Low-Pressure Fuel Pump Control via Dynamic Pressure
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Solution Overview
Problem
In fuel supply systems for gasoline direct injection engines, there is a conflict between achieving optimal fuel efficiency and stability, leading to increased fuel consumption and potential engine hesitation or stall, due to the generation of cavities or bubbles in the low-pressure fuel pump line.
Innovation Solution
A method of controlling the low-pressure fuel pump by using the fuel consumption amount as a control variable, incorporating feedforward control to minimize fuel consumption, and employing a fuel temperature model to set target fuel pressures, thereby reducing fuel consumption and preventing bubble formation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the target pressure of the low-pressure fuel pump is raised to ensure stability of fuel supply, then the stability of fuel supply is improved, but fuel consumption increases and fuel efficiency deteriorates
Solution Approach 1:
The patent implements dynamic control of the low-pressure fuel pump by continuously adjusting the target pressure based on real-time fuel temperature measurements and saturation vapor pressure characteristics. The control system transitions from a static high-pressure setting to a dynamic pressure profile that adapts to changing fuel conditions, thereby maintaining fuel supply stability only when necessary while reducing fuel consumption during normal operating conditions.
Solution Approach 2:
The patent changes the control parameter from a fixed high target pressure to a variable target pressure that is dynamically calculated based on fuel temperature and saturation vapor pressure. By using the relationship between fuel temperature and saturation vapor pressure to determine the appropriate target pressure, the system optimizes the balance between fuel supply stability and fuel consumption efficiency.
2Reliability
If the target pressure of the low-pressure fuel pump is raised to prevent cavities or bubbles, then the stability of fuel supply is improved, but fuel consumption increases
Solution Approach 1:
The patent applies preliminary action by measuring the fuel temperature in advance and using it to predict the saturation vapor pressure before controlling the fuel pump. This allows the system to proactively adjust the target pressure to prevent cavity or bubble formation before they occur, rather than reacting after the problem arises, thereby maintaining fuel supply stability while avoiding excessive fuel consumption.
Solution Approach 2:
The patent implements a feedback control mechanism where the fuel temperature is continuously measured and fed back to the control system, which then adjusts the target pressure of the low-pressure fuel pump accordingly. This closed-loop feedback ensures that the target pressure is always appropriate for the current fuel conditions, preventing cavities or bubbles while minimizing fuel consumption.
Data Source
AI summary
A method of controlling a low-pressure fuel pump may include: identifying a fuel consumption amount of the low-pressure fuel pump in response to a feedforward fuel control; determining a motor driving base duty based on the fuel consumption amount; and identifying a target fuel pressure based on the pressure of fuel.