CN102645335A - Method for locating top dead center of six cylinder engine - Google Patents

Abstract

The invention relates to a method for locating a top dead center of a six cylinder engine. The method includes the steps of installing an acceleration vibration sensor on the six cylinder engine and connecting a computer through a vibration signal collecting instrument, collecting vibration response time domain signals of six cylinders, changing the vibration response time domain signals to complex signals, obtaining combustion impact response characteristic parameters of the six cylinders, listing digital quantization matrixes, setting the combustion impact response characteristic parameters as XA, XB, XC, XD, XE and XF respectively, listing each of the matrixes corresponding to the combustion impact response characteristic parameters of the working cylinders, and multiplying and summing elements of each of the matrixes correspondingly and comparing to obtain the XA which is among maximum values and corresponds to an engine working cylinder which the top dead center corresponds to as well. By means of the method for locating the top dead center of the six cylinder engine, the accurate location of the engine top dead center is achieved, the identifying speed of an engine fault cylinder is improved, the diagnosing time of the engine fault cylinder is shortened, the method is simple, the operation is easy, and the maintenance of the engine is facilitated.

Description

The method of location six cylinder engine top dead centre

Technical field

The invention belongs to engine art, especially a kind of method of locating the six cylinder engine top dead centre.

Background technology

Six cylinder engine is used more extensive on automobile; When in-engine cylinder body breaks down; Mean speed that can the calculation engine bent axle and according to the vibratory response characteristic of corresponding each cylinder of engine of top dead centre signal; And the job order through each working cylinder of engine, promptly 1,5,3,6,2,4, and the duty of each cylinder of the shock response characteristic of corresponding each cylinder of engine diagnosis identification and trouble location thereof, type; This just requires the top dead center position must be accurately, could accurately locate and diagnoses breakdown in the motor cylinder and fault type.The signal acquiring method of top dead centre commonly used is the flywheel subsides reflecting piece to engine, gathers the top dead centre signal through photoelectric sensor, and the acceleration vibration transducer is gathered the acceleration vibration signal that engine cylinder covers measuring point.The top dead centre signal is corresponding with the acceleration vibration signal; But in the operation of actual paster; Photoelectric sensor is aimed at very difficulty of engine flywheel paster, and paster is very time-consuming, so be easy to cause the dislocation of corresponding each cylinder of top dead centre signal; To such an extent as to the job order of the engine cylinder of acceleration vibration signal of gathering and correspondence usually can not be accurately corresponding, carry out the running state analysis of each cylinder of engine according to this and the accurate diagnosis of fault cylinder is discerned very difficult.

Summary of the invention

The objective of the invention is to overcome the deficiency of prior art; A kind of method of locating the six cylinder engine top dead centre is provided, and this method has realized the accurate location to engine tope center, has improved the recognition speed of engine failure cylinder; Shortened the Diagnostic Time of engine failure cylinder; Method is simple, and is easy to operate, made things convenient for the maintenance maintenance of engine.

The present invention solves its technical matters and realizes through following technical scheme:

A kind of method of locating the six cylinder engine top dead centre, the step that its method comprises is:

⑴, between first cylinder of six cylinder engine and second cylinder, be provided with to be provided with between first measuring point, second cylinder and the 3rd cylinder to be provided with between the 3rd measuring point, the 5th cylinder and the 6th cylinder between second measuring point, the 4th cylinder and the 5th cylinder the 4th measuring point is set; One acceleration vibration transducer is installed respectively on each measuring point, and this acceleration vibration transducer connects computing machine through the vibration signals collecting appearance;

⑵, six working cylinders of collection engine are no less than the acceleration vibration signal of a dust cycle, obtain the vibratory response time-domain signal of six working cylinders of engine;

⑶, the vibratory response time-domain signal of six working cylinders of engine is carried out the Xi Er baud conversion, obtain the complex signal of six working cylinders of engine;

⑷, the complex signal of six working cylinders of engine is extracted, obtained the burning shock response characteristic parameter of six working cylinders of engine with gaussian basis ripple correlativity filtering method;

⑸, draw the digital quantization matrix A between measuring point and six working cylinders of engine according to the row order of first measuring point, second measuring point, the 3rd measuring point, the 4th measuring point:

Matrix $A=\left[\begin{array}{cccccc}1.0& 0& 0.5& 0& 1.0& 0\\ 0.5& 0& 1.0& 0& 1.0& 0.5\\ 0& 1.0& 0.5& 0.5& 0& 1.0\\ 0& 1.0& 0& 1.0& 0& 0.5\end{array}\right]$

⑹, setting engine crankshaft corner are that 0 degree, 120 degree, 240 are spent, 360 degree, 480 are spent, the burning shock response characteristic parameter of 600 degree is respectively XA, XB, XC, XD, XE, XF;

⑺, list with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XA, XB, XC, XD, XE, XF and to form matrix B;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XB, XC, XD, XE, XF, XA and to form Matrix C;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XC, XD, XE, XF, XA, XB and to form matrix D;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XD, XE, XF, XA, XB, XC and to form matrix E;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XE, XF, XA, XB, XC, XD and to form matrix F;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XF, XA, XB, XC, XD, XE and to form matrix G;

⑻, the corresponding one by one back summation of multiplying each other of each numerical value of matrix A and matrix B is obtained S1;

The corresponding one by one back summation of multiplying each other of each numerical value of matrix A and Matrix C is obtained S2;

The corresponding one by one back summation of multiplying each other of each numerical value of matrix A and matrix D is obtained S3;

The corresponding one by one back summation of multiplying each other of matrix A and each numerical value of matrix E is obtained S4;

The corresponding one by one back summation of multiplying each other of each numerical value of matrix A and matrix F is obtained S5;

The corresponding one by one back summation of multiplying each other of matrix A and each numerical value of matrix G is obtained S6;

⑼, get S1, S2, S3, S4, S5, S6 intermediate value the maximum, the engine operation cylinder that the XA in this value the maximum is corresponding is exactly the corresponding engine operation cylinder of top dead centre.

And described six cylinder engine is six cylinder diesel motors or six cylinder gasoline engines.

Advantage of the present invention and beneficial effect are:

The method of this location six cylinder engine top dead centre has realized the accurate location to engine tope center, has improved the recognition speed of engine failure cylinder, has shortened the Diagnostic Time of engine failure cylinder, and method is simple, and is easy to operate, made things convenient for the maintenance maintenance of engine.

Figure of description

Fig. 1 is the oscillogram in four continuous working circulations of the first measuring point measured signal.

Embodiment

Through specific embodiment the present invention is made further detailed description below, following examples are descriptive, are not determinate, can not limit protection scope of the present invention with this.

A kind of method of locating the six cylinder engine top dead centre, the step that its method comprises is:

⑴, between first cylinder of six cylinder engine and second cylinder, be provided with to be provided with between first measuring point, second cylinder and the 3rd cylinder to be provided with between the 3rd measuring point, the 5th cylinder and the 6th cylinder between second measuring point, the 4th cylinder and the 5th cylinder the 4th measuring point is set; One acceleration vibration transducer is installed respectively on each measuring point, and this acceleration vibration transducer connects computing machine through the vibration signals collecting appearance;

⑵, six working cylinders of collection engine are no less than the acceleration vibration signal of a dust cycle, obtain the vibratory response time-domain signal of six working cylinders of engine;

⑶, the vibratory response time-domain signal of six working cylinders of engine is carried out the Xi Er baud conversion, obtain the complex signal of six working cylinders of engine;

⑷, the complex signal of six working cylinders of engine is extracted, obtained the burning shock response characteristic parameter of six working cylinders of engine with gaussian basis ripple correlativity filtering method;

⑸, draw the digital quantization table 1 between measuring point and six working cylinders of engine according to the row order of first measuring point, second measuring point, the 3rd measuring point, the 4th measuring point

Table 1

Write the digitizing arrangement of table 1 as matrix form, obtained matrix A:

Matrix $A=\left[\begin{array}{cccccc}1.0& 0& 0.5& 0& 1.0& 0\\ 0.5& 0& 1.0& 0& 1.0& 0.5\\ 0& 1.0& 0.5& 0.5& 0& 1.0\\ 0& 1.0& 0& 1.0& 0& 0.5\end{array}\right]$

⑹, setting engine crankshaft corner are that 0 degree, 120 degree, 240 are spent, 360 degree, 480 are spent, the burning shock response characteristic parameter of 600 degree is respectively XA, XB, XC, XD, XE, XF;

⑺, list with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XA, XB, XC, XD, XE, XF and to form matrix B;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XB, XC, XD, XE, XF, XA and to form Matrix C;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XC, XD, XE, XF, XA, XB and to form matrix D;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XD, XE, XF, XA, XB, XC and to form matrix E;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XE, XF, XA, XB, XC, XD and to form matrix F;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XF, XA, XB, XC, XD, XE and to form matrix G;

⑻, the corresponding one by one back summation of multiplying each other of each numerical value of matrix A and matrix B is obtained S1;

The corresponding one by one back summation of multiplying each other of each numerical value of matrix A and Matrix C is obtained S2;

The corresponding one by one back summation of multiplying each other of each numerical value of matrix A and matrix D is obtained S3;

The corresponding one by one back summation of multiplying each other of matrix A and each numerical value of matrix E is obtained S4;

The corresponding one by one back summation of multiplying each other of each numerical value of matrix A and matrix F is obtained S5;

The corresponding one by one back summation of multiplying each other of matrix A and each numerical value of matrix G is obtained S6;

⑼, get S1, S2, S3, S4, S5, S6 intermediate value the maximum, the engine operation cylinder that the XA in this value the maximum is corresponding is exactly the corresponding engine operation cylinder of top dead centre.Corresponding engine operation cylinder was the corresponding engine operation cylinder of top dead centre when just corresponding working cylinder multiplied each other in the XA in this value the maximum and the matrix A.Six cylinder engine in the present embodiment is six cylinder diesel motors, and described six cylinder engine also can be six cylinder gasoline engines.

To choose four working cycle vibratory response time-domain signals is example, and its time domain waveform is shown in accompanying drawing 1.In order to confirm the pairing engine cylinder of top dead centre number accurately, its vibratory response time-domain signal is transformed to complex signal, again its complex signal is carried out correlativity filtering and extracted the characteristic parameter of burning shock response.List with each measuring point of matrix A shock response characteristic parameter that burns one to one following through calculate extracting to draw with the listed sequence of XA, XB, XC, XD, XE, XF:

The matrix B that forms does $\left[\begin{array}{cccccc}19& 59& 20& 50& 21& 25\\ 20& 62& 51& 23& 21& 60\\ 48& 20& 57& 13& 60& 42\\ 138& 15& 28& 16& 72& 20\end{array}\right]$

The corresponding one by one back summation of multiplying each other of each numerical value of matrix A and matrix B is obtained S1

Be S1=1.0 * 19+0.5 * 20+0 * 48+0 * 138+0 * 59+0 * 62+1.0 * 20+1.0 * 15+0.5 * 20+1.0 * 51+0.5 * 57+0 * 28+0 * 50+0 * 23+0.5 * 13+1.0 * 16+1.0 * 21+1.0 * 21+0 * 60+0 * 72+0 * 25+0.5 * 60+1.0 * 42+0.5 * 20=300

In like manner the corresponding one by one back summation of multiplying each other of each numerical value of matrix A and Matrix C is obtained S2=543.5

The corresponding one by one back summation of multiplying each other of each numerical value of matrix A and matrix D is obtained S3=274.5

The corresponding one by one back summation of multiplying each other of matrix A and each numerical value of matrix E is obtained S4=666.5

The corresponding one by one back summation of multiplying each other of each numerical value of matrix A and matrix F is obtained S5=275.5

The corresponding one by one back summation of multiplying each other of matrix A and each numerical value of matrix G is obtained S6=578.5

The S1 that more than calculates, S2, S3, S4, S5, S6 intermediate value the maximum are S4=666.5; Obtaining matching result according to the corresponding relation in the combination is: the C1 cylinder in the corresponding matrix A of XD; C5 cylinder in the corresponding matrix A of XE, the C3 cylinder in the corresponding matrix A of XF, the C6 cylinder in the corresponding matrix A of XA; C2 cylinder in the corresponding matrix A of XB, the C4 cylinder in the corresponding matrix A of XC.Hence one can see that, and top dead centre is corresponding to the C6 cylinder, i.e. the 6# cylinder; This is with number consistent with the corresponding cylinder of the top dead centre that pastes the reality that the reflecting piece method obtains.Explain that the present invention can confirm the corresponding cylinder of top dead centre number accurately and efficiently.Thus, to the detection of the duty of each cylinder of engine, very important basis is provided to the location of fault cylinder, the diagnosis identification of fault type.

Chinese and Western of the present invention that baud conversion computing method and gaussian basis ripple correlativity filtering method are method of the prior art.Below sketch burning shock response parameter extracting method based on the filtering of gaussian basis ripple correlativity:

(1) the Xi Er baud conversion of vibratory response time-domain signal, Xi Er baud English is the real signal x (t) that Hilbert considers any vibratory response, can be expressed as:

Vibratory response real signal x (t) to recording converts its corresponding complex signal to, must carry out the Hilbert conversion to vibratory response real signal x (t):

$H\left(t\right)=\frac{1}{\mathrm{\π}}{\∫}_{-\∞}^{+\∞}\frac{x\left(\mathrm{\τ}\right)}{t-\mathrm{\τ}}\mathrm{d\τ}---\left(2\right)$

The complex signal that then former real signal x (t) is corresponding is Z (t):

In the formula (3), A (t) is the amplitude function; is phase function.Its expression formula is:

$A\left(t\right)=\sqrt{x{\left(t\right)}^2+H{\left(t\right)}^2},$

Because the vibration signal of actual measurement is grouped into by some one-tenth, x (t) can be expressed as:

x(t)=x ₁(t)+x ₂(t)+…x _i(t)+…i＝1,2,…(4)

In the formula (4), x _i(t) can be the slow varying signal or unifrequency (enhancing/decay) oscillator signal of amplitude and phase place.And the Hilbert conversion is linear transformation, so following expression formula is arranged:

(5)

(2) extract burning shock response characteristic parameter with the filtering of gaussian basis ripple correlativity

If the Gauss of unit energy (Gauss) first-harmonic function is:

$A(t,f_c,\mathrm{\α})=\frac{1}{\sqrt{\sqrt{\mathrm{\π}}\mathrm{\α}}}{e}^{2\mathrm{i\πt}{f}_c-\frac{t^2}{2{\mathrm{\α}}^2}}---\left(6\right)$

In the formula (6), f _cBe the first-harmonic centre frequency, unit is Hz; α is a time scale, and unit is a second s.The mould of corresponding (6) is that 1 discrete first-harmonic sequence is:

${\{A_k(f_c,\mathrm{\α})=\frac{1}{\sqrt{\sqrt{\mathrm{\π}}\mathrm{\α}{f}_s}}{e}^{2\mathrm{i\πk}{f}_c/f_s-\frac{k^2}{2{\mathrm{\α}}^2{f_s}^2}}\}}_{k\∈Z}---\left(7\right)$

In the formula (7), f _sBe SF, unit is Hz.The expression formula of the finite term of modus ponens (7) is:

${\{A_k(f_c,\mathrm{\α})=\frac{1}{\sqrt{\sqrt{\mathrm{\π}}\mathrm{\α}{f}_s}}{e}^{2\mathrm{i\πk}{f}_c/f_s-\frac{k^2}{2{\mathrm{\α}}^2{f_s}^2}}\}}_{k=-N}^N,(N/f_s\≥3\mathrm{\α})---\left(8\right)$

In formula (6) ~ formula (8), two basic parameter f of first-harmonic _cWith α all be the bound variable that scope is arranged:

f _c∈[0,f _s/2]；α∈[α ₁，α ₂](9)

Can be through the arc tangent conversion with top independent variable f _cBecome with the scope of α that (∞ ,+independent variable u, v on ∞) has

$f_c=f_s(\frac{1}{4}+\frac{1}{2\mathrm{\π}}{\tan }^{-1}u);$ $\mathrm{\α}={\mathrm{\α}}_1+({\mathrm{\α}}_2-{\mathrm{\α}}_1)(\frac{1}{2}+\frac{1}{\mathrm{\π}}{\tan }^{-1}v)---\left(10\right)$

Then about (f _c, expression formula α) can be used in field of definition for (∞ ,+∞) (u, variable is v) represented:

A _k(f _c,α)=A _k(f _c(u),α(v))=B _k(u,v) (11)

Because the variation of the field of definition of independent variable then is optimized u, v unconstrained optimization method capable of using.

If with B _k(u v) is the first-harmonic column vector, [x _k] be complex signal section column vector to be matched, length is all 2N+1, and then this signal segment to the projection P of first-harmonic is:

$P\left(\right[x_k\left]\right|\left[B_k(u,v)\right])=<\left[x_k\right],\left[B_k(u,v)\right]>={\left[B_k(u,v)\right]}^H\&CenterDot;\left[x_k\right]=\underset{k}{\mathrm{\&Sigma;}}{x}_k{B}_k{(u,v)}^{*}---\left(12\right)$

The first-harmonic expression formula be (τ=α):

$G(t,\mathrm{\&tau;},f_c)=A*\exp (-\frac{t^2}{2*{\mathrm{\&tau;}}^2}+j*2*\mathrm{\&pi;}*f_c*t),-3*\mathrm{\&tau;}\&le;t\&le;3*\mathrm{\&tau;}---\left(13\right)$ 。

Claims (2)

1. method of locating the six cylinder engine top dead centre, it is characterized in that: the step that this method comprises is:

⑴, between first cylinder of six cylinder engine and second cylinder, be provided with to be provided with between first measuring point, second cylinder and the 3rd cylinder to be provided with between the 3rd measuring point, the 5th cylinder and the 6th cylinder between second measuring point, the 4th cylinder and the 5th cylinder the 4th measuring point is set; One acceleration vibration transducer is installed respectively on each measuring point, and this acceleration vibration transducer connects computing machine through the vibration signals collecting appearance;

⑵, six working cylinders of collection engine are no less than the acceleration vibration signal of a dust cycle, obtain the vibratory response time-domain signal of six working cylinders of engine;

⑶, the vibratory response time-domain signal of six working cylinders of engine is carried out the Xi Er baud conversion, obtain the complex signal of six working cylinders of engine;

⑷, the complex signal of six working cylinders of engine is extracted, obtained the burning shock response characteristic parameter of six working cylinders of engine with gaussian basis ripple correlativity filtering method;

⑸, draw the digital quantization matrix A between measuring point and six working cylinders of engine according to the row order of first measuring point, second measuring point, the 3rd measuring point, the 4th measuring point:

Matrix $A=\left[\begin{array}{cccccc}1.0& 0& 0.5& 0& 1.0& 0\\ 0.5& 0& 1.0& 0& 1.0& 0.5\\ 0& 1.0& 0.5& 0.5& 0& 1.0\\ 0& 1.0& 0& 1.0& 0& 0.5\end{array}\right]$

⑹, setting engine crankshaft corner are that 0 degree, 120 degree, 240 are spent, 360 degree, 480 are spent, the burning shock response characteristic parameter of 600 degree is respectively XA, XB, XC, XD, XE, XF;

⑺, list with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XA, XB, XC, XD, XE, XF and to form matrix B;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XB, XC, XD, XE, XF, XA and to form Matrix C;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XC, XD, XE, XF, XA, XB and to form matrix D;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XD, XE, XF, XA, XB, XC and to form matrix E;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XE, XF, XA, XB, XC, XD and to form matrix F;

List with each measuring point of matrix A shock response characteristic parameter that burns one to one according to the listed sequence of XF, XA, XB, XC, XD, XE and to form matrix G;

⑻, the corresponding one by one back summation of multiplying each other of each numerical value of matrix A and matrix B is obtained S1;

The corresponding one by one back summation of multiplying each other of each numerical value of matrix A and Matrix C is obtained S2;

The corresponding one by one back summation of multiplying each other of each numerical value of matrix A and matrix D is obtained S3;

The corresponding one by one back summation of multiplying each other of matrix A and each numerical value of matrix E is obtained S4;

The corresponding one by one back summation of multiplying each other of each numerical value of matrix A and matrix F is obtained S5;

The corresponding one by one back summation of multiplying each other of matrix A and each numerical value of matrix G is obtained S6;

⑼, get S1, S2, S3, S4, S5, S6 intermediate value the maximum, the engine operation cylinder that the XA in this value the maximum is corresponding is exactly the corresponding engine operation cylinder of top dead centre.

2. the method for location according to claim 1 six cylinder engine top dead centre is characterized in that: described six cylinder engine is six cylinder diesel motors or six cylinder gasoline engines.

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