CN102944422B - Driving load fatigue representing and testing method for transmission system of automobile - Google Patents

Abstract

The invention discloses a driving load fatigue representing and testing method for a transmission system of an automobile, comprising the following steps of: (1) acquiring a transmission input torque, a driving wheel axle vibration acceleration and a transmission gear signal on a test field; (2) acquiring expected response signals when the automobile actually runs at all gears; (3) mounting a transmission system and calculating a frequency response function of the system; (4) calculating initial driving signals of a linear vibration exciter and a torque vibration exciter; (5) calculating a driving signal correction corresponding to an error, and recording a final driving signal at the gear; (6) acquiring final driving signals at all the gears; and (7) carrying out a fatigue durability test on the transmission system by respectively taking the final driving signals at all the gears as inputs. The method can be used for well reflecting the load of the transmission system of the automobile in the actual running process and simulating and representing stress and fatigue conditions of the transmission system indoors when the automobile runs actually, so that the fatigue life of the transmission system of the automobile is accurately and efficiently checked indoors.

Description

Car transmissions travel load fatigue reproduction test method

Technical field

The present invention relates to a kind of car transmissions method for testing performance, particularly relate to a kind of car transmissions and travel load fatigue reproduction test method.

Background technology

Current most of car is all preposition forerunner's arrangement form, its kinematic train forms primarily of variator (main reducing gear and differential mechanism and variator are integrated) and length semiaxis, these component combinations, play a part as running car transmitting torque together.Car transmissions are subject to the double action of the dynamic loading that the effect of alternate torque and wheel bob cause in actual travel process, the destruction of its parts and assembly, the overwhelming majority is the inefficacy owing to causing under these two kinds of load actings in conjunction, for verifying in indoor car transmissions fatigue reliability performance and examine, need mainly to travel load to car transmissions two kinds simulate and reproduce, then under the load condition reproduced, carry out fatigue life test, this will improve experimental accuracy and efficiency greatly.At present, test unit and the method for simulation reconstruction while of car transmissions moment of torsion and wheel bob dynamic loading is not also had both at home and abroad.

Summary of the invention

For above shortcomings in prior art, the invention provides a kind of car transmissions and travel load fatigue reproduction test method.This test method can well reflect vehicle transmission tie up to real vehicle travel in load, in the stressing conditions of lab simulation reproducing car transmissions when real vehicle travels and tired situation, to the examination carrying out automotive transmission fatigue lifetime precise and high efficiency in indoor.

In order to solve the problems of the technologies described above, present invention employs following technical scheme:

Car transmissions travel load fatigue reproduction test method, have employed a kind of car transmissions in the method and travel load fatigue reproduction test system, this pilot system comprises the first linear vibration exciter, the second linear vibration exciter, the first hold-down support, the second hold-down support, acceleration transducer, reverse vibration generator, torque sensor and computer control system, described first linear vibration exciter and the second linear vibration exciter are vertically arranged, the piston rod of the first linear vibration exciter and the second linear vibration exciter arranges a brace table respectively, each brace table is provided with one can the support slide unit of this brace table horizontal slip relatively, described first hold-down support is vertically fixed on the support slide unit above the first linear vibration exciter, described second hold-down support is vertically fixed on the support slide unit above the second linear vibration exciter, described first hold-down support and the second hold-down support are equipped with acceleration transducer, described torque sensor is connected with reverse vibration generator, described first linear vibration exciter, second linear vibration exciter and reverse vibration generator are controlled by computer control system, the signal input computer control system that acceleration transducer and torque sensor gather,

The method comprises the steps:

(1), strain-type torque sensor is installed on transmission input shaft, wheel hub installs acceleration transducer, gather the vibration acceleration of gear-box input torque and output terminal at testing field, and gather Transmission gear signal simultaneously;

(2), according to gear signal, the torque signal gathered and acceleration signal are carried out to cutting, reject singular term pre-service, and obtain Expected Response signal during each gear actual travel, Expected Response signal when recording this gear actual travel is y _dt () is 3 × 1 matrixes;

(3), car transmissions being arranged on car transmissions travels in load fatigue reproduction test system, reverse vibration generator is connected with the power input shaft of variator, the long jackshaft of variator is fixedly connected with the first hold-down support, the short jackshaft of variator is fixedly connected with the second hold-down support, applies white noise signal x by computer control system to linear vibration exciter and reverse vibration generator _nt (), collects the response signal y of acceleration transducer and torque sensor _rt (), calculates frequency response function H (f) of this pilot system by formula (1);

$H\left(f\right)=\frac{S_{\mathrm{xy}}\left(f\right)}{S_{\mathrm{xx}}\left(f\right)}---\left(1\right)$

In formula: S _xx(f)-white noise signal x _nthe autopower spectral density of (t);

S _xy(f)-white noise signal x _n(t) and sensor response signal y _rcross-spectral density between (t);

H (f)-acceleration transducer and torque sensor and the frequency response function between linear vibration exciter and reverse vibration generator are 3 × 3 matrixes;

(4), with Expected Response signal y during this gear actual travel _dt () is simulated target, the initial driving signal according to formula (2) and (3) calculated line vibrator and reverse vibration generator:

X ₀(f)＝H ^-1(f)Y _d(f) (2)

x ₀(t)＝IFFT[X ₀(f)] (3)

In formula: H ^-1the inverse matrix of (f)-H (f);

Y _d(f)-Expected Response signal y _dthe Fourier transform of (t);

X ₀(t)-linear vibration exciter and reverse vibration generator initial driving signal;

X ₀(f)-x ₀the Fourier transform of (t);

(5), with initial driving signal drive linear vibration exciter and reverse vibration generator, gather the response signal y of acceleration transducer and torque sensor simultaneously ₀t (), calculates time domain response and frequency domain response weighted error with formula (4), (5), (6) and (7), by formula (8) and drive singal correction corresponding to (9) error of calculation:

△ _t(t)＝y _d(t)-y ₀(t) (4)

△ _f(f)＝Y _d(f)-Y ₀(f) (5)

△ _f(t)＝IFFT[△ _f(f)] (6)

△(t)＝0.7×△ _t(t)+0.3×△ _f(t) (7)

X _e(f)＝H ^-1(f)△(f) (8)

x _e(t)＝IFFT[X _e(f)] (9)

In formula: △ _t(t)-time domain response error signal;

Y ₀(f)-sensor response signal y ₀the Fourier transform of (t);

△ _f(f)-frequency domain response error signal;

△ _f(t)-frequency domain response error signal △ _fthe inverse Fourier transform of (f);

△ (t)-time domain response and frequency domain response weighted error;

The Fourier transform of △ (f)-△ (t);

X _ethe corresponding drive singal of (t)-error;

X _e(f)-x _ethe Fourier transform of (t);

Correction drive singal is x ₁(t)=x ₀(t)+α x _e(t);

In formula, α is attenuation coefficient, and initial value gets 0.5 usually, suitably increases or reduce according to iteration convergence situation, but must meet: 0 < α≤1;

To revise drive singal x ₁t (), as driving, the process constantly repeated before in this step carries out iteration, and with formula (10) calculating error values △ in real time _n, when each sensor response error≤5%, record final drive singal, this final drive singal is the final drive singal of this gear;

${\mathrm{\&Delta;}}_n=(0.7\&times;\frac{\sqrt{\underset{t}{\mathrm{\&Sigma;}}{(y_d\left(t\right)-y_n\left(t\right))}^2}}{\sqrt{\underset{t}{\mathrm{\&Sigma;}}{y}_d^2\left(t\right)}}+0.3\&times;\frac{\sqrt{\underset{f}{\mathrm{\&Sigma;}}{(Y_d\left(f\right)-Y_n\left(f\right))}^2}}{\sqrt{\underset{f}{\mathrm{\&Sigma;}}{Y}_d^2\left(f\right)}})\&times;100\%---\left(10\right)$

In formula: △ _n-the n-th iteration error value;

Y _nt response signal that ()-n-th time iteration gathers;

Y _n(f)-y _nthe Fourier transform of (t);

(6), repeat step (4) and step (5), Expected Response signal during each gear actual travel to variator carries out simulative iteration, obtains the final drive singal of each gear;

(7), respectively with the final drive singal of each gear for input, variator is fixed on corresponding gear, fatigue durability test is carried out to kinematic train.

Compared with prior art, car transmissions traveling load fatigue reproduction test method tool of the present invention has the following advantages:

1, use linear vibration exciter and reverse vibration generator simulated automotive kinematic train output axle shaft wheel bob dynamic loading and automotive transmission actual travel torsion load respectively, well reflect vehicle transmission tie up to real vehicle travel in load.

2, the multi parameters control method of time domain error and error of frequency domain weighting is applied, in the stressing conditions of lab simulation reproducing car transmissions when real vehicle travels and tired situation, to the examination carrying out automotive transmission fatigue lifetime precise and high efficiency in indoor.

Accompanying drawing explanation

Fig. 1 is the front view that car transmissions travel load fatigue reproduction test system;

Fig. 2 is the vertical view that car transmissions travel load fatigue reproduction test system.

In accompanying drawing: 1-mounting foundation; 2-the first linear vibration exciter; 3-support slide unit; 4-the first hold-down support; 5-acceleration transducer; 6-long jackshaft; 7-reverse vibration generator; 8-torque sensor; 9-variator bearing; 10-variator; 11-short jackshaft; 12-support platform; 13-support platform column; 14-torque sensor; 15-reverse vibration generator pedestal; 16-brace table; 17-the second linear vibration exciter; 18-the second hold-down support.

Embodiment

Below in conjunction with the drawings and specific embodiments, the invention will be further described.

Car transmissions travel load fatigue reproduction test method, have employed a kind of car transmissions in the method and travel load fatigue reproduction test system.As shown in Figure 1, 2, these car transmissions traveling load fatigue reproduction test system comprises mounting foundation 1, variator bearing 9, support platform 12, support platform column 13, torque sensor pedestal 14, reverse vibration generator pedestal 15, first linear vibration exciter 2, second linear vibration exciter 17, first hold-down support 4, second hold-down support 18, acceleration transducer 5, reverse vibration generator 7, torque sensor 8 and computer control system.First linear vibration exciter 2 and the second linear vibration exciter 17 are vertically arranged in mounting foundation 1, are used for the bob of simulating wheel.Support platform 12 is horizontally set on the top of mounting foundation 1 by three support platform columns 13, and support platform 12 is for supporting reverse vibration generator 7, torque sensor 8 and variator 10.The piston rod of the first linear vibration exciter 2 and the second linear vibration exciter 3 arranges a brace table 16 respectively, each brace table 16 is provided with one can the support slide unit 3 of this brace table 16 horizontal slip relatively, the effect supporting slide unit 3 supports hold-down support, support slide unit 3 to slide in the horizontal direction on brace table 16, the change of distance during to compensate wheel bob simultaneously.First hold-down support 4 is vertically fixed on the support slide unit 3 above the first linear vibration exciter 2, second hold-down support 18 is vertically fixed on the support slide unit 3 above the second linear vibration exciter 17, and the first hold-down support 4 and the second hold-down support 18 are equipped with acceleration transducer 5.Torque sensor 8 is arranged in support platform 12 by torque sensor pedestal 14, and reverse vibration generator 7 is arranged in support platform 12 by reverse vibration generator pedestal 15, and variator 10 is arranged in support platform 12 by variator bearing 9.Torque sensor 8 is connected with reverse vibration generator 7 and is connected by the power input shaft of reverse vibration generator 7 with variator 10, and reverse vibration generator 7 is used for simulated engine and outputs to the dynamic torsion of variator.First linear vibration exciter 2, second linear vibration exciter 17 and reverse vibration generator 7 are controlled by computer control system, the signal input computer control system that acceleration transducer 5 and torque sensor 8 gather.

The ultimate principle of this pilot system is: the acceleration first gathering automotive transmission input torque and wheel hub vertical direction when real vehicle travels, and carry out signal cutting and process according to gear, then white noise signal is applied respectively with linear vibration exciter and reverse vibration generator, gather acceleration transducer and torque sensor output, calculate the frequency response function of this pilot system, the analysis of wheel vertical directional acceleration gathered when travelling according to real vehicle and torque, calculated line vibrator and reverse vibration generator input signal, and constantly carry out iteration, acceleration transducer and torque sensor simulate the analysis of wheel vertical directional acceleration and drive train torque that gather when real vehicle travels, the traveling load of power train is well reproduced on this system, finally under real load condition, carry out torture test according to each gear.

These car transmissions travel load fatigue reproduction test method and comprise the steps:

(1), strain-type torque sensor is installed on transmission input shaft, wheel hub installs acceleration transducer, gather the vibration acceleration of gear-box input torque and output terminal at testing field, and gather Transmission gear signal simultaneously.

(2), according to gear signal, the torque signal gathered and acceleration signal are carried out to cutting, reject singular term pre-service, and obtain Expected Response signal during each gear actual travel, Expected Response signal when recording this gear actual travel is y _dt () is 3 × 1 matrixes.

(3), car transmissions being arranged on car transmissions travels in load fatigue reproduction test system, reverse vibration generator is connected with the power input shaft of variator, the long jackshaft of variator is fixedly connected with the first hold-down support, the short jackshaft of variator is fixedly connected with the second hold-down support, applies white noise signal x by computer control system to linear vibration exciter and reverse vibration generator _nt (), collects the response signal y of acceleration transducer and torque sensor _rt (), calculates frequency response function H (f) of this pilot system by formula (1);

$H\left(f\right)=\frac{S_{\mathrm{xy}}\left(f\right)}{S_{\mathrm{xx}}\left(f\right)}---\left(1\right)$

In formula: S _xx(f)-white noise signal x _nthe autopower spectral density of (t);

S _xy(f)-white noise signal x _n(t) and sensor response signal y _rcross-spectral density between (t);

H (f)-acceleration transducer and torque sensor and the frequency response function between linear vibration exciter and reverse vibration generator are 3 × 3 matrixes.

(4), with Expected Response signal y during this gear actual travel _dt () is simulated target, the initial driving signal according to formula (2) and (3) calculated line vibrator and reverse vibration generator:

X ₀(f)＝H ^-1(f)Y _d(f) (2)

x ₀(t)＝IFFT[X ₀(f)] (3)

In formula: H ^-1the inverse matrix of (f)-H (f);

Y _d(f)-Expected Response signal y _dthe Fourier transform of (t);

X ₀(t)-linear vibration exciter and reverse vibration generator initial driving signal;

X ₀(f)-x ₀the Fourier transform of (t).

(5), with initial driving signal drive linear vibration exciter and reverse vibration generator, gather the response signal y of acceleration transducer and torque sensor simultaneously ₀t (), calculates time domain response and frequency domain response weighted error with formula (4), (5), (6) and (7), by formula (8) and drive singal correction corresponding to (9) error of calculation:

△ _t(t)＝y _d(t)-y ₀(t) (4)

△ _f(f)＝Y _d(f)-Y ₀(f) (5)

△ _f(t)＝IFFT[△ _f(f)] (6)

△(t)＝0.7×△ _t(t)+0.3×△ _f(t) (7)

X _e(f)＝H ^-1(f)△(f) (8)

x _e(t)＝IFFT[X _e(f)] (9)

In formula: △ _t(t)-time domain response error signal;

Y ₀(f)-sensor response signal y ₀the Fourier transform of (t);

△ _f(f)-frequency domain response error signal;

△ _f(t)-frequency domain response error signal △ _fthe inverse Fourier transform of (f);

△ (t)-time domain response and frequency domain response weighted error;

The Fourier transform of △ (f)-△ (t);

X _ethe corresponding drive singal of (t)-error;

X _e(f)-x _ethe Fourier transform of (t);

Correction drive singal is x ₁(t)=x ₀(t)+α x _e(t);

In formula, α is attenuation coefficient, and initial value gets 0.5 usually, suitably increases or reduce according to iteration convergence situation, but must meet: 0 < α≤1;

To revise drive singal x ₁t (), as driving, the process constantly repeated before in this step carries out iteration, and with formula (10) calculating error values △ in real time _n, when each sensor response error≤5%, record final drive singal, this final drive singal is the final drive singal of this gear;

${\mathrm{\&Delta;}}_n=(0.7\&times;\frac{\sqrt{\underset{t}{\mathrm{\&Sigma;}}{(y_d\left(t\right)-y_n\left(t\right))}^2}}{\sqrt{\underset{t}{\mathrm{\&Sigma;}}{y}_d^2\left(t\right)}}+0.3\&times;\frac{\sqrt{\underset{f}{\mathrm{\&Sigma;}}{(Y_d\left(f\right)-Y_n\left(f\right))}^2}}{\sqrt{\underset{f}{\mathrm{\&Sigma;}}{Y}_d^2\left(f\right)}})\&times;100\%---\left(10\right)$

In formula: △ _n-the n-th iteration error value;

Y _nt response signal that ()-n-th time iteration gathers;

Y _n(f)-y _nthe Fourier transform of (t).

(6), repeat step (4) and step (5), Expected Response signal during each gear actual travel to variator carries out simulative iteration, obtains the final drive singal of each gear.

(7), respectively with the final drive singal of each gear for input, variator is fixed on corresponding gear, fatigue durability test is carried out to kinematic train.

What finally illustrate is, above embodiment is only in order to illustrate technical scheme of the present invention and unrestricted, although with reference to preferred embodiment to invention has been detailed description, those of ordinary skill in the art is to be understood that, can modify to technical scheme of the present invention or equivalent replacement, and not departing from aim and the scope of technical solution of the present invention, it all should be encompassed in the middle of right of the present invention.

Claims (1)

1. car transmissions travel load fatigue reproduction test method, it is characterized in that, have employed a kind of car transmissions in the method and travel load fatigue reproduction test system, this pilot system comprises the first linear vibration exciter, the second linear vibration exciter, the first hold-down support, the second hold-down support, acceleration transducer, reverse vibration generator, torque sensor and computer control system, described first linear vibration exciter and the second linear vibration exciter are vertically arranged, the piston rod of the first linear vibration exciter and the second linear vibration exciter arranges a brace table respectively, each brace table is provided with one can the support slide unit of this brace table horizontal slip relatively, described first hold-down support is vertically fixed on the support slide unit above the first linear vibration exciter, described second hold-down support is vertically fixed on the support slide unit above the second linear vibration exciter, described first hold-down support and the second hold-down support are equipped with acceleration transducer, described torque sensor is connected with reverse vibration generator, described first linear vibration exciter, second linear vibration exciter and reverse vibration generator are controlled by computer control system, the signal input computer control system that acceleration transducer and torque sensor gather,

The method comprises the steps:

(1), strain-type torque sensor is installed on transmission input shaft, wheel hub installs acceleration transducer, gather the vibration acceleration of gear-box input torque and output terminal at testing field, and gather Transmission gear signal simultaneously;

(2), according to gear signal, the torque signal gathered and acceleration signal are carried out to cutting, reject singular term pre-service, and obtain Expected Response signal during each gear actual travel, Expected Response signal when recording this gear actual travel is y _dt () is 3 × 1 matrixes;

(3), car transmissions being arranged on car transmissions travels in load fatigue reproduction test system, reverse vibration generator is connected with the power input shaft of variator, the long jackshaft of variator is fixedly connected with the first hold-down support, the short jackshaft of variator is fixedly connected with the second hold-down support, applies white noise signal x by computer control system to linear vibration exciter and reverse vibration generator _nt (), collects the response signal y of acceleration transducer and torque sensor _rt (), calculates frequency response function H (f) of this pilot system by formula (1);

$H\left(f\right)=\frac{S_{\mathrm{xy}}\left(f\right)}{S_{\mathrm{xx}}\left(f\right)}---\left(1\right)$

In formula: S _xx(f)-white noise signal x _nthe autopower spectral density of (t);

S _xy(f)-white noise signal x _ncross-spectral density between (t) and sensor response signal yr (t);

H (f)-acceleration transducer and torque sensor and the frequency response function between linear vibration exciter and reverse vibration generator are 3 × 3 matrixes;

(4), with Expected Response signal y during this gear actual travel _dt () is simulated target, the initial driving signal according to formula (2) and (3) calculated line vibrator and reverse vibration generator:

X ₀(f)＝H ^-1(f)Y _d(f) (2)

x ₀(t)＝IFFT[X ₀(f)] (3)

In formula: H ^-1the inverse matrix of (f)-H (f);

Y _d(f)-Expected Response signal y _dthe Fourier transform of (t);

X ₀(t)-linear vibration exciter and reverse vibration generator initial driving signal;

X ₀(f)-x ₀the Fourier transform of (t);

(5), with initial driving signal drive linear vibration exciter and reverse vibration generator, gather the response signal y of acceleration transducer and torque sensor simultaneously ₀t (), calculates time domain response and frequency domain response weighted error with formula (4), (5), (6) and (7), by formula (8) and drive singal correction corresponding to (9) error of calculation:

Δ _t(t)＝y _d(t)-y ₀(t) (4)

Δ _f(f)＝Y _d(f)-Y ₀(f) (5)

Δ(t)＝0.7×Δ _t(t)+0.3×Δ _f(t) (7)

X _e(f)＝H ^-1(f)Δ(f) (8)

x _e(t)＝IFFT[X _e(f)] (9)

In formula: Δ _t(t)-time domain response error signal;

Y ₀(f)-sensor response signal y ₀the Fourier transform of (t);

Δ _f(f)-frequency domain response error signal;

Δ _f(t)-frequency domain response error signal Δ _fthe inverse Fourier transform of (f);

Δ (t)-time domain response and frequency domain response weighted error;

The Fourier transform of Δ (f)-Δ (t);

X _ethe corresponding drive singal of (t)-error;

X _e(f)-x _ethe Fourier transform of (t);

Correction drive singal is x ₁(t)=x ₀(t)+α x _e(t);

In formula, α is attenuation coefficient, and initial value gets 0.5 usually, suitably increases or reduce according to iteration convergence situation, but must meet: 0 < α≤1;

To revise drive singal x ₁t (), as driving, the process constantly repeated before in this step carries out iteration, and with formula (10) calculating error values Δ in real time _n, when each sensor response error≤5%, record final drive singal, this final drive singal is the final drive singal of this gear;

${\mathrm{\&Delta;}}_n=(0.7\&times;\frac{\sqrt{\underset{t}{\mathrm{\&Sigma;}}{(y_d\left(t\right)-y_n\left(t\right))}^2}}{\sqrt{\underset{t}{\mathrm{\&Sigma;}}{y}_d^2\left(t\right)}})+0.3\&times;\frac{\sqrt{\underset{f}{\mathrm{\&Sigma;}}{(Y_d\left(f\right)-Y_n\left(f\right))}^2}}{\sqrt{\underset{f}{\mathrm{\&Sigma;}}{Y}_d^2\left(f\right)}}\&times;100\%---\left(10\right)$

In formula: Δ _n-the n-th iteration error value;

Y _nt response signal that ()-n-th time iteration gathers;

Y _n(f)-y _nthe Fourier transform of (t);

(6), repeat step (4) and step (5), Expected Response signal during each gear actual travel to variator carries out simulative iteration, obtains the final drive singal of each gear;

(7), respectively with the final drive singal of each gear for input, variator is fixed on corresponding gear, fatigue durability test is carried out to kinematic train.