U5, the connection between the twelfth resistor R12 and the fourth operational amplifier U4 is connected to one end of the fourteenth resistor R14, the other end of the fourteenth resistor R14 is connected to the non-inverting input end of the fifth operational amplifier U5, the connection between the twelfth resistor R12 and the third capacitor C3 is connected to one end of the fourth capacitor C4, the other end of the fourth capacitor C4 is connected to the output end of the fifth operational amplifier U5, one end of the thirteenth resistor R13 is connected to the fourth capacitor C4, the connection between the third capacitor C3 and the fifth operational amplifier U5 is connected to the other end of the thirteenth resistor R13, the connection between the fourteenth resistor R14 and the fifth operational amplifier U5 is connected to one end of the fifteenth resistor R15, and the other end of the fifteenth resistor R15 is grounded.

[0064] Specifically, since the active low-pass filter structure in the filtering module has a certain delay, if the filtered electrical signal processed by the filtering module is directly processed, it will cause the data processing to be too slow and lead to inaccurate weighing of defective products. Therefore, a phase shift module is used to perform forward phase compensation on the filtered electrical signal, thereby correcting the sampling timing, ensuring the judgment stability and result accuracy, and achieving the real-time performance of signal processing. Therefore, an active all-pass filter structure is constructed using the twelfth resistor R12, the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, the third capacitor C3, the fourth capacitor C4, and the fifth operational amplifier U5. This structure is used to compensate for the signal delay brought by the previous low-pass filter structure.

[0065] More specifically, the twelfth resistor R12 is used as the input channel of the phase shift module and is connected to the output end of the fourth operational amplifier U4. The thirteenth resistor R13 constitutes a feedback network. The fourteenth resistor R14 is connected to the non-inverting input end of the fifth operational amplifier U5. The fifteenth resistor R15 is connected between the non-inverting input of the fifth operational amplifier U5 and the ground to form a bias. The third capacitor C3 is connected between the twelfth resistor R12 and the inverting input end of the fifth operational amplifier U5. The fourth capacitor C4 is used as a feedback capacitor and is connected between the output of the fifth operational amplifier U5 and the connection between the twelfth resistor R12 and the third capacitor C3, realizing the phase rotation of the filtered electrical signal output by the filtering module in the full frequency band without changing the amplitude response. By setting reasonable parameters, a fixed-angle forward phase can be achieved, effectively improving the capture response accuracy of short-time overloaded objects under dynamic weighing.

[0066] Based on the above embodiments, as an alternative embodiment, as Figure 5 shown, Figure 5 FIG. shows a schematic structural diagram of a weighing sensor. The weighing sensor includes a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, and a nineteenth resistor R19. One end of the sixteenth resistor R16 is connected to one end of the seventeenth resistor R17. The other end of the seventeenth resistor R17 is connected to one end of the eighteenth resistor R18. The other end of the eighteenth resistor R18 is connected to one end of the nineteenth resistor R19. The other end of the nineteenth resistor R19 is connected to the other end of the sixteenth resistor R16. The connection between the sixteenth resistor R16 and the nineteenth resistor R19 is connected to a DC input signal source.

[0067] Specifically, the weighing sensor utilizes a Wheatstone bridge structure composed of multiple resistors to achieve the function of converting force into voltage output. The sixteenth resistor R16, the seventeenth resistor R17, the eighteenth resistor R18, and the nineteenth resistor R19 form a four-arm resistor bridge. Among them, the sixteenth resistor R16 and the seventeenth resistor R17 are connected in series to form a first branch, and the eighteenth resistor R18 and the nineteenth resistor R19 are connected in series to form a second branch. The two branches are connected in parallel to form a closed loop. The DC input power supply is connected to the node between the sixteenth resistor R16 and the nineteenth resistor R19 to provide an excitation voltage, ensuring that an electrical signal can be stably output during the weighing process, thereby outputting a first electrical signal L1 and a second electrical signal L2.

[0068] More specifically, when an external pressure acts on the weighing sensor body, that is, when the measured object is placed on the sensing area of the weighing sensor, the resistance value of the bridge arm changes slightly, resulting in the bridge voltage being no longer balanced. As a result, a differential voltage signal is output at the diagonal node. The voltage value represented by this differential voltage signal is linearly related to the magnitude of the external force and changes with time. Moreover, the amplitude of the electrical signal output by this weighing sensor is in the millivolt order of magnitude.

[0069] Based on the above embodiments, as an alternative embodiment, the dynamic weighing filter circuit further includes an analog-to-digital conversion module. The analog-to-digital conversion module is connected to the phase-shifting processing module and is used to perform analog-to-digital conversion processing on the weighing electrical signal and output a digital encoded value.

[0070] Specifically, the analog-to-digital conversion module is used to convert the analog weighing electrical signal into a processable digital encoded value. This module is connected to the phase-shifting module and uses the weighed electrical signal after filtering and phase-shifting processing as the input signal source. The analog-to-digital conversion module can select a 12-bit or 16-bit high-precision ADC chip, and achieve range matching by setting the reference voltage and input range. For example, when the input signal amplitude range is 0–2V and the ADC resolution is 4096 levels, each level represents a voltage change of approximately 0.49mV. Therefore, during the sampling process, the analog input signal is converted into the corresponding digital encoded value and output to the processor for subsequent digital conversion and weighing judgment.

[0071] Please refer to Figure 6 , Figure 6 FIG. is a schematic flow chart of a dynamic weighing filtering method applied to the above dynamic weighing filtering circuit provided by an embodiment of the present application. The dynamic weighing filtering method includes:

[0072] S1. Collect the electrical signal output by the weighing sensor.

[0073] Specifically, after starting the weighing device equipped with the dynamic weighing filtering circuit, the weighing device can be a weighing instrument. After placing the object to be measured in the weighing sensing area of the weighing device, the weighing sensor converts its acting force into an analog voltage signal. The weight information of the object to be measured is converted by the weighing sensor into the output of the bridge differential pressure generated after being stressed, that is, the electrical signal is obtained. Since the electrical signal is usually at the millivolt level before being processed, its amplitude is linearly related to the measured weight, and thus enters the next signal processing process.

[0074] More specifically, by obtaining the dual-channel output differential voltage signals from the weighing sensor, namely the first electrical signal L1 and the second electrical signal L2, the amplitudes of these two electrical signals are generally between 0–20mV. Since the obtained electrical signals have noise and bias without amplification and filtering and are not suitable for direct sampling, the analog signal is sent into the subsequent signal conditioning path through the interface circuit for amplification and filtering. The electrical signal changes significantly in amplitude as the object is applied and removed.

[0075] S2. Perform signal amplification and filtering processing on the electrical signal and output the filtered electrical signal, and analyze the phase response characteristic information of the filtered electrical signal according to the filtered electrical signal.

[0076] Specifically, amplification processing is performed by a signal processing module connected to a load cell. The signal processing module performs gain amplification on the electrical signal output by the load cell. During the signal amplification process, the millivolt-level signal is boosted to the volt-level to meet the ADC input dynamic range requirements. Subsequently, filtering processing is carried out by a filtering module connected to the signal processing module. The filtering module filters the amplified electrical signal output by the signal processing module. In the filtering stage, a low-pass active filter structure is adopted to attenuate noise components such as high-frequency jitter and power frequency interference in the signal. After filtering, the signal exhibits a curve characteristic that changes smoothly with the weight. The output filtered electrical signal serves as the input judgment basis for whether phase shift compensation is required subsequently, and its quality directly determines the credibility of the final sampled data and the weighing accuracy.

[0077] Exemplarily, a second-order active low-pass filtering structure constructed by an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a first capacitor C1, a second capacitor C2, and a fourth operational amplifier U4 is used to filter out high-frequency noise. The transfer function of this second-order active low-pass filtering structure is: , where A is the gain (A < 3), and it is expressed as: , and the cut-off frequency is expressed as: , so different frequency bands of high-frequency noise can be filtered by adjusting relevant parameters. In the embodiments of the present application, the parameters are selected as R8 = R9 = R, and C1 = C2 = C.

[0078] More specifically, the phase delay degree is judged according to the time difference between the response change characteristic of the filtered electrical signal and the sampling clock. By setting a reference standard phase response or detecting the offset position of the signal rising edge relative to the sampling point, it is evaluated whether there is a significant lag trend in the current signal. When it is detected that the signal response has a fixed delay greater than the set threshold relative to the control beat, it is determined that there is a phase shift. Phase response hysteresis will cause the weighing judgment to be advanced or delayed. Therefore, it is necessary to calculate and judge whether the current filtered electrical signal needs compensation processing.

[0079] S3. Determine whether to perform phase shift compensation processing based on the phase response characteristic information, and output a weighing electrical signal. Perform analog-to-digital conversion processing on the weighing electrical signal and output a digital encoded value.

[0080] Specifically, it is determined whether and how to perform phase adjustment on the signal according to the foregoing phase analysis result to correct or compensate for the phase delay introduced by the low-pass filter. For example, if the analysis finds that the phase delay of the main weight signal frequency component exceeds the preset allowable time lag, which may cause subsequent weight determination and rejection actions to be untimely, then a phase shift compensation process is initiated, such as through an all-pass filter. The purpose of this process is to appropriately advance the phase of the signal, so as to restore the real-time nature of the signal as much as possible, and ensure that the weighing system can quickly respond to rapidly changing weight signals. If the delay degree is higher than the acceptable range, it will automatically switch to the signal output channel with a phase shift compensation path and output the compensated signal. After the above amplification, filtering, and possible phase shift compensation processes, an optimized analog electrical signal is obtained, which is considered to be the analog electrical quantity that can most accurately reflect the weight of the item at present, that is, the weighing electrical signal.

[0081] Exemplarily, since the active low-pass filter structure in the filtering module has a certain time delay, if the filtered electrical signal processed by the filtering module is directly processed, it will cause the data processing to be too slow and result in inaccurate weighing of defective products. Therefore, an active all-pass filter structure is constructed using the twelfth resistor R12, the thirteenth resistor R13, the fourteenth resistor R14, the fifteenth resistor R15, the third capacitor C3, the fourth capacitor C4, and the fifth operational amplifier U5. The transfer function of this active all-pass filter structure is , where , , , , so as to perform forward phase compensation on the filtered electrical signal, thereby correcting the sampling timing, ensuring the judgment stability and result accuracy, and achieving the real-time nature of signal processing.

[0082] More specifically, the finally determined weighing electrical signal is input to the analog-to-digital conversion module. The sampling operation is triggered through a preset sampling period, and the analog voltage signal is quantized bit by bit into a digital coding value and output to the register. The coding value is a unitless integer value, and the numerical range is related to the ADC resolution and the reference voltage. For example, a 12-bit ADC can convert the analog voltage signal into an integer between 0 and 4095, thereby converting the analog signal into a digital signal.

[0083] Based on the above embodiments, as an optional embodiment, the dynamic weighing filtering method further includes:

[0084] S4. Sampling the item to be measured according to a preset time period to obtain the sampling weighing data of the item to be measured, and constructing a sampling data window according to the sampling weighing data.

[0085] Specifically, through periodic sampling interrupts set by a timer, at a fixed and preset time interval, such as every 5 milliseconds or 20 milliseconds, continuously read and record the current digital coding values, and use these digital coding values as sampled weighing data points. Based on these sampled weighing data, constructing a sampled data window means storing a series of such sampled weighing data points collected in a recent period of time in a first-in-first-out (FIFO) queue or an array of fixed size. For example, always retain the latest 50 sampled data points. This set containing a series of sampled data arranged in chronological order constitutes the sampled data window. After construction, it enters the stability identification and judgment step.

[0086] S5. Obtain the sampling information of adjacent sample points within the sampled data window, and calculate the average change amount of the sampled data window according to the sampling information.

[0087] Specifically, perform a difference operation on all adjacent sampling points in the sampling window to obtain the fluctuation amplitude and calculate its average value as the weighing fluctuation judgment benchmark. The expression for calculating the average change amount is , where N represents the length of the sampling window, represents the average change amount, which is an evaluation index for the stability of data changes within the current weighing window. This average change amount can reflect whether the weighing signal tends to be stable or is still fluctuating violently. For example, if an item is just placed on the sensor, the average change amount of the first few data windows will be relatively large, and when the item is stationary, this value will decrease significantly.

[0088] S6. If the average change amount is less than the preset weighing steady state threshold, then judge that the weighing state of the measured item is in a stable state, calculate the average weight value of the sampled data window, and output the average weight value as the weight value of the measured item.

[0089] Specifically, compare the calculated average change amount of the sampled data window with a preset reference value, which is used to define whether the weighing process reaches a stable state, that is, the preset weighing steady state threshold. This preset weighing steady state threshold needs to be determined according to the actual application scenario and weighing accuracy requirements. For example, for high-precision weighing, this threshold may be set to a very small weight unit. Judging that the weighing state of the measured item is in a stable state means that if the calculated average change amount is lower than this set threshold, it is considered that the reading on the weighing sensor has basically stopped jumping significantly and has reached a stable state that can be trusted. After confirming that the weighing state is stable, sum up all the sampled weighing data stored in the current sampled data window (these data may already be weight values after preliminary calibration and conversion), and then divide by the number of sample points in the window to obtain the arithmetic average of these data. Output the average weight value as the weight value of the measured item. That is, the expression for the steady state weight value is , the arithmetic mean method can effectively suppress the influence of small fluctuations within the window and improve the weighing stability and consistency. Therefore, the calculated average weight value is used as the final valid result of this weighing operation. For example, if the average change is less than 0.05 grams, it is considered stable. At this time, the average value of the data within the calculation window is calculated as the gram weight of the item reported finally.

[0090] Based on the above embodiments, as an alternative embodiment, the weighing data is converted from the digital coding value through a calibration conversion formula, and the calibration conversion formula is expressed as:

[0091]

[0092] In the formula, W(t) is the weighing data at time t, k is the proportionality coefficient, V(t) is the digital coding value at time t, and b is the offset.

[0093] Specifically, immediately after sampling the digital coding value, the conversion logic is called to convert the coding value into weighing data with actual physical meaning. The conversion process uses the linear mapping model established in the calibration stage, expressed by the formula , where V(t) is the digital coding value sampled at the current time point, which is an integer value without unit output by a 12-bit or 16-bit ADC. k represents the weight increment corresponding to the unit code value, and the unit can be g / LSB or kg / LSB. b is the offset value used to compensate for the initial output of the system under no-load conditions, that is, the weight value corresponding to V(t)=0. For example, when the system is initially set or calibrated regularly, at least two standard weights with known weights are used for calibration. By reading their respective corresponding stable digital coding values and solving the system of equations simultaneously, the unique k value and b value are obtained. Therefore, during normal weighing operations, whenever a new digital coding value V(t) is obtained, it is immediately substituted into this formula for calculation, so as to obtain a calibrated and accurate weighing data W(t). For example, if k is obtained as 0.005 grams / unit code and b is -2.5 grams through calibration, when the digital coding value V(t) output by the ADC is 1500, the actual weighing data W(t) is calculated as 0.005⋅1500−2.5 = 7.5−2.5 = 5.0 grams, which ensures the accuracy and consistency of the measurement results.

[0094] In summary, by collecting the weighing electrical signals output by the weighing sensor, the embodiments of the present application can ensure real-time data collection when effectively triggered, thus avoiding resource waste caused by invalid sampling. By performing amplification, filtering, and phase processing on the weighing electrical signals and then performing analog-to-digital conversion, the quality of the signals can be optimized before entering the digital domain, thereby improving the stability and accuracy of the digital coding values, reducing the interference processing burden on the subsequent software side, and outputting a high-quality digital signal source during the dynamic weighing process, which helps to improve the overall detection accuracy and reduce the operation pressure of the MCU.

[0095] It should be understood that the magnitudes of the sequence numbers of the steps in the above embodiments do not imply the order of execution. The order of execution of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0096] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A dynamic weighing filter circuit, characterized in that, The dynamic weighing filter circuit includes: A weighing sensor for converting the weight of an object to be measured into an electrical signal; A signal processing module connected to the weighing sensor for generating an amplified electrical signal according to the electrical signal; A filtering module connected to the signal processing module for filtering the amplified electrical signal to obtain a filtered electrical signal; A phase shift module connected to the filtering module for performing phase processing on the filtered electrical signal and outputting a weighing electrical signal.

2. The dynamic weighing filter circuit according to claim 1, wherein The signal processing module includes a first operational amplifier U1, a second operational amplifier U2, a third operational amplifier U3, a first resistor R1, a second resistor R2, and a third resistor R3. The non-inverting input terminal of the first operational amplifier U1 is connected to the first output terminal of the weighing sensor. The output terminal of the first operational amplifier U1 is connected to one end of the second resistor R2. The other end of the second resistor R2 is connected to the inverting input terminal of the third operational amplifier U3. The inverting input terminal of the first operational amplifier U1 is connected to one end of the first resistor R1. The other end of the first resistor R1 is connected to the inverting input terminal of the second operational amplifier U2. The non-inverting input terminal of the second operational amplifier U2 is connected to the second output terminal of the weighing sensor. The output terminal of the second operational amplifier U2 is connected to one end of the third resistor R3. The other end of the third resistor R3 is connected to the non-inverting input terminal of the third operational amplifier U3. The output terminal of the third operational amplifier U3 is connected to the input terminal of the filtering module.

3. The dynamic weighing filter circuit according to claim 2, wherein The signal processing module further includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. The connection between the first operational amplifier U1 and the first resistor R1 is connected to one end of the fourth resistor R4. The connection between the first operational amplifier U1 and the second resistor R2 is connected to the other end of the fourth resistor R4. The connection between the second operational amplifier U2 and the first resistor R1 is connected to one end of the fifth resistor R5. The connection between the second operational amplifier U2 and the third resistor R3 is connected to the other end of the fifth resistor R5. The connection between the third operational amplifier U3 and the second resistor R2 is connected to one end of the sixth resistor R6. The connection between the third operational amplifier U3 and the filtering module is connected to the other end of the sixth resistor R6. The connection between the third resistor R3 and the third operational amplifier U3 is connected to one end of the seventh resistor R7. The other end of the seventh resistor R7 is grounded.

4. The dynamic weighing filter circuit according to claim 3, wherein The filtering module includes an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a first capacitor C1, a second capacitor C2, and a fourth operational amplifier U4. One end of the eighth resistor R8 is connected to the output end of the third operational amplifier U3. The other end of the eighth resistor R8 is connected to one end of the ninth resistor R9. The other end of the ninth resistor R9 is connected to the inverting input end of the fourth operational amplifier U4. The non-inverting input end of the fourth operational amplifier U4 is connected to one end of the tenth resistor R10. The other end of the tenth resistor R10 is grounded. The output end of the fourth operational amplifier U4 is connected to the input end of the phase-shifting module. The connection point of the eighth resistor R8 and the ninth resistor R9 is connected to one end of the first capacitor C1. The other end of the first capacitor C1 is connected to the output end of the fourth operational amplifier U4. The connection point of the fourth operational amplifier U4 and the tenth resistor R10 is connected to one end of the eleventh resistor R11. The other end of the eleventh resistor R11 is connected to the output end of the fourth operational amplifier U4. The connection point of the fourth operational amplifier U4 and the ninth resistor R9 is connected to one end of the second capacitor C2. The other end of the second capacitor C2 is grounded.

5. The dynamic weighing filter circuit according to claim 4, wherein The phase-shifting module includes a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a third capacitor C3, a fourth capacitor C4, and a fifth operational amplifier U5. One end of the twelfth resistor R12 is connected to the output end of the fourth operational amplifier U4. The other end of the twelfth resistor R12 is connected to one end of the third capacitor C3. The other end of the third capacitor C3 is connected to the inverting input end of the fifth operational amplifier U5. The connection point of the twelfth resistor R12 and the fourth operational amplifier U4 is connected to one end of the fourteenth resistor R14. The other end of the fourteenth resistor R14 is connected to the non-inverting input end of the fifth operational amplifier U5. The connection point of the twelfth resistor R12 and the third capacitor C3 is connected to one end of the fourth capacitor C4. The other end of the fourth capacitor C4 is connected to the output end of the fifth operational amplifier U5. One end of the thirteenth resistor R13 is connected to the fourth capacitor C4. The connection point of the third capacitor C3 and the fifth operational amplifier U5 is connected to the other end of the thirteenth resistor R13. The connection point of the fourteenth resistor R14 and the fifth operational amplifier U5 is connected to one end of the fifteenth resistor R15. The other end of the fifteenth resistor R15 is grounded.

6. The dynamic weighing filter circuit according to claim 5, wherein, The weighing sensor includes a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, and a nineteenth resistor R19. One end of the sixteenth resistor R16 is connected to one end of the seventeenth resistor R17. The other end of the seventeenth resistor R17 is connected to one end of the eighteenth resistor R18. The other end of the eighteenth resistor R18 is connected to one end of the nineteenth resistor R19. The other end of the nineteenth resistor R19 is connected to the other end of the sixteenth resistor R16. The connection between the sixteenth resistor R16 and the nineteenth resistor R19 is connected to a DC input signal source.

7. The dynamic weighing filter circuit according to claim 1, wherein The dynamic weighing filter circuit further includes an analog-to-digital conversion module. The analog-to-digital conversion module is connected to the phase shift processing module and is used to perform analog-to-digital conversion processing on the weighing electrical signal and output a digital coding value.

8. A dynamic weighing filtering method is applied to a dynamic weighing filtering circuit as described in any one of claims 1-7, characterized in that, The dynamic weighing filtering method includes: Collecting the electrical signal output by the weighing sensor; Performing signal amplification and filtering processing on the electrical signal and then outputting a filtered electrical signal, and analyzing the phase response characteristic information of the filtered electrical signal according to the filtered electrical signal; Judging whether to perform phase shift compensation processing through the phase response characteristic information and outputting a weighing electrical signal, performing analog-to-digital conversion processing on the weighing electrical signal, and outputting a digital coding value.

9. The dynamic weighing filtering method according to claim 8, wherein The dynamic weighing filtering method further includes: Sampling the measured item according to a preset time period to obtain the sampled weighing data of the measured item, and constructing a sampled data window according to the sampled weighing data; Obtaining the sampling information of adjacent sample points within the sampled data window, and calculating the average change amount of the sampled data window according to the sampling information; If the average change amount is less than a preset weighing steady state threshold, it is determined that the weighing state of the measured item is in a stable state, calculating the average weight value of the sampled data window, and outputting the average weight value as the weight value of the measured item.

10. The dynamic weighing filtering method according to claim 9, characterized in that, The weighing data is obtained by conversion through a calibration conversion formula from the digital coding value. The calibration conversion formula is expressed as: Where W(t) is the weighing data at time t, k is the proportionality coefficient, V(t) is the digital coding value at time t, and b is the offset.

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