CN203257549U

CN203257549U - Lean burn gasoline engine constant torque self-learning control system provided with NOx absorption reduction catalytic converter

Info

Publication number: CN203257549U
Application number: CN 201320215799
Authority: CN
Inventors: 岳东鹏; 李志军; 刘磊; 陈韶舒; 石传龙
Original assignee: Tianjin University of Technology
Current assignee: Tianjin University of Technology
Priority date: 2013-04-25
Filing date: 2013-04-25
Publication date: 2013-10-30
Anticipated expiration: 2023-04-25

Abstract

The utility model relates to an internal combustion engine lean burn tail gas control technology, in particular to a lean burn gasoline engine constant torque self-learning control system provided with a NOx absorption reduction catalytic converter. The lean burn gasoline engine constant torque self-learning control system comprises an ECU main controller, an engine rotating speed monitoring module, an engine torque monitoring module, an original machine thick burn MAP storage unit, an original machine lean burn MAP storage unit, an auxiliary thick burn MAP storage unit and an auxiliary lean burn MAP storage unit. The original machine lean burn MAP storage unit 5 and the auxiliary lean burn MAP storage unit 7 are connected with the ECU main controller 1 in a double-direction mode. The lean burn gasoline engine constant torque self-learning control system has the advantages that compared with the prior art, through dynamic adjustment of a MAP, optimal adjustment of throttle percentage and a spark advance angle is achieved.

Description

The permanent moment of torsion automatic learning control system of gasoline engine of being furnished with NOx absorbing and reducing catalytic converter

Technical field

The utility model relates to internal-combustion engine Rarefied combustion tail gas control technique, relates to particularly a kind of gasoline engine periodicity alternate run of being furnished with NOx absorbing and reducing catalytic converter of realizing and keep output speed and the constant control system of moment of torsion when lean-burn working state and dense combustion working state.

Background technique

The petrol engine lean burn technology can improve the fuel economy of petrol engine effectively, and the discharging of reduction HC, CO, yet because the tail gas that motor is discharged is in the atmosphere of oxygen content surplus, so that traditional triple effect catalytic converter TWC lost efficacy, can't under oxygen-enriched environment, efficiently remove NOx.This just needs to adopt the exhaust aftertreatment technology to reduce a large amount of NOx dischargings that produce under the lean burn conditions.NOx absorbing and reducing catalytic converter LNT(Lean-NOx-Trap) can effectively reduce the discharging of gasoline engine NOx.Gasoline engine is when adopting NOx absorbing and reducing catalyzed conversion preprocessor LNT work, its periodically alternation in lean-burn working state (NOx adsorptive process) and dense combustion working state (NOx reduction process) so that finish LNT in achieving lean combustion in engine state NOx adsorption and dense combustion state reducing NOx emissions thing process.If merely keep throttle opening constant, only keep certain mixer concentration by fuel injection amount, will inevitably make the external output torque of petrol engine produce larger fluctuation, cause the larger variation of engine speed, so that the driveability deterioration of vehicle.Therefore need a kind of gasoline engine that can keep when dense rare conversion, substantially to keep external output speed and the constant control system of moment of torsion.

Summary of the invention

The purpose of this utility model is in air-fuel ratio, dense combustion step change procedure, guarantees the automatic learning control system of petrol engine rotational speed and moment of torsion constant output.

The permanent moment of torsion automatic learning control system of gasoline engine of being furnished with NOx absorbing and reducing catalytic converter, definition: the MAP figure of rotating speed, moment of torsion and throttle opening is former machine MAP figure during different air fuel ratio A/F, and machine MAP figure in its Central Plains can be divided into again the dense combustion of former machine MAP figure and former machine lean-burn MAP figure; Under different air fuel ratio A/F and the different ignition advance angle condition take the MAP figure of rotating speed, moment of torsion and throttle opening for auxiliary MAP figure, wherein auxiliary MAP figure can be divided into again auxiliary dense combustion MAP and schemes and assist lean-burn MAP to scheme; Comprise:

ECU master controller 1, the engine speed monitoring modular 2 that links to each other with the ECU master controller respectively, Engine torque monitoring modular 3, former machine MAP figure storage unit 9, auxiliary MAP figure storage unit 10;

Described former machine MAP figure storage unit comprises: the dense combustion of former machine MAP figure storage unit 4, former machine lean-burn MAP figure storage unit 5;

Described auxiliary MAP figure storage unit comprises: auxiliary dense combustion MAP figure storage unit 6, auxiliary lean-burn MAP figure storage unit 7;

It is two-way the connection between described former machine lean-burn MAP figure storage unit 5, auxiliary lean-burn MAP figure storage unit 7 and the ECU master controller 1, according to engine speed is poor former machine lean-burn MAP figure storage unit and auxiliary lean-burn MAP figure storage unit are dynamically adjusted, kept optimal data.

The utility model is with respect to the advantage of prior art: by the dynamic adjustment of MAP figure, realize the optimal adjustment of throttle opening and ignition advance angle, when having realized that dense, phase process is switched, moment of torsion and rotating speed are controlled in driver's acceptable scope; Both guarantee the processing of LNT to NOx, also guaranteed driver or motroist's travelling comfort.

Description of drawings

Fig. 1 is the utility model system authority schematic representation.Among the figure, 1 represents the ECU master controller, 2 represent the engine speed monitoring modular, and 3 represent the Engine torque monitoring modular, the dense combustion of the 4 former machines of representative MAP figure storage unit, the former machine lean-burn MAP figure storage unit of 5 representatives, the auxiliary dense combustion MAP figure storage unit of 6 representatives, the auxiliary lean-burn MAP figure storage unit of 7 representatives, 8 represent motor, the former machine MAP figure storage unit of 9 representatives, the auxiliary MAP figure storage unit of 10 representatives.

The automatically controlled gasoline engine of CA3GA2 of transforming among Fig. 2 embodiment 1 air fuel ratio A/F be under 12 o'clock each throttle openings moment of torsion with the change curve of rotating speed.

Fig. 3 is that the automatically controlled gasoline engine of CA3GA2 of transforming among the embodiment 1 is 20 o'clock at air fuel ratio A/F, and moment of torsion is with the change curve of rotating speed under each throttle opening that obtains by self study.

Embodiment

In conjunction with Fig. 1-3 explanation specific implementation of the present utility model.

Be furnished with the permanent moment of torsion automatic learning control system of gasoline engine of NOx absorbing and reducing catalytic converter, comprise:

Described auxiliary MAP figure storage unit comprises: auxiliary dense combustion MAP figure storage unit 6, auxiliary lean-burn MAP figure storage unit 7.

Control procedure is as follows:

In the periodic step change procedure of engine air-fuel ratio, engine speed monitoring module monitors engine speed changes, Engine torque monitoring module monitors moment of torsion exporting change; The ECU master controller at first calls the MAP figure adjusting joint valve opening in the former machine MAP figure storage unit, until the fluctuation absolute value of rotating speed is less than the particular value Q of certain setting, and the torque ripple absolute value is during less than the particular value P of certain setting, and this process is the coarse adjustment process;

Identical before if above-mentioned adjusting can not realize moment of torsion output and switch, the ECU master controller calls the MAP figure operation in the auxiliary MAP figure storage unit, until make the moment of torsion output after switching between rare, dense combustion or dense, the lean-burn before identical with switching; This process is the thin tuning process.

Described former machine MAP figure, auxiliary MAP figure is in the dynamic adjustment process, when dense combustion regenerative process, record the deviation of this process medium speed, with this deviation as input quantity, when motor moves with the lean-burn adsorptive process, when calculating next regenerative process by certain algorithm to the reduction value of air fuel ratio throttle opening and ignition timing, and write down the reduction value of each generation and the deviation of each regenerative process rotating speed, each deviation is compared, and with the rotating speed deviation in qualified wave range the time each corresponding reduction value scheme as former machine lean-burn MAP, the increment graph of auxiliary lean-burn MAP figure stores, the corresponding reduction value of undesirable deviation is rejected, and rule constantly moves in circles according to this.

ECU produces the increment graph of former machine lean-burn MAP figure, an auxiliary lean-burn MAP figure by self study in the engine operation process, and the analysis of the increment MAP figure upper-position unit when shutting down is finished to determine whether former machine lean-burn MAP figure, auxiliary lean-burn MAP figure are made amendment.

In the present embodiment: select the automatically controlled gasoline engine of CA3GA2 of transformation, dense combustion air fuel ratio A/F is 12, and lean-burn air fuel ratio A/F is 20; Q=50rpm; P=5N.m, adopting pid algorithm is the basis, uses for reference the principle of fuzzy control and neuron network, finds gradually optimum algorithm in the process of test.

Claims

1. the permanent moment of torsion automatic learning control system of gasoline engine of being furnished with NOx absorbing and reducing catalytic converter, definition: the MAP figure of rotating speed, moment of torsion and throttle opening is former machine MAP figure during different air fuel ratio A/F, and machine MAP figure in its Central Plains can be divided into again the dense combustion of former machine MAP figure and former machine lean-burn MAP figure; Under different air fuel ratio A/F and the different ignition advance angle condition take the MAP figure of rotating speed, moment of torsion and throttle opening for auxiliary MAP figure, wherein auxiliary MAP figure can be divided into again auxiliary dense combustion MAP and schemes and assist lean-burn MAP to scheme; It is characterized in that, comprising:

ECU master controller (1), the engine speed monitoring modular (2) that links to each other with the ECU master controller respectively, Engine torque monitoring modular (3), former machine MAP figure storage unit (9), auxiliary MAP figure storage unit (10);

Described former machine MAP figure storage unit comprises: the dense combustion of former machine MAP figure storage unit (4), former machine lean-burn MAP figure storage unit (5);

Described auxiliary MAP figure storage unit comprises: auxiliary dense combustion MAP figure storage unit (6), auxiliary lean-burn MAP figure storage unit (7);

It is two-way the connection between described former machine lean-burn MAP figure storage unit, auxiliary lean-burn MAP figure storage unit and the ECU master controller, according to engine speed is poor former machine lean-burn MAP figure storage unit and auxiliary lean-burn MAP figure storage unit are dynamically adjusted, kept optimal data.