CN-121993305-A - Air-fuel ratio closed-loop control method for switch oxygen sensor capable of improving multiplexing Kuang Shi capacity

CN121993305ACN 121993305 ACN121993305 ACN 121993305ACN-121993305-A

Abstract

The invention provides a closed-loop control method for an air-fuel ratio of an on-off oxygen sensor capable of improving multiplexing Kuang Shi capacity, which comprises the steps of S1 initializing working condition mark parameters of the on-off oxygen sensor, S2 obtaining air inflow of an engine, filtering the air inflow of the engine to obtain filtered air inflow, judging whether the air inflow is in a stable working condition or a dynamic working condition according to the air inflow and the filtered air inflow, outputting a working condition state mark, S3 inputting the working condition state mark into a parameter coordination module, outputting corresponding air-fuel ratio control items according to the working condition state mark by the parameter coordination module, and S4 adjusting the adjusting force of closed-loop control enrichment or lean by the on-off oxygen sensor according to the air-fuel ratio control items. The invention is based on the self-defined automatic identification algorithm of the engine operation working condition, can effectively distinguish the dynamic working condition and the steady-state working condition, and matches with the independent PI control parameter of each working condition, thereby realizing the requirements of both the quick response capability of the dynamic working condition and the low amplitude of the steady-state working condition.

Inventors

QI ZHENGGANG
PENG LUN
HE FULIN

Assignees

联合汽车电子（重庆）有限公司

Dates

Publication Date: 20260508
Application Date: 20260327

Claims (7)

1. A method for closed loop control of air-fuel ratio of a switching oxygen sensor for improving multiplexing Kuang Shi capability, comprising: s1, initializing working condition marking parameters of a switch oxygen sensor; S2, acquiring air inlet flow of an engine, filtering the air inlet flow of the engine to obtain filtered air inlet flow, judging whether the air inlet flow is in a stable working condition or a dynamic working condition according to the air inlet flow and the filtered air inlet flow, and outputting a working condition state mark; S3, inputting the working condition state mark into a parameter coordination module, and outputting a corresponding air-fuel ratio control item by the parameter coordination module according to the working condition state mark; And S4, adjusting the adjusting force of closed-loop control enrichment or lean according to the air-fuel ratio control item by the switch oxygen sensor.
2. The method for closed loop control of air-fuel ratio of a switch oxygen sensor for a lift multiplexer Kuang Shi as set forth in claim 1, wherein said condition indicating parameters include at least: Working condition state sign Working condition state sign of previous round Time of last-turn working condition timer Working condition timer time And resetting the working condition mark parameter to be: 。
3. The method for closed-loop control of air-fuel ratio of an on-off oxygen sensor for improving multiplexing Kuang Shi capacity according to claim 2, wherein said obtaining the intake air flow of the engine, filtering the intake air flow of the engine to obtain a filtered intake air flow, determining whether the engine is in a stable working condition or a dynamic working condition according to the intake air flow and the filtered intake air flow, and outputting a working condition status flag, includes: s201, acquiring air inlet flow of engine in real time ; S202, filtering the air inlet flow of the engine to obtain filtered air inlet flow ; S203, the intake air flow rate And filtering the intake air flow Taking the difference value, then taking the absolute value to output the absolute difference value, and representing as: S204, judging the absolute difference value and the first threshold value, if the absolute difference value is larger than the first threshold value, judging that Outputting the working condition state mark as a dynamic working condition, and repeatedly executing the step S201, otherwise executing the step S205; s205, further reading the working condition state mark of the previous round, judging whether the working condition is a dynamic working condition, if so, calculating the working condition timer time And judging the execution time of the working condition timer Whether the threshold value is larger than the second threshold value, if so, judging that Outputting the working condition state mark as a stable working condition, and repeatedly executing the step S201, otherwise judging that And outputting the working condition state mark as a dynamic working condition, repeating the step S201, and directly outputting the working condition state mark as a stable working condition if the working condition state mark is not judged to be the dynamic working condition, and repeating the step S201.
4. A method for closed loop control of air-fuel ratio of a switch oxygen sensor for improving multiplexing Kuang Shi capabilities as described in claim 3, wherein said if yes, calculating a duty timer time Comprises: First, calculating the working condition timer time : Wherein, the The method comprises the steps of executing a cycle for software and executing: The working condition timer time is set in the next round The time of the working condition timer of the previous round is replaced in the calculation And (5) participating in working condition timer time calculation.
5. A method of closed loop control of air-fuel ratio of a switch oxygen sensor for a capability of lifting a multiplex Kuang Shi as defined in claim 3, wherein said condition status flag is input to a parameter coordination module, said parameter coordination module outputs a corresponding air-fuel ratio control term based on said condition status flag, comprising: S301, the parameter coordination module receives the working condition state mark, when the working condition state mark is a dynamic working condition, a closed loop P item is output as a dynamic P item, a closed loop I item is a dynamic I item, and otherwise, the step S302 is executed; S302, when the working condition state mark is a stable working condition, outputting a closed loop P item to be a steady state P item, and outputting a closed loop I item to be a steady state I item.
6. A method for closed loop control of air-fuel ratio of a switch oxygen sensor for lifting multiple Kuang Shi capacities as recited in claim 3, wherein said filtered intake air flow rate Comprising: It is expressed as: Wherein, the For the previous round of filtering the intake air flow, As a result of the filter coefficients being calibratable, A cycle is executed for the software.
7. The method for closed loop control of air-fuel ratio of a switch oxygen sensor for lifting a multiplex Kuang Shi capability as defined in claim 3, wherein said first threshold and said second threshold The first threshold value is 3-6 kg/h, and the second threshold value is 2-4 s.

Description

Air-fuel ratio closed-loop control method for switch oxygen sensor capable of improving multiplexing Kuang Shi capacity Technical Field The invention relates to the technical field of air-fuel ratio of engines, in particular to a closed-loop control method for an air-fuel ratio of a switch oxygen sensor, which improves the capability of multiplexing Kuang Shi. Background In an engine air-fuel ratio control system, a switching oxygen sensor has a larger cost advantage than a wide-range oxygen sensor, and the application of the switching oxygen sensor in the market of high-order emission regulations is gradually expanded. But an EMS system for switching oxygen is adopted, the air-fuel ratio shows larger oscillation amplitude, and the achievement of acceptance indexes such as oil consumption, circulation fluctuation and the like is not facilitated. This is because it is difficult to combine the small amplitude air-fuel ratio requirement in steady-state conditions with the transient air-fuel ratio response rate requirement in dynamic conditions using a conventional single-mode closed-loop control scheme. Disclosure of Invention Aiming at the problems in the prior art, the invention provides a closed-loop control method for the air-fuel ratio of a switch oxygen sensor capable of improving the capability of multiplexing Kuang Shi, so as to solve the technical problems that the prior art adopts a traditional single-mode closed-loop control scheme, and is difficult to consider the air-fuel ratio small-amplitude requirement under a steady-state working condition and the air-fuel ratio transient response rate requirement under a dynamic working condition. The invention provides a closed-loop control method for the air-fuel ratio of a switch oxygen sensor, which improves the capability of multiplexing Kuang Shi, and comprises the following steps: s1, initializing working condition marking parameters of a switch oxygen sensor; S2, acquiring air inlet flow of an engine, filtering the air inlet flow of the engine to obtain filtered air inlet flow, judging whether the air inlet flow is in a stable working condition or a dynamic working condition according to the air inlet flow and the filtered air inlet flow, and outputting a working condition state mark; S3, inputting the working condition state mark into a parameter coordination module, and outputting a corresponding air-fuel ratio control item by the parameter coordination module according to the working condition state mark; And S4, adjusting the adjusting force of closed-loop control enrichment or lean according to the air-fuel ratio control item by the switch oxygen sensor. Optionally, the working condition sign parameter at least includes: Working condition state sign Working condition state sign of previous roundTime of last-turn working condition timerWorking condition timer timeAnd resetting the working condition mark parameter to be: 。 optionally, the obtaining the air intake flow of the engine, filtering the air intake flow of the engine to obtain a filtered air intake flow, and determining whether the air intake flow is in a stable working condition or a dynamic working condition according to the air intake flow and the filtered air intake flow, and outputting a working condition state sign, including: s201, acquiring air inlet flow of engine in real time ; S202, filtering the air inlet flow of the engine to obtain filtered air inlet flow; S203, the intake air flow rateAnd filtering the intake air flowTaking the difference value, then taking the absolute value to output the absolute difference value, and representing as: S204, judging the absolute difference value and the first threshold value, if the absolute difference value is larger than the first threshold value, judging that Outputting the working condition state mark as a dynamic working condition, and repeatedly executing the step S201, otherwise executing the step S205; s205, further reading the working condition state mark of the previous round, judging whether the working condition is a dynamic working condition, if so, calculating the working condition timer time And judging the execution time of the working condition timerWhether the threshold value is larger than the second threshold value, if so, judging thatOutputting the working condition state mark as a stable working condition, and repeatedly executing the step S201, otherwise judging thatAnd outputting the working condition state mark as a dynamic working condition, repeating the step S201, and directly outputting the working condition state mark as a stable working condition if the working condition state mark is not judged to be the dynamic working condition, and repeating the step S201. Optionally, if yes, calculating the working condition timer timeComprises: First, calculating the working condition timer time For software execution period and time of working condition timer in next roundTime of working condition timer replaced by last