A Ship Shaft Power Detection System Based on Shaft Power Meter

Abstract

This invention relates to the field of ship propulsion system condition monitoring technology, specifically a ship shaft power detection system based on a shaft power meter. It includes: a data acquisition module for real-time acquisition of impact vibration acceleration, transmission compensation power, real-time interference frequency, and real-time ambient temperature; an impact state identification module for determining the predicted signal-to-noise ratio and the current operating mode; a time-division multiplexing execution module for responding to the current operating mode determined by the impact state identification module, executing corresponding power supply and measurement methods to output the original strain value; an adaptive compensation module for obtaining the filtered strain value and outputting the final compensated strain measurement value; and a performance closed-loop control module for feedforward adjustment of the charging time of the time-division multiplexing execution module. This system physically resolves the inherent conflict between electromagnetic interference from wireless power supply and high-fidelity signal measurement, ensuring the authenticity and reliability of the data.

Description

Technical Field

[0001] This invention relates to the field of ship propulsion system condition monitoring technology, specifically a ship shaft power detection system based on a shaft power meter. Background Technology

[0002] Ship shaft power is a core parameter for evaluating propulsion system efficiency, optimizing fuel consumption, and monitoring the health status of critical equipment. For rotating drive shafts, accurate measurement of shaft power typically relies on strain gauges bonded to the shaft surface and wireless signal transmission and equipment power supply to avoid the use of wear-prone and unreliable slip ring structures.

[0003] To ensure the stable operation of measuring equipment under impact, the wireless power supply system must possess dynamic power compensation capabilities, i.e., rapidly increasing the transmission power to counteract the attenuation of magnetic coupling. However, this adaptively enhanced transmission power generates an extremely strong electromagnetic interference field, which directly couples into the highly sensitive strain measurement circuit, causing a severe deterioration in the signal-to-noise ratio of the output signal, or even completely submerging the actual strain signal in electromagnetic noise. Therefore, in a strong impact environment, there is an inherent fundamental contradiction between the reliability requirements of wireless power supply and the requirements of high-fidelity signal measurement: the measures taken to ensure energy supply physically undermine the effectiveness of the measurement. Existing technical solutions have failed to effectively resolve this contradiction, often resulting in severe distortion or even complete loss of the acquired shaft power data during the most critical impact events, making it impossible to provide a reliable basis for the ultimate performance evaluation and structural safety of the ship's propulsion system.

[0004] The information disclosed in the background section above is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the present invention discloses a ship shaft power detection system based on a shaft power meter. Specifically, the technical solution of the present invention includes:

[0006] The data acquisition module is used to acquire impact vibration acceleration, transmission compensation power, real-time interference frequency, and real-time ambient temperature in real time.

[0007] The impact state identification module is used to determine the predicted signal-to-noise ratio based on the preset logistic function model and the transmission compensation power obtained by the data acquisition module; and to combine the predicted signal-to-noise ratio with the impact vibration acceleration and compare it with the preset working mode switching threshold to determine the current working mode.

[0008] The time-division multiplexing execution module is used to respond to the current working mode determined by the impact state identification module, execute the corresponding power supply and measurement methods, and output the original strain value.

[0009] The adaptive compensation module is used to filter the original strain value based on the real-time interference frequency obtained by the data acquisition module to obtain the filtered strain value; and to perform temperature correction on the filtered strain value based on the real-time ambient temperature and the preset exponential compensation model to output the final compensated strain measurement value.

[0010] The performance closed-loop control module is used to adjust the charging time of the time-division multiplexing execution module based on the initial characteristics of the impact vibration acceleration obtained by the data acquisition module; and after the impact event ends, it corrects the working mode switching threshold used by the impact state identification module in a closed loop based on historical performance data.

[0011] Preferably, the impact state identification module determines the predicted signal-to-noise ratio, specifically including:

[0012] The transmitted compensation power is substituted into the logistic function model used to describe the electromagnetic interference saturation effect to calculate the predicted signal-to-noise ratio.

[0013] Preferably, the current working mode includes:

[0014] The steady-state mode is determined when the amplitude of the impact vibration acceleration is lower than a first preset threshold and the predicted signal-to-noise ratio is higher than a preset signal-to-noise ratio threshold.

[0015] The disturbance mode is determined when the amplitude of the impact vibration acceleration is higher than a first preset threshold and lower than a second preset threshold, or when the predicted signal-to-noise ratio is lower than a preset signal-to-noise ratio threshold.

[0016] The impact mode is determined when the amplitude of the impact vibration acceleration is higher than a second preset threshold.

[0017] Preferably, the time-division multiplexing execution module responds to the current operating mode as a disturbance mode or an impact mode, specifically including:

[0018] Within the pulse charging window, the onboard energy storage unit is charged wirelessly, and the measurement circuit is in sleep mode during this time.

[0019] Within the silent measurement window, the wireless power transmitter is turned off, and the onboard energy storage unit powers the measurement circuit to perform interference-free data acquisition and obtain the original strain value.

[0020] Preferably, the adaptive compensation module performs filtering processing, specifically including:

[0021] The normalized notch center angular frequency is determined based on the real-time interference frequency and the preset system sampling frequency.

[0022] An adaptive second-order infinite impulse response notch filter is constructed based on the normalized notch center angular frequency.

[0023] An adaptive second-order infinite impulse response notch filter was used to process the original strain value to filter out ice electrical noise, resulting in the filtered strain value.

[0024] Preferably, the adaptive compensation module performs temperature correction, specifically including:

[0025] The filtered strain value, real-time ambient temperature, and reference calibration temperature are substituted into an exponential compensation model used to correct strain gauge sensitivity drift caused by extremely low temperatures to determine the final compensated strain measurement value.

[0026] Preferably, the performance closed-loop control module performs feedforward adjustments, specifically including:

[0027] By integrating the impact vibration acceleration during the impact leader stage, the velocity increment characterizing the impact intensity is obtained.

[0028] Based on the speed increment and the preset feedforward gain coefficient, the normal duration of the pulse charging window is extended to generate an enhanced charging window duration;

[0029] Update the enhanced charging window duration to the time-division multiplexing execution module.

[0030] Preferably, the performance closed-loop control module performs closed-loop correction, specifically including:

[0031] After a shock event ends, the lowest signal-to-noise ratio and capacitor voltage drop recorded during the event are collected as historical performance data.

[0032] Based on historical performance data, the first preset threshold and the second preset threshold included in the adaptive optimization working mode switching threshold are optimized.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] 1. This system, through the coordinated intelligent identification of impact states and time-division multiplexing execution, solves the inherent conflict between electromagnetic interference from wireless power supply and high-fidelity signal measurement at the physical level. When the system detects a disturbance or impact mode, it switches to an innovative working mode of pulse charging and silent measurement, completely shutting off the interference source within the measurement window. This ensures that even under extreme conditions of strong impact and violent fluctuations in magnetic coupling, it can still acquire original strain signals with a high signal-to-noise ratio, fundamentally guaranteeing the authenticity and reliability of the data.

[0035] 2. This system incorporates an adaptive compensation module to cope with multi-physics coupling interference in polar environments. This module integrates an adaptive digital notch filter and a nonlinear temperature compensation model. The former accurately filters out ice electrical noise caused by ice breaking and dynamic frequency drift based on real-time acquired interference frequencies; the latter accurately corrects the nonlinear sensitivity drift of strain gauges at extremely low temperatures based on real-time temperature. This dual compensation mechanism ensures high accuracy of measurement results in complex environments.

[0036] 3. This system constructs a feedforward control mechanism based on impact prediction, realizing an intelligent upgrade from passive response to active defense. By integrating the impact vibration acceleration leading wave in real time, the system can predict the intensity of the main impact and accordingly extend the wireless charging time in advance, storing more energy for the onboard energy storage unit. This proactive strategy can effectively avoid the loss of critical data due to energy depletion during the most severe impact, significantly improving the system's data survival rate and continuity under extreme impact.

[0037] 4. This system is designed with a closed-loop correction circuit based on historical performance data, giving the system the ability to learn and optimize itself. After each impact event, the system analyzes key performance indicators such as the lowest signal-to-noise ratio and capacitor voltage drop during that event, and adaptively optimizes the acceleration threshold for switching operating modes based on this analysis. This highest-level control closed loop enables the system to continuously adapt to changing external conditions and its own state, ensuring its long-term robustness and optimal performance. Attached Figure Description

[0038] The present invention will be further explained below with reference to the accompanying drawings and embodiments:

[0039] Figure 1 This is a system structure block diagram of the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0041] Example 1:

[0042] Please see Figure 1 A ship shaft power detection system based on a shaft power meter, comprising:

[0043] The data acquisition module is used to acquire impact vibration acceleration, transmission compensation power, real-time interference frequency, and real-time ambient temperature in real time.

[0044] The impact state identification module is used to determine the predicted signal-to-noise ratio based on the preset logistic function model and the transmission compensation power obtained by the data acquisition module; and to combine the predicted signal-to-noise ratio with the impact vibration acceleration and compare it with the preset working mode switching threshold to determine the current working mode.

[0045] The time-division multiplexing execution module is used to respond to the current working mode determined by the impact state identification module, execute the corresponding power supply and measurement methods, and output the original strain value.

[0046] The adaptive compensation module is used to filter the original strain value based on the real-time interference frequency obtained by the data acquisition module to obtain the filtered strain value; and to perform temperature correction on the filtered strain value based on the real-time ambient temperature and the preset exponential compensation model to output the final compensated strain measurement value.

[0047] The performance closed-loop control module is used to adjust the charging time of the time-division multiplexing execution module based on the initial characteristics of the impact vibration acceleration obtained by the data acquisition module; and after the impact event ends, it corrects the working mode switching threshold used by the impact state identification module in a closed loop based on historical performance data.

[0048] This embodiment provides a ship shaft power detection system based on a shaft power meter, aiming to solve the technical problem of data distortion or loss caused by the inherent conflict between electromagnetic interference from wireless power supply and high-fidelity signal measurement in traditional wireless detection systems under extreme impact conditions such as ship icebreaking. The system achieves high-precision and high-reliability continuous shaft power detection in environments with strong impact and multi-physics field coupling interference by constructing a complete technical closed loop that integrates state perception, time-division multiplexing, adaptive compensation and closed-loop control.

[0049] The system includes the following core modules:

[0050] The data acquisition module aims to provide comprehensive, real-time multiphysics data input for system state assessment, adaptive compensation, and closed-loop control. In this embodiment, the module integrates a series of sensors, specifically including: an acceleration sensor for real-time acquisition of shaft impact vibration acceleration characterizing the intensity of external impact loads. A monitoring unit located within the wireless power supply system controller is used to monitor in real time the transmit compensation power, which is dynamically adjusted to counteract the decrease in magnetic coupling coefficient caused by shock. A broadband electromagnetic pulse detector is used to acquire in real time the dominant interference frequencies generated by the ice-electric effect in polar ice-breaking environments. ; and a low-temperature sensor for acquiring real-time ambient temperature that has a significant impact on the physical properties of materials. ;

[0051] In addition, the module continuously monitors and outputs the real-time terminal voltage of the onboard energy storage unit. The real-time signal-to-noise ratio estimate of the original strain value sequence provides data input for subsequent modules;

[0052] The impact state identification module aims to accurately determine the current external environmental impact level of the system based on real-time acquired data, and provide a decision-making basis for subsequent operating mode switching. In this embodiment, the module uses a preset logistic function model that describes the nonlinear impact of electromagnetic interference on signal quality, and inputs the transmit compensation power obtained by the data acquisition module. This allows for the calculation of a predicted signal-to-noise ratio. This module will monitor the impact vibration acceleration in real time. The amplitude and the predicted signal-to-noise ratio The system is dynamically compared with a set of preset working mode switching thresholds to ultimately determine whether the system should be in steady state mode, disturbance mode or impact mode.

[0053] The time-division multiplexing execution module aims to execute the optimal power supply and measurement strategy based on the instructions from the impact state identification module, thereby physically avoiding electromagnetic interference. When the system is in steady-state mode, this module operates in a traditional synchronous and continuous power supply and measurement mode. When the system is identified as being in a disturbance or impact mode, the module switches to an innovative time-division multiplexing mode with pulsed power supply and silent measurement. In this mode, the data acquisition cycle is divided into two independent windows: charging and measurement. During the measurement window, wireless power supply is completely shut off, physically eliminating interference sources and ensuring high-fidelity output of the original strain values. ;

[0054] The adaptive compensation module aims to perform a secondary correction on the original strain value output by the time-division multiplexing execution module to eliminate the influence of other environmental factors such as ice electrical noise and low temperature effects on measurement accuracy. In this embodiment, the module performs sequential compensation based on the real-time interference frequency obtained by the data acquisition module. Construct an adaptive digital notch filter for... Filtering is performed to precisely remove ice electrical noise, and the filtered strain value is obtained. Subsequently, it is based on real-time ambient temperature. With a pre-defined exponential compensation model for correcting the low-temperature nonlinear effects of materials, for Temperature correction is applied, resulting in a fully compensated and highly reliable strain measurement value. ;

[0055] The performance closed-loop control module aims to endow the system with self-learning and self-optimization capabilities, enabling it to upgrade from passive response to active defense. This module contains two control logics: it is based on the impact vibration acceleration acquired by the data acquisition module. The initial characteristic, namely the leading wave, is used for feedforward control to predict the arrival of the main impact in advance and adjust the charging time of the extended time-division multiplexing execution module accordingly. After a complete impact event ends, the module analyzes the system performance indicators recorded during the event, such as the minimum signal-to-noise ratio and capacitor voltage drop, as historical performance data. Based on this data, the module performs closed-loop correction and adaptive optimization of the working mode switching threshold used by the impact state identification module.

[0056] Through the collaborative work of the above modules, this embodiment constructs a closed-loop detection system capable of proactively sensing the environment, making intelligent decisions, executing precisely, adaptively compensating, and continuously optimizing itself. It resolves the inherent contradiction between wireless power supply and high-precision measurement in environments with strong interference, ensuring that continuous, accurate, and reliable shaft power data can be obtained even under extreme conditions such as ship icebreaking, greatly improving the robustness and safety of ship propulsion system status monitoring.

[0057] Example 2:

[0058] The impact state identification module determines the predicted signal-to-noise ratio, specifically including:

[0059] Substitute the transmit compensation power into the logistic function model used to describe the electromagnetic interference saturation effect to calculate the predicted signal-to-noise ratio;

[0060] This embodiment, based on Embodiment 1, further explains the specific implementation method of the impact state identification module in determining the predicted signal-to-noise ratio; its purpose is to quantify the wireless power supply compensation power by establishing a mathematical model that is closer to physical reality. For the signal-to-noise ratio of the measured signal The nonlinear degradation effect, namely the adaptive power supply enhancement measurement interference effect defined in this invention;

[0061] In this embodiment, the impact state identification module determines the predicted signal-to-noise ratio, specifically through the following methods:

[0062] This module will use the transmit compensation power monitored in real time by the data acquisition module. Substituting a pre-defined logistic function model that describes the saturation or breakdown effect of electromagnetic interference on the measurement circuit, the current predicted signal-to-noise ratio is calculated. The model was initially derived from classical functions in physics that describe phase transitions or saturation phenomena. Here, it is used to accurately characterize the threshold effect in which signal quality drops sharply after the electromagnetic interference intensity exceeds the filtering and shielding capabilities of the measurement circuit.

[0063] The specific mathematical expression for this model is as follows:

[0064] ;

[0065] in, This refers to the current transmit compensation power being... The predicted signal-to-noise ratio at that time; this is a dimensionless pure number, which is the direct output of the model and is used to characterize the quality of the predicted signal;

[0066] This refers to the wireless power transmission compensation power; its dimension is watts (W), which is collected in real time by the data acquisition module. It is dynamically adjusted to counteract the decrease in magnetic coupling coefficient caused by impact, and therefore indirectly reflects the intensity of the impact;

[0067] : refers to the reference signal-to-noise ratio under zero-compensation power; it is a dimensionless pure number that serves as the ideal upper limit for signal quality; it is used for calibration testing of the system in a laboratory environment without impact.

[0068] This refers to the critical power threshold at which the signal-to-noise ratio begins to deteriorate significantly; its dimension is watts (W), and its function is to define the trigger point for the interference breakdown effect; it is not determined during model operation, but rather obtained through dedicated experiments during the model calibration phase; specifically, a series of discrete and constant external impacts are applied on a test bench to form a set of compensation power values ​​for calibration. And measure the stable signal-to-noise ratio corresponding to each power level. Based on this set of multiple data points The calibration dataset was fitted using nonlinear least squares regression analysis. The initial value can be set with reference to the transmit power corresponding to the electromagnetic interference saturation point of the front-end amplifier.

[0069] This refers to the attenuation sensitivity coefficient; its dimension is the reciprocal of power, W. -1 This ensures that the exponent term is dimensionless; its function is to control the signal-to-noise ratio above a certain threshold. The steepness of the subsequent descent curve; and The two methods are similar, both involving the calibration datasets described above. Simultaneous determination is achieved through nonlinear least squares fitting;

[0070] This model enables the system to assess the potential impact of current power supply intensity on signal quality online and in real time; when the model predicts... Below the preset valid data threshold When the system anticipates that the synchronous continuous working mode is unreliable and must switch to the time-division multiplexing mode, it can predict that the synchronous continuous working mode is unreliable and must switch to the time-division multiplexing mode. Compared with simple linear relationship assumptions or fixed empirical thresholds, the logistic function model used in this embodiment can more accurately and non-linearly characterize the physical process of adaptive power-enhanced measurement interference. This makes the system's prediction of signal quality more accurate, thereby realizing more intelligent and timely mode switching decisions, effectively avoiding data pollution caused by untimely switching or unnecessary data interruption caused by excessively frequent switching, and improving the decision accuracy and operating efficiency of the entire system.

[0071] Example 3:

[0072] Current working modes include:

[0073] The steady-state mode is determined when the amplitude of the impact vibration acceleration is lower than a first preset threshold and the predicted signal-to-noise ratio is higher than a preset signal-to-noise ratio threshold.

[0074] The disturbance mode is determined when the amplitude of the impact vibration acceleration is higher than a first preset threshold and lower than a second preset threshold, or when the predicted signal-to-noise ratio is lower than a preset signal-to-noise ratio threshold.

[0075] The impact mode is determined when the amplitude of the impact vibration acceleration is higher than a second preset threshold.

[0076] This embodiment further explains the specific division and determination logic of the current working mode based on embodiment 1; by establishing a multi-level state division system, the system can take corresponding response strategies with different granularities that are precisely matched to the severity of the impact and the predicted signal quality.

[0077] In this embodiment, the current working mode is divided into the following three types, and the determination logic is as follows:

[0078] Steady-state mode: when the impact vibration acceleration The amplitude is lower than the first preset threshold. And the predicted signal-to-noise ratio calculated by the logistic function model. Higher than the preset signal-to-noise ratio threshold At that time, the system is determined to be in steady state mode; the first preset threshold It is a lower acceleration threshold used to distinguish between environmental noise and meaningful low-intensity disturbances, and its function is to define the absolutely stable operating range of the system; preset signal-to-noise ratio threshold. It is the minimum acceptable signal quality standard, which serves as the bottom line to ensure data validity. In this mode, external shocks are weak, and the electromagnetic interference of the power supply system on the measurement is negligible. The system adopts the most efficient power supply and measurement synchronous continuous operation mode.

[0079] Disturbance mode: when impact vibration acceleration The amplitude is higher than the first preset threshold. And below the second preset threshold At that time, or in predicting the signal-to-noise ratio Below the preset signal-to-noise ratio threshold When the system is in disturbance mode, the second preset threshold is used. This is a higher acceleration threshold used to distinguish between general disturbances and severe impacts; the triggering conditions for this mode cover two situations: the mechanical impact has reached a moderate intensity but has not yet reached the most dangerous level; or, in the case of a less severe mechanical impact, compensation power is reduced due to other factors such as coil misalignment. This increases the predictive signal-to-noise ratio, thus improving the accuracy of the prediction signal-to-noise ratio. Premature deterioration; in this mode, the system will trigger and switch to time-division multiplexing mode;

[0080] Impact mode: When the impact vibration acceleration The amplitude is higher than the second preset threshold. At this time, the system is identified as being in shock mode; this mode indicates that the system is experiencing the most severe external shock; in this mode, the system will trigger and switch to an enhanced time-division multiplexing operating mode, and combine feedforward control for active defense.

[0081] All of the above thresholds , , All of these are based on extensive statistical analysis of historical ice-breaking data or similar working condition data, combined with laboratory simulation test results to comprehensively determine the parameters. The core technical consideration in its design is to seek the optimal balance between ensuring data acquisition quality and maintaining system response speed and data continuity. This three-mode classification system enables the system to manage different levels of risk in a differentiated manner, avoiding the traditional one-size-fits-all start-stop control, and instead realizing a refined, gradient response strategy commensurate with the risk level. This not only ensures the highest data fidelity in the disturbance and impact modes at critical moments, but also maximizes data continuity and system operating efficiency in the steady-state mode during safe periods.

[0082] Example 4:

[0083] The time-division multiplexing execution module responds to whether the current operating mode is disturbance mode or impact mode, specifically including:

[0084] Within the pulse charging window, the onboard energy storage unit is charged wirelessly, and the measurement circuit is in sleep mode during this time.

[0085] Within the silent measurement window, the wireless power transmitter is turned off, and the onboard energy storage unit powers the measurement circuit to perform interference-free data acquisition and obtain the original strain value.

[0086] This embodiment, based on embodiment 1, further explains the specific execution process of the time-division multiplexing execution module under a specific working mode; its purpose is to elaborate in detail how, when the system enters a disturbance mode or impact mode, the energy transmission and signal measurement processes are completely separated on a microsecond-level time scale, thereby physically eliminating the electromagnetic interference source.

[0087] In this embodiment, the time-division multiplexing execution module responds to the current operating mode as either disturbance mode or impact mode, and its specific execution logic is divided into two alternating stages:

[0088] In the pulse charging window Inside, the module performs an energy replenishment operation; at this time, the wireless power supply system transmitter rapidly charges the onboard energy storage unit mounted on the rotating shaft in the form of high-power pulses; to ensure that the electromagnetic field during the charging process does not affect subsequent measurements, the measurement circuit is in a dormant state and does not perform any data acquisition; the onboard energy storage unit refers to an energy buffer device mounted on the measuring front end that rotates with the shaft, which in this embodiment is preferably a miniature supercapacitor; its function is to independently power the sensor and measurement circuit during the wireless power supply shutdown period; its minimum required capacity The following formula should be used in the design to ensure that the voltage drop does not affect the normal operation of the circuit during the longest expected silent measurement period:

[0089] ;

[0090] in, This refers to the power consumption of the sensor in measurement mode, and is relevant to the circuit design and core chip datasheet. The maximum expected duration of silence is calculated by statistical analysis of the duration of historical shock events with an added safety margin. This is the initial full-charge voltage of the energy storage unit, which is relevant to the circuit design. The maximum allowable voltage drop is specified in the core chip datasheet.

[0091] In silent measurement window Inside, the module performs high-fidelity data acquisition. At this time, the wireless power transmitter is completely shut down, eliminating electromagnetic interference. The measurement circuit is independently powered by a fully charged onboard energy storage unit. In this pure electromagnetic environment, the strain gauges and their conditioning circuitry at the front end perform interference-free data acquisition. After A / D conversion, the raw strain values ​​are obtained. ;

[0092] These two windows and Together they form a complete time-division multiplexing microcycle. ; The duration is determined by the time required for data acquisition and conversion, while The duration is determined by charging efficiency and energy demand; the duty cycle of both can be dynamically adjusted according to the real-time needs of the system, such as feedforward control logic; by constructing a time-separated execution sequence of pulse charging and silent measurement, this embodiment achieves complete decoupling of the energy transmission process and the signal measurement process at the physical level; this design eliminates the electromagnetic interference of wireless power supply to high-sensitivity strain measurement, which is the core execution guarantee for the system to still capture high-fidelity, high signal-to-noise ratio original signals in strong interference environments.

[0093] Example 5:

[0094] The adaptive compensation module performs filtering processing, specifically including:

[0095] The normalized notch center angular frequency is determined based on the real-time interference frequency and the preset system sampling frequency.

[0096] An adaptive second-order infinite impulse response notch filter is constructed based on the normalized notch center angular frequency.

[0097] An adaptive second-order infinite impulse response notch filter was used to process the original strain value to filter out ice electrical noise and obtain the filtered strain value.

[0098] This embodiment further explains the specific implementation of filtering in the adaptive compensation module based on embodiment 1; its purpose is to accurately eliminate narrowband, high-energy electromagnetic pulse interference generated by the unique ice-electric effect in the polar ice-breaking environment through a filtering technology that can dynamically adapt to changes in environmental noise.

[0099] In this embodiment, the adaptive compensation module performs filtering processing, specifically including the following sequential steps:

[0100] Based on real-time interference frequency With the preset system sampling frequency Determine the normalized notch center angular frequency Real-time interference frequency The dominant frequency of ice electrical noise is captured in real time by the broadband electromagnetic pulse detector in the data acquisition module, and is acquired in real time by the sensor; the system sampling frequency. This is the sampling rate of the system's A / D conversion, a fixed value for the system design; the calculation is performed using the following formula, the purpose of which is to convert the physical frequency into the normalized digital frequency required in the digital filter design:

[0101] ;

[0102] Based on the normalized notch center angular frequency An adaptive second-order infinite impulse response (IIR) notch filter is constructed in real time. While the filter's initial design is based on standard filter design theory in digital signal processing, its core innovation lies in the dynamic nature of its parameters; its transfer function... Based on real-time calculations Dynamic adjustment, the expression is as follows:

[0103] ;

[0104] in, Delay operator for units; Let be the pole radius, which is a constant close to 1, for example... Its function is to determine the bandwidth of the notch filter; The closer the value is to 1, the narrower the notch, and the less impact it has on useful signals at nearby frequencies, but the stability of the filter will be slightly reduced. The selection of this value is the result of a trade-off between filter selectivity and stability based on design experience.

[0105] The constructed adaptive second-order IIR notch filter is used to analyze the original strain value sequence. Real-time processing is performed, and ice electrical noise is filtered out through transfer function calculations to finally obtain the filtered strain value. ;because Is it following The filter is updated in real time, thus enabling it to lock onto and continuously suppress changing ice-electric interference frequencies. Compared to conventional filters using fixed parameters, the adaptive notch filter in this embodiment can track and accurately eliminate non-stationary ice-electric noise in real time. This adaptive characteristic ensures that the filter maintains optimal suppression even when the ice-electric interference frequency drifts, while preserving the effective frequency components in the original strain signal to the maximum extent, greatly improving the accuracy of measurements in the special electromagnetic environment of the polar regions.

[0106] Example 6:

[0107] The adaptive compensation module performs temperature correction, specifically including:

[0108] The filtered strain value, real-time ambient temperature, and reference calibration temperature are substituted into the exponential compensation model used to correct the strain gauge sensitivity drift caused by extremely low temperatures to determine the final compensated strain measurement value.

[0109] This embodiment further explains the specific implementation of temperature correction in the adaptive compensation module based on embodiment 1. Its purpose is to accurately compensate for the nonlinear effects caused by the extreme low temperature of the polar environment, such as -40°C, on the material physical properties of sensing elements such as strain gauges, especially the drift in sensitivity, thereby ensuring the accuracy of the measurement results in a wide temperature range.

[0110] In this embodiment, the adaptive compensation module performs temperature correction, the core of which is the application of an exponential compensation model specifically designed to correct strain gauge sensitivity drift caused by extremely low temperatures; the specific implementation steps are as follows:

[0111] The filtered strain value obtained from the previous steps Real-time ambient temperature acquired by the data acquisition module and a preset reference calibration temperature. These values ​​are then substituted into the exponential compensation model to calculate and determine the final compensated strain measurement. ;

[0112] The specific mathematical expression of the compensation model is as follows:

[0113] ;

[0114] in, This refers to the final strain measurement value after compensation; it is a dimensionless value and is the final output of this module.

[0115] This refers to the strain value after ice electrical noise filtering; this is the input for this step.

[0116] This refers to the real-time ambient temperature; its dimension is Celsius (°C) or Kelvin (K), and it is collected in real time by the low-temperature sensor of the data acquisition module.

[0117] This refers to the reference calibration temperature; it is a constant, such as 25°C, representing the reference temperature for the sensor's factory calibration or normal operation.

[0118] This refers to the material's temperature drift coefficient; its dimension is the reciprocal of temperature, K. -1 Its function is to characterize the basic trend of strain gauge sensitivity changing with temperature;

[0119] : refers to the nonlinear relationship index; it is a dimensionless parameter; its function is to correct the nonlinear relationship between sensitivity and temperature, especially in the deep cryogenic region;

[0120] To ensure the independence of the variable domain, parameters and It is not calculated during model runtime, but predetermined during the calibration phase; the sensor is placed in a high and low temperature test chamber at a series of discrete, constant calibration temperature points. On top of that, precise force-strain calibration experiments were conducted to obtain experimentally measured values ​​of the strain gauge sensitivity coefficient at each temperature point. Based on this set of multiple data points The calibration dataset was fitted using nonlinear regression analysis. and These two global constants characterize material properties;

[0121] Compared to traditional linear temperature compensation methods, the exponential compensation model used in this embodiment can more accurately fit and correct the significant nonlinear drift characteristics exhibited by strain gauge materials in the extremely low temperature region. This high-order compensation method based on physical models and experimental calibration ensures that the measurement system can maintain a high degree of measurement consistency and accuracy across a huge temperature range from room temperature to extreme cold, greatly enhancing the system's environmental adaptability.

[0122] Example 7:

[0123] The performance closed-loop control module performs feedforward adjustments, specifically including:

[0124] By integrating the impact vibration acceleration during the impact leader stage, the velocity increment characterizing the impact intensity is obtained.

[0125] Based on the speed increment and the preset feedforward gain coefficient, the normal duration of the pulse charging window is extended to generate an enhanced charging window duration;

[0126] Update the enhanced charging window duration to the time-division multiplexing execution module;

[0127] This embodiment further explains the specific implementation of feedforward adjustment in the performance closed-loop control module based on embodiment 1; its purpose is to transform the system from a passive post-event response to an active pre-event defense by introducing a feedforward control logic based on impact prediction in order to cope with the upcoming severe impact.

[0128] In this embodiment, the performance closed-loop control module performs feedforward adjustments to proactively increase the system's energy reserves. The specific execution steps are as follows:

[0129] Using acceleration signals The initial characteristic, namely the leading wave before the arrival of the main shock wave, affects the impact vibration acceleration during the impact leading stage. By performing integration, a physical quantity that characterizes the intensity of the impending main impact—the velocity increment—is obtained. ; the initial impact phase This refers to a time window from the beginning of a significant change in the acceleration signal to the arrival of the main impact peak; the determination of this window is based on the prior analysis of the response propagation characteristics of a specific ship and shafting under impact; the initial source of this calculation is the combination of the feedforward control concept in control theory and physical intuition, that is, the precharge amount should be proportional to the predicted impact intensity.

[0130] Based on the calculated velocity increment With a preset feedforward gain coefficient Extend the normal duration of the pulse charging window in the time-division multiplexing execution module. To generate an enhanced charging window duration ;

[0131] The mathematical expression for this control law is:

[0132] ;

[0133] in, Adjusted duration of the enhanced charging window, in seconds;

[0134] The duration of a typical pulse charging window, in seconds;

[0135] : Feedforward gain coefficient; its dimension is the reciprocal of velocity s / m, to ensure that the value in parentheses is dimensionless; this is a key tunable parameter, which adjusts the sensitivity of the precharge amount to the predicted impact intensity; it is determined through system simulation and a large amount of experimental data optimization, with the goal of maximizing energy reserves while ensuring that key impact peak data is not lost.

[0136] That is, the speed increment. The unit is meters per second;

[0137] The calculated enhanced charging window duration Real-time updates to the time-division multiplexing execution module, replacing the original regular duration. This module will use [the following] during the next charging cycle. The system performs pulse charging for longer periods; this feedforward adjustment mechanism gives the system the ability to anticipate future impacts and take countermeasures in advance; by actively increasing the energy reserves of the onboard energy storage unit before the arrival of a severe impact, it effectively ensures that the measurement system still has sufficient power to complete multiple silent measurement cycles during the most intense impact and the lowest wireless power supply magnetic coupling efficiency, thereby avoiding the loss of the most critical data due to energy depletion; this realizes the intelligent upgrade of the system from passive adaptation to active defense.

[0138] Example 8:

[0139] The performance closed-loop control module performs closed-loop correction, specifically including:

[0140] After a shock event ends, the lowest signal-to-noise ratio and capacitor voltage drop recorded during the event are collected as historical performance data.

[0141] Based on historical performance data, the first preset threshold and the second preset threshold included in the adaptive optimization working mode switching threshold are optimized.

[0142] This embodiment further explains the specific implementation method of closed-loop correction in the performance closed-loop control module based on embodiment 1; its purpose is to build an outermost self-learning and self-optimizing closed loop for the system based on long-term operating experience, so that it can continuously adapt to the ever-changing external environment such as different ice conditions and its own state such as component aging.

[0143] In this embodiment, the performance closed-loop control module performs closed-loop correction. Its logic is to retrospectively evaluate and optimize the system's control strategy after a complete impact event. The specific steps are as follows:

[0144] After a complete impact event, for example, when the acceleration signal recovers to a steady-state level after a long period, the performance closed-loop control module processes the real-time data output by relevant modules within the event's time window to extract key performance indicators as historical performance data. Specifically, this module analyzes the real-time signal-to-noise ratio sequence during the impact period and determines the lowest value as the minimum signal-to-noise ratio. Simultaneously, by analyzing the real-time capacitor terminal voltage sequence... Calculate the maximum voltage drop ;

[0145] Based on this newly acquired historical performance data, the system adaptively optimizes and corrects the operating mode switching threshold used in the impact state identification module, specifically by adjusting the first preset threshold included therein. With the second preset threshold If the system detects that in multiple impact events, although the acceleration amplitude has not yet reached... ,but The effective data threshold has been frequently reached. This may indicate Setting it too high will cause the system to enter time-division multiplexing mode too late; in this case, the system will automatically adjust it slightly lower. ;

[0146] Conversely, if the system detects that even at accelerations exceeding... Afterwards, the signal quality remained very good, and the system switched between steady-state and disturbance modes too frequently, which may indicate... If the setting is too low, the system will adjust it appropriately. Similar logic also applies to... and feedforward gain coefficient Adjustments, for example, if frequent occurrences during shocks If the value is too high, it indicates insufficient battery power, and the system will increase the power level accordingly. ;

[0147] This closed-loop correction mechanism constitutes the highest level of intelligence in the system, using post-event performance as feedback to continuously optimize its internal control logic. This enables the system to learn from experience and continuously adjust its risk judgment criteria based on actual operating results, thereby maintaining the best balance in long-term operation. It achieves a high degree of adaptability to changing ice conditions, sea conditions, and its own operating conditions, ensuring the long-term robustness and optimal performance of the entire detection scheme.

[0148] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A shaft power detection system for a marine vessel based on a shaft power meter, characterized by, The method comprises the following steps: A data acquisition module is used to acquire real-time shock vibration acceleration, real-time interference frequency, real-time environmental temperature, and real-time transmission compensation power in real time; An impact state recognition module is used to determine a predicted signal-to-noise ratio based on a preset logistic function model and the transmission compensation power acquired by the data acquisition module; and the predicted signal-to-noise ratio and the shock vibration acceleration are combined to compare with a preset working mode switching threshold to determine a current working mode; A time division multiplexing execution module is used to execute a corresponding power supply and measurement mode in response to the current working mode determined by the impact state recognition module to output an original strain value; An adaptive compensation module is used to filter the original strain value based on the real-time interference frequency acquired by the data acquisition module to obtain a filtered strain value; and the filtered strain value is temperature-corrected based on the real-time environmental temperature and a preset exponential compensation model to output a final compensated strain measurement value; A performance closed-loop control module is used to feed forward adjust a charging duration of the time division multiplexing execution module based on a starting feature of the shock vibration acceleration acquired by the data acquisition module; and the working mode switching threshold used by the impact state recognition module is closed-loop corrected based on historical performance data after the end of the shock event; The current working mode comprises: A steady state mode is determined when the amplitude of the shock vibration acceleration is lower than a first preset threshold and the predicted signal-to-noise ratio is higher than a preset signal-to-noise ratio threshold; A disturbance mode is determined when the amplitude of the shock vibration acceleration is higher than the first preset threshold and lower than a second preset threshold, or when the predicted signal-to-noise ratio is lower than the preset signal-to-noise ratio threshold; An impact mode is determined when the amplitude of the shock vibration acceleration is higher than the second preset threshold; The time division multiplexing execution module in response to the current working mode being the disturbance mode or the impact mode specifically comprises: In a pulse charging window, the on-board energy storage unit is charged by wireless power supply, and the measurement circuit is dormant at this time; In a silent measurement window, the wireless power supply transmission end is closed, the on-board energy storage unit supplies power to the measurement circuit to perform interference-free data acquisition to obtain the original strain value. The impact state recognition module determines the predicted signal-to-noise ratio specifically comprising: The transmission compensation power is substituted into the logistic function model for describing electromagnetic interference saturation effect to solve the predicted signal-to-noise ratio.

2. The shaft power detection system based on shaft power meter according to claim 1, characterized in that, The adaptive compensation module performs filtering specifically comprising: A normalized notch center angular frequency is determined according to the real-time interference frequency and a preset system sampling frequency; 3. The shaft power detection system based on shaft power meter according to claim 1, characterized in that, An adaptive second-order infinite impulse response notch filter is constructed based on the normalized notch center angular frequency; The adaptive second-order infinite impulse response notch filter is used to process the original strain value to filter out ice noise to obtain the filtered strain value. The adaptive compensation module performs temperature correction specifically comprising: The filtered strain value, the real-time environmental temperature, and a reference calibration temperature are substituted into an exponential compensation model for correcting strain gauge sensitivity drift caused by extremely low temperature to determine the final compensated strain measurement value.

4. The shaft power detection system based on shaft power meter according to claim 1, characterized in that, The performance closed-loop control module performs feed forward adjustment specifically comprising: The shock vibration acceleration is integrated in a pre-impact stage to obtain a velocity increment representing the impact intensity; 5. The shaft power detection system based on shaft power meter according to claim 1, characterized in that, ​ ​ According to the speed increment and a preset feedforward gain coefficient, a conventional length of the pulse charging window is extended to generate an enhanced charging window length; The enhanced charging window length is updated to a time division multiplexing execution module.

6. The shaft power detection system based on shaft power meter according to claim 1, characterized in that, The performance closed loop control module performs closed loop correction, specifically including: After an impact event ends, the lowest signal-to-noise ratio and the capacitor voltage drop recorded during the event are collected as historical performance data; According to the historical performance data, the first preset threshold and the second preset threshold contained in the working mode switching threshold are adaptively optimized.

Images