A measuring system and method for resolving multiple position information from a single ac signal

Abstract

The application discloses a kind of single-way ac signal solution multiple position information measurement system and method, comprising: frequency characteristic module, for the transformation of several objects to be measured position conversion into first output signal, the first output signal includes with several objects to be measured position transformation one-to-one corresponding ac voltage signal;Addition circuit module, for the first output signal is superimposed, generates second output signal, and the second output signal includes single ac voltage signal;Sampling system module, for the second output signal is converted into digital signal, obtains the amplitude-frequency characteristic of the second output signal, according to the amplitude-frequency characteristic obtains the position of each object to be measured.Solve the problem of high hardware cost of existing multi-position information acquisition system.The hardware cost of simultaneously measuring multiple position system is reduced, and the purpose of improving the synchronization of system acquisition is realized.

Description

Technical Field

[0001] This application relates to the field of computer technology, and in particular to a measurement system and method for calculating multiple location information from a single AC signal. Background Technology

[0002] In industrial production or scientific research experiments, it is sometimes necessary to collect the position of objects to achieve functions such as safety monitoring or automated control. Commonly used measurement methods include the following:

[0003] One method utilizes the propagation time of energy waves to determine the position of an object, such as using radar, ultrasonic sensors, or infrared sensors. Its advantage is that it allows for non-contact measurement, but its disadvantages include poor directionality, requirements on the measurement area of ​​the object, and the inability for multiple sensors of the same type to operate simultaneously, otherwise interference will occur.

[0004] The second method involves taking pictures of the object to be measured with a camera, processing the images with a computer, and analyzing their features to determine their location. Its advantage is that it allows for non-contact measurement, but its disadvantages include higher hardware and software development costs, and it is subject to strict environmental requirements, making it unsuitable for measurement needs in dusty or sandy environments.

[0005] Third, the displacement of an object is converted into changes in parameters such as resistance, inductance, and capacitance within the system. The position of the measured object is then calculated by measuring changes in electrical signals such as voltage, current, and frequency output from the sensor. This acquisition method is flexible, simple in structure, and has strong anti-interference capabilities. Compared to the previous two methods, it is adaptable to more working conditions, has fewer requirements for the measured object and the operating environment, is more commonly used, and is relatively inexpensive. It has been widely applied in industries such as machine tool processing and testing instruments.

[0006] Currently, for the third measurement method, if the acquisition system needs to simultaneously measure the positions of multiple objects, it is typically necessary to configure an analog-to-digital converter (ADC) channel for the output of each object's position sensor. Furthermore, if simultaneity is required, the conversion time and sampling level hold time of the ADC are critical; otherwise, it is difficult to guarantee the simultaneity of multi-channel data acquisition. The more object positions the system needs to measure, the more ADC channels are required, and the higher the demands on circuit performance, which significantly increases the hardware cost of the multi-position information acquisition system. Summary of the Invention

[0007] This application provides a measurement system and method for calculating multiple location information from a single AC signal, which solves the problem in the prior art where the more object locations that need to be measured, the more analog-to-digital converter channels are required, and the higher the requirements for circuit performance, resulting in a significant increase in the hardware requirements of the multi-location information acquisition system.

[0008] To address the above problems, this application provides the following technical solution:

[0009] In a first aspect, embodiments of this application provide a measurement system for calculating multiple location information from a single AC signal, including:

[0010] The frequency characteristic module is used to convert the changes in the positions of several objects under test into a first output signal. The first output signal includes an AC voltage signal that corresponds one-to-one with the changes in the positions of the several objects under test.

[0011] An adder circuit module is used to superimpose the first output signal to generate a second output signal, wherein the second output signal includes a single AC voltage signal;

[0012] The sampling system module is used to convert the second output signal into a digital signal, obtain the amplitude-frequency characteristics of the second output signal, and obtain the position of each object to be measured based on the amplitude-frequency characteristics.

[0013] Furthermore, the frequency characteristic module includes a frequency characteristic circuit, which includes:

[0014] An oscillating circuit is used to convert the positional change of at least one object under test into a first output signal.

[0015] The signal processing circuit is used to filter and scale the first output signal to improve signal quality. The filtering process is used to attenuate signals outside the effective operating frequency band, and the scaling process is used to adjust the signal amplitude to a suitable level.

[0016] Furthermore, the oscillation circuit includes a Wien bridge oscillation circuit.

[0017] Furthermore, if there are multiple frequency characteristic circuits in the measurement system, then the effective operating frequency bands P of each frequency characteristic circuit do not overlap.

[0018] Furthermore, the addition circuit module employs an addition circuit, which includes at least one input terminal and one output terminal. The at least one input terminal is used to input AC voltage signals output by a corresponding number of frequency characteristic circuits, and the output terminal is used to output the superimposed AC voltage signals.

[0019] Furthermore, the sampling system includes:

[0020] A digital-to-analog converter circuit is used to convert the second output signal into a digital signal;

[0021] A computer system is used to convert the second output signal into a digital signal, perform a Fourier transform to obtain the amplitude-frequency characteristics of the second output signal, and obtain the position of each object under test based on the amplitude-frequency characteristics.

[0022] Secondly, embodiments of this specification also provide a measurement method for calculating multiple location information from a single AC signal, used to implement any of the systems described in the first aspect, comprising:

[0023] Acquire a first output signal, which includes an AC voltage signal that corresponds one-to-one with the position changes of a plurality of objects to be measured.

[0024] The first output signal is superimposed to generate a second output signal, the second output signal including a single AC voltage signal;

[0025] The second output signal is converted into a digital signal to obtain the amplitude-frequency characteristics of the second output signal, and the position of each object to be measured is obtained based on the amplitude-frequency characteristics.

[0026] The above-mentioned at least one technical solution adopted in the embodiments of this application can achieve the following beneficial effects: the system can simultaneously represent the position of multiple objects in the system by outputting one analog signal, and the measurement circuit is mainly an analog circuit with good anti-interference performance; the system only needs to configure one analog-to-digital converter channel to meet the acquisition requirements, and the requirements for the conversion time of the analog-to-digital converter and the sampling level holding time are low, thus achieving low cost; non-contact measurement can be realized, and it can be used in harsh measurement environments such as dusty, sandy, or high-temperature environments. Attached Figure Description

[0027] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0028] Figure 1 This is a schematic diagram of the structure of a measurement system for calculating multiple location information from a single AC signal, as provided in this embodiment.

[0029] Figure 2 This is a circuit diagram of a measurement system for calculating multiple location information from a single AC signal, provided in this embodiment.

[0030] Figure 3 This is a schematic flowchart illustrating a measurement method for calculating multiple location information from a single AC signal, as provided in this embodiment.

[0031] Figure 4 This describes the relationship between the insertion depth of the iron rod and the frequency of the output signal in the frequency characteristic circuit provided in this embodiment. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] Currently, if a data acquisition system needs to simultaneously measure the positions of multiple objects, it typically requires a dedicated analog-to-digital converter (ADC) channel for the output of each object's position sensor. Furthermore, if simultaneity is required, the conversion time and sampling hold time of the ADC are critical; otherwise, it's difficult to guarantee the simultaneity of multi-channel data acquisition. The more object positions the system needs to measure, the more ADC channels are required, and the higher the demands on circuit performance, significantly increasing the hardware cost of the multi-position information acquisition system.

[0034] Therefore, this application provides a measurement system for calculating multiple location information from a single AC signal. Utilizing the characteristic that AC voltage signals can contain multiple frequency signals, a frequency characteristic circuit converts the position change of the object under test into a change in the output signal frequency. An adder circuit module then superimposes these multiple signals for output, enabling the simultaneous measurement of multiple object positions using only one AC signal. This reduces the hardware cost of systems requiring simultaneous multi-location measurements and improves the synchronization of system acquisition.

[0035] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0036] This embodiment provides a measurement system for calculating multiple location information from a single AC signal. Please refer to [link / reference]. Figure 1 As shown, it includes:

[0037] The frequency feature module 100 is used to convert the changes in the positions of several objects under test into a first output signal, wherein the first output signal includes an AC voltage signal that corresponds one-to-one with the changes in the positions of several objects under test.

[0038] For specific implementation details, please refer to [link / reference]. Figure 2 As shown, the frequency characteristic module includes a frequency characteristic circuit, which includes:

[0039] The oscillation circuit 101 is used to convert the position change of at least one object under test into a first output signal.

[0040] The signal processing circuit 102 is used to filter and scale the first output signal to improve the signal quality. The filtering process is used to attenuate signals outside the effective operating frequency band, and the scaling process is used to adjust the signal amplitude to a suitable level.

[0041] Specifically, the oscillation circuit, preferably a Wien bridge oscillation circuit, includes at least one variable inductor. When the variable inductor changes, the frequency of the AC voltage signal output by the oscillation circuit also changes accordingly. The variable inductor can directly correlate the inductance value in the circuit with the position change of the object under test through mechanical structure, or indirectly by using a magnetic material near the inductor coil to affect the self-inductance or mutual inductance coefficient. That is, the oscillation circuit of the frequency characteristic circuit can convert the position change of the object under test into a frequency change of the output signal.

[0042] In the frequency characteristic circuit described above, the frequency f of the AC signal output by the oscillator circuit is related to the position x of the object under test by f = F(x), and the frequency f of the designed oscillator circuit output signal is within the interval... It has monotonicity.

[0043] In the formula, D represents the effective range of the position of the object to be measured, and the relationship F(x) can be calculated theoretically or fitted using actual measurement data. In the above relationship f = F(x), within the interval... superior, P is called the effective operating frequency band of the frequency characteristic circuit. Furthermore, if there are multiple frequency characteristic circuits in the measurement system, the effective operating frequency bands P of each frequency characteristic circuit do not overlap.

[0044] The signal processing circuit in the frequency characteristic circuit can filter and scale the AC voltage signal output by the oscillator circuit to improve signal quality. The filtering process is used to attenuate signals outside the effective operating frequency band, and the scaling process adjusts the signal amplitude to a suitable level.

[0045] The adder circuit module 200 is used to superimpose the first output signal to generate a second output signal, the second output signal including a single AC voltage signal;

[0046] In specific implementation, the adder circuit module adopts an adder circuit, which includes at least one input terminal and one output terminal. The at least one input terminal is used to input AC voltage signals output from corresponding frequency characteristic circuits, and the output terminal is used to output the superimposed AC voltage signals. The adder circuit is a non-inverting proportional adder circuit composed of operational amplifiers, expressed by the following expression:

[0047] u O =u I1 +u I2 +…+u In(1)

[0048] Among them, u O To output the superimposed AC voltage signal, u In This represents the AC voltage signal output by the nth input frequency characteristic circuit in the system.

[0049] The sampling system module 300 is used to convert the second output signal into a digital signal, obtain the amplitude-frequency characteristics of the second output signal, and obtain the position of each object to be measured based on the amplitude-frequency characteristics.

[0050] In practice, the sampling system includes:

[0051] The digital-to-analog converter circuit 301 is used to convert the second output signal into a digital signal;

[0052] Computer system 302 is used to convert the second output signal into a digital signal, perform Fourier transform, obtain the amplitude-frequency characteristics of the second output signal, and obtain the position of each object to be measured based on the amplitude-frequency characteristics.

[0053] Specifically, an ADC circuit refers to an analog-to-digital converter circuit, which can convert analog signals into digital signals. ADC circuits are used to process analog signal quantities u... O Sampling is performed, and the computer system uses the sampling results to perform Fourier transform, which can then be analyzed. O Digital operations such as signal spectrum characteristics.

[0054] Preferred:

[0055] 1) The sampling system for signal u O The sampling frequency is greater than or equal to 5 times the maximum value of the effective operating frequency band in the frequency characteristic circuit;

[0056] 2) The number of sampling points should be determined such that the frequency resolution in the Fourier transform analysis results is 0.1 Hz. The amplitude-frequency response obtained after performing Fourier transform analysis on the sampling results is the signal u. O It can be represented as:

[0057] u O =ΣU K ×sin(2πkf d ×t) (2)

[0058] In the formula, f d U represents the resolution of frequencies in the spectrum after Fourier transform analysis. K It represents the amplitude of the signal at the k-th frequency point in the spectrum (i.e., the frequency is k×fd).

[0059] The signal u is obtained o After determining the amplitude-frequency characteristics, the next step is to find the position frequency point f corresponding to each frequency characteristic circuit.n Through the relation:

[0060]

[0061] Calculate the position x of the object to be measured. n .

[0062] In the formula, f n The frequency point with the largest amplitude in the effective operating frequency band P of the nth frequency characteristic circuit is represented by x. n Indicates the position of the nth object to be measured. This represents the inverse function of the relationship between frequency f and position x of the object under test in the nth frequency characteristic circuit determined above.

[0063] This embodiment can simultaneously indicate the position of multiple objects in the system by outputting one analog signal, and the measurement circuit is mainly an analog circuit, which has good anti-interference performance. The system only needs to configure one analog-to-digital converter channel to meet the acquisition requirements, and the requirements for the conversion time of the analog-to-digital converter and the sampling level holding time are low, which achieves low cost. It can realize non-contact measurement and can be used in harsh measurement environments such as dusty, sandy or high temperature environments.

[0064] This embodiment provides a measurement method for calculating multiple location information from a single AC signal, used to implement any of the systems described in the first aspect. Please refer to [link / reference needed]. Figure 3 As shown, it includes:

[0065] Step 001: Obtain the first output signal, which includes an AC voltage signal that corresponds one-to-one with the position changes of several objects under test.

[0066] Step 002: Superimpose the first output signal to generate a second output signal, wherein the second output signal includes a single AC voltage signal;

[0067] Step 003: Convert the second output signal into a digital signal to obtain the amplitude-frequency characteristics of the second output signal, and obtain the position of each object to be measured based on the amplitude-frequency characteristics.

[0068] In one possible application, please refer to Figure 2 and Figure 4 As shown, the sampling system includes an ADC circuit and a computer system (the controller is preferably a DSP controller TMS320F28335). The ADC circuit has a sampling rate of 5kSPS and requires 50,000 samples for each calculation.

[0069] The system is used to measure the position of two iron rods, specifically the insertion depth of inductors in two frequency characteristic circuits. When the magnetically conductive iron rods approach the inductor coils of the frequency characteristic circuits, they affect the inductor's self-inductance and mutual inductance coefficients, indirectly influencing the inductance value in the circuit. The relationship between the insertion depth of the iron rods in the frequency characteristic circuit and its output signal frequency is shown in the figure below. Figure 4 As shown. In this embodiment, the effective operating frequency band of frequency characteristic circuit 1 is defined as P1 = [750, 1000] Hz, and the effective operating frequency band of frequency characteristic circuit 2 is defined as P2 = [400, 700] Hz.

[0070] The specific workflow is as follows:

[0071] The computer system controls the ADC circuit to start sampling, and processes the output signal u of the adder circuit module. O Data was collected at a sampling rate of 5kSPS, with 50,000 samples.

[0072] Fourier transform was performed on the 50,000 sampled data points to obtain the amplitudes of 5,500 frequency points with a frequency interval of 0.1 Hz and a frequency range of [400, 700] Hz and [750, 1000] Hz.

[0073] Among the amplitude values ​​of the obtained 5500 frequency points, find the frequency point with the largest amplitude in the frequency range of [400, 700] Hz and [750, 1000] Hz.

[0074] Based on the frequency points of the maximum amplitude within the two effective operating frequency bands and the relationship between the insertion depth of the iron rod and its output signal frequency in the frequency characteristic circuit, the insertion depth of the two iron rods to be tested in the system can be calculated.

[0075] The specific data from a single practical operation is as follows:

[0076] The insertion depth of iron rod 1 is x1:100mm. The frequency of the output signal of the frequency characteristic circuit 1 is measured to be 855.45Hz. In the amplitude-frequency characteristic, it is found that there is a maximum amplitude value in the effective interval P1[750,1000]Hz at frequency f1:855.5Hz. The insertion depth is calculated to be 95.1mm.

[0077] The insertion depth of iron rod 2 is x2: 200mm. The frequency of the output signal of the frequency characteristic circuit 2 is measured to be 583.92Hz. In the amplitude-frequency characteristic, it is found that there is a maximum amplitude value in the effective interval P2 [400, 700]Hz at the frequency f2: 583.9Hz. The insertion depth is calculated to be 198.8mm.

[0078] The results show that by adjusting the output signal u of the adder circuit module... OAfter acquiring and performing Fourier transforms, and finding the frequency point with the largest amplitude in the effective operating frequency band of each frequency characteristic circuit, the position of each object under test in the system can be calculated simultaneously through the pre-calibrated correspondence between frequency and position.

[0079] The beneficial effect of this invention is that, compared with the acquisition method that configures an analog-to-digital converter channel for the output of each position sensor, this method only needs to use one analog-to-digital converter channel to measure information from multiple positions, thus reducing the hardware cost of the measurement system.

[0080] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0081] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A measurement system for calculating multiple location information from a single AC signal, characterized in that, include: The frequency characteristic module is used to convert the changes in the positions of several objects under test into a first output signal. The first output signal includes an AC voltage signal that corresponds one-to-one with the changes in the positions of the several objects under test. The frequency characteristic module contains multiple frequency characteristic circuits, and the effective operating frequency bands P of each frequency characteristic circuit do not overlap. An adder circuit module is used to superimpose the first output signal to generate a second output signal, wherein the second output signal includes a single AC voltage signal; The sampling system module is used to convert the second output signal into a digital signal, obtain the amplitude-frequency characteristics of the second output signal, find the frequency point with the largest amplitude in each effective working frequency band, and calculate the position of the object to be measured.

2. The measurement system for calculating multiple location information from a single AC signal as described in claim 1, characterized in that, The frequency characteristic module includes a frequency characteristic circuit, which includes: An oscillating circuit is used to convert the positional change of at least one object under test into a first output signal. The signal processing circuit is used to filter and scale the first output signal to improve signal quality. The filtering process is used to attenuate signals outside the effective operating frequency band, and the scaling process is used to adjust the signal amplitude to a suitable level.

3. The measurement system for calculating multiple location information from a single AC signal as described in claim 2, characterized in that, The oscillation circuit includes a Wien bridge oscillation circuit.

4. A measurement system for calculating multiple location information from a single AC signal as described in claim 2, characterized in that, The frequency f of the AC voltage signal output by the oscillation circuit is related to the position x of the object under test by f=F(x), and the frequency f of the output signal of the oscillation circuit is within the interval x. D has monotonicity; In the formula, D is the effective range of the position of the object to be measured; the relationship F(x) is calculated theoretically or fitted using actual measurement data; in the relationship f=F(x), within the interval x On D, f P is called the effective operating frequency band of the frequency characteristic circuit.

5. The measurement system for calculating multiple location information from a single AC signal as described in claim 1, characterized in that, The addition circuit module employs an addition circuit, which includes at least one input terminal and one output terminal. The at least one input terminal is used to input AC voltage signals output by a corresponding number of frequency characteristic circuits, and the output terminal is used to output the superimposed AC voltage signals.

6. The measurement system for calculating multiple location information from a single AC signal as described in claim 5, characterized in that, The adder circuit is a non-inverting proportional adder circuit composed of operational amplifiers, expressed by the following expression: in, To output the superimposed AC voltage signal. This represents the AC voltage signal output by the nth input frequency characteristic circuit in the system.

7. The measurement system for calculating multiple location information from a single AC signal as described in claim 6, characterized in that, The sampling frequency of the sampling system for signal u0 is greater than or equal to 5 times the maximum value of the effective operating frequency band in the frequency characteristic circuit; the number of sampling points should be determined so that the frequency resolution in the Fourier transform analysis results is 0.1Hz.

8. The measurement system for calculating multiple location information from a single AC signal as described in claim 1, characterized in that, The sampling system includes: A digital-to-analog converter circuit is used to convert the second output signal into a digital signal; A computer system is used to convert the second output signal into a digital signal, perform a Fourier transform to obtain the amplitude-frequency characteristics of the second output signal, and obtain the position of each object under test based on the amplitude-frequency characteristics.

9. A measurement system for calculating multiple location information from a single AC signal as described in claim 8, characterized in that, The position of each object under test can be obtained based on its amplitude-frequency characteristics, and can be expressed by the following expression: in, This represents the frequency point with the largest amplitude in the effective operating frequency band P of the nth frequency characteristic circuit. Indicates the position of the nth object to be measured. This represents the inverse function of the relationship between frequency f and position x of the object under test in the nth frequency characteristic circuit determined above.

10. A measurement method for calculating multiple location information from a single-channel AC signal, used to implement the system described in any one of claims 1-9, characterized in that, include: Acquire a first output signal, the first output signal including an AC voltage signal that corresponds one-to-one with the position changes of a plurality of objects to be measured; The first output signal is superimposed to generate a second output signal, the second output signal including a single AC voltage signal; The second output signal is converted into a digital signal to obtain the amplitude-frequency characteristics of the second output signal, and the position of each object to be measured is obtained based on the amplitude-frequency characteristics.

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