Single-line transmission sensor array acquisition system based on frequency addressing

Abstract

The invention discloses a single-line transmission sensing array acquisition system based on frequency addressing, and belongs to the technical field of flexible electronics and sensing. The system comprises a sensing array, a signal conditioning circuit, a signal processing unit and a signal gathering circuit, each unit in the sensing array comprises a sine wave generating circuit and a flexible pressure-sensitive element, and is provided with a four-side redundant connection structure; the signal gathering circuit realizes single-line transmission for a single common signal line; the signal conditioning circuit eliminates signal saturation crosstalk through a dynamic range optimization module; the signal processing unit extracts pressure information through FFT, digital filtering and envelope detection. Wiring is simplified, crosstalk between units is eliminated, the damage resistance and sensing capacity of the system are improved, pressure data can be collected in a high-precision mode, and the system is suitable for scenes such as health monitoring and industrial monitoring.

Description

Technical Field

[0001] This invention relates to the field of flexible electronics and sensing technology, and in particular to a sensing array acquisition system that achieves high-capacity, crosstalk-free, and highly reliable data acquisition under a single-line transmission architecture by optimizing the dynamic range at the system level and integrating a damage-resistant structure. Background Technology

[0002] With the rapid development of the Internet of Things and health monitoring technologies, flexible sensor arrays have shown great potential in fields such as motion analysis, medical rehabilitation, and human-computer interaction.

[0003] Currently, flexible sensor array data acquisition technology mainly faces the following technical bottlenecks: First, traditional flexible sensor arrays mostly adopt parallel wiring schemes. For a sensor array containing M rows and N columns, M×N×2 or M×N+1 wires are usually required for signal connection and acquisition. This topology results in messy internal wiring, complex structure, low reliability, and difficulty in integrating into small spaces, which seriously restricts its practical application.

[0004] Second, while existing frequency modulation-based single-wire transmission technology achieves single-wire signal transmission, it suffers from serious technical flaws: as the number of sensing units increases, the superposition of signals from each unit on the common bus leads to overall signal amplitude saturation, causing nonlinear distortion and resulting in severe inter-unit crosstalk. This crosstalk manifests as a large number of high-order harmonics in the frequency domain, polluting the operating frequency bands of other sensing units, leading to errors in pressure information extraction and a decrease in recognition accuracy. Existing technologies fail to provide an effective solution, limiting the practical application value of single-wire transmission systems.

[0005] Furthermore, traditional sensor arrays lack damage-resistant design in their physical structure. When the array is subjected to external impact, bending, or local cutting, the wires are prone to breakage, causing one or more sensing units to fail completely. This results in poor overall system reliability and makes it difficult to operate stably for a long time in harsh environments such as sports wearables and industrial monitoring.

[0006] Therefore, there is an urgent need in this field for a new type of data acquisition system that can fundamentally solve the crosstalk problem and achieve high precision, high reliability and damage resistance under a single-line transmission architecture. Summary of the Invention

[0007] The primary objective of this invention is to provide a frequency-addressable single-line transmission sensor array acquisition system. Through innovative dynamic range optimization design and damage-resistant structure, it fundamentally eliminates crosstalk problems caused by signal saturation. Furthermore, it uses fast Fourier transform, digital filtering, and demodulation algorithms to recover pressure data of each unit from the single-line composite signal without crosstalk, while ensuring that the system can still function normally even when some hardware is damaged.

[0008] To achieve the above objectives, the present invention adopts the following technical solution: A frequency-addressable single-wire transmission sensor array acquisition system includes: a sensor array, a signal conditioning circuit, a signal processing unit, and a signal summarization circuit, specifically: The sensing array comprises multiple sensing units, each of which includes a sine wave generating circuit and a flexible pressure-sensitive element. The sine wave generating circuit is configured to generate a carrier signal of a specific frequency, and the specific frequencies of different sensing units are different. The flexible pressure-sensitive element is coupled to the sine wave generating circuit and is used to modulate the amplitude of the carrier signal according to the applied pressure. The signal aggregation circuit is a common signal line that connects the output terminals of multiple sensing units in parallel, so as to realize single-line signal transmission. The signal conditioning circuit is connected to the common signal line and is used to condition the transmitted composite signal, including a buffer amplifier and a dynamic range optimization module; The signal processing unit is electrically connected to the signal conditioning circuit. After converting the output analog signal into a digital signal through an analog-to-digital converter, it runs a specific signal processing method to extract the pressure information of each sensing unit from the composite signal. The signal processing unit is configured to perform the following processes: S1: Execute a fast Fourier transform algorithm to transform the composite signal from the time domain to the frequency domain; S2: Based on the specific frequency of each sensing unit, separate the modulation signal corresponding to each sensing unit from the frequency domain; S3: Demodulate the separated modulation signals to obtain the pressure information of each sensing unit. Each of the sensing units is connected to the common signal line and the power line via four wires, which are arranged on the four sides of the sensing unit to form a redundant connection structure. This structure is configured such that when any one or more wires are cut due to external force, as long as at least one side of the wire remains connected, the sensing unit can continue to receive power and transmit signals, thereby ensuring that the system maintains its complete function in the event of local damage.

[0009] Furthermore, the sine wave generating circuit is a Wien bridge oscillator circuit, and its specific frequency is determined by the parameters of the RC frequency selection network in the circuit.

[0010] Furthermore, the flexible pressure-sensitive element is coupled in series with the sine wave generating circuit to form an amplitude modulation circuit.

[0011] Furthermore, the buffer amplifier is used to increase the input impedance and drive subsequent circuits; the dynamic range optimization module includes a high-voltage operational amplifier and a signal attenuation unit.

[0012] Furthermore, the signal processing unit separates the signal from the frequency domain by performing bandpass filtering with the specific frequency of each sensing unit as the center frequency.

[0013] Furthermore, the signal processing unit is configured via a built-in software program to perform the following steps: Step 1: Receive and preprocess the composite time-domain signal; Step 2: Convert the signal to the frequency domain using the Fast Fourier Transform algorithm; Step 3: Based on the specific frequency of each sensing unit, execute a digital bandpass filtering algorithm to separate each modulation signal; Step 4: Demodulate each signal using the envelope detection algorithm to obtain the pressure-time series.

[0014] Furthermore, the dynamic range optimization module includes a high-voltage operational amplifier and a signal attenuation unit; the signal conditioning circuit uses a high-voltage operational amplifier, and an attenuation network or a programmable gain amplifier is provided at the front end of the analog-to-digital converter of the signal processing unit.

[0015] Preferably, the signal attenuation unit can be a programmable gain amplifier, and the signal processing unit is configured to: first detect the signal amplitude output by the high-voltage operational amplifier, and then dynamically adjust the gain of the programmable gain amplifier based on the detection result, so as to avoid saturation of the analog-to-digital converter.

[0016] The redundant connection structure forms a multi-path power supply and signal transmission network by evenly arranging wires on the four sides of each sensing unit and interconnecting them using flexible printed circuit wiring. This design ensures that even if external damage causes all three sides of the wires to break, as long as at least one side of the wire remains connected, the necessary power and signal path can be provided to the sensing unit, thereby greatly enhancing the system's environmental adaptability and durability.

[0017] The dynamic range optimization module works by increasing the voltage margin of the front-end circuit, allowing the sum of the output amplitudes of the sensor array to still be amplified within the linear range even when the output amplitudes of each unit are set sufficiently small. Subsequently, through back-end attenuation, the signal is precisely adapted to the ADC's range. This method significantly expands the total number of sensor units the system can accommodate without sacrificing the system's signal-to-noise ratio, and fundamentally avoids frequency domain crosstalk caused by saturation distortion.

[0018] Through the above technical solutions, this invention constructs a single-line transmission sensor array acquisition system based on dynamic range optimization and damage-resistant design. It proposes and implements a crosstalk-free sensor array acquisition system based on frequency addressing and dynamic range optimization, ensuring the purity of the signals separated from each unit in the frequency domain. Simultaneously, the system's robustness is improved through a four-sided redundant connection structure. The advantages of this invention are: crosstalk-free transmission characteristics, large system capacity, high hardware integration, strong damage resistance, and high practicality, making it suitable for embedded deployment. This invention is applicable to scenarios such as personalized health monitoring and medical rehabilitation assessment, and has good prospects for widespread application in practice.

[0019] Obviously, based on the above description of the present invention, and according to common technical knowledge and conventional methods in the field, various other modifications, substitutions or alterations can be made without departing from the basic technical concept of the present invention. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the redundant connection structure of the present invention; Figure 2 This is a schematic diagram illustrating the damage resistance of the sensor array in this invention; Figure 3 This is a schematic diagram of the sensing unit circuit of the present invention; Figure 4 This is a flowchart illustrating the overall hardware structure and software processing of the system of the present invention. Detailed Implementation

[0021] The following detailed embodiments further illustrate the above-described content of the present invention. However, this should not be construed as limiting the scope of the present invention to the following examples. All technologies implemented based on the above-described content of the present invention fall within the scope of the present invention.

[0022] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0023] Example 1: System Hardware Implementation and Redundant Connection Structure

[0024] The system includes a sensor array, a signal conditioning circuit, a signal processing unit, and a signal summarization circuit. The sensor array consists of 50 sensor units, which are interconnected by ribbon cables. Each ribbon cable includes a common signal line and a power line (in this embodiment, it includes 1 signal line and 3 power lines), and outputs at the end through a single common signal line.

[0025] Each sensing unit employs a Wien bridge oscillator circuit to generate a specific frequency carrier wave, with a flexible varistor connected in series with the circuit to achieve amplitude modulation. By carefully selecting the resistor and capacitor combination parameters of the frequency selection network, a unique identifier frequency is assigned to each unit.

[0026] One of the key innovations of this invention lies in the redundant connection structure. For example... Figure 1 As shown, each sensing unit has wires arranged along its four sides, connecting to a common signal line and a power line, respectively. These wires are interconnected via flexible printed circuit boards, forming redundant wiring on all four sides. When the sensing array is subjected to external impact, cutting, or bending, even if three of the wires break, as long as at least one wire remains connected, the sensing unit can still receive power and transmit signals normally, thus ensuring that the system maintains functional integrity under localized damage. (Refer to...) Figure 2 This design significantly improves the system's reliability in scenarios susceptible to physical damage, such as wearable devices and industrial sensors.

[0027] Another core innovation of this invention lies in the dynamic range optimization module in the signal conditioning circuit. For example... Figure 3 As shown, this module uses a high-voltage operational amplifier to ensure linear processing of large-amplitude signals, and a precision voltage divider network to accurately attenuate the signal to the ADC input range.

[0028] Example 2: Software Architecture and Processing Flow

[0029] The system software portion of this invention primarily runs on a signal processing unit (e.g., a microprocessor, DSP, or computer), and its core task is to process composite signals acquired from a single common signal line. Logically, the software can be divided into signal preprocessing and frequency domain analysis modules. The overall processing flow is as follows: Figure 4 As shown, the specific steps are as follows: S1. Signal Acquisition and Preprocessing The time-domain composite voltage signal from the common signal line is continuously sampled using an analog-to-digital converter (ADC).

[0030] The acquired digital signals undergo necessary preprocessing, such as DC bias removal and preliminary filtering to suppress power frequency interference and high-frequency noise, in order to prepare clean signal data for subsequent frequency domain analysis.

[0031] S2. Frequency Domain Transformation and Signal Separation The preprocessed time-domain composite signal is then transformed into its frequency domain. The Fast Fourier Transform (FFT) algorithm is preferred, converting the signal from the time domain to the frequency domain to obtain its spectrum. This algorithm transforms the discrete-time domain signal x(n) into a discrete-frequency domain signal X(k), and its calculation formula is as follows:

[0032] in, N The number of sampling points. x ( n ) is the first n Each time-domain sampled value, X ( k ) is the firstk Each frequency domain component (spectral line). j It is the imaginary unit. Through this transformation, the spectrum of the composite signal is revealed, and the amplitude at a specific frequency of each sensing unit reflects its pressure modulation depth.

[0033] In the frequency domain, digital bandpass filtering is performed based on the specific frequency (carrier frequency) of each pre-calibrated sensing unit. This involves generating a digital bandpass filter (such as an FIR or IIR filter) centered at its specific frequency for each sensing unit, accurately separating the amplitude-modulated signal component corresponding to each unit from the composite spectrum. This step is crucial to the invention, ensuring the acquisition of the independent signal of each sensing unit without crosstalk.

[0034] S3. Signal demodulation and pressure information reconstruction The amplitude-modulated signal of each separated sensing unit is demodulated. Envelope detection algorithm is preferred, i.e., the envelope of the signal is extracted using the Hilbert transform method. For a real-valued signal... s ( t ), its analytical signal z ( t From the original signal and its Hilbert transform Together they constitute:

[0035] Among them, Hilbert transform Defined as:

[0036] In the above formula: s ( t () represents the input real-valued time-domain signal, which is a continuous-time function. In the integral, this signal is expressed as... s ( τ The calculation is performed in the form of ); express s ( t The Hilbert transform result of the signal is orthogonal to the phase of the original signal. t This indicates the time point corresponding to the transformed signal; τ It is an integral variable; pv Indicates Cauchy's principal value; In practical digital processing, this transformation is efficiently implemented through fast convolution or frequency domain methods based on FFT / IFFT. Ultimately, the envelope of the signal... e ( t That is, the modulus of the analytic signal:

[0037] The envelope e ( tThis is the demodulated signal proportional to the pressure applied to the flexible pressure-sensitive element. It is also the analog signal corresponding to the pressure change applied to the flexible pressure-sensitive element. Through calibration, the amplitude of the envelope is converted into a specific pressure value, thus obtaining the pressure-time series data of each sensing unit over a period of time.

[0038] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A frequency-addressable single-wire transmission sensor array acquisition system, characterized in that, include: Sensor array, signal conditioning circuit, signal processing unit, and signal summarization circuit. The sensing array comprises multiple sensing units, each of which includes a sine wave generating circuit and a flexible pressure-sensitive element. The sine wave generating circuit is configured to generate a carrier signal of a specific frequency, and the specific frequencies of different sensing units are different. The flexible pressure-sensitive element is coupled in series with the sine wave generating circuit and is used to change its resistance value according to the applied pressure to modulate the amplitude of the carrier signal. The signal aggregation circuit is a common signal line that connects the output terminals of multiple sensing units in parallel, so as to realize single-line signal transmission. The signal conditioning circuit is connected to the common signal line and is used to condition the transmitted composite signal. It includes a buffer amplifier and a dynamic range optimization module, and is then connected to an analog-to-digital converter to acquire data and convert it into a digital signal. The signal processing unit is electrically connected to the signal conditioning circuit. After converting the output analog signal into a digital signal through an analog-to-digital converter, it runs a specific signal processing method to extract the pressure information of each sensing unit from the composite signal. Each of the sensing units is connected to the common signal line and the power line via four wires, which are arranged on the four sides of the sensing unit to form a redundant connection structure. This structure is configured such that when any one or more wires are cut due to external force, as long as at least one side of the wire remains connected, the sensing unit can continue to receive power and transmit signals, thereby ensuring that the system maintains its complete function in the event of local damage.

2. The frequency-addressable single-wire transmission sensor array acquisition system according to claim 1, characterized in that, The sine wave generating circuit is a Wien bridge oscillator circuit, and its specific frequency is determined by the parameters of the RC frequency selection network in the circuit.

3. The frequency-addressable single-wire transmission sensor array acquisition system according to claim 1, characterized in that, The flexible pressure-sensitive element is coupled in series with the sine wave generating circuit to form an amplitude modulation circuit.

4. The frequency-addressable single-wire transmission sensor array acquisition system according to claim 1, characterized in that, The buffer amplifier is used to increase the input impedance and drive subsequent circuits; the dynamic range optimization module includes a high-voltage operational amplifier and a signal attenuation unit.

5. The frequency-addressable single-wire transmission sensor array acquisition system according to claim 1, characterized in that, The signal processing unit separates the signal from the frequency domain by performing bandpass filtering with the specific frequency of each sensing unit as the center frequency.

6. The frequency-addressable single-wire transmission sensor array acquisition system according to claim 1, characterized in that, The signal processing unit is configured via a built-in software program to perform the following steps: Step 1: Receive and preprocess the composite time-domain signal; Step 2: Convert the signal to the frequency domain using the Fast Fourier Transform algorithm; Step 3: Based on the specific frequency of each sensing unit, execute a digital bandpass filtering algorithm to separate each modulation signal; Step 4: Demodulate each signal using the envelope detection algorithm to obtain the pressure-time series.

7. The frequency-addressable single-wire transmission sensor array acquisition system according to claim 1, characterized in that, The dynamic range optimization module includes a high-voltage operational amplifier and a signal attenuation unit; the signal conditioning circuit uses a high-voltage operational amplifier, and an attenuation network or a programmable gain amplifier is provided at the front end of the analog-to-digital converter of the signal processing unit.

8. The frequency-addressable single-wire transmission sensor array acquisition system according to claim 1, characterized in that, The dynamic range optimization module increases the voltage margin of the front-end circuit, allowing the output amplitude of each sensing unit to be set sufficiently small, while ensuring that the total signal is processed within the linear range. Then, the signal is adapted to the ADC range through back-end attenuation, thereby expanding the system capacity while avoiding crosstalk.

9. The frequency-addressable single-wire transmission sensor array acquisition system according to claim 1, characterized in that, The redundant connection structure is interconnected through flexible printed circuit wiring. The wires are evenly distributed on the four sides of the sensing unit to form a four-sided redundant wiring. When external damage causes some wires to break, the sensing unit maintains power supply and signal transmission through the remaining connected wires, thereby achieving high reliability operation of the system in harsh environments.

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