阅读说明：本技术 柴油机自适应式进气压力系统诊断方法及装置 (Self-adaptive type air inlet pressure system diagnosis method and device for diesel engine ) 是由 杜鑫 胡佳富 尤险峰 于 2020-04-24 设计创作，主要内容包括：本发明涉及一种柴油机自适应式进气压力系统诊断方法及装置,涉及发动机技术领域,用于降低进气节流阀的差异对进气压力系统诊断的影响,从而提升车辆运行的可靠性。本发明的柴油机自适应式进气压力系统诊断方法及装置,通过自适应式进气压力计算模块的调整和更新,以确保循环内进气压力测量值P-(测量)与自适应式进气压力计算模块计算所获得的计算输出值P-(计算)之差的绝对值的总和最小,因此本发明的自适应的进气压力计算模型是在考虑了发动机零部件(主要是进气节流阀)个体差异的基础上,对每台发动机,在不影响其性能及排放的前提下,找到适应与每台发动机个体的自适应式进气压力计算模型,从而使进气压力系统诊断的可靠性更高。(The invention relates to a method and a device for diagnosing a self-adaptive intake pressure system of a diesel engine, relating to the technical field of engines and being used for reducing the influence of the difference of an intake throttle valve on the diagnosis of the intake pressure system so as to improve the running reliability of a vehicle. The invention relates to a method and a device for diagnosing a self-adaptive intake pressure system of a diesel engine, which ensure a measured value P of the intake pressure in circulation by adjusting and updating a self-adaptive intake pressure calculation module Measuring The calculated output value P obtained by calculation with the self-adaptive intake pressure calculating module Computing The sum of the absolute values of the differences is minimal, so the adaptive intake pressure calculation model of the present invention is based on consideration of engine components (mainlyIs an air inlet throttle valve) on the basis of individual difference, an adaptive air inlet pressure calculation model which is adaptive to each engine individual is found for each engine on the premise of not influencing the performance and emission of each engine, so that the reliability of diagnosis of an air inlet pressure system is higher.)

1. A method for diagnosing an adaptive intake pressure system for a diesel engine, comprising:

s10: judging whether the operation condition of the engine meets the calculation requirement of the self-adaptive intake pressure system, if so, executing step S20;

s20: from the measurement P of the pressure of the inlet air in the cycle_MeasuringCalculating output value P of self-adaptive air inlet pressure calculating module_ComputingChecking to make | P_Computing-P_MeasuringThe sum of | is minimum, so that the self-adaptive intake pressure calculation module is self-adaptively adjusted;

s30: and operating the adjusted self-adaptive intake pressure calculation module, judging whether the performance and the emission index of the engine meet the requirements, and if so, diagnosing by the self-adaptive intake pressure system according to the adjusted intake pressure calculation module.

2. The diesel engine adaptive intake pressure system diagnostic method as set forth in claim 1, wherein the step S20 includes the substeps of:

s21: obtaining feed-forward input value P of intake pressure module through initial intake pressure calculation module_{Feed forward}；

S22: the self-adaptive intake pressure calculation module feeds forward an input value P according to the intake pressure module_{Feed forward}And a measurement value P of the pressure of the intake air in the cycle_MeasuringCalculating output value P of self-adaptive air inlet pressure calculating module_ComputingPerforming frequency-by-frequency iteration to make | P_Computing-P_MeasuringThe sum of | is minimum, so that the adaptive intake pressure calculation module is adaptively adjusted.

3. The diesel engine adaptive intake pressure system diagnostic method according to claim 1 or 2, wherein in step S20, the measured value P of the intake pressure in the cycle is_MeasuringMeasured by an intake manifold pressure sensor.

4. The method for diagnosing an adaptive intake air pressure system for a diesel engine according to claim 1 or 2, wherein the initial intake air pressure calculating module obtains the feed forward input value P of the intake air pressure module according to the operation condition of the engine in step S21_{Feed forward}。

5. The method of diagnosing an adaptive intake air pressure system for a diesel engine according to claim 1 or 2, wherein the operation condition of the engine is obtained by the engine intake system module and the engine operation condition module in step S10.

6. The method for diagnosing the adaptive intake air pressure system of the diesel engine as claimed in claim 5, wherein the operation conditions of the engine include an engine speed, an engine indicated torque, a compressor inlet air temperature, a compressor inlet air pressure, a compressor outlet air temperature, a compressor outlet air pressure, an intake throttle position, an ambient temperature, an ambient pressure, a vehicle operation speed and an engine operation time in step S10.

7. The diagnostic device for the self-adaptive intake pressure system of the diesel engine is characterized by comprising a self-adaptive intake pressure system, wherein the self-adaptive intake pressure system comprises a self-adaptive intake pressure calculating module; when the operation condition of the engine meets the calculation requirement of the self-adaptive intake pressure system, the self-adaptive intake pressure calculation module calculates the intake pressure according to the intake pressure measured value P in the cycle_MeasuringCalculating output value P of self-adaptive air inlet pressure calculating module_ComputingChecking to make | P_Computing-P_MeasuringThe sum of | is minimum, so that the self-adaptive intake pressure calculation module is self-adaptively adjusted; and if the performance and the emission index of the engine meet the requirements by operating the adjusted self-adaptive intake pressure computing module, the self-adaptive intake pressure system diagnoses according to the adjusted intake pressure computing module.

8. The diagnostic apparatus for an adaptive intake air pressure system for a diesel engine as set forth in claim 7 wherein the adaptive intake air pressure calculation module calculates the feed forward input value P based on the intake air pressure module_{Feed forward}And a measurement value P of the pressure of the intake air in the cycle_MeasuringTo self-adaptive intake pressure calculation modelCalculated output value P of block_ComputingPerforming frequency-by-frequency iteration to make | P_Computing-P_MeasuringThe sum of | is minimum, so that the adaptive intake pressure calculation module is adaptively adjusted.

9. The diesel engine adaptive intake pressure system diagnostic device according to claim 7 or 8, characterized in that the intake pressure module feedforward input value P_{Feed forward}The measured value P of the air inlet pressure in the cycle is obtained by an initial air inlet pressure calculating module according to the running working condition of the engine_MeasuringMeasured by an intake manifold pressure sensor.

10. The diesel engine adaptive intake air pressure system diagnostic device according to claim 7 or 8, wherein the operating conditions of the engine include engine speed, engine indicated torque, compressor inlet intake air temperature, compressor inlet intake air pressure, compressor outlet intake air temperature, compressor outlet intake air pressure, intake throttle position, ambient temperature, ambient pressure, vehicle operating speed, and engine operating time.

Technical Field

The invention relates to the technical field of engines, in particular to a method and a device for diagnosing a self-adaptive intake pressure system of a diesel engine.

Background

With the development of social economy, the national degree of attention on environmental protection is higher and higher, and the products of the national six have been continuously logged in the market according to different regional requirements.

A more serious test is that the six products In China must meet the OBD real-time monitoring capability, and the introduction of the IUPR (In-Use Performance Ratio) presents an unprecedented challenge to the vehicle diagnosis system, wherein the intake pressure system must report the IUPR In real time. The intake pressure system diagnosis needs to compare the intake pressure estimation value with the intake pressure sensor measurement value under the specified diagnosis condition, and when the sum of the absolute values of the difference values reaches or exceeds the specified limit value in a certain time, the trip computer reports the fault code of the intake pressure system. Because the air inlet throttle valve is crucial to the pressure influence of the air inlet system, when the difference of the air inlet throttle valve is large, the diagnosis output of the pressure of the air inlet system can be directly influenced, and fault codes are frequently exposed by a traveling computer, so that the running reliability of a vehicle can be reduced.

Disclosure of Invention

The invention provides a method and a device for diagnosing a self-adaptive intake pressure system of a diesel engine, which are used for reducing the influence of the difference of an intake throttle valve on the diagnosis of the intake pressure system so as to improve the running reliability of a vehicle.

According to a first aspect of the present invention, there is provided a method for diagnosing an adaptive intake pressure system of a diesel engine, comprising:

s10: judging whether the operation condition of the engine meets the calculation requirement of the self-adaptive intake pressure system, if so, executing step S20;

s20: from the measurement P of the pressure of the inlet air in the cycle_MeasuringCalculating output value P of self-adaptive air inlet pressure calculating module_ComputingChecking to make | P_Computing-P_MeasuringOfThe sum is minimum, so that the self-adaptive intake pressure calculation module is self-adaptively adjusted;

s30: and operating the adjusted self-adaptive intake pressure calculation module, judging whether the performance and the emission index of the engine meet the requirements, and if so, diagnosing by the self-adaptive intake pressure system according to the adjusted intake pressure calculation module.

In one embodiment, step S20 includes the following sub-steps:

s21: obtaining feed-forward input value P of intake pressure module through initial intake pressure calculation module_{Feed forward}；

S22: the self-adaptive intake pressure calculation module feeds forward an input value P according to the intake pressure module_{Feed forward}And a measurement value P of the pressure of the intake air in the cycle_MeasuringCalculating output value P of self-adaptive air inlet pressure calculating module_ComputingPerforming frequency-by-frequency iteration to make | P_Computing-P_MeasuringThe sum of | is minimum, so that the adaptive intake pressure calculation module is adaptively adjusted.

In one embodiment, in step S20, the intake pressure measurement P is taken during the cycle_MeasuringMeasured by an intake manifold pressure sensor.

In one embodiment, in step S21, the initial intake pressure calculation module obtains the feed forward input value P of the intake pressure module based on the operating condition of the engine_{Feed forward}。

In one embodiment, the operating conditions of the engine are obtained by the engine air intake system module and the engine operating condition module in step S10.

In one embodiment, the operating conditions of the engine include engine speed, engine indicated torque, compressor inlet air inlet temperature, compressor inlet air inlet pressure, compressor outlet air inlet temperature, compressor outlet air inlet pressure, air inlet throttle position, ambient temperature, ambient pressure, vehicle operating speed, and engine operating time in step S10.

According to a second aspect of the present invention, there is provided a diagnostic device for an adaptive intake pressure system of a diesel engine, comprising an adaptive filterThe adaptive intake pressure system comprises an adaptive intake pressure calculating module; when the operation condition of the engine meets the calculation requirement of the self-adaptive intake pressure system, the self-adaptive intake pressure calculation module calculates the intake pressure according to the intake pressure measured value P in the cycle_MeasuringCalculating output value P of self-adaptive air inlet pressure calculating module_ComputingChecking to make | P_Computing-P_MeasuringThe sum of | is minimum, so that the self-adaptive intake pressure calculation module is self-adaptively adjusted; and if the performance and the emission index of the engine meet the requirements by operating the adjusted self-adaptive intake pressure computing module, the self-adaptive intake pressure system diagnoses according to the adjusted intake pressure computing module.

In one embodiment, the adaptive intake pressure calculation module calculates the feed forward input value P based on the intake pressure module_{Feed forward}And a measurement value P of the pressure of the intake air in the cycle_MeasuringCalculating output value P of self-adaptive air inlet pressure calculating module_ComputingPerforming frequency-by-frequency iteration to make | P_Computing-P_MeasuringThe sum of | is minimum, so that the self-adaptive intake pressure calculation module is self-adaptively adjusted;

in one embodiment, the intake pressure module feedforward input value P_{Feed forward}The measured value P of the air inlet pressure in the cycle is obtained by an initial air inlet pressure calculating module according to the running working condition of the engine_MeasuringMeasured by an intake manifold pressure sensor.

In one embodiment, the operating conditions of the engine include engine speed, engine indicated torque, compressor inlet air temperature, compressor inlet air pressure, compressor outlet air temperature, compressor outlet air pressure, inlet throttle position, ambient temperature, ambient pressure, vehicle operating speed, and engine operating time.

Compared with the prior art, the invention has the advantages that: through adjustment and update of the adaptive intake pressure calculation module, the measured value P of the intake pressure in the cycle is ensured_MeasuringCalculated output obtained by calculation with adaptive intake pressure calculation moduleValue P_ComputingThe sum of absolute values of the differences is minimum, so that the self-adaptive intake pressure calculation model of the invention is a self-adaptive intake pressure calculation model which is adaptive to each engine on the premise of not influencing the performance and emission of each engine on the basis of considering the individual difference of engine parts (mainly an intake throttle valve), thereby ensuring higher reliability of the diagnosis of the intake pressure system.

Drawings

The invention will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings.

FIG. 1 is a flow chart of a method for diagnosing an adaptive intake pressure system for a diesel engine according to an embodiment of the present invention;

FIGS. 2 and 3 illustrate the operation of the adaptive intake pressure system diagnostic method for a diesel engine according to an embodiment of the present invention;

fig. 4 is a schematic view illustrating the installation of the adaptive nox control apparatus for a diesel engine according to the embodiment of the present invention.

Reference numerals:

1-intake throttle valve (IAT); 2-Exhaust Throttle Valve (ETV); 3-an intake manifold; 4-an engine; 5-intake manifold temperature sensor; 6-intake manifold pressure sensor; 7-an exhaust manifold; 8-a traveling computer (ECU), 9-a post-processing system; 10-aftertreatment inlet nox sensor; 11-aftertreatment inlet temperature sensor; 12-particulate trap (DPF) inlet temperature sensor; 13-Selective Catalytic Reduction (SCR) inlet temperature sensing, 14-tailpipe nitrogen oxide sensor.

Detailed Description

The invention will be further explained with reference to the drawings.

1-3, the present invention provides a method for diagnosing an adaptive intake pressure system for a diesel engine, comprising the following steps.

Firstly, obtaining the operation condition of the engine. The running working condition of the engine is obtained by an engine air inlet system module and an engine running working condition module in a running computer.

The operation conditions of the engine comprise engine speed, engine indicated torque, compressor inlet air inlet temperature, compressor inlet air inlet pressure, compressor outlet air inlet temperature, compressor outlet air inlet pressure, air inlet throttle position, ambient temperature, ambient pressure, vehicle operation speed and engine operation time.

And secondly, judging whether the operating condition of the engine meets the calculation requirement of the engine by the self-adaptive air inlet pressure system, and if so, adaptively adjusting the self-adaptive air inlet pressure calculation module.

The calculation requirement of the adaptive intake pressure system may be a preset parameter range, and if the parameter falls into the preset parameter range, that is, the accumulated operating condition meets the calculation requirement, the adaptive intake pressure calculation module will aim at the intake pressure measurement value P in the cycle_MeasuringAnd the calculation output value P of the self-adaptive intake pressure calculation module_ComputingAnd (6) checking.

And thirdly, adaptively adjusting the adaptive intake pressure calculation module. From the measurement P of the pressure of the inlet air in the cycle_MeasuringCalculating output value P of self-adaptive air inlet pressure calculating module_ComputingChecking to make | P_Computing-P_MeasuringThe sum of | is minimal, i.e. P_MeasuringAnd P_ComputingThe sum of the absolute values of the differences is minimized, thereby adaptively adjusting the adaptive intake pressure calculation module.

Specifically, firstly, the feed-forward input value P of the intake pressure module is obtained by the initial intake pressure calculation module according to the running condition of the engine_{Feed forward}. Secondly, the self-adaptive intake pressure calculation module feeds forward an input value P according to the intake pressure module_{Feed forward}And a measurement value P of the pressure of the intake air in the cycle_MeasuringCalculating output value P of self-adaptive air inlet pressure calculating module_ComputingPerforming frequency-by-frequency iteration to make | P_Computing-P_MeasuringThe sum of | is minimum, so that the adaptive intake pressure calculation module is adaptively adjusted, and the operation speed of the adaptive intake pressure calculation module can be increased.

In other words, the adaptive intake pressure calculation module is to be used initiallyOutput value of initial intake pressure calculation module (i.e. feed-forward input value P of intake pressure module)_{Feed forward}) And the measured value P of the air inlet pressure sensor in the circulation_MeasuringAnd performing comparative analysis to correct the original intake pressure module so as to obtain the adjusted self-adaptive intake pressure calculation module.

Wherein the measurement value P of the pressure of the intake air in the cycle_MeasuringMeasured by an intake manifold pressure sensor.

Thus, the above-described cyclic intake pressure measurement P_MeasuringIs a measurement value obtained by measuring a plurality of times over a certain period of time. Similarly, the calculation output value P of the adaptive intake pressure calculation module_ComputingIs obtained by iterating for many times in a certain time.

As shown in fig. 2, the adaptive intake pressure calculation module collects intake system parameters and engine operating condition parameters of the engine through the adaptive engine intake module and the adaptive engine operating condition module during calculation.

And fourthly, loading the adjusted self-adaptive air inlet pressure calculation module into a traveling crane computer for operation. And monitoring the performance and emission index of the engine, judging whether the performance and emission index meet the requirements, if so, solidifying the adjusted self-adaptive intake pressure calculation module to a traveling computer, and diagnosing the self-adaptive intake pressure system according to the adjusted intake pressure calculation module. The calculated output value P obtained by the adjusted self-adaptive air inlet pressure calculating module_ComputingWith a measurement P of the pressure of the inlet air in the cycle_MeasuringThe sum of the differences is minimum and is far smaller than a specified limit value, so that the fault diagnosis code reporting frequency caused by the difference of the air intake throttle valves can be reduced, and the aim of improving the running reliability of the vehicle and the engine is fulfilled.

Therefore, according to the invention, aiming at engines of different application types, according to the operation conditions of the engine collected by a traveling computer, when the accumulated operation conditions meet the calculation requirements, the self-adaptive system can carry out comparative analysis on the output value of the initial air inlet pressure model and the measured value of the air inlet pressure sensor, and corrects the original air inlet pressure module through the self-adaptive air inlet pressure calculation module, so that the influence of the difference of the air inlet throttle valve on the diagnosis of the air inlet pressure system can be effectively reduced on the premise of ensuring that the engine meets performance and emission indexes, and the reliability of the fault diagnosis of the air inlet pressure system and the effective operation of a vehicle is further improved.

Furthermore, as the running mileage of the vehicle increases, the performance of the engine changes to a certain extent, so the invention can realize the adjustment and update of the adaptive intake pressure calculation module in the whole life cycle of the engine, namely, when the running working condition of the engine meets the calculation requirement of the adaptive intake pressure system, the vehicle computer can activate the adaptive intake pressure calculation module to perform the calculation function, so as to adjust and update the adaptive intake pressure calculation module according to the current working condition of the engine, ensure that the engine is in the emission quality guarantee period or even in the whole life cycle, effectively reduce the frequency of the pressure fault diagnosis code reporting of the intake system on the premise that the performance and the emission of the engine meet the requirement, and improve the reliability of the effective running of the vehicle.

According to a second aspect of the invention, the invention provides a diagnostic device for an adaptive intake pressure system of a diesel engine, which is used for carrying out diagnosis by the method, and comprises the adaptive intake pressure system, wherein the adaptive intake pressure system comprises an adaptive intake pressure calculating module; when the operation condition of the engine meets the calculation requirement of the self-adaptive intake pressure system, the self-adaptive intake pressure calculation module calculates the intake pressure according to the intake pressure measured value P in the cycle_MeasuringCalculating output value P of self-adaptive air inlet pressure calculating module_ComputingChecking to make | P_Computing-P_MeasuringThe sum of | is minimum, so that the self-adaptive intake pressure calculation module is self-adaptively adjusted; and if the performance and the emission index of the engine meet the requirements by operating the adjusted self-adaptive intake pressure computing module, the self-adaptive intake pressure system diagnoses according to the adjusted intake pressure computing module.

The self-adaptive intake pressure calculation module feeds forward an input value P according to the intake pressure module_{Feed forward}And a measurement value P of the pressure of the intake air in the cycle_MeasuringCalculating output value P of self-adaptive air inlet pressure calculating module_ComputingPerforming frequency-by-frequency iteration to make | P_Computing-P_MeasuringThe sum of | is minimum, so that the self-adaptive intake pressure calculation module is self-adaptively adjusted;

feed-forward input value P of intake pressure module_{Feed forward}The measured value P of the air inlet pressure in the cycle is obtained by an initial air inlet pressure calculating module according to the running working condition of the engine_MeasuringMeasured by an intake manifold pressure sensor.

The operation conditions of the engine comprise engine speed, engine indicated torque, compressor inlet air inlet temperature, compressor inlet air inlet pressure, compressor outlet air inlet temperature, compressor outlet air inlet pressure, air inlet throttle position, ambient temperature, ambient pressure, vehicle operation speed and engine operation time.

Fig. 4 is a schematic view showing the installation of the adaptive nox control apparatus for a diesel engine according to the present invention. The engine 4 is connected with the intake manifold 3 and the exhaust manifold 7 respectively, and the intake manifold 3 is provided with an intake manifold temperature sensor 5 for acquiring intake temperature and an intake manifold pressure sensor 6 for acquiring intake pressure. An intake throttle valve (IAT)1 and an Exhaust Throttle Valve (ETV)2 are provided at the front end of the intake manifold 3 and the rear end of the exhaust manifold 7, respectively.

The post-processing unit 9 is disposed on the exhaust pipe, and is connected to a traveling computer (ECU) 8. The aftertreatment unit includes a catalytic oxidation (DOC) treatment unit, a particulate trap (DPF), a selective catalytic reduction treatment unit (SCR), and an Ammonia Slip Catalyst (ASC). Specifically, sensors such as aftertreatment inlet nox sensor 10, aftertreatment inlet temperature sensor 11, diesel particulate trap (DPF) inlet temperature sensor 12, Selective Catalytic Reduction (SCR) inlet temperature sensor 13, and tailpipe nox sensor 14 may be provided. The specific structure and implementation of the post-processing unit 9 may refer to a post-processing unit in the prior art, and the present invention is not described in detail herein.

The traveling crane computer 8 receives a certain circulation collected by the intake manifold pressure sensor 8Internal intake pressure measurement P_MeasuringThe cycle includes operating time fractions for different operating conditions.

In summary, the invention uses the initial intake pressure calculation module to obtain the feed-forward input value P of the intake pressure module_{Feed forward}As feed-forward input, by comparing the measured value of the in-cycle ratio intake pressure P_MeasuringThe calculated output value P obtained by calculation with the self-adaptive intake pressure calculating module_ComputingAdjusting the adaptive intake pressure calculation module to ensure the measurement value P of intake pressure in the cycle_MeasuringThe calculated output value P obtained by calculation with the self-adaptive intake pressure calculating module_ComputingThe sum of the absolute values of the differences is minimized, and the adaptive intake pressure calculation model is adjusted and updated accordingly. In the process, the engine performance and the emission are required to be ensured to meet the requirements under the condition of an air inlet closed loop.

And the adjusted updated adaptive intake pressure calculation model will be used for subsequent intake pressure calculation and diagnosis. Therefore, the self-adaptive intake pressure calculation model of the invention is a self-adaptive intake pressure calculation model which is suitable for each engine on the premise of not influencing the performance and emission of each engine on the basis of considering the individual difference of engine parts (mainly an intake throttle valve), thereby ensuring higher reliability of the diagnosis of the intake pressure system.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.