Fuel Delivery Pressure Control Without Sensors
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Solution Overview
Problem
Existing fuel delivery systems for internal combustion engines are complex and costly due to the need for additional pressure sensors, and methods without sensors often provide suboptimal control due to CPU-intensive calculations and inaccurate characteristic variables, assuming a hydraulic orifice behavior that is not always applicable.
Innovation Solution
A method that determines fuel delivery system pressure by calculating the volume difference between the fuel quantity delivered by the pump and the engine's fuel requirement, using a calibration point where the fuel delivery quantity matches the engine's consumption, and accounting for secondary pump requirements, without the need for dedicated pressure sensors, allowing for precise pressure determination through characteristic diagrams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If dedicated pressure sensors are installed in the fuel delivery system, then pressure determination becomes direct and accurate, but device complexity and cost increase
Solution Approach 1:
The patent extracts the pressure sensing function from dedicated pressure sensors and relocates it to the existing electric motor of the fuel delivery pump. The motor's current consumption serves as an indirect measurement of system pressure, eliminating the need for separate pressure sensing components while maintaining measurement capability.
Solution Approach 2:
The patent introduces the electric motor's current consumption as an intermediary parameter that correlates with fuel delivery system pressure. Instead of directly measuring pressure with sensors, the system uses current consumption data as a mediator to infer pressure conditions, thereby avoiding additional sensing hardware.
2Device complexity
If characteristic diagrams and CPU-intensive calculations are used to determine operating mode, then pressure control can be achieved without sensors, but control precision deteriorates
Solution Approach 1:
The patent implements a feedback mechanism where the control unit continuously monitors the actual current consumption of the electric motor and compares it with characteristic values stored in memory. Based on this feedback comparison, the system dynamically determines the operating mode and adjusts the fuel delivery accordingly, replacing complex CPU calculations with simpler lookup and comparison operations.
Solution Approach 2:
The patent performs preliminary characterization of the fuel delivery system during manufacturing or calibration, storing characteristic current consumption values for different pressure conditions and operating modes in memory. This preliminary action enables the control unit to quickly determine operating modes during operation without requiring real-time complex calculations, thereby improving both speed and precision.
3Ease of manufacture
If the fuel delivery system is simplified by removing pressure sensors, then costs are reduced, but the ability to detect and measure pressure deteriorates
Solution Approach 1:
The patent enables the electric motor to serve dual functions: driving the fuel delivery pump and simultaneously sensing system pressure through its current consumption. The motor essentially monitors itself, providing pressure detection capability without requiring external sensing components, thereby reducing manufacturing costs while maintaining measurement ability.
Solution Approach 2:
The patent makes the electric motor multi-functional by having it perform both the mechanical function of driving the fuel pump and the sensing function of detecting system pressure through current monitoring. This universal approach eliminates the need for separate pressure sensors, simplifying the system and reducing costs while preserving pressure detection capability.
Data Source
AI summary
A method for controlling a fuel delivery system of an internal combustion engine, having a fuel delivery pump that is driven by an electric motor. The pressure that prevails in the fuel delivery system is determined by a volume difference between the fuel quantity delivered by the fuel delivery pump and the fuel requirement of the internal combustion engine and/or of the fuel delivery system.