CN103615531B - A kind of clutch's jointing process method for diagnosing faults based on SDG model and system - Google Patents

Abstract

The invention provides a kind of clutch's jointing process method for diagnosing faults based on SDG model and system.The method utilizes SDG model to carry out the diagnosis of clutch, carrying out transmission system and automatic handling system analyzing on the basis of also founding mathematical models, set up the SDG model of clutch, take into full account each variable affecting clutch work, and simplify some node according to physical condition and demand, utilize the data that sensor detects, judge each node symbol, compatible path is determined with this, then according to principle of probability, according to the large young pathbreaker's branch road sequence of fault possibility occurrence, first the reason node of the maximum branch road of fault possibility occurrence is investigated, this node is exactly probably source of trouble place, if not, other branch road is checked again according to above-mentioned sequence, so just substantially increase the efficiency of diagnosis.

Description

A kind of clutch's jointing process method for diagnosing faults based on SDG model and system

Technical field

The present invention relates to the basic field carrying out clutch's jointing process fault diagnosis based on SDG model, particularly relate to a kind of AMT heavy-duty off-road vehicle clutch's jointing process method for diagnosing faults based on SDG model and system.

Background technique

AMT(automatic mechanical transmission) be automated mechanical transmission based on dry clutch and mechanical transmission, the control of clutch is the key of AMT.Can clutch and operating mechanism thereof normally work the realization of the fundamental function such as starting and gear-change operation by directly affecting vehicle, and then affect the power character of vehicle, Economy and smoothness.For AMT Major off road vehicle, mostly adopt dry clutch, the many employings of operating mechanism air pressure assisted formula hydraulic operation form.Due to heavy-duty off-road vehicle work under bad environment and clutch operating system series connection link many, therefore easily break down.

Existing wrong operation of motor diagnostic method mainly contains extremum method, Analysis design method.Although above method can diagnose out the fault of clutch, there are two point defects, that is: (1) does not carry out fault diagnosis from car load angle to clutch, loses of overall importance; (2) time in looking up the fault source is longer, and therefore efficiency is lower.SDG(signed digraph) model describes a kind of effective means of scale complex system, the relation that influences each other between each variable of system can be clearly represented, for propagation, the Timeliness coverage source of trouble studying fault provides model foundation by node and directed edge.Therefore, SDG model is used to carry out to AMT heavy-duty off-road vehicle clutch's jointing process the significance that fault diagnosis has.

Summary of the invention

Main purpose of the present invention is to solve AMT heavy-duty off-road vehicle clutch's jointing process fault diagnosis difference of overall importance, problem that diagnosis efficiency is low, embodiments provides a kind of AMT heavy-duty off-road vehicle clutch's jointing process method for diagnosing faults based on SDG model and system, by carrying out dynamic analysis and mathematical modeling to clutch's jointing process, thus set up the SDG model of clutch's jointing process, by actual measured amount and the analysis to model interior joint and directed edge, find out the source of trouble, complete fault diagnosis functions.

Technological scheme provided by the invention is as follows:

Based on a clutch's jointing process method for diagnosing faults for SDG model, it is characterized in that, comprise the following steps:

Step 1, clutch's jointing process analysis;

Step 2, clutch's jointing process SDG model is set up and model simplification;

Step 3, based on the clutch's jointing process fault diagnosis of SDG model.

Further, step 1 specifically comprises:

Step 1.1, drive train power Epidemiological Analysis;

Step 1.2, clutch automatic handling system mathematical modeling;

Wherein, step 1.1 and step 1.2 perform order in no particular order.

Further, in step 1.1, the dynamics formula that engine power exports clutch active part to is:

$I_e{\stackrel{\·}{\mathrm{\ω}}}_e\left(t\right)=M_e\left(t\right)-M_c\left(t\right)---\left(1\right)$

ω _e(t)=ω ₁(t)（2）

Clutch secondary part to the dynamics formula of driving wheel is:

$I_o{\stackrel{\·}{\mathrm{\ω}}}_1\left(t\right)=M_c\left(t\right)-\frac{M_r\left(t\right)}{i_g{i}_o\mathrm{\η}}---\left(3\right)$

${\mathrm{\ω}}_r\left(t\right)=\frac{{\mathrm{\ω}}_1\left(t\right)}{i_g{i}_o}---\left(4\right)$

In formula (1)-(4): M _ethe effective Driving Torque of-motor; M _c-clutch transmission torque; M _r-ground drag square; ω _e-engine crankshaft rotational angular velocity, i.e. clutch active part rotational angular velocity; the derivative of-engine crankshaft rotational angular velocity, i.e. engine crankshaft rotational angle acceleration; ω ₁-transmission input shaft rotational angular velocity, i.e. clutch secondary part rotational angular velocity; the derivative of-transmission input shaft rotational angular velocity, i.e. transmission input shaft rotational angle acceleration; ω _r-driving wheel rotational angular velocity; I _e-crank-connecting rod mechanism for engine and clutch active part are converted to the rotary inertia on bent axle; I _o-clutch secondary part, the car load inertia be connected with speed changer are converted to the rotary inertia on transmission input shaft; i _othe resultant gear ratio of-main reducing gear and wheel reductor; i _g-transmission ratio; The mechanical efficiency of η-power train.

Further, in step 1.2, clutch automatic handling system mathematical model is:

$\left\{\begin{array}{c}{l}_1=\mathrm{\Δl}+\frac{k_1}{D_2^2}(k_2{D}_3^{2}x+l_4{D}_4^2)\\ P_1=\frac{4{D_2}^2{F}_{\mathrm{sp}}}{\mathrm{\π}{k}_1{k}_2{\mathrm{\η}}_1{D_1}^2{D}_3^2}+\frac{4F_{\mathrm{ta}}}{\mathrm{\π}{k}_1{D_1}^2}\\ \frac{\mathrm{\π}{D_1}^2}{4}\·\frac{d{l}_1}{\mathrm{dt}}=\mathrm{\θ}{C}_d\sqrt{\frac{2P_1}{\mathrm{\ρ}}}\end{array}\right.$

In formula: l ₁-clutch control cylinder piston stroke; l ₄the stroke needed for air valve opened by-reversing piston; The clutch control cylinder free travel in △ l-elimination separating mechanism gap; The stroke of x-clutch release bearing; k ₁-tread portion sub-transmission ratio; k ₂-release bearing lever transmission ratio; P ₁-clutch control cylinder working pressure; P ₂-hydraulic main cylinder working pressure; D ₁-clutch control cylinder rodless cavity piston diameter; D ₂-hydraulic main cylinder piston diameter; D ₃-gas power-assisted clutch release slave cylinder hydraulic part piston diameter; D ₄the hydraulic work chamber diameter of-reversing piston; F _spthe elastic force that-clutch diaphragm spring produces; F _tathe elastic force that-clutch pedal Returnning spring produces; η ₁the transmission efficiency of-clutch operation; C _d-flow coefficient; ρ-hydraulic oil density; θ-Flow valve opening area.

Further, step 2 specifically comprises:

Step 2.1, the setting control of vehicle drive system and the control of clutch automatic handling system are unity loop control respectively, setup control process and the point that may break down;

Step 2.2, the cunning chosen in engaging process is rubbed the stage, sets up its SDG model;

Step 2.3, deletes can not survey node according to system physical condition, simplifies SDG model.

Further, step 3 specifically comprises:

Step 3.1, according to the normal value of node to strain capacity the threshold epsilon of normal state is in node _kdetermine the node symbol in SDG model;

Step 3.2, analyzes node and directed edge, deletes normal node and non-conforming path;

Step 3.3, according to probability statistics principle, determines the fault rate of compatible path successively;

Step 3.4, the root node of the compatible path of the maximum probability that breaks down is exactly the source of trouble place of maximum possible;

Step 3.5, checks whether root node related device breaks down, and if so, proceeds to step 3.6, if not, ignores this root node, proceed to the source of trouble that step 3.4 continues to find successively maximum possible;

Step 3.6, determine that the device broken down is the source of trouble, flow process terminates.

Preferably, described clutch is AMT heavy-duty off-road vehicle clutch.

The application also provides a kind of clutch's jointing process fault diagnosis system based on SDG model, it is characterized in that, comprises with lower device:

For the device that clutch's jointing process is analyzed;

Set up and the device of model simplification for clutch's jointing process SDG model;

For carrying out the device of fault diagnosis based on the clutch's jointing process of SDG model.

SDG model is utilized to carry out the diagnosis of clutch, carrying out transmission system and automatic handling system analyzing on the basis of also founding mathematical models, set up the SDG model of clutch, take into full account each variable affecting clutch work, and simplify some node according to the actual requirements, utilize the data that sensor detects, judge each node symbol, compatible path is determined with this, then according to principle of probability, according to the large young pathbreaker's branch road sequence of fault possibility occurrence, first the reason node of the maximum branch road of fault possibility occurrence is investigated, this node is exactly probably source of trouble place, if not, other branch road is checked again according to above-mentioned sequence, so just substantially increase the efficiency of diagnosis.

Accompanying drawing explanation

In order to be illustrated more clearly in the embodiment of the present invention or technological scheme of the prior art, be briefly described to the accompanying drawing used required in embodiment or prior art below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.

Fig. 1 is the AMT heavy-duty off-road vehicle clutch's jointing process method for diagnosing faults flow chart based on SDG model in the embodiment of the present invention;

Fig. 2 is the AMT heavy-duty off-road vehicle clutch's jointing process method for diagnosing faults preferred flow charts based on SDG model in the embodiment of the present invention;

Fig. 3 is each variable plotted curve of clutch's jointing process in the embodiment of the present invention;

Fig. 4 is Automatic control mechanism for clutch sketch in the embodiment of the present invention;

Clutch's jointing process control structure figure in the embodiment of the present invention, wherein, Fig. 5 (a) is that in the embodiment of the present invention, car load power transmission system control structure figure, Fig. 5 (b) they are automatic handling system control structure figure in the embodiment of the present invention;

Fig. 6 is clutch's jointing process SDG model in the embodiment of the present invention;

Fig. 7 is clutch's jointing process SDG simplified model in the embodiment of the present invention;

Fig. 8 is the relation in the embodiment of the present invention between solenoid-operated proportional Flow valve electric current and flow;

Part of nodes change curve in time when breaking down in the embodiment of the present invention; Wherein, Fig. 9 (a) is clutch release bearing stroke change curve in time; Fig. 9 (b) is solenoid-operated proportional Flow valve pulse width modulated values change curve in time; Fig. 9 (c) is engine crankshaft rotational angular velocity change curve in time; Fig. 9 (d) is driving wheel rotational angular velocity change curve in time; Fig. 9 (e) is transmission input shaft rotational angular velocity change curve in time; Fig. 9 (f) is solenoid-operated proportional Flow valve electric current change curve in time;

Clutch's jointing process SDG fault model in the embodiment of the present invention, wherein, Figure 10 (a) is AMT Major off road vehicle clutch's jointing process SDG fault model in the embodiment of the present invention, and Figure 10 (b) is the SDG fault model removing normal node and non-conforming path in the embodiment of the present invention.

Wherein, the implication of Fig. 4 reference character is as follows:

1-clutch control cylinder; 2-solenoid-operated proportional Flow valve; 3-hydraulic main cylinder liquid storage room; 4-hydraulic main cylinder; 5-gas assisted hydraulic clutch release slave cylinder; 6-gas assisted hydraulic slave cylinder piston; 7-reversing piston; 8-auxiliary follow up piston; 9-air valve; 10-pressurized gas; 11-separating arm; 12-disengaging yoke; 13-diaphragm spring; 14-separator levers and platen; 15-driven disc; 16-independent oil sources.

Embodiment

In order to make those skilled in the art can understand feature of the present invention and technology contents further, refer to following detailed description for the present invention and accompanying drawing, accompanying drawing only provides reference and explanation, is not used for limiting the present invention.

Below in conjunction with drawings and Examples, technological scheme of the present invention is described.

See Fig. 1-2, it is the AMT heavy-duty off-road vehicle clutch's jointing process method for diagnosing faults flow chart based on SDG model in the embodiment of the present invention.

The method can comprise:

Step 1, clutch's jointing process analysis;

Step 2, clutch's jointing process SDG model is set up and model simplification;

Step 3, the clutch's jointing process based on SDG model carries out fault diagnosis.

Wherein, step 1 specifically comprises further

Step 1.1, drive train power Epidemiological Analysis;

Step 1.2, clutch automatic handling system mathematical modeling step.

Step 2 specifically comprises further:

Step 2.1, the setting control of vehicle drive system and the control of clutch automatic handling system are unity loop control respectively, setup control process and the point that may break down;

Step 2.2, the cunning chosen in engaging process is rubbed the stage, sets up its SDG model (without transmission of torque stage and synchronous phase corresponding clutch automatic handling system and vehicle drive system SDG model respectively);

Step 2.3, deletes can not survey node according to system physical condition, simplifies SDG model.

Step 3 specifically comprises further:

Step 3.1, according to the normal value of node to strain capacity the threshold epsilon of normal state is in node _kdetermine the node symbol in SDG model;

Step 3.2, analyzes node and directed edge, deletes normal node and non-conforming path;

Step 3.3, according to probability statistics principle, determines the fault rate of compatible path successively;

Step 3.4, the root node of the compatible path of the maximum probability that breaks down is exactly the source of trouble place of maximum possible;

Step 3.5, checks whether root node related device breaks down, and if so, proceeds to step 3.6, if not, ignores this root node, proceed to the source of trouble that step 3.4 continues to find successively maximum possible;

Step 3.6, determine that the device broken down is the source of trouble, flow process terminates.

Below in conjunction with accompanying drawing above-mentioned steps made and illustrating.

1 clutch's jointing process analysis

Study clutch's jointing process fault diagnosis to apply SDG model, clutch's jointing process analysis is important foundation.Heavy-duty off-road vehicle clutch's jointing process of the present invention is analyzed from car load transmission system and clutch automatic handling system two aspects below with reference to Fig. 3-Fig. 4.

1.1 drive train power analyses

For the engaging process of clutch, it is representative that starting engages most.Therefore, the engaging process of clutch when the present invention is to start to walk, its drive train power formula is as follows:

(1) engine power exports clutch active part to

For the component of this part, effective Driving Torque M of motor _efor driving torque, the transmitting torque M of clutch _cfor resisting moment.Then according to two free body motion equation, can obtain:

$I_e{\stackrel{\·}{\mathrm{\ω}}}_e\left(t\right)=M_e\left(t\right)-M_c\left(t\right)---\left(1\right)$

ω _e(t)=ω ₁(t)（2）

(2) clutch secondary part is to driving wheel

For this part component, the torque M that clutch transmits _cfor driving torque, the ground drag square M suffered by driving wheel _rit is resisting moment.Then

$I_o{\stackrel{\·}{\mathrm{\ω}}}_1\left(t\right)=M_c\left(t\right)-\frac{M_r\left(t\right)}{i_g{i}_o\mathrm{\η}}---\left(3\right)$

${\mathrm{\ω}}_r\left(t\right)=\frac{{\mathrm{\ω}}_1\left(t\right)}{i_g{i}_o}---\left(4\right)$

In formula (1)-(4): M _ethe effective Driving Torque of-motor; M _c-clutch transmission torque; M _r-ground drag square; ω _e-engine crankshaft rotational angular velocity, i.e. clutch active part rotational angular velocity; the derivative of-engine crankshaft rotational angular velocity, i.e. engine crankshaft rotational angle acceleration; ω ₁-transmission input shaft rotational angular velocity, i.e. clutch secondary part rotational angular velocity; the derivative of-transmission input shaft rotational angular velocity, i.e. transmission input shaft rotational angle acceleration; ω _r-driving wheel rotational angular velocity; I _e-crank-connecting rod mechanism for engine and clutch active part are converted to the rotary inertia on bent axle; I _o-clutch secondary part, the car load inertia be connected with speed changer are converted to the rotary inertia on transmission input shaft; i _othe resultant gear ratio of-main reducing gear and wheel reductor; i _g-transmission ratio; The mechanical efficiency of η-power train.

According to M _cdifference, clutch's jointing process can be divided into without transmission of torque stage, sliding stage and the synchronous phase of rubbing, wherein without the transmission of torque stage, for eliminating the gap of the driving and driven part of clutch, this stage M _c(t)=0, ω ₁(t)=0.Slide and rub the stage, clutch transmission torque M _cby the decision such as working surface number of the action radius of the impacting force on rubbing surface, frictional force, friction pair material and friction plate, be defined as follows:

M _c=μ _cF _cR _cZ _c（5）

In formula (5): μ _c-friction factor; F _c-act on total impacting force on rubbing surface; R _c-mean friction radius; Z _c-fricting working surface number.

Synchronous phase, the sliding end that rubs of the driving and driven part of clutch, M _c(t)=M _e(t), ω _e(t)=ω ₁(t).

Engaging process rotational speed omega _e, ω ₁torque M _cand bearing travel x changes as shown in Figure 3 in time.

1.2 clutch automatic handling system mathematical modelings

(1) clutch automatic handling system principle

Fig. 4 represents AMT Major off road vehicle Automatic control mechanism for clutch.It is divided into two parts: first portion is the automatic actuating element of clutch, comprise independent oil sources, clutch control cylinder, proportional flow solenoid valve etc., second portion is the original actuating element of clutch, comprises gas assisted hydraulic clutch release slave cylinder, pressurized gas, clutch disengaging lever etc.This mechanism is hydraulic air booster type, can realize clutch quick separating and gentle engagement, not only considers automatic manipulation but also remain artificial emergency maneuver function, originate in clutch pedal, end at the release bearing in clutch housing during design.During automatic manipulation, adopting solenoid-operated proportional Flow valve, by PWM(pulse duration modulation) control mode regulates its operating voltage, and then realizes the switching that oil circuit connects and the adjustment of coming in and going out oil mass, handle cylinder stroke with these solenoidoperated cluthes, realize the automatic manipulation for clutch; Hand control is consistent with the maneuverability pattern of manual transmission vehicle.

(2) Automatic control mechanism for clutch mathematical model

With reference to Fig. 4, can obtain according to kinematic relation and conservation of volume:

l ₁=△l+k ₁l ₂（6）

l ₃=k ₂x（7）

$l_2{D}_2^2=l_3{D}_3^2+l_4{D}_4^2---\left(8\right)$

In formula (6)-(8): l ₁-clutch control cylinder piston stroke; l ₂-hydraulic main cylinder piston stroke; l ₃-gas assisted hydraulic slave cylinder piston stroke; l ₄the stroke needed for air valve opened by-reversing piston; The clutch control cylinder free travel in △ l-elimination separating mechanism gap; D ₂-hydraulic main cylinder piston diameter; D ₃-gas power-assisted clutch release slave cylinder hydraulic part piston diameter; D ₄the hydraulic work chamber diameter of-reversing piston; k ₁-tread portion sub-transmission ratio; k ₂-release bearing lever transmission ratio; The stroke of x-clutch release bearing; .

Ignore the loss of system transmission efficiency and acceleration resistance, and without the effect of gas power-assisted in engaging process, therefore manipulation cylinder and slave cylinder piston is stressed meets respectively:

$\frac{\mathrm{\π}{P}_2{D_2}^2}{4}+F_{\mathrm{ta}}=\frac{\mathrm{\π}{k}_1{D_1}^2{P}_1}{4}---\left(9\right)$

$F_{\mathrm{sp}}=k_2{\mathrm{\η}}_1{P}_2\frac{\mathrm{\π}{D_3}^2}{4}---\left(10\right)$

Because clutch control cylinder adopts asymmetrical cylinder, therefore the flow equation of Flow valve rodless cavity is:

$Q=\mathrm{\θ}{C}_d\sqrt{\frac{2P_1}{\mathrm{\ρ}}}---\left(11\right)$

In formula (9)-(11): P ₁-clutch control cylinder working pressure; P ₂-hydraulic main cylinder working pressure; D ₁-clutch control cylinder rodless cavity piston diameter; F _spthe elastic force that-clutch diaphragm spring produces; F _tathe elastic force that-clutch pedal Returnning spring produces; η ₁the transmission efficiency of-clutch operation; C _d-flow coefficient; ρ-hydraulic oil density; θ-Flow valve opening area; Q-valve flow.

According to conservation of volume asymmetric cylinder flow equation be:

$Q=\frac{\mathrm{\π}{D_1}^2}{4}\·\frac{d{l}_1}{\mathrm{dt}}---\left(12\right)$

By formula (6), (7), (8), (9), (10), (11), (12) solve respectively, can obtain clutch automatic handling system mathematical model in engaging process:

$\left\{\begin{array}{c}{l}_1=\mathrm{\Δl}+\frac{k_1}{D_2^2}(k_2{D}_3^{2}x+l_4{D}_4^2)\\ P_1=\frac{4{D_2}^2{F}_{\mathrm{sp}}}{\mathrm{\π}{k}_1{k}_2{\mathrm{\η}}_1{D_1}^2{D}_3^2}+\frac{4F_{\mathrm{ta}}}{\mathrm{\π}{k}_1{D_1}^2}\\ \frac{\mathrm{\π}{D_1}^2}{4}\·\frac{d{l}_1}{\mathrm{dt}}=\mathrm{\θ}{C}_d\sqrt{\frac{2P_1}{\mathrm{\ρ}}}\end{array}\right.---\left(13\right)$

2 clutch's jointing process SDG models are set up and model simplification

2.1SDG model related definition

Definition 1:SDG model is SDG digraph G ₀function combination wherein:

(1) digraph G ₀be made up of node and branch road, wherein node represents variable, and branch road represents the relation between variable.If the deviation of a variable directly can cause the deviation of another variable, then couple together with branch road between the node that Two Variables is corresponding, point to Outcome Variable by causal variable.Concrete composition is as shown in table 1:

Table 1 digraph G ₀composition

(2) function be made up of two-part, be respectively the sign function of node and the sign function of branch road.

The sign function of node is obtaining value method as the formula (14),

In formula (14): X _k-node n _kto the actual value of strain capacity; -node n _kto the normal value of strain capacity; ε _k-node n _kbe in the threshold value of normal state.

The sign function of branch road is "+", "-" represent that causal variable and Outcome Variable are the relations of positive correlation, negative correlation respectively.Usually with solid arrow represent positive correlation, dotted arrow represents negative correlation.

Definition 2: in SDG model, if then claim node n _kfor effective node; If this branch road is then claimed to be compatible branch road.

The correlation of SDG model and fault illustrates, fault can only along effective node and compatible propagation.

2.2 clutch's jointing process SDG models are set up

From the analysis of first portion to clutch's jointing process: under the control of drive singal, regulate clutch position and engaging speed, thus the friction torque that change clutch transmits, have adjusted the output torque that motor passes to wheel simultaneously.The control of vehicle drive system and the control of clutch operating system are unity loop control structure respectively, and control procedure and the point that may break down are as shown in Fig. 5 (a), Fig. 5 (b).

By analyzing above, and in conjunction with Heuristics, choosing the most complicated cunning of engaging process and rubbing the stage, set up SDG model as shown in Figure 6, wherein, without transmission of torque stage and synchronous phase corresponding clutch automatic handling system and vehicle drive system SDG model respectively.In Fig. 6, I-electromagnetic valve current; T-ambient temperature, t-engaging time, remaining variables is with implication is identical above.

Because model process of establishing is based on Full Vehicle Dynamics model and automatic handling system mathematical model, therefore accuracy is high.

2.3 clutch's jointing process SDG model simplifications

In practical engineering application, for the SDG model that Fig. 6 sets up, due to the restriction of measurement means, economic condition etc., some state variable is difficult to obtain, such as: solenoid valve opening degree θ etc.Therefore need to delete can not survey node according to system physical condition, simplify SDG model, simplification principle comprises according to the simplification of node measurability and simplifies two kinds of methods according to process additional information.

According to above-mentioned simplification principle, in conjunction with clutch control hardware platform measurability energy, Fig. 6 clutch is engaged SDG model simplification as shown in Figure 7.

3 based on the clutch's jointing process fault diagnosis of SDG model

3.1SDG model interior joint symbol is determined

According to the explanation to node symbol function provided in definition 1, the symbol of node be known, first will determine the normal value of node to strain capacity the threshold epsilon of normal state is in node _k.For clutch's jointing process, the main state adopting the method for movement tendency analysis to determine different node.Fig. 8 represents the relation between solenoid-operated proportional Flow valve electric current and flow, when proportional flow electromagnetic valve work electric current is less than I ₁(corresponding pwm ₁) time, now clutch engages; When electromagnetic valve work electric current is at I ₁~ I ₂(corresponding pwm ₁~ pwm ₂) time, clutch is in hold mode; When electromagnetic valve work electric current is greater than I ₂(corresponding pwm ₂) time, now clutch separation, when therefore clutch engages, I node and pwm node symbol differentiate as shown in table 2.

Table 2I node and pwm node symbol defining method

Other node also can determine its symbol according to similar approach, does not repeat one by one at this.

3.2 instance analysis

In certain preventing test, driver hangs 1 grade of starting, and gear signal is normal, and after releasing of brake, brake signal is normal, and vehicle does not move forward, and through looking into, clutch does not engage.Within the scope of 0 ~ 6.5s, each node curve is as shown in Fig. 9 (a), Fig. 9 (b), Fig. 9 (c), Fig. 9 (d), Fig. 9 (e), Fig. 9 (f).In figure, abscissa is the time, and unit is second; The measuring range of current sensor is 0 ~ 5A.

The AMT Major off road vehicle clutch's jointing process SDG fault model shown in Figure 10 (a) can be obtained according to Fig. 9 (a)-Fig. 9 (f).Remove normal node and non-conforming path, can Figure 10 (b) be obtained.

Easily know according to Figure 10 (b), cause clutch the fault branch of normal engagement can not have 3, that is:

$\left\{\begin{array}{c}I(+)\→x(+)\→{\mathrm{\ω}}_1(-)\→{\mathrm{\ω}}_r(-)\\ I(+)\→x(+)\→{\stackrel{\·}{\mathrm{\ω}}}_1(-)\\ I(+)\→x(+)\→{\mathrm{\ω}}_e(-)\end{array}\right.$

And the public part of these 3 branch roads is I (+) → x (+), according to probability statistics principle, this part possibility broken down is maximum, and from introducing SDG model, two nodes connected by a branch road, point to Outcome Variable by causal variable, the source of trouble that therefore possibility is maximum is the part relevant to circuit, namely certain section of circuit to this branch road of solenoid valve from ECU to cable breaks down, and tackles this branch road and investigates.Through looking into, failure cause is solenoid valve short circuit, and cause return opening not open, clutch engages unsuccessfully, and fault diagnosis completes.Analyzed as can be seen from above, utilize SDG model to carry out fault diagnosis to clutch, compared to conventional method, can determine guilty culprit branch road fast, efficiency significantly improves.

The beneficial effect that 3.3 technical solution of the present invention are brought

Conventional method can determine whether certain part there occurs fault fast, but the part broken down is exactly not necessarily the source of trouble, and therefore the efficiency in conventional method localizing faults source is lower.And utilize SDG model to carry out the diagnosis of clutch, carrying out transmission system and automatic handling system analyzing on the basis of also founding mathematical models, set up the SDG model of clutch, take into full account each variable affecting clutch work, and simplify some node according to physical condition and demand, utilize the data that sensor detects, judge each node symbol, compatible path is determined with this, then according to principle of probability, according to the large young pathbreaker's branch road sequence of fault possibility occurrence, first the reason node of the maximum branch road of fault possibility occurrence is investigated, this node is exactly probably source of trouble place, if not, other branch road is checked again according to above-mentioned sequence, so just substantially increase the efficiency of diagnosis.

Above-described embodiment of the present invention, does not form limiting the scope of the present invention.Any amendment done within the spirit and principles in the present invention, equivalent replacement and improvement etc., all should be included within claims of the present invention.

Claims (6)

1., based on a clutch's jointing process method for diagnosing faults for SDG model, it is characterized in that, comprise the following steps:

Step 1, clutch's jointing process analysis;

Step 2, clutch's jointing process SDG model is set up and model simplification;

Step 3, based on the clutch's jointing process fault diagnosis of SDG model;

Wherein, described step 2 specifically comprises:

Step 2.1, the setting control of vehicle drive system and the control of clutch automatic handling system are unity loop control respectively, setup control process and the point that may break down; Step 2.2, the cunning chosen in engaging process is rubbed the stage, sets up its SDG model; Step 2.3, deletes can not survey node according to system physical condition, simplifies SDG model;

Described step 3 specifically comprises:

Step 3.1, according to the normal value of node to strain capacity the threshold epsilon of normal state is in node _kdetermine the node symbol in SDG model; Step 3.2, analyzes node and directed edge, deletes normal node and non-conforming path; Step 3.3, according to probability statistics principle, determines the fault rate of compatible path successively;

Step 3.4, the root node of the compatible path of the maximum probability that breaks down is exactly the source of trouble place of maximum possible;

Step 3.5, checks whether root node related device breaks down, and if so, proceeds to step 3.6, if not, ignores this root node, proceed to the source of trouble that step 3.4 continues to find successively maximum possible; Step 3.6, determine that the device broken down is the source of trouble, flow process terminates.

2. the clutch's jointing process method for diagnosing faults based on SDG model according to claim 1, it is characterized in that, step 1 specifically comprises:

Step 1.1, drive train power Epidemiological Analysis;

Step 1.2, clutch automatic handling system mathematical modeling;

Wherein, step 1.1 and step 1.2 perform order in no particular order.

3. the clutch's jointing process method for diagnosing faults based on SDG model according to claim 2, is characterized in that, in step 1.1, the dynamics formula that engine power exports clutch active part to is:

ω _e(t)＝ω ₁(t)(2)

Clutch secondary part to the dynamics formula of driving wheel is:

In formula (1)-(4): M _ethe effective Driving Torque of-motor; M _c-clutch transmission torque; M _r-ground drag square; ω _e-engine crankshaft rotational angular velocity, i.e. clutch active part rotational angular velocity; the derivative of-engine crankshaft rotational angular velocity, i.e. engine crankshaft rotational angle acceleration; ω ₁-transmission input shaft rotational angular velocity, i.e. clutch secondary part rotational angular velocity; the derivative of-transmission input shaft rotational angular velocity, i.e. transmission input shaft rotational angle acceleration; ω _r-driving wheel rotational angular velocity; I _e-crank-connecting rod mechanism for engine and clutch active part are converted to the rotary inertia on bent axle; I _o-clutch secondary part, the car load inertia be connected with speed changer are converted to the rotary inertia on transmission input shaft; i _othe resultant gear ratio of-main reducing gear and wheel reductor; i _g-transmission ratio; The mechanical efficiency of η-power train.

4. the clutch's jointing process method for diagnosing faults based on SDG model according to claim 2, is characterized in that, in step 1.2, clutch automatic handling system mathematical model is:

In formula: l ₁-clutch control cylinder piston stroke; l ₄the stroke needed for air valve opened by-reversing piston; The clutch control cylinder free travel in Δ l-elimination separating mechanism gap; The stroke of x-clutch release bearing; k ₁-tread portion sub-transmission ratio; k ₂-release bearing lever transmission ratio; P ₁-clutch control cylinder working pressure; P ₂-hydraulic main cylinder working pressure; D ₁-clutch control cylinder rodless cavity piston diameter; D ₂-hydraulic main cylinder piston diameter; D ₃-gas power-assisted clutch release slave cylinder hydraulic part piston diameter; D ₄the hydraulic work chamber diameter of-reversing piston; F _spthe elastic force that-clutch diaphragm spring produces; F _tathe elastic force that-clutch pedal Returnning spring produces; η ₁the transmission efficiency of-clutch operation; C _d-flow coefficient; ρ-hydraulic oil density; θ-Flow valve opening area.

5. according to the clutch's jointing process method for diagnosing faults based on SDG model one of claim 1-4 Suo Shu,

It is characterized in that, described clutch is AMT heavy-duty off-road vehicle clutch.

6., for a fault diagnosis system for the clutch's jointing process method for diagnosing faults based on SDG model as claimed in claim 1, it is characterized in that, comprise with lower device:

For the device that clutch's jointing process is analyzed;

Set up and the device of model simplification for clutch's jointing process SDG model;

For carrying out the device of fault diagnosis based on the clutch's jointing process of SDG model.