Marine diesel engine rotating speed measurement data processing method based on optimized mean filtering algorithm

Abstract

The invention aims to provide a marine diesel engine rotating speed measurement data processing method based on an optimized mean filtering algorithm, and belongs to the field of diesel engines. Comprising the following steps: acquiring a rotating speed square-wave pulse signal of a marine diesel engine, and generating a square-wave pulse time sequence and a square-wave pulse time interval sequence; calculating to obtain a corresponding rotating speed value sequence to be processed; sequentially storing elements in the amplitude limiting rotating speed value sequence into a rotating speed value array according to a sequence; sorting the data in the rotating speed value array from small to large to obtain an ordered rotating speed value array; extreme values of all elements of the ordered rotating speed value array are removed, the arithmetic average value of the remaining elements is solved, and the calculation result serves as the final rotating speed value. According to the method, abnormal components in the rotating speed data of the marine diesel engine can be efficiently identified and eliminated, the required array length is far less than the sampling amount required by multi-order difference in the prior art, the filtering effect can be ensured, the operation memory can be effectively reduced, and the rotating speed calculation real-time performance of the diesel engine can be remarkably improved.

Description

Technical Field

[0001] The present invention relates to a diesel engine measurement method, specifically a speed measurement method. Background Technology

[0002] Currently, the diesel engine speed monitoring technology in the marine industry mostly uses electromagnetic pulse speed sensors. The core principle is electromagnetic induction. When measuring diesel engine speed, the crankshaft drives a signal disc to rotate. The teeth of the signal disc cut the magnetic field formed by the sensor's magnetic core, thereby generating an alternating voltage in the sensor's induction coil and outputting a speed voltage pulse signal. The diesel engine speed can then be calculated by the functional relationship between the diesel engine speed and the frequency of the pulse signal and the number of teeth on the sensor's signal disc. However, in practical applications, diesel engine speed monitoring is easily affected by external factors such as high-frequency mechanical vibration, power supply noise, and electromagnetic interference. This causes intermittent, continuous, or periodic noise signals to mix into the speed voltage pulse signal, resulting in a significant deviation between the calculated speed value and the actual speed value.

[0003] To address the significant discrepancy between calculated and actual speed measurements, filtering algorithms are typically used to smooth the speed-voltage pulse signal data. Taking the traditional mean filtering algorithm as an example, its principle is to smooth individual pulse signal data within a certain sampling period. Second sampling, take The average value of the sampled data is used as the output of the sampling period. Although traditional mean filtering algorithms can smooth the fluctuations of pulse signals and eliminate noise to a certain extent, they cannot completely filter out the noise of the pulse signals collected by the speed sensor when faced with strong external interference, and there is still a large deviation between the calculated speed value and the true value. Therefore, this invention proposes an optimized mean filtering algorithm for processing diesel engine speed measurement data to ensure the accuracy and reliability of the measurement results.

[0004] Patent document CN116304571A (publication date June 23, 2023) discloses a method for processing engine speed measurement data. This method "uses a square wave time series acquired by an eddy current speed measurement system to generate a square wave interval time series, optimizes the square wave interval time series to generate an interval time series tuple, and obtains the calculated speed through the interval time series tuple. A multi-order difference and multi-point prediction method is used to check and replace outliers in the calculated speed to obtain an optimized speed, and the optimized speed is then subjected to mean-smoothing filtering to obtain the output speed." This method performs well in dealing with low-frequency pulse interference, suppressing speed jumps to a certain extent and improving speed measurement accuracy. However, it performs poorly when dealing with external high-frequency pulse interference or periodic noise signals. Furthermore, when processing large amounts of data, it not only consumes more memory but also reduces the real-time performance of speed measurement. Summary of the Invention

[0005] The purpose of this invention is to provide a method for processing marine diesel engine speed measurement data based on an optimized mean filtering algorithm, which can accurately remove noise signals from marine diesel engine speed measurement data, suppress abnormal jumps in speed monitoring data, and accurately calculate the real-time speed of marine diesel engines.

[0006] The objective of this invention is achieved as follows: This invention discloses a method for processing marine diesel engine speed measurement data based on an optimized mean filtering algorithm, characterized by the following steps: (1) Obtain the square wave pulse signal of the ship's diesel engine speed based on the electromagnetic pulse sensor, and record the continuous pulse signal. The time corresponding to the rising edge of each square wave pulse signal Generate square wave pulse time series :{ , , , , }; (2) For square wave pulse time series Calculate the time difference between each adjacent moment to generate a square wave pulse time interval sequence. ; (3) Based on the functional relationship between diesel engine speed, square wave pulse time interval, and number of teeth on sensor signal disk, the square wave pulse time interval sequence is calculated. The corresponding sequence of rotational speed values ​​to be processed ; (4) Set the upper limit of the speed fluctuation threshold according to the transient speed characteristics of the diesel engine. The sequence of rotational speed values ​​to be processed The rotational speed values ​​are sequentially subjected to abrupt change judgment, and the rotational speed values ​​that meet the abrupt change conditions are... Values ​​identified as mutation interference terms are replaced, while speed values ​​that do not meet the mutation criteria are retained, thus generating a stable speed value sequence. ; (5) Based on the diesel engine speed characteristics and rated speed Set the upper limit threshold for the speed variation range For the stationary speed value sequence The rotational speed values ​​are sequentially limited, and those exceeding the upper speed limit are... The speed values ​​are discarded directly, and the remaining speed values ​​are used to generate a limited speed value sequence. ; (6) The limited speed value sequence The elements in the array are stored sequentially into the rotational speed value array. Integers whose array length is 5 or more; (7) Determine the speed value array If the data in the array is full, proceed to step (8). If it is not full, continue repeating steps (1) to (7) while waiting for new data to be stored, until the speed value array is full. The element is full; (8) Use bubble sort to sort the speed value array The data is sorted in ascending order to obtain an ordered array of rotational speed values. At this time, the ordered rotational speed value array The minimum and maximum values ​​are the values ​​at the two ends of the array; (9) Based on the ordered speed value array Calculate and obtain the final speed output result. For an ordered array of rotational speed values Remove the extreme values ​​from all elements, then calculate the arithmetic mean of the remaining elements, and use the result as the final rotational speed value. .

[0007] The present invention may also include: 1. The functional relationship between the diesel engine speed and the square wave pulse time interval and the number of teeth on the sensor signal disk in step (3) is as follows: in, for The rotational speed value corresponding to the square wave pulse time interval. The number of teeth on the signal disk of the electromagnetic pulse speed sensor.

[0008] 2. The conditions for judging sudden changes in the marine diesel engine speed value in step (4) are as follows: in, This is the upper limit of the speed fluctuation threshold per unit time, which is the maximum instantaneous fluctuating speed that a ship engine can achieve.

[0009] 3. The limiting judgment conditions in step (5) are as follows: in, The first in the steady-state speed value sequence One rotational speed value; This is the upper limit threshold for the range of variation of marine diesel engine speed, that is, the maximum instantaneous speed value that the marine engine can achieve; This refers to the rated speed of the ship's engine. This represents the ratio between the maximum instantaneous speed and the rated speed of a ship's engine.

[0010] 4. Step (9) The calculation logic formula is as follows: .

[0011] The advantages of this invention are: (1) The present invention combines the speed characteristics of marine diesel engines to preprocess the speed sequence, which can efficiently identify and remove abnormal components in the speed data of marine diesel engines, including but not limited to high-frequency signals, abnormal jump values, periodic noise caused by mechanical vibration or electromagnetic interference; (2) The array length required by the present invention is much less than the sampling amount required by the multi-order difference method in the prior art. It can effectively reduce the running memory while ensuring the filtering effect, and significantly improve the real-time performance of diesel engine speed calculation. Overall, it improves the accuracy and reliability of marine diesel engine speed measurement. Attached Figure Description

[0012] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0013] The invention will now be described in more detail with reference to the accompanying drawings: Combination Figure 1 The specific steps of this invention are as follows: S1: Acquire square wave pulse signals of marine diesel engine speed based on electromagnetic pulse sensors and record continuous pulses. The time corresponding to the rising edge of each square wave pulse signal generates a square wave pulse time sequence. Specifically, the diesel engine crankshaft drives the electromagnetic pulse sensor signal disk to rotate. The disk teeth cut the magnetic field formed by the sensor's magnetic core, generating a magnetic induction phenomenon. This causes the coil in the sensor to generate an alternating voltage pulse signal. The electromagnetic pulse sensor processes the changing voltage signal into a square wave pulse signal, records the time corresponding to the rising edge of each square wave pulse signal, and generates a square wave pulse time series. :{ , , , , , }.in: : No. The time corresponding to the rising edge of each square wave pulse signal.

[0014] S2: For the square wave pulse time sequence obtained in step S1 Calculate the time difference between each adjacent moment to generate a square wave pulse time interval sequence. :{ , , , , }.in: (1) S3: Based on the functional relationship between diesel engine speed, square wave pulse time interval, and the number of teeth on the sensor signal disk, the square wave pulse time interval sequence is calculated. The corresponding sequence of rotational speed values ​​to be processed :{ , , , , The functional relationship between diesel engine speed and square wave pulse time interval and the number of teeth on the sensor signal disc is as follows: (2) in, : The rotational speed value corresponding to the square wave pulse time interval, in units of .

[0015] The number of teeth on the signal disk of an electromagnetic pulse speed sensor.

[0016] S4: Set the upper limit of the speed fluctuation threshold based on the transient speed characteristics of the diesel engine. The sequence of rotational speed values ​​to be processed The rotational speed values ​​are sequentially subjected to abrupt change judgment, and the rotational speed values ​​that meet the abrupt change conditions are... It was identified as a mutation interference term, and then... Alternative Rotational speed values ​​that do not meet the mutation conditions are retained to generate a stable rotational speed value sequence. :{ , , , , The conditions for judging sudden changes in marine diesel engine speed are as follows: (3) in, The upper limit of the unit time speed fluctuation threshold, that is, the maximum instantaneous fluctuating speed that a ship engine can achieve, is measured in units of... In practical applications, the acceleration and deceleration rates of marine diesel engines need to meet the rigid requirements of safety boundaries. This is based on the transient speed characteristics of marine diesel engines. The typical value is .

[0017] S5: Based on the diesel engine speed characteristics and rated speed Set the upper limit threshold for the speed variation range For the stationary speed value sequence The rotational speed values ​​are individually limited and judged; for those exceeding the upper limit of rotational speed... The speed values ​​that are not specified are directly discarded, and the remaining speed values ​​form a limited speed value sequence. :{ , , , , The limiting judgment conditions are as follows: (4) in, The first in the steady-state speed value sequence One rotational speed value; The upper limit threshold of the range of marine diesel engine speed variation, i.e., the maximum instantaneous speed that a marine engine can achieve, is measured in units of... ; Rated speed of marine engine, unit is .

[0018] The relationship between the maximum instantaneous speed and the rated speed of a marine engine is determined in practical applications based on the speed characteristics of marine diesel engines. The typical value is .

[0019] S6: Transform the limiting speed value sequence The elements in the array are stored sequentially into the rotational speed value array. :[ , , , , ]. Among them, array The array length is , The value is an integer of 5 or higher.

[0020] S7: Determine the speed value array If the data in the array is full, proceed to step 8; otherwise, repeat steps S1-S7 until new data is stored, until the speed value array is full. Elements are full S8: Use bubble sort to sort the speed value array The data is sorted in ascending order to obtain an ordered array of rotational speed values. :[ , , , , At this point, the ordered rotational speed value array... The minimum and maximum values ​​are the values ​​at the two ends of the array.

[0021] S9: Based on the ordered array of rotational speed values Calculate and obtain the final speed output result. For an ordered array of rotational speed values Find the extreme values ​​of all elements, then calculate the arithmetic mean of the remaining elements to obtain the result. This will be used as the final output speed value of the marine diesel engine. The calculation logic formula is as follows: (5).

Claims

1. A method for processing marine diesel engine speed measurement data based on an optimized mean filtering algorithm, characterized in that: Includes the following steps: (1) Obtain the square wave pulse signal of the ship's diesel engine speed based on the electromagnetic pulse sensor, and record the continuous pulse signal. The time corresponding to the rising edge of each square wave pulse signal Generate square wave pulse time series :{ , , , , }; (2) For square wave pulse time series Calculate the time difference between each adjacent moment to generate a square wave pulse time interval sequence. ; (3) Based on the functional relationship between diesel engine speed, square wave pulse time interval, and number of teeth on sensor signal disk, the square wave pulse time interval sequence is calculated. The corresponding sequence of rotational speed values ​​to be processed ; (4) Set the upper limit of the speed fluctuation threshold according to the transient speed characteristics of the diesel engine. The sequence of rotational speed values ​​to be processed The rotational speed values ​​are sequentially subjected to abrupt change judgment, and the rotational speed values ​​that meet the abrupt change conditions are... Values ​​identified as mutation interference terms are replaced, while speed values ​​that do not meet the mutation criteria are retained, thus generating a stable speed value sequence. ; (5) Based on the diesel engine speed characteristics and rated speed Set the upper limit threshold for the speed variation range For the stationary speed value sequence The rotational speed values ​​are sequentially limited, and those exceeding the upper speed limit are... The speed values ​​are discarded directly, and the remaining speed values ​​are used to generate a limited speed value sequence. ; (6) The limited speed value sequence The elements in the array are stored sequentially into the rotational speed value array. Integers whose array length is 5 or more; (7) Determine the speed value array If the data in the array is full, proceed to step (8). If it is not full, continue repeating steps (1) to (7) while waiting for new data to be stored, until the speed value array is full. The element is full; (8) Use bubble sort to sort the speed value array The data is sorted in ascending order to obtain an ordered array of rotational speed values. At this time, the ordered rotational speed value array The minimum and maximum values ​​are the values ​​at the two ends of the array; (9) Based on the ordered speed value array Calculate and obtain the final speed output result. For an ordered array of rotational speed values Remove the extreme values ​​from all elements, then calculate the arithmetic mean of the remaining elements, and use the result as the final rotational speed value. .

2. The method for processing marine diesel engine speed measurement data based on an optimized mean filtering algorithm according to claim 1, characterized in that: The functional relationship between the diesel engine speed and the square wave pulse time interval and the number of teeth on the sensor signal disk in step (3) is as follows: in, for The rotational speed value corresponding to the square wave pulse time interval. The number of teeth on the signal disk of the electromagnetic pulse speed sensor.

3. The method for processing marine diesel engine speed measurement data based on an optimized mean filtering algorithm according to claim 1, characterized in that: The conditions for judging sudden changes in the marine diesel engine speed in step (4) are as follows: in, This is the upper limit of the speed fluctuation threshold per unit time, which is the maximum instantaneous fluctuating speed that a ship engine can achieve.

4. The method for processing marine diesel engine speed measurement data based on an optimized mean filtering algorithm according to claim 1, characterized in that: The limiting judgment conditions for step (5) are as follows: in, The first in the steady-state speed value sequence One rotational speed value; This is the upper limit threshold for the range of variation of marine diesel engine speed, that is, the maximum instantaneous speed value that the marine engine can achieve; This refers to the rated speed of the ship's engine. This represents the ratio between the maximum instantaneous speed and the rated speed of a ship's engine.

5. The method for processing marine diesel engine speed measurement data based on an optimized mean filtering algorithm according to claim 1, characterized in that: Step (9) The calculation logic formula is as follows: 。

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