Control method for cold start of engine
By obtaining the operating parameters of the battery and selecting appropriate cold start control parameters, the problem of abnormal injector driving waveform when the engine starts at low temperature is solved, and the normal start-up and adaptability of the engine under low temperature conditions is achieved.
Patent Information
- Application Number
- CN202411381582.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2024-12-27
AI Technical Summary
When the engine starts under low temperature conditions, the battery voltage is low, resulting in abnormal driving waveform of the fuel injector, affecting the duration of fuel injection, and may lead to the problem of injecting fuel.
By obtaining the operating parameters of the battery, determine whether it is in cold start mode, and select the calibrated cold start control parameters based on the intake air temperature and voltage threshold, including Bst current, Hd current, Pk current, boost pulse width and peak pulse width, to ensure spraying The oiler works normally.
Ensure normal fuel injection of the engine fuel injector under low temperature conditions, improve the engine's adaptability to ambient temperature and battery voltage, and ensure that the engine can start normally.
Smart Images
Figure CN119195920A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to engine control technology, and more particularly to a control method for cold starting of an engine. Background Art
[0002] At present, no matter what environment the engine is started in, its injector is only controlled by one driving current and pulse width. However, when the engine is at low temperature, the battery discharges quickly, the storage capacity decreases, and the voltage is low. At the moment of engine starting, the battery voltage will be pulled down even lower. Due to the abnormal waveform of the injector drive under low voltage, the injector drive current will be deformed and the pulse width will be reduced, which will eventually cause the injection duration to be too short to support the normal injection of the injector, affecting the normal injection of the injector, and even causing the injection failure. Summary of the invention
[0003] The technical problem to be solved by the present invention is to provide a control method for cold starting of an engine in view of the deficiencies in the prior art, thereby ensuring that the engine can be started at a low temperature.
[0004] The control method for cold start of an engine described in the present invention is characterized in that the working parameters of a battery are obtained, and whether the battery is in a cold start working mode is determined according to the working parameters. If so, the injector is controlled to spray fuel with the calibrated cold start control parameters; otherwise, the injector is controlled to spray fuel with the original start control parameters.
[0005] As a further improvement, the operating parameters of the battery include battery voltage and intake air temperature.
[0006] Furthermore, when the intake air temperature is lower than a set temperature threshold, the injector is controlled to spray fuel with a calibrated cold start control parameter 1, and the calibrated cold start control parameter 1 includes: Bst current calibration value during cold start, Hd current calibration value during cold start, Pk current calibration value during cold start, boost pulse width during cold start, and peak pulse width during cold start.
[0007] Furthermore, when the battery voltage is less than a set voltage threshold, the injector is controlled to spray fuel using a calibrated cold start control parameter 2, and the calibrated cold start control parameter 2 includes: boost pulse width when the battery voltage is too low, peak pulse width when the battery voltage is too low, Bst current calibration value when the battery voltage is too low, Hd current calibration value when the battery voltage is too low, and Pk current calibration value when the battery voltage is too low.
[0008] Furthermore, when the intake air temperature is lower than a set temperature threshold and the battery voltage is lower than a set voltage threshold, weight analysis is performed on the intake air temperature and the battery voltage respectively, and a calibrated cold start control parameter is selected according to the weight analysis result.
[0009] Furthermore, the weight analysis is specifically as follows: taking the ratio of the difference between the temperature threshold and the intake temperature to the temperature threshold as the temperature weight, taking the ratio of the difference between the voltage threshold and the battery voltage to the voltage threshold as the voltage weight, judging the size of the temperature weight and the voltage weight, and then taking the working parameter with a large weight as the target to select the corresponding calibrated cold start control parameter.
[0010] Beneficial Effects
[0011] The advantages of the present invention are that when the engine is cold started, the injector is controlled according to the calibrated cold start control parameters, so that the injector can normally spray fuel under low temperature conditions, which satisfies the need to adapt to lower ambient temperatures and lower battery voltages when the engine is cold started, thereby ensuring that the engine starts working at low temperatures and has the advantage of greater adaptability. BRIEF DESCRIPTION OF THE DRAWINGS
[0012] Figure 1 It is a schematic flow chart of the control method of the present invention. DETAILED DESCRIPTION
[0013] The present invention will be further described below in conjunction with the embodiments, but it does not constitute any limitation to the present invention. Any limited number of modifications made by anyone within the scope of the claims of the present invention are still within the scope of the claims of the present invention.
[0014] See also Figure 1 The present invention provides a control method for cold starting of an engine. The method obtains the working parameters of the battery and determines whether the battery is in the cold starting working mode according to the working parameters. If so, the injector is controlled to spray fuel with the calibrated cold starting control parameters; otherwise, the injector is controlled to spray fuel with the original starting control parameters. In this way, the injector of the engine can spray fuel normally under low temperature conditions, which satisfies the need to adapt to lower ambient temperature and lower battery voltage during cold starting of the engine, ensures that the engine can start working at low temperatures, and has the advantage of stronger adaptability.
[0015] The working parameters of the battery include the battery voltage and the intake air temperature. In this embodiment, the battery working temperature is determined by acquiring the intake air temperature, and no additional temperature sensor is required on the battery, thus avoiding the cost problem caused by additional hardware.
[0016] Based on the battery voltage and intake air temperature, there are three control logics for cold start.
[0017] When the intake air temperature is lower than the set temperature threshold, the injector is controlled to spray fuel with the calibrated cold start control parameter 1. The calibrated cold start control parameter 1 includes: Bst current calibration value during cold start, Hd current calibration value during cold start, Pk current calibration value during cold start, boost pulse width during cold start, and peak pulse width during cold start.
[0018] When the battery voltage is less than the set voltage threshold, the injector is controlled to spray fuel with the calibrated cold start control parameter 2. The calibrated cold start control parameter 2 includes: boost pulse width when the battery voltage is too low, peak pulse width when the battery voltage is too low, Bst current calibration value when the battery voltage is too low, Hd current calibration value when the battery voltage is too low, and Pk current calibration value when the battery voltage is too low.
[0019] When the intake air temperature is less than the set temperature threshold and the battery voltage is less than the set voltage threshold, the intake air temperature and the battery voltage are weighted and analyzed respectively, and the calibrated cold start control parameter is selected according to the weight analysis result. Specifically, the ratio of the difference between the temperature threshold and the intake air temperature to the temperature threshold is used as the temperature weight, and the ratio of the difference between the voltage threshold and the battery voltage to the voltage threshold is used as the voltage weight. The size of the temperature weight and the voltage weight is judged, and then the corresponding calibrated cold start control parameter is selected with the working parameter with the largest weight as the target. That is, when the temperature weight is greater than the voltage weight, the calibrated cold start control parameter one is selected; when the voltage weight is greater than the temperature weight, the calibrated cold start control parameter two is selected.
[0020] By setting the above three control logics, the battery can ensure the normal starting of the engine under different working parameters, and the targeted selection of cold start control parameters under different working parameters is realized, thereby improving the adaptability of the engine to the environment when starting.
[0021] The calibration of specific cold start control parameters can be carried out through actual tests. The calibration principle is: under the actual intake temperature or battery voltage conditions, the Hd current value, Pk current value, boost pulse width and peak pulse width corresponding to the injection amount of the injector that can make the engine cold start normally are used as calibration values.
[0022] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention, which will not affect the effect of the implementation of the present invention and the practicality of the patent.
Claims
1. A control method for cold starting of an engine, characterized in that: The working parameters of the battery are obtained, and it is determined whether the battery is in a cold start working mode according to the working parameters. If so, the fuel injector is controlled to spray fuel with the calibrated cold start control parameters; otherwise, the fuel injector is controlled to spray fuel with the original start control parameters.
2. The engine cold start control method according to claim 1, characterized in that: The operating parameters of the battery include battery voltage and intake air temperature.
3. The engine cold start control method according to claim 2, characterized in that: When the intake air temperature is lower than the set temperature threshold, the injector is controlled to spray fuel with the calibrated cold start control parameter 1, and the calibrated cold start control parameter 1 includes: Bst current calibration value during cold start, Hd current calibration value during cold start, Pk current calibration value during cold start, boost pulse width during cold start, and peak pulse width during cold start.
4. The engine cold start control method according to claim 2, characterized in that: When the battery voltage is less than the set voltage threshold, the injector is controlled to spray fuel using the calibrated cold start control parameter 2, and the calibrated cold start control parameter 2 includes: boost pulse width when the battery voltage is too low, peak pulse width when the battery voltage is too low, Bst current calibration value when the battery voltage is too low, Hd current calibration value when the battery voltage is too low, and Pk current calibration value when the battery voltage is too low.
5. The engine cold start control method according to any one of claims 2 to 4, characterized in that: When the intake air temperature is lower than a set temperature threshold and the battery voltage is lower than a set voltage threshold, weight analysis is performed on the intake air temperature and the battery voltage respectively, and a calibrated cold start control parameter is selected according to the weight analysis result.
6. The engine cold start control method according to claim 5, characterized in that: The weight analysis is specifically as follows: taking the ratio of the difference between the temperature threshold and the intake temperature to the temperature threshold as the temperature weight, taking the ratio of the difference between the voltage threshold and the battery voltage to the voltage threshold as the voltage weight, judging the size of the temperature weight and the voltage weight, and then taking the working parameter with a large weight as the target to select the corresponding calibrated cold start control parameter.