Fuel Pressure Pulsation Prediction in Engine Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing control systems for internal combustion engines face challenges in accurately controlling fuel injection amounts due to fuel pressure pulsations, which are not adequately addressed by relying solely on rotational speed corrections, as other factors like engine load and temperature also influence actual fuel pressure values.
Innovation Solution
The system predicts fuel pressure values using an electronic control unit that calculates a center fuel pressure value based on recent detection values from the fuel pressure sensor, amplitude, and initial phase, and adjusts the smoothing coefficient according to the difference between target and calculated pressure values, allowing for more accurate control during pulsation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fuel injection amounts are controlled based on detection values of the fuel pressure sensor during pulsation, then the control system can respond to actual fuel pressure conditions, but the detection values become largely different from actual fuel pressure values during port injection, leading to inaccurate control
Solution Approach 1:
The system performs preliminary action by calculating the center fuel pressure value, amplitude, and initial phase of pulsation before port injection occurs. These parameters are computed in advance based on detection values obtained during the suction stroke, enabling the ECU to predict actual fuel pressure conditions at the time of injection and compensate for pulsation effects proactively
Solution Approach 2:
The invention introduces intermediary parameters (center fuel pressure value, amplitude, initial phase) that mediate between the raw detection values and the actual fuel pressure conditions during injection. These intermediary parameters serve as a bridge to translate sensor data into accurate predictions of fuel pressure at injection timing, resolving the discrepancy between detection and actual values
2Device complexity
If a map based on rotational speed is used to control fuel injection amounts during pulsation, then control can be simplified, but the control accuracy deteriorates because actual fuel pressure is influenced by multiple factors including load, temperature, and fuel characteristics
Solution Approach 1:
The system changes parameters by computing dynamic characteristics (center fuel pressure value, amplitude, initial phase) from detection data instead of relying on static rotational speed maps. This allows the control system to adapt to varying operating conditions (load, temperature, fuel characteristics) by extracting real-time pulsation parameters that reflect actual fuel pressure conditions
Solution Approach 2:
The invention implements feedback by continuously monitoring detection values during the suction stroke and using them to calculate pulsation parameters that inform control decisions during injection. This closed-loop approach allows the system to adapt to changing conditions based on actual sensor data rather than pre-defined maps
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A control system of an internal combustion engine includes an electronic control unit (41). The electronic control unit (41) is configured to: (i) obtain a detection value of a fuel pressure sensor (28) at fixed sampling time intervals; (ii) calculate a center fuel pressure value of a pulsation of the fuel pressure, based on at least a first latest fuel pressure value and a second latest fuel pressure value as detection values of the fuel pressure sensor (28), (iii) calculate an amplitude of the pulsation of the fuel pressure, based on at least the second latest fuel pressure value and the first latest fuel pressure value; (iv) calculate an initial phase of the pulsation of the fuel pressure, based on at least one of the second latest fuel pressure value and the first latest fuel pressure value, and (v) predict a fuel pressure value corresponding to the crank angle, based on a predetermined formula.