Fuel injector flow correction method based on vehicle conditions

Abstract

The invention provides a fuel injector flow correction method based on vehicle conditions. The method comprises the steps that whether a vehicle state meets an SPC self-learning condition or not is judged, if yes, a rail pressure point needing to be learned is selected on a selected fuel injector, then a controller controls the rail pressure point to reach a set value of the rail pressure point, and then a single-step progressive pulse width adjustment injection test is conducted on the selected fuel injector; meanwhile, the controller monitors the rotating speed deviation value of an air cylinder where the selected fuel injector is located and other air cylinders, the difference between the deviation value change and a theoretical change value is compared, and if the difference between the deviation value change and the theoretical change value is within a set tolerance range, normalization processing is conducted on the deviation value change curve and the theoretical change value curve to obtain an actual MDP value; and then the deviation of the actual MDP value relative to a MDP design value is determined, and finally the MDP deviation is compensated by using a calibration scale. The design is simple and convenient in correction process, low in cost and good in robustness.

Description

technical field [0001] The invention belongs to the technical field of engines, and in particular relates to a fuel injector flow correction method based on vehicle conditions. Background technique [0002] The car engine injects fuel, mixes fuel and air in a certain proportion, and burns to provide energy. The fuel injection quantity of the engine is usually based on the signals transmitted by the engine speed, vehicle speed, throttle position, water temperature, air flow meter or pressure sensor, etc., to calculate the fuel injection time required by the engine under different states, that is, the fuel injection quantity. [0003] Accurate control of fuel injection quantity can reduce fuel consumption, improve fuel utilization rate, reduce exhaust emissions, and is of great significance to environmental protection. However, the aging and wear of fuel injectors will directly affect the accuracy of fuel injection quantity, so it is necessary to control the fuel injection qua...

AI Technical Summary

Problems solved by technology

The method currently used is mainly to correct the small fuel volume of the injector through the cylinder pressure detection under the condition of the engine running backwards. In this method, not only the cylinder pressure sensor needs to be installed to detect the cylinder pressure, but the cost of the engine is increased. Moreover, the calibration process is more complicated and the robustness is poor.

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