Parallel bus ultrasonic array high-precision synchronization method and system
By employing two delay adjustments and frequency calibration methods, the problem of inconsistent time among channels in a distributed ultrasonic array was solved, achieving high-precision data synchronization and enabling stable operation in complex scenarios.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- NINGBO ABENI INFRARED TECH CO LTD
- Filing Date
- 2026-05-15
- Publication Date
- 2026-06-12
AI Technical Summary
Distributed ultrasonic arrays suffer from time synchronization errors between data channels, leading to beam pointing deviation and positioning ambiguity. Existing methods are costly and unsuitable for scenarios where multiple sensors are distributed.
A two-stage delay adjustment strategy is adopted. First, the local delay is adjusted by broadcasting the synchronization electrical signal waveform from the master control base station. Then, a globally unified delay alignment is performed. Combined with frequency detection and dual delay calibration, high-precision synchronization is achieved.
Without relying on expensive hardware, high-precision time alignment of data from various terminals was achieved, improving the system's operational reliability and stability, and meeting the needs of accurate measurement and collaborative control in practical application scenarios.
Smart Images
Figure CN122195212A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of signal processing technology, specifically to a high-precision synchronization method and system for a parallel bus ultrasonic array. Background Technology
[0002] In fields such as industrial automation, power equipment monitoring, and non-destructive testing, distributed ultrasonic sensor arrays are widely used in scenarios such as partial discharge localization, structural defect detection, and fluid condition monitoring. Ultrasonic arrays utilize multiple sensor terminals arranged at different spatial locations, leveraging the phase difference and time difference of arrival of signals from each channel to achieve beamforming, feature extraction, noise reduction, or event localization, thereby achieving higher spatial resolution and detection sensitivity than single-point sensors.
[0003] However, the normal operation of a distributed ultrasonic array is highly dependent on the precise time relationship between the data from each channel. Because the sensor terminals in the array are spatially distributed, and each terminal is equipped with an independent local crystal clock source, frequency deviations and initial phase differences are inevitable between the terminals. Simultaneously, the acoustic path length of the ultrasonic signal from the sound source to different terminals varies, and individual differences exist in the analog front-end circuits and ADC sampling circuits of each terminal, resulting in asynchronous acquisition times for the signals from each channel. Without time synchronization, directly processing the raw data from each channel will introduce significant time errors, leading to beam pointing deviation, positioning ambiguity, or even complete failure. Furthermore, a single time synchronization operation cannot permanently eliminate clock deviations; the clock of each terminal will drift over time and change with changes in the surrounding environment.
[0004] It is important to note that the essence of synchronization is time alignment. The purpose of synchronization is not to require that the hardware clocks of each terminal be physically identical, nor is it merely to adjust the acquisition parameters of each terminal in real time. Rather, it is to accurately determine the error of each terminal's clock relative to a unified time reference, as well as the relative delay of the acoustic signal arriving at each terminal. This allows for the alignment of the sampled data from each channel to the same time coordinate system during the data processing stage. In other words, each terminal operates independently; synchronization essentially involves obtaining the arbitrary instantaneous clock deviation of any terminal, and the backend uses this deviation to calculate and align the data.
[0005] Existing synchronization methods have the following limitations: Traditional methods use a unified sampling clock shared by multiple terminals, which requires expensive clock distributors to distribute a high-speed clock over a transmission distance of several meters, or advanced time synchronization equipment. This is not suitable for power switchgear scenarios: multiple ultrasonic sensors are located on different switchgear doors, and the number of these switchgear may reach more than 20 cabinets, covering a distance of more than 10 meters. Multi-channel centralized instruments are expensive and have complex wiring.
[0006] Therefore, a high-precision synchronization method suitable for distributed ultrasonic arrays is needed, capable of stable delay adjustment and high-precision time alignment of multi-channel data. This method employs a two-stage delay adjustment strategy: each terminal first performs self-delay adjustment based on the measured clock error (first delay adjustment), achieving preliminary compensation for local time; based on this, the system then performs a globally unified delay alignment calculation (second delay adjustment), unifying the data from each terminal to a global time reference, thereby achieving high-precision synchronization without relying on expensive hardware. Summary of the Invention
[0007] To address the shortcomings of existing methods and the inadequacies of practical applications, this paper proposes a method to achieve high-precision synchronization of ultrasonic arrays in parallel buses, improve the reliability and stability of system operation, and enable the system to meet the requirements of accurate measurement and collaborative control in practical application scenarios. In a first aspect, this invention provides a high-precision synchronization method for a parallel bus ultrasonic array. The method includes the following steps: a master control base station broadcasts a synchronization electrical signal waveform to each terminal via a bus; a terminal acquisition unit acquires the electrical signal waveform and analyzes, corrects, and estimates the clock deviation to obtain clock deviation detection results for different terminals; based on the clock deviation detection results, the local delay of different terminals is adjusted to obtain a delay-adjusted terminal; system delay parameters of each terminal are obtained through equidistant acoustic calibration pulses; the system delay parameters are subjected to dual delay calibration to obtain delay parameters for different terminals; the acoustic calibration pulse waveforms of different terminals are precisely aligned using subsampling point interpolation based on the delay parameters to determine the time acquisition nodes of different terminals; a synchronization alignment operation is performed based on the delay-adjusted terminal, the delay parameters, and the time acquisition nodes to obtain aligned sampled data; statistical detection and confidence evaluation are performed on the aligned sampled data to ensure the synchronization of the parallel bus ultrasonic sensor array and the long-term operation of the terminals; finally, equivalent synchronization sampled data is output.
[0008] This invention fully considers the differences between different hardware by using frequency detection and local delay adjustment, as well as dual delay calibration and subsampling fine alignment, and performs personalized processing on each terminal, enabling the system to achieve high-precision data synchronization under different conditions.
[0009] Optionally, the main control base station broadcasts a synchronization electrical signal waveform to each terminal via a bus. The terminal acquisition unit collects the electrical signal waveform and analyzes, corrects, and estimates the clock deviation to obtain clock deviation detection results for different terminals. Based on the clock deviation detection results, the local delay of each terminal is adjusted to obtain a delayed terminal. This includes: collecting electrical signal waveforms from different terminals using the terminal acquisition unit and obtaining electrical information for each terminal; integrating the electrical information from different terminals to obtain a terminal electrical signal; constructing a time offset analysis formula based on the terminal electrical signal; performing time offset analysis on the edge sequence in the terminal electrical signal using the time offset analysis formula and obtaining the time offset analysis result; and obtaining the corrected global time based on the time offset analysis result and the terminal electrical signal. The corrected global time of this invention can provide a unified time reference for all terminals, enabling each terminal to operate within the same time frame, further improving the time synchronization of each terminal in the ultrasonic array under a parallel bus environment.
[0010] Optionally, the main control base station broadcasts a synchronization electrical signal waveform to each terminal via a bus. The terminal acquisition unit acquires the electrical signal waveform and analyzes, corrects, and estimates the clock deviation to obtain clock deviation detection results for different terminals. Based on the clock deviation detection results, the local delay of each terminal is adjusted to obtain a delayed terminal. This includes: constructing an instantaneous frequency deviation calculation formula based on the edge sequence and the corrected global time; obtaining the instantaneous frequency deviation of the edge sequence through the instantaneous frequency deviation calculation formula; introducing a recursive formula for exponential smoothing filtering; performing exponential smoothing filtering on the instantaneous frequency deviation using the recursive formula to obtain a smoothed frequency deviation estimate; and obtaining the clock deviation detection results for different terminals based on the smoothed frequency deviation estimate. The instantaneous frequency deviation calculation formula constructed in this invention can fully utilize the time and frequency information in the edge sequence and can calculate the instantaneous frequency deviation at each edge moment by combining it with the corrected global time reference.
[0011] Optionally, adjusting the local latency of different terminals based on the clock skew detection result to obtain a latency-adjusted terminal includes: setting a convergence threshold based on the edge sequence, the corrected global time, and the clock skew detection result; analyzing the inter-frame change rate of the frequency deviation based on the smoothed frequency deviation estimate; determining that the frequency deviation has converged when the inter-frame change rate is less than the convergence threshold, and using the smoothed frequency deviation estimate as the clock skew detection result of the terminal; adjusting the local latency of different terminals according to the clock skew detection result to obtain a latency-adjusted terminal. This invention adjusts the weights of different terminals based on the clock skew detection result, enabling a more scientific and reasonable allocation of weights among different terminals.
[0012] Optionally, the step of obtaining the system delay parameters of each terminal through equidistant acoustic calibration pulses and performing dual delay calibration on the system delay parameters to obtain the delay parameters of different terminals includes: emitting equidistant acoustic calibration pulses using an ultrasonic buzzer and an ultrasonic buzzer in the base station to obtain the terminal system delay parameters; performing initial calibration on the terminal acoustic signals in the terminal system delay parameters to obtain the initial system delay; performing continuous calibration on the terminal acoustic signals to obtain the system delay of different terminals; combining the initial system delay and the system delays of different terminals to obtain the fused system delay of different terminals; and obtaining the delay parameters of different terminals based on the fused system delay of different terminals. This invention obtains the delay parameters of different terminals through dual delay calibration, which allows for more rational resource allocation based on the delay parameters, improving data transmission efficiency.
[0013] Optionally, the step of performing subsampling point interpolation and fine alignment of the acoustic calibration pulse waveforms of different terminals in conjunction with the delay parameter to determine the time acquisition nodes of different terminals includes: establishing a terminal search window determination function based on the terminal acoustic signal; determining the half-width of the search window for different terminals through the terminal search window determination function; and determining the hourly sampling time of different terminals based on the terminal acoustic signal and the half-width of the search window. This invention determines the half-width of the search window for different terminals based on the terminal search window determination function, and then combines this with the acoustic signal to determine the hourly sampling time, which can accurately locate the time acquisition node of each terminal and improve the accuracy of time synchronization.
[0014] Optionally, the step of performing subsampling point interpolation fine alignment on the acoustic calibration pulse waveforms of different terminals in conjunction with the delay parameter to determine the time acquisition nodes of different terminals includes: introducing a subsampling point parabolic interpolation method; and performing subsampling point interpolation fine alignment based on the subsampling point parabolic interpolation method and the hourly sampling time of the different terminals to determine the time acquisition nodes of different terminals. This invention's dual delay calibration provides a basic correction for time synchronization; the subsampling point parabolic interpolation method performs more refined signal processing, further compensating for errors caused by delay.
[0015] Optionally, the step of performing a synchronization alignment operation based on the delayed terminal, the delay parameter, and the time acquisition node to obtain aligned sampled data includes: performing a synchronization alignment operation based on the delayed terminal, the delay parameter, and the time acquisition node to obtain a global timestamp after alignment of sampling points of different terminals; and obtaining aligned sampled data based on the global timestamp after alignment of sampling points of different terminals. The global timestamps after alignment of sampling points from different terminals satisfy the following relationship: , in, Indicates the first The global timestamp after aligning the sampling points of each terminal. This represents the pulse arrival time estimate obtained after subsampling and fine alignment. This represents the fusion delay parameter obtained from dual delay calibration. This represents the clock offset calculated through time offset analysis. This represents the cumulative drift compensation term caused by the crystal oscillator frequency deviation.
[0016] The formula of this invention integrates multiple factors that affect time synchronization. By comprehensively considering these factors, it can more accurately calculate the global timestamp after the sampling points of each terminal are aligned, thus effectively improving the time synchronization accuracy.
[0017] Optionally, statistical detection and confidence assessment are performed on the aligned sampled data to ensure the synchronization of the parallel bus ultrasonic sensor array and the long-term operation of the terminals. The final output of equivalent synchronization sampled data includes: statistical analysis of the residual offset, mean, and standard deviation of different terminals based on the aligned sampled data; detection of different terminals based on the residual offset, mean, and standard deviation, and obtaining the offset trend of different terminals; confidence assessment of different terminals based on the offset trend, obtaining the confidence calculation result of different terminals; adjustment of the operation and maintenance management scheme of different terminals in combination with the offset trend and the confidence calculation result, so as to achieve the synchronization of the parallel bus ultrasonic sensor array and the long-term operation of different terminals; and output of equivalent synchronization sampled data through the parallel bus ultrasonic sensor array. The offset trend and confidence of different terminals in this invention can predict the direction of change of the terminal time synchronization state, ensure the long-term synchronization and stable operation of the array, and further ensure the time consistency of each terminal in the ultrasonic array.
[0018] Secondly, the present invention also provides a high-precision synchronization system for a parallel bus ultrasonic array, capable of efficiently executing a high-precision synchronization method for a parallel bus ultrasonic array provided by the present invention. The system includes an input device, a processor, an output device, and a memory, wherein the input device, processor, output device, and memory are interconnected. The memory includes a computer-readable storage medium as described in the first aspect of the present invention, and is used to store a computer program. The computer program includes program instructions, and the processor is configured to call the program instructions. The high-precision synchronization system for a parallel bus ultrasonic array provided by the present invention has a compact structure, strong applicability, and greatly improves operating efficiency. Attached Figure Description
[0019] Figure 1 This is a flowchart of the parallel bus ultrasonic array high-precision synchronization method of the present invention; Figure 2A schematic diagram of the connection between different terminal nodes in the parallel bus ultrasonic array high-precision synchronization method of the present invention; Figure 3 A schematic diagram of the parallel bus ultrasonic array high-precision synchronization system of the present invention. Detailed Implementation
[0020] Specific embodiments of the present invention will now be described in detail. It should be noted that the embodiments described herein are for illustrative purposes only and are not intended to limit the invention. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that these specific details are not necessary to practice the invention. In other instances, well-known circuits, software, or methods have not been specifically described to avoid obscuring the invention.
[0021] Throughout this specification, references to "an embodiment," "an embodiment," "an example," or "an example" mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of the invention. Therefore, the phrases "in an embodiment," "in an embodiment," "an example," or "an example" appearing in various places throughout the specification do not necessarily refer to the same embodiment or example. Furthermore, specific features, structures, or characteristics can be combined in one or more embodiments or examples in any suitable combination and / or sub-combination. Moreover, those skilled in the art will understand that the illustrations provided herein are for illustrative purposes and are not necessarily drawn to scale.
[0022] Please see Figure 1 To achieve high-precision synchronization of ultrasonic sensor arrays in a distributed environment and ensure high reliability and stability of the system, meeting the requirements of accurate measurement and collaborative control in practical scenarios, this invention proposes a high-precision synchronization method for parallel bus ultrasonic sensor arrays. This method employs a two-stage delay adjustment strategy: each terminal first performs local delay adjustment based on the measured clock error (first delay adjustment) to achieve preliminary compensation of local time; then, during the data processing phase, the system performs globally unified synchronization alignment based on delay parameters (second delay adjustment), unifying the data from each terminal to a global time reference. The method includes the following steps: It should be noted that the parallel bus in this invention refers to each terminal node being connected in parallel to the same shared transmission bus through its respective communication interface. Please refer to [link to relevant documentation]. Figure 2Among them, A01 is the global time base; the MCU is model AG32VF407, which can realize the terminal control function; A02 is an ultrasonic buzzer; A03 is a parallel bus; A04 is a TAU (terminal acquisition unit); A05 is an ultrasonic sensor; A06 is a local crystal oscillator clock source; A07 is the main control base station; A08 is the terminal device. The main control base station broadcasts synchronization signals to all terminals through this bus, which is not multiple independent buses connected in parallel.
[0023] S1. Bus electrical signal acquisition, clock error measurement and terminal local delay adjustment: This step uses the common electrical signal waveform on the bus to measure the error of each terminal's local clock relative to the global reference; each terminal adjusts its local delay according to the measured error parameters to achieve preliminary compensation of local time, that is, to complete the first delay adjustment in this embodiment.
[0024] Each terminal is connected to the main control base station via a bus. The main control base station broadcasts a synchronization signal waveform to all terminals via the bus. This waveform has specific timing level characteristics and known edge times. In a specific embodiment, it is a square wave pulse sequence with a fixed frequency or a modulated waveform with a specific synchronization preamble. The purpose is to provide a common time reference for each terminal, so that each terminal can determine the deviation between its local clock and the global reference by testing the specific timing level of the waveform.
[0025] In this embodiment, the acquisition unit of each terminal is configured with an ADC to sample the electrical signal waveform on the bus at a predetermined sampling rate to obtain a waveform sampling sequence. The ADC sampling rate is set to 192kHz to meet the high-precision sampling requirements of the electrical signal and ensure that subtle changes in the waveform can be captured; the bus baud rate is set to 1Mbps to ensure the data transmission rate on the bus. In practical applications, due to the inherent frequency deviation and phase difference of the local crystal oscillators of each terminal, the sampling results of each terminal for the same bus waveform will show different edge timing measurements and period measurements. This embodiment uses the above differences to infer the clock error of each terminal.
[0026] This embodiment S1 specifically includes the following sub-steps: Step S101: Use the terminal acquisition unit to acquire electrical signals from different terminals.
[0027] In this embodiment, the Terminal Acquisition Unit (TAU) synchronously acquires the electrical signal waveform on the bus via an ADC. In an optional embodiment, the terminal acquisition unit needs to be configured with hardware initialization before information acquisition: the ADC sampling rate is set to 192kHz, the bus baud rate is set to 1Mbps, and a DMA counter synchronization mode is used to achieve efficient data transmission and synchronous processing, reducing latency and errors during data transmission. This enables fast data transmission without consuming CPU resources, which helps ensure the time consistency of data from different terminals during transmission and processing.
[0028] In this embodiment, the terminal acquisition unit mainly utilizes the 8-bit synchronization preamble at the beginning of each frame of the protocol for edge capture. Specifically, the MCU input acquisition peripheral is configured to a dual-edge-triggered mode. When the edge of the preamble is detected, it automatically latches 7 edge moments, achieving a resolution of 50ns to obtain the edge sequence. This provides accurate data points for subsequent time offset analysis and frequency deviation calculation.
[0029] The falling edge of the time marker bit following the preamble is latched by hardware, and the ADC DMA counter value is read simultaneously to record the current sampling position. This crucial timing information provides a reference for subsequent timing analysis and delay adjustment, helping to establish accurate timing relationships.
[0030] Step S102: Integrate the electrical signals from different terminals to obtain the terminal electrical signal.
[0031] In this embodiment, each terminal caches and preprocesses the collected electrical signal waveform data to remove obvious noise interference and abnormal sampling points. The processed electrical signal waveform is then integrated with the corresponding timestamp information to form a structured terminal electrical signal dataset, providing standardized input data for subsequent time offset analysis and frequency deviation calculation.
[0032] Step S103: Construct a time offset analysis formula based on the terminal electrical signal.
[0033] In this embodiment, based on the global timestamp (recorded by the master base station) carried in the terminal electrical signal acquisition time frame and the local acquisition time, a time offset analysis formula is further established to calculate the clock offset.
[0034] The above time offset analysis formula satisfies the following relationship: , in, This indicates the deviation between the local clock and the global clock. Indicates the local capture time. Represents the global timestamp. This indicates system latency. System latency includes signal transmission delay on the bus, terminal hardware processing latency, etc., which can be obtained through pre-measurement or calibration. This embodiment's analysis considers system latency and can accurately calculate the deviation between the local clock and the global clock, providing an accurate basis for subsequent terminal local latency adjustments.
[0035] Step S104: Perform time offset analysis on the edge sequence in the terminal electrical signal using the time offset analysis formula, and obtain the time offset analysis results.
[0036] In this embodiment, the time offset analysis formula described above is used to perform time offset analysis on the edge sequence in the terminal electrical signal. By calculating the deviation between the local clock and the global clock at each edge moment, the time offset analysis result can be obtained. This result reflects the fixed phase offset of each terminal's local clock relative to the global reference, providing direct compensation parameters for subsequent terminal local delay adjustment.
[0037] Step S105: Obtain the corrected global time based on the time offset analysis results and the terminal electrical signal.
[0038] In this embodiment, by referring to the time offset analysis results described above, the local timestamp is mapped to the global reference, establishing a correspondence between local and global time. Simultaneously, using the frequency deviation estimate obtained in subsequent steps, a precise sampling sequence number is established. To global time The mapping relationship described above can adapt to the needs of actual application scenarios, simplify the complexity of time synchronization, and ensure the relative time consistency of sampled data between different terminals.
[0039] Step S106: Construct an instantaneous frequency deviation calculation formula based on the edge sequence and the corrected global time to obtain the instantaneous frequency deviation of the edge sequence.
[0040] In this embodiment, based on edge sequence The difference between the total duration of the 6-bit interval covered by the measured preamble edge and the nominal value is calculated, and an instantaneous frequency deviation calculation formula is constructed, which satisfies the following relationship: , in, Indicates instantaneous frequency deviation. This indicates the 7th edge time. This indicates the time of the first edge. This represents the nominal bit period. The above calculation formula considers the two time-scale causes of crystal oscillator frequency deviation (inherent factory deviation and temperature-driven drift), which can accurately reflect the instantaneous frequency deviation of the terminal and provide key data for subsequent clock deviation detection.
[0041] Based on the actual duration of 6 bit cycles covered by the 7 edges of the preamble. , and the nominal duration By comparison, the instantaneous deviation can be calculated using the instantaneous frequency deviation calculation formula. .
[0042] Step S107 introduces the recursive formula for exponential smoothing filtering to perform exponential smoothing filtering on the instantaneous frequency deviation in order to obtain a smoothed frequency deviation estimate.
[0043] In this embodiment, in order to suppress edge jitter noise caused by bus electromagnetic interference, a recursive formula for exponential smoothing filtering is introduced.
[0044] The above recursive formula satisfies the following relationship: , in, Indicates the first The smoothed frequency deviation estimate of the frame. Represents the filter coefficients. Indicates the first The instantaneous frequency deviation measurement of the frame. Indicates the first The smoothed frequency deviation estimate of the frame. Filter coefficients. The range of values is In this embodiment, the filter coefficient is set to 0.1, meaning that the current value accounts for only 10%. This effectively suppresses noise while preserving the trend of frequency deviation changes, obtaining a smooth frequency deviation estimate, and ultimately obtaining an accurate clock deviation detection result.
[0045] Step S108 obtains the clock deviation detection results for different terminals based on the smoothed frequency deviation estimate.
[0046] In this embodiment, a convergence threshold is set based on the edge sequence, the corrected global time, and the clock skew detection result. This embodiment sets it to... Furthermore, based on the smoothed frequency deviation estimate, the inter-frame change rate of frequency deviation is analyzed, and the dynamic situation of frequency deviation is continuously monitored. When the inter-frame change rate is less than the convergence judgment threshold, it is determined that the frequency deviation estimation has converged, and the smoothed frequency deviation estimate is used as the clock deviation detection result of the terminal.
[0047] When the inter-frame change rate is greater than or equal to the convergence threshold, i.e., the frequency does not converge and multiple retests fail to converge, it means that the data collected in step S1 and the related implementation content have become invalid. At this time, global calibration is triggered, requiring the terminal electrical signal to be collected again and the relevant steps in S1 to be repeated. The global calibration triggering mechanism in this embodiment can promptly handle situations where the system is unstable due to various physical factors, avoiding the impact of invalid data on the synchronization effect.
[0048] Step S109: Adjust the local delay of different terminals according to the clock deviation detection results to obtain the delayed terminal.
[0049] In this embodiment, each terminal determines the time offset based on the measured time offset. and frequency deviation estimate The system performs self-adjustment of local latency (first latency adjustment). In an optional embodiment, different terminals measure the clock error by testing the specific timing level of the bus. In subsequent data acquisition and processing, the local timestamp is compensated for with a fixed phase based on the time offset, and the sampling interval is dynamically corrected based on the frequency deviation estimate, so that the local time is closer to the global reference. The above-mentioned local latency adjustment is completed autonomously by the terminal without changing the hardware clock frequency or requiring real-time intervention from the host computer, effectively reducing the system communication burden and synchronization delay.
[0050] Furthermore, each terminal writes the adjusted delay parameters to its local storage, and automatically performs local compensation based on the written values during subsequent detection processes, thereby improving the time accuracy of the terminal's own data. After the above delay adjustment, the terminal's local time has been initially aligned with the global benchmark, providing a foundation for subsequent globally unified synchronization alignment, i.e., the second delay adjustment.
[0051] By implementing the above steps, the terminal electrical signal is acquired, the clock error is measured, and the local delay of the terminal is adjusted. This results in a delayed terminal, which provides an important guarantee for the high-precision synchronization and stable operation of the parallel bus ultrasonic sensor array.
[0052] S2, System Delay Parameter Calibration This step primarily involves obtaining system delay parameters for each terminal through equidistant acoustic calibration pulse testing. In practical applications, system delay encompasses the combined delays of numerous factors, including acoustic transmission path delay, electrical transmission path delay, and communication computation delay. Simultaneously, high-precision pulse arrival times are obtained through subsampling point interpolation for fine alignment, providing spatial-temporal parameters for global synchronization alignment.
[0053] In this embodiment, the sensors of each terminal are used to collect ultrasonic signals. Since the propagation path length of the ultrasonic signal from the sound source to each sensor is different, and there are individual differences in the acoustic coupling conditions, analog front-end circuits, and ADC triggering times of each terminal, even though each terminal has completed local delay adjustment in S1, the absolute time and relative delay of the sound wave signal arriving at each terminal are still significantly different. Therefore, it is necessary to specifically calibrate the sound wave transmission delay.
[0054] This embodiment S2 specifically includes the following sub-steps: Step S201: Use an ultrasonic buzzer to emit equidistant sound wave calibration pulses with the ultrasonic buzzer in the base station to obtain the terminal system delay parameters.
[0055] In this embodiment, a two-stage sound source is used to emit acoustic calibration pulses to obtain the system delay parameters of each terminal. During the initial calibration phase (before installation), each terminal is arranged on the same circumference, with an ultrasonic buzzer placed at the center as an equidistant sound source at a distance of 2-3 meters. The ultrasonic buzzer is activated to emit ultrasonic calibration pulses, and simultaneously, the sensors of each terminal acquire the waveform of these calibration pulses. These steps are completed in a test environment before factory shipment or installation to obtain the pure hardware delay baseline of each terminal under controlled conditions with consistent sound path. During the continuous operation phase (after installation), a base station ultrasonic buzzer acquisition method is used. An ultrasonic buzzer is integrated on the base station to emit ultrasonic calibration pulses at preset time intervals. Simultaneously with the emission of calibration pulses, multiple probes are controlled to simultaneously acquire test data.
[0056] The calibration pulse waveforms acquired through the above two methods are integrated and processed to calculate the system delay parameters of each terminal. These system delay parameters comprehensively reflect the overall delay caused by many factors such as sound wave propagation, electrical signal conditioning, ADC sampling triggering, and communication calculation, providing basic data for subsequent processing.
[0057] Step S202: Initial calibration of the terminal acoustic wave signal in the above system delay parameters is performed to obtain the initial system delay.
[0058] In this embodiment, during the initial calibration process, a high-precision baseline provided by an equidistant portable sound source is used to calculate the system delay parameters based on the sound wave signals of each terminal.
[0059] The formula for calculating the initial system delay is: , in, Indicates the initial system delay. Indicates pulse The average arrival time, Indicates the time when the pulse is transmitted (base station time, global time). This indicates the transmission time calculated based on the distance. The aforementioned pulse... The average arrival time is obtained by averaging the arrival times of multiple pulses, which reduces the impact of random errors. Based on the above formula, the measured arrival time is subtracted from the transmission time and flight time, and the remaining value is the inherent system delay of different terminals.
[0060] Step S203: Continuously calibrate the terminal acoustic wave signal in the above system delay parameters to obtain the system delay of different terminals.
[0061] In this embodiment, continuous calibration utilizes an ultrasonic transmitter permanently installed on the base station to calculate the terminal system delay after deducting known sound path differences from the periodically emitted calibration pulses.
[0062] The formula for calculating terminal system latency is as follows: , in, This indicates the terminal obtained from base station calibration. System delay, Indicates terminal The recorded arrival time of this pulse, Indicates the base station transmission time. Indicates distance, This represents the speed of sound. During the calculation process, the speed of sound needs to be corrected according to environmental conditions to improve the accuracy of the calculation results.
[0063] Step S204: By combining the initial system delay and the system delay of different terminals, the system delay after fusion of different terminals can be obtained.
[0064] In this embodiment, based on the initial system delay and the system delay of different terminals, the system delay parameters after fusion are calculated using fusion coefficients. The formula for calculating the fused terminal system delay parameters is as follows: , in, Indicates the merged terminal System delay, Represents the fusion coefficient. This represents the high-precision baseline value obtained from the initial equidistant calibration. This represents the latest observation obtained from continuous base station calibration. The initial equidistant calibration described above has high accuracy but cannot be updated in real time; continuous calibration can capture changes in physical parameters but has slightly lower accuracy. As the operating time increases, the fusion coefficient can be gradually reduced. The value of relies more on the latest continuously calibrated data to reflect long-term drift and avoid errors caused by a single inaccurate measurement.
[0065] Step S205: Obtain the latency parameters of different terminals based on the system latency after fusion of different terminals.
[0066] In this embodiment, based on the fused terminal system latency parameters, the latency parameters of different terminals can be obtained. The latency parameters of different terminals are written into the memory of each terminal. In the subsequent detection process, the system can automatically compensate according to the written values, thereby improving the accuracy and reliability of the detection.
[0067] By accurately obtaining the terminal system delay parameters through the above implementation steps, and effectively calculating the delay parameters of different terminals, a strong guarantee is provided for the stable operation and accurate detection of the system.
[0068] Step S206: Based on the aforementioned terminal acoustic signal, establish a terminal search window determination function to determine the half-width of the search window for different terminals.
[0069] In this embodiment, the expected arrival time of the sound pulse for each terminal is accurately calculated by utilizing the acoustic signals from different terminals and combining the known transmission time and distance information of the base station. The frequency window range in this embodiment needs to comprehensively consider the window corresponding to the standard deviation of the output from the previous step and the uncertainty of the acoustic delay. For frequency offset drift window, As a calibration window, actual measurements can be taken from the terminal to accurately reflect the actual situation. Simultaneously, a safety margin is determined based on the terminal's acoustic signal and historical experience values. The safety margin is calculated to be 6 times the standard deviation. The range of values for .
[0070] The terminal search window determination function established in this embodiment satisfies the following relationship: , in, This represents the half-width of the search window (unit: number of sampling points). This indicates taking the maximum value. Indicates the frequency offset drift window. Indicates the calibration window. This indicates the safety margin. The search window half-width for each terminal can be accurately calculated using the terminal search window determination function, providing a suitable range for subsequent pulse arrival location detection.
[0071] In an optional embodiment, the half-width of the search window for each terminal is accurately calculated based on the terminal search window determination function. At a sampling rate of 192kHz, fine alignment at the level of 0.5μs can be achieved between two sampling points, providing more accurate data support for accurately determining the pulse arrival position.
[0072] Step S207: Determine the hourly sampling time of different terminals based on the aforementioned terminal acoustic wave signal and the half-width of the search window.
[0073] In this embodiment, after the base station transmits the calibration pulse, the ADC of each terminal independently acquires the pulse waveform near the expected arrival location. By independently detecting the arrival of pulses within the window and finding the sampling point where the amplitude peak is located as the integer arrival estimate, the whole-hour sampling time of each terminal can be obtained, and thus the integer part of the terminal time acquisition node can be preliminarily determined.
[0074] Step S208: Introduce the subsampling point parabolic interpolation method, and perform subsampling point interpolation fine alignment based on the subsampling point parabolic interpolation method and the hourly sampling time of different terminals to determine the time acquisition node of different terminals.
[0075] In this embodiment, a subsampling point parabolic interpolation method is introduced to handle the situation where the peak value may fall between two sampling points. By analyzing the waveform envelope near the peak value, the peak value position can be determined more accurately. The subsampling offset after weighting the energy of the multi-pulse results is obtained by weighting the received energy. Taking into account the influence of each pulse, the time acquisition node of each terminal is determined by combining the whole-hour sampling time, so as to achieve high-precision determination and effectively solve the residual deviation problem.
[0076] By combining the integer sampling time and energy-weighted subsampling offset of each terminal obtained above, the time acquisition node of each terminal can be determined by calculation. In this embodiment, the integer part and the fractional part are combined to achieve high-precision determination of the terminal time acquisition node.
[0077] The above implementation steps enable precise alignment of the terminal acoustic signal by subsampling point interpolation using delay parameters, accurately determining the time acquisition nodes of different terminals, effectively solving the residual deviation problem, and improving the overall performance and accuracy of the high-precision synchronization method for parallel bus ultrasonic sensor arrays.
[0078] S3. Based on the synchronization alignment of the terminals after delay adjustment, a globally unified delay adjustment is finally achieved. In this embodiment, by using the clock error parameter measured in step S1 (which has been adjusted locally by each terminal) and the delay parameter measured in step S2, the original sampled data of each terminal is globally unified for delay alignment (second delay adjustment) at the data processing end, so that the data of each channel can be synchronized under a unified global time reference.
[0079] In this embodiment, after the local delay adjustment of the terminals in step S1 (first delay adjustment), the local time of each terminal has initially approached the global reference. However, there are still time deviations between terminals caused by factors such as differences in sound wave transmission paths, inherent system delays, and residual frequency offset accumulation drift. Therefore, it is necessary to perform globally unified synchronization alignment (second delay adjustment) in the data processing stage to accurately map the sampled data of all terminals to the global time coordinate system.
[0080] This embodiment S3 specifically includes the following sub-steps: Step S301 involves performing a synchronization alignment operation based on the terminal after delay adjustment, the delay parameter, and the time acquisition node to obtain the global timestamp after the sampling points of different terminals are aligned.
[0081] In this embodiment, during the synchronization alignment operation, different terminals have different delays and time deviations, and the crystal oscillator frequency deviation will also cause cumulative drift. Therefore, it is necessary to take into account multiple factors to perform time alignment on the sampled data of different terminals.
[0082] This embodiment uses a specific total delay compensation formula to unify the sampling data of different terminals under a global timestamp, so that the data collected by different terminals at the same time have the same time identifier in the global time system, effectively eliminating the time difference between terminals.
[0083] Meanwhile, a unified global timestamp provides a common time reference for data from different terminals, making the data from each terminal consistent and comparable in the time dimension. This lays the foundation for subsequent data processing and analysis, enabling more accurate judgment and analysis of ultrasonic events.
[0084] In this embodiment, the global timestamps after aligning sampling points from different terminals satisfy the following relationship: , in, Indicates the first The global timestamp after aligning the sampling points of each terminal. This represents the pulse arrival time estimate obtained after fine alignment via subsampling point interpolation. This represents the fusion delay parameter obtained from dual delay calibration. This indicates the residual clock offset after local delay adjustment at the terminal. This represents the cumulative drift compensation term caused by the crystal oscillator frequency deviation.
[0085] Unlike step S1, the above formula focuses on addressing the cumulative effect of residual frequency offset across a large number of sampling points between the two corrections. The physical meaning of the above four compensation terms lies in: based on the arrival time of the sound wave... Using the time reference point, known system delays are subtracted sequentially. Residual clock offset after local delay adjustment at the terminal and cumulative drift caused by frequency offset Thus, the terminal Any sampling point Mapped to a unified global time coordinate system.
[0086] In this embodiment, the global timestamp after aligning the sampling points of different terminals is a unified time identifier obtained after synchronization and alignment operations, which is mainly used for subsequent unified processing of data from each terminal.
[0087] The pulse arrival time estimate obtained after subsampling point interpolation and fine alignment reflects the preliminary pulse arrival time information on different terminals and is the basis for subsequent compensation calculations.
[0088] In real-world systems, terminals experience various latency issues, such as signal transmission delay and hardware processing delay. By employing a dual latency calibration method to comprehensively consider these factors and obtain the fused latency parameters described above, effective latency compensation can be achieved.
[0089] Because the clocks of different terminals may differ, resulting in inconsistent time bases, each terminal in S1 has performed local delay adjustments, eliminating most of the fixed clock offset; the remaining clock deviation... By further compensating during the global alignment stage using the above formula, the impact of residual clock skew on data time alignment can be eliminated.
[0090] The crystal oscillator is a key component for generating clock signals in a terminal. However, slight deviations in crystal oscillator frequency can lead to cumulative time drift over time. Indicates the first The time drift per unit sampling point caused by the crystal oscillator frequency deviation of each terminal. This refers to the sequence number of the current sampling point. This refers to the index of the reference sampling point, calculated... and The product of these factors compensates for accumulated drift, which can further improve the accuracy of time alignment.
[0091] After the calculation of the above total delay compensation formula, the ultrasonic event data on any sensor is aligned and synchronized to the global timestamp. That is, the data collected by different terminals at the same physical moment have the same time identifier in the global time system, which facilitates the system to perform subsequent calculations and processing, such as data fusion, target localization, motion analysis, etc.
[0092] Step S302: Obtain aligned sampled data based on the global timestamps after aligning the sampling points of different terminals.
[0093] In this embodiment, the original sampling data of different terminals are reorganized and rearranged based on the global timestamps after the sampling points of different terminals are aligned. At the same time, the data is sorted according to the global timestamps to ensure that the data can be accurately matched under the same global timestamp. The above data organization method facilitates subsequent data processing and improves data processing efficiency.
[0094] Next, the aligned sampled data from each terminal are integrated to form a unified dataset. Each data point in the dataset carries a global timestamp, which accurately reflects the physical time of data collection. The integrated and aligned sampled data can also be stored in a designated storage device or database for subsequent data retrieval and analysis.
[0095] The above implementation steps enable synchronization and alignment between the adjusted terminal, delay parameters, and time acquisition nodes, accurately obtaining aligned sampled data and providing reliable data support for further system analysis and decision-making. This synchronization and alignment operation constitutes a globally unified second delay adjustment, further achieving high-precision time synchronization across the entire system based on the first delay adjustment already completed locally on the terminal.
[0096] S4. Synchronous quality assessment and calibration status monitoring This step evaluates the synchronization quality after the global unified delay adjustment in step S3, and determines whether the clock error parameter measured in step S1 and the delay parameter measured in step S2 are still valid. When the parameter fails, recalibration is triggered (the terminal local delay adjustment in step S1 and the global unified delay adjustment in step S3 are re-executed).
[0097] Because the terminal crystal oscillator drifts slowly due to factors such as temperature and aging, and acoustic coupling conditions may change due to mechanical vibration, coupling agent loss, etc., the previously calibrated clock error parameters and delay parameters may gradually deviate from their true values. Therefore, it is necessary to continuously monitor the synchronization quality and trigger recalibration when necessary. It should be clarified that when a decline in synchronization quality is detected, the system's response is to trigger recalibration (i.e., repeat the clock error measurement and terminal local delay adjustment in step S1, and the system delay parameter calibration in step S2, and then re-execute the global unified delay adjustment in step S3), rather than performing online adjustments or corrections to the terminal hardware.
[0098] This embodiment S4 specifically includes the following sub-steps: Step S401: Statistically analyze the residual offset, mean, and standard deviation of different terminals based on the aligned sampled data.
[0099] In this embodiment, relevant data is extracted for each terminal from the aligned sampled data. To ensure data integrity and accuracy, potentially abnormal data is preliminarily screened and processed, removing data points that clearly exceed reasonable limits.
[0100] For each terminal, its sampled data is compared with the theoretical ideal data to calculate the residual offset. The residual offset reflects the difference between the actual data of the terminal and the ideal synchronization state under the existing calibration parameters, and is an important basis for subsequent analysis.
[0101] Record the most recent data for each terminal Secondary residual offset, in this embodiment, Specifically, the number of times was set to 100. Then, statistical methods were used to calculate the mean and standard deviation of the residual offset. The mean reflects the average level of the residual offset, while the standard deviation reflects the degree of fluctuation of the residual offset. The above reference indicators provide a data foundation for monitoring the terminal's operating status and help to understand the accuracy and stability of the terminal's data transmission.
[0102] Step S402: Detect different terminals based on residual offset, mean, and standard deviation, and obtain the offset trend of different terminals.
[0103] In this embodiment, if the mean value calculated above deviates from zero, it indicates that the data transmission path has undergone a systematic shift under the existing calibration parameters, which means that the sampling data of the terminal cannot accurately reflect the actual situation and the accuracy of the transmission path is affected. When the standard deviation is large, it indicates that the path state is unstable. Possible reasons include, but are not limited to, loose contact surfaces, insecure sensor installation, environmental interference, etc., which lead to large fluctuations in the signal transmission process.
[0104] In an optional embodiment, the offset trend of each terminal is judged based on the analysis results of the mean and standard deviation. If the mean continues to increase and the standard deviation is also large, it indicates that the offset of the terminal not only has a cumulative effect, but also fluctuates violently, and the stability of the transmission path is poor.
[0105] This embodiment analyzes the offset trend based on the mean and standard deviation, which can promptly identify potential problems in the data transmission path, providing a basis for taking targeted measures and helping to ensure the accuracy of terminal sampling data.
[0106] Step S403 assesses the confidence level of different terminals based on the offset trend, thus obtaining the confidence level calculation results for different terminals.
[0107] In this embodiment, considering that changes in the physical environment during ultrasonic detection, such as temperature, humidity, and pressure, can affect sensor performance and signal transmission, leading to abnormal residual offset, the embodiment uses statistical analysis of the residual offset trend. If the offset is too large or the fluctuation is severe, the system can automatically reduce the weight of the terminal in the positioning algorithm, effectively preventing false alarms caused by inaccurate terminal data.
[0108] Therefore, the following confidence scoring function is used to calculate the confidence score for each terminal: , in, Indicates terminal confidence level Indicates offset sensitivity. This represents the mean of the residuals. Indicates the sensitivity of the fluctuation coefficient. This represents the standard deviation of the residuals. The offset sensitivity mentioned above is mainly used to adjust the degree of influence of the offset on the confidence level; the fluctuation coefficient sensitivity can adjust the degree of influence of the fluctuation on the confidence level; the confidence level calculation results mentioned above can effectively prevent false alarms caused by inaccurate terminal data, and can improve the accuracy and reliability of the positioning algorithm.
[0109] In one embodiment, when the confidence level of a terminal remains low, it means that the transmission path drift has accumulated to the point that the calibration parameters are unreliable. At this time, an early warning can be issued, changing system maintenance from passively discovering problems to proactively issuing warnings. This helps relevant personnel to take measures in advance and prevent the problem from worsening.
[0110] Step S404: Adjust the operation and maintenance management schemes of different terminals based on the offset trend and confidence calculation results to achieve synchronization of the parallel bus ultrasonic sensor array and long-term operation of different terminals.
[0111] In this embodiment, maintenance strategies for different terminals are formulated. First, a reasonable confidence threshold needs to be set. In this embodiment, it is set to 0.5. When the confidence of a terminal is continuously lower than the confidence threshold, a maintenance reminder can be issued in a timely manner. The maintenance reminder includes information such as the terminal number and confidence trend, so that staff can intuitively understand the actual situation of different terminals on the maintenance interface.
[0112] In one specific embodiment, if the confidence level of a terminal remains below the confidence level threshold for more than one hour, the maintenance interface will generate a maintenance reminder, alerting relevant maintenance personnel to check the sensor installation status, suction cup adsorption force, coupling agent status, cable connection, and other conditions of the terminal.
[0113] In one specific embodiment, for cases where the transmission path drifts slowly, relevant personnel can re-perform the two-stage sound source calibration (i.e., re-perform step S1 of bus electrical signal acquisition, clock error measurement, and terminal local delay adjustment, and step S2 of system delay parameter calibration) to update the system delay parameters and ensure the accuracy of data from different terminals. After the update is completed, the system again performs step S3 of global unified delay adjustment to restore the high-precision synchronization state.
[0114] The above-mentioned different operation and maintenance strategies help to achieve synchronization of parallel bus ultrasonic sensor arrays and long-term stable operation of different terminals.
[0115] In complex environments, changes in the physical environment can affect the synchronization of ultrasonic sensor arrays. The above-described implementation can monitor the operating status of the terminals in real time, promptly identify and address potential problems, and effectively ensure the time synchronization accuracy of different terminals in complex environments. Accurate time synchronization is the foundation for the normal operation of distributed systems and plays a crucial role in the collaborative work of ultrasonic sensor arrays.
[0116] The method in this embodiment ensures the accuracy and reliability of terminal data through monitoring, evaluation, and operation and maintenance management, providing data support for further analysis and decision-making in distributed systems, and further improving the practical performance and application value of the high-precision synchronization method for parallel bus ultrasonic sensor arrays.
[0117] System Implementation Examples Please see Figure 3 In an optional embodiment, the present invention also provides a high-precision synchronization system for a parallel bus ultrasonic sensor array. This system includes a processor, an input device, an output device, and a memory, all interconnected. The memory stores a computer program, which includes program instructions. The processor is configured to call these instructions and execute the specific steps of the high-precision synchronization method and related embodiments of the parallel bus ultrasonic sensor array provided by the present invention. The high-precision synchronization system for a parallel bus ultrasonic sensor array of the present invention is structurally complete and objectively stable.
[0118] This invention provides a high-precision synchronization system for a parallel bus ultrasonic sensor array. The functional components can be integrated into a single processing unit, or each component can exist independently, or two or more components can be integrated into one unit. The integrated components can be implemented in hardware or software.
[0119] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.
Claims
1. A high-precision synchronization method for a parallel bus ultrasonic array, characterized in that, Includes the following steps: The main control base station broadcasts and sends a synchronization electrical signal waveform to each terminal via a bus. The terminal acquisition unit collects the electrical signal waveform and analyzes, corrects, and estimates the clock deviation to obtain the clock deviation detection results of different terminals. Based on the clock deviation detection results, the local delay of different terminals is adjusted to obtain the delayed terminal. The system delay parameters of each terminal are obtained by equidistant acoustic calibration pulses. The system delay parameters are then subjected to double delay calibration to obtain the delay parameters of different terminals. The acoustic calibration pulse waveforms of different terminals are then finely aligned by subsampling point interpolation based on the delay parameters to determine the time acquisition nodes of different terminals. Based on the delay adjustment terminal, the delay parameter and the time acquisition node, a synchronization and alignment operation is performed to obtain aligned sampled data; Statistical testing and confidence assessment are performed on the aligned sampled data to ensure the synchronization of the parallel bus ultrasonic sensor array and the long-term operation of the terminal, and finally output equivalent synchronized sampled data.
2. The high-precision synchronization method for parallel bus ultrasonic arrays according to claim 1, characterized in that, The main control base station broadcasts a synchronization electrical signal waveform to each terminal via a bus. The terminal acquisition unit acquires the electrical signal waveform, analyzes and corrects it, and estimates the clock deviation to obtain clock deviation detection results for different terminals. Based on the clock deviation detection results, the local delay of each terminal is adjusted to obtain a delay-adjusted terminal, including: The terminal acquisition unit is used to acquire the electrical signal waveforms of different terminals and obtain the electrical information of different terminals; The electrical information from the different terminals is integrated to obtain the terminal electrical signal; A time offset analysis formula is constructed based on the terminal electrical signal; The time offset analysis formula is used to perform time offset analysis on the edge sequence in the terminal electrical signal, and the time offset analysis results are obtained. The corrected global time is obtained based on the time offset analysis results and the terminal electrical signal.
3. The high-precision synchronization method for parallel bus ultrasonic arrays according to claim 2, characterized in that, The main control base station broadcasts a synchronization electrical signal waveform to each terminal via a bus. The terminal acquisition unit acquires the electrical signal waveform, analyzes and corrects it, and estimates the clock deviation to obtain clock deviation detection results for different terminals. Based on the clock deviation detection results, the local delay of each terminal is adjusted to obtain a delay-adjusted terminal, including: A formula for calculating instantaneous frequency deviation is constructed based on the edge sequence and the corrected global time. The instantaneous frequency deviation of the edge sequence is obtained through the instantaneous frequency deviation calculation formula; Introduce the recursive formula for exponential smoothing filtering; The instantaneous frequency deviation is subjected to exponential smoothing filtering using the recursive formula to obtain a smoothed frequency deviation estimate. The clock deviation detection results for different terminals are obtained based on the smoothed frequency deviation estimation value.
4. The high-precision synchronization method for parallel bus ultrasonic arrays according to claim 3, characterized in that, The step of adjusting the local latency of different terminals based on the clock deviation detection result to obtain a latency-adjusted terminal includes: A convergence threshold is set based on the edge sequence, the corrected global time, and the clock skew detection result. The inter-frame rate of change of frequency deviation is analyzed based on the smoothed frequency deviation estimate. When the inter-frame change rate is less than the convergence determination threshold, it is determined that the frequency deviation has converged, and the smoothed frequency deviation estimate is used as the clock deviation detection result of the terminal. Based on the clock deviation detection results, the local latency of different terminals is adjusted to obtain the latency-adjusted terminal.
5. The high-precision synchronization method for parallel bus ultrasonic arrays according to claim 1, characterized in that, The process of obtaining system delay parameters for each terminal by using equidistant acoustic calibration pulses, and then performing dual delay calibration on these system delay parameters to obtain delay parameters for different terminals includes: The terminal system delay parameters are obtained by emitting equidistant sound wave calibration pulses using an ultrasonic buzzer and an ultrasonic buzzer in the base station. The initial system delay is obtained by initially calibrating the terminal acoustic signal in the terminal system delay parameters. The system delay of different terminals is obtained by continuously calibrating the acoustic wave signal of the terminal. The system latency after fusion of different terminals is obtained by combining the initial system latency and the system latency of the different terminals; The latency parameters of different terminals are obtained based on the system latency after the different terminals are integrated.
6. The high-precision synchronization method for parallel bus ultrasonic arrays according to claim 1, characterized in that, The step of performing subsampling point interpolation fine alignment on the acoustic calibration pulse waveforms of different terminals in conjunction with the delay parameter to determine the time acquisition nodes of different terminals includes: A terminal search window determination function is established based on the terminal acoustic wave signal. The half-width of the search window for different terminals is determined by the terminal search window determination function; The hourly sampling time of different terminals is determined based on the terminal acoustic signal and the half-width of the search window.
7. The high-precision synchronization method for parallel bus ultrasonic arrays according to claim 6, characterized in that, The step of performing subsampling point interpolation fine alignment on the acoustic calibration pulse waveforms of different terminals in conjunction with the delay parameter to determine the time acquisition nodes of different terminals includes: Introducing a subsampling point parabolic interpolation method; Based on the subsampling point parabolic interpolation method and the hourly sampling time of the different terminals, subsampling point interpolation fine alignment is performed to determine the time acquisition node of the different terminals.
8. The high-precision synchronization method for parallel bus ultrasonic arrays according to claim 1, characterized in that, The step of performing a synchronization and alignment operation based on the delayed-adjusted terminal, the delay parameter, and the time acquisition node to obtain aligned sampled data includes: Based on the time adjustment terminal, the delay parameter and the time acquisition node, a synchronization alignment operation is performed to obtain the global timestamp after the sampling points of different terminals are aligned. The aligned sampling data is obtained based on the global timestamps after alignment of the sampling points from the different terminals. The global timestamps after alignment of sampling points from different terminals satisfy the following relationship: ， in, Indicates the first The global timestamp after aligning the sampling points of each terminal. This represents the pulse arrival time estimate obtained after subsampling and fine alignment. This represents the fusion delay parameter obtained from dual delay calibration. This represents the clock offset calculated through time offset analysis. This represents the cumulative drift compensation term caused by the crystal oscillator frequency deviation.
9. The high-precision synchronization method for parallel bus ultrasonic arrays according to claim 1, characterized in that, Statistical testing and confidence assessment are performed on the aligned sampled data to ensure the synchronization of the parallel bus ultrasonic sensor array and the long-term operation of the terminal. The final output of equivalent synchronized sampled data includes: Based on the aligned sampled data, statistical analysis was performed on the residual offset, mean, and standard deviation of different terminals; The residual offset, the mean, and the standard deviation are used to detect different terminals and obtain the offset trend of different terminals. Based on the offset trends of the different terminals, confidence levels are assessed for different terminals to obtain confidence level calculation results for different terminals; The operation and maintenance management schemes for different terminals are adjusted based on the offset trend and the confidence calculation results to achieve synchronization of the parallel bus ultrasonic sensor array and long-term operation of different terminals. The parallel bus ultrasonic sensor array outputs equivalent synchronous sampling data.
10. A high-precision synchronization system for a parallel bus ultrasonic array, characterized in that, The system includes a processor, an input device, an output device, and a memory, which are interconnected. The memory stores a computer program, which includes program instructions. The processor is configured to invoke the program instructions to execute the high-precision synchronization method for a parallel bus ultrasonic array as described in any one of claims 1-9.