CN-115169389-B - Crankshaft stop position detection method based on key phase and fluted disc distance sensor

CN115169389BCN 115169389 BCN115169389 BCN 115169389BCN-115169389-B

Abstract

A crankshaft stop position detection method based on key phase and fluted disc distance sensors relates to the technical field of equipment state monitoring. The method comprises the steps of setting a data sequence length ratio of an original processing signal and a phase reference signal as a sequence length ratio, constructing an adjusting function containing parameters to be optimized, constructing an adjusting vector through the sequence length ratio and the adjusting function, acquiring a fitting processing signal and a phase target based on the original processing signal and the adjusting vector, establishing an error function of the fitting processing signal and the phase reference signal, adopting a differential evolution method, taking the error function as an optimizing target, optimizing parameters to be optimized in the adjusting function, calculating corresponding parameters to be optimized under the condition of the minimum value of the optimizing target, recording the parameters to be optimized as optimizing parameters, calculating the phase target again based on the optimizing parameters, and determining the stop phase of a crankshaft. The invention is helpful for analyzing the dynamic balance characteristic of the rotation motion of the crankshaft.

Inventors

LI HE
JIANG ZHINONG
ZHI HAIFENG
YIN JINGUAN
MAO ZHIWEI
ZHANG JINJIE

Assignees

北京化工大学
中国北方发动机研究所(天津)

Dates

Publication Date: 20260512
Application Date: 20220624

Claims (8)

1. A crankshaft stop position detection method based on a key phase and fluted disc distance sensor is characterized by comprising the following steps: a key phase sensor and a fluted disc distance sensor are installed, a key phase signal of each revolution of a crankshaft and a gear tooth distance signal of a flywheel fluted disc of the crankshaft are respectively obtained, the two signals are continuously and synchronously collected, and the key phase signal threshold trigger phase is marked as a crankshaft reference 0 phase; in the stage that the equipment operates at the rated rotating speed, determining the starting and stopping time of one circle of crankshaft rotation through threshold triggering based on the key phase signal, and intercepting a gear tooth distance signal segment corresponding to the complete circle of crankshaft rotation taking the crankshaft reference 0 phase as the starting point to obtain a phase reference signal because the key phase signal and the gear tooth distance signal are synchronously collected; in a deceleration stopping stage when the equipment runs at the rated rotating speed until the rotating speed is zero, determining the corresponding moment of the last 0 phase mark before the crankshaft stops based on the key phase signal through threshold triggering, determining the corresponding moment of the crankshaft stops based on the gear tooth distance signal through dynamic self-adaptive threshold triggering, and intercepting the gear tooth distance signal between the two moments to obtain an original processing signal; The data sequence length ratio of the original processing signal and the phase reference signal is a sequence length ratio, an adjusting function containing parameters to be optimized is constructed, an adjusting vector is constructed through the sequence length ratio and the adjusting function, and a fitting processing signal and a phase target are obtained based on the original processing signal and the adjusting vector; Establishing an error function of the fitting processing signal and the phase reference signal, optimizing parameters to be optimized in an adjusting function by taking the error function as an optimizing target by adopting a differential evolution method, calculating corresponding parameters to be optimized under the condition of the minimum value of the optimizing target, recording the parameters as optimizing parameters, calculating a phase target again based on the optimizing parameters, and determining the stop phase of the crankshaft.
2. The method of claim 1, wherein the threshold setting of the key phase signal threshold triggering method is determined by equation one: equation one: Wherein, the method comprises the steps of, Triggering a threshold for the key phase signal; Is the phase maximum value of the key; Phase minimum for the key; Calculating coefficient for key phase threshold, regulating according to first rotation speed obtained by self-contained tachometer of field device and second rotation speed obtained by key phase sensor, if the second rotation speed is greater than first rotation speed, reducing Value of otherwise increase And (3) the value is equal to the second rotating speed and the first rotating speed.
3. The method of claim 1, wherein the tooth distance signal dynamic adaptive threshold triggered threshold calculation is determined by equation two: Formula II: Wherein, the method comprises the steps of, Triggering a threshold value for the gear tooth distance signal; Representing the magnitude of the gear tooth distance signal after the crankshaft is completely stopped; A coefficient is calculated for the gear tooth distance signal trigger threshold, the value of which should be equal to the accuracy of the on-site gear tooth distance sensor.
4. The method of claim 1, wherein obtaining a data sequence length ratio of the raw processed signal to the phase reference signal, the sequence length ratio, comprises: obtaining the ratio of the length of the data sequence of the original processing signal to the length of the data sequence of the phase reference signal by using a formula III And (3) a formula III: Wherein, the method comprises the steps of, As a result of the phase reference signal, For the original processing of the signal, I.e. the length of the sequence is calculated, For the sequence length of the phase reference signal, The length of the sequence of the original processed signal, Is the ratio of the length of the phase reference signal to the length of the original processed signal sequence.
5. The method of claim 1, wherein an adjustment function is established with the adjustment vector The regulating function is a combined function taking a power function and an exponential function as basic functions, and the regulating function expression is as shown in a formula IV: equation four: Wherein, the method comprises the steps of, For the regulating function, e is a natural base, x is a function argument value, Respectively the first, second and third parameters to be optimized ; Order the And carrying the adjusting function, and establishing an adjusting vector, wherein the adjusting vector is shown in a formula five: Formula five: Wherein, the method comprises the steps of, I.e. the adjustment vector; i.e. take the q-based argument into the fourth calculated, regulating function A factor variable value of (2); is the sequence length of the phase reference signal; is the ratio of the length of the phase reference signal to the length of the original processed signal sequence.
6. The method of claim 1, wherein a fitting process signal is obtained based on the raw process signal and the adjustment vector And a phase target N; Finding a positive integer phase target N, requiring the adjustment vector The sum of the first N terms of (2) is less than or equal to the original processing signal Sequence length of (2) The adjustment vector The sum of the first n+1 terms of (2) is greater than the original processed signal Sequence length of (2) ; Second, a matrix T is established, the number of lines is required and the sequence length of the original processing signal is required Equal, the number of columns is N, and the value of the matrix is initialized to be zero; thirdly, assigning a value to the matrix T according to columns, and enabling i=1, 2,..N, wherein the value from the ith column, the jth row to the kth row of the matrix T is z; wherein j is equal in value to the adjustment vector The integer portion of the sum of the preceding i terms; k is equal in value to the adjustment vector The integer part of the sum of the preceding i+1 terms of (c), z being equal in value to ; Fourth, the signal is processed through the original process by applying the formula six Multiplying the obtained signal by matrix T matrix to obtain fitting signal ; Formula six: Wherein, the method comprises the steps of, For the matrix multiplication to be performed, The original processed signal can be regarded as behavior 1, listed as Is a matrix of (a); matrix T behavior The columns are N; as the fitting process signal, a matrix of row 1 and column N can be considered.
7. The method of claim 5, wherein establishing a fit processes the signal With phase reference signals Selecting a differential evolution optimization algorithm DE, and adjusting the function by taking the minimum mean square error as a target The minimum optimization is carried out on the parameters to be optimized, and the optimal parameters to be optimized are obtained, which comprises the following steps: Obtaining optimal parameters to be optimized by applying a formula seven: Formula seven: The DE is a differential evolution optimization algorithm, which is a widely applied optimization algorithm, has a standard flow, and can acquire the parameter value to be optimized under the optimal condition of the optimization target in the optimization direction only by setting initial parameters, parameters to be optimized, an optimization target and the optimization direction; initial parameters include population size=50, probability of variance=0.5, maximum training times=200; The parameters to be optimized are the first, second and third parameters to be optimized ; The optimized direction is Minimizing; The optimization target is , wherein, Processing signals for fitting The value of the ith sequence point of (c); is a phase reference signal N, i.e. fitting the processed signal The number of columns of (a); i.e. at the optimization objective At minimum, the differential evolution algorithm gives Is a value of (a).
8. The method according to claim 7, wherein, in the following steps In the case of recalculating the phase target Determining a crankshaft shutdown phase, comprising: Will be Taking into formula IV, calculating the regulating function, and recording as And then the method Taking into formula five, calculating the adjustment vector at the moment, and recording as Finding a positive integer The requirements are that Front of (2) The sum of the terms is less than or equal to the original processing signal Sequence length of (2) The said Front of (2) The sum of +1 terms is greater than the original processed signal Sequence length of (2) Based on the positive integer Calculating a shutdown phase by applying a formula eight; formula eight: Wherein, the method comprises the steps of, In order to re-calculate the phase target, For the phase reference signal sequence length; is the crankshaft shutdown phase.

Description

Crankshaft stop position detection method based on key phase and fluted disc distance sensor Technical Field The application relates to the technical field of equipment state monitoring, in particular to a crankshaft stop position detection method based on a key phase and fluted disc distance sensor. Background The diesel engine is a widely applied power machine, is used for on-line monitoring and predicting state change, and has very important engineering significance for ensuring safe and long-term reliability of the operation of the diesel engine. On-line monitoring technologies based on vibration, oil, temperature, acoustic emission, in-cylinder pressure, instantaneous rotation speed, torsional vibration, output power and the like are used as hot spots in the field of diesel engine state monitoring for a long time, and a great monitoring technology result is formed. The crankshaft of the diesel engine is one of the most critical moving parts, and the stop phase refers to the angular difference of a mark on the crankshaft relative to a certain fixed reference position when the rotating speed of the diesel engine is reduced until the diesel engine stops, and the angular difference is used for calculating the specific phase after the crankshaft stops moving. And the long-term monitoring and recording of the shutdown phase after each shutdown of a diesel engine are performed, and the statistical analysis of the long-term monitoring result is helpful for the analysis of the dynamic balance characteristic of the rotary motion of the crankshaft. Theoretically, a good diesel engine state means that the rotating parts always keep dynamic balance, and each time the engine is stopped, the phase should be at any angle, and the result is that the engine is uniformly distributed at random. If the dynamic balance is poor, the probability distribution of the shutdown phase is monitored to deviate from the random uniform distribution seriously, namely, in a certain smaller area, the probability value of the shutdown phase is far greater than that of other equal-width areas, and the problem of poor dynamic balance of the crankshaft can be reflected. However, among the related monitoring technologies of diesel engines, there are few monitoring technologies for the above-described crank stop phase. Disclosure of Invention The embodiment of the application provides a crankshaft stop position detection method based on a key phase and fluted disc distance sensor, belongs to the technical field of diesel engine fault monitoring and diagnosis, and is beneficial to analyzing dynamic balance characteristics of crankshaft rotation motion. The technical scheme comprises the following steps: 1. a crankshaft stop position detection method based on a key phase and fluted disc distance sensor is characterized by comprising the following steps: a key phase sensor and a fluted disc distance sensor are installed, a key phase signal of each revolution of a crankshaft and a gear tooth distance signal of a flywheel fluted disc of the crankshaft are respectively obtained, the two signals are continuously and synchronously collected, and the key phase signal threshold trigger phase is marked as a crankshaft reference 0 phase; In the stage that the equipment operates at the rated rotating speed, determining the starting and stopping time of one circle of crankshaft rotation based on the key phase signal through threshold triggering, and intercepting a gear tooth distance signal segment corresponding to the complete circle of crankshaft rotation taking the crankshaft reference 0 phase as the starting point to obtain a phase reference signal because the key phase signal and the gear tooth distance signal are synchronously collected; in a deceleration stopping stage when the equipment runs at the rated rotating speed until the rotating speed is zero, determining the corresponding moment of the last 0 phase mark before the crankshaft stops based on the key phase signal through threshold triggering, determining the corresponding moment of the crankshaft stops based on the gear tooth distance signal through dynamic self-adaptive threshold triggering, and intercepting the gear tooth distance signal between the two moments to obtain an original processing signal; the data sequence length ratio of the original processing signal and the phase reference signal is a sequence length ratio, an adjusting function containing parameters to be optimized is constructed, an adjusting vector is constructed through the sequence length ratio and the adjusting function, and a fitting processing signal and a phase target are obtained based on the original processing signal and the adjusting vector; Establishing an error function of the fitting processing signal and the phase reference signal, optimizing parameters to be optimized in an adjusting function by taking the error function as an optimizing target by adopting a differential evolution method, calculating corres