Crankshaft Angle Estimation Using Combustion Speed Feedback
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Solution Overview
Problem
Current internal combustion engines face challenges in accurately estimating crankshaft angles where 50% of the injected fuel is burned, which affects torque output and engine efficiency.
Innovation Solution
An engine control system that estimates crankshaft angles based on combustion speed, engine speed, air mass per cylinder, spark timing, and predetermined spark timing, using modules to calculate and adjust these angles to optimize fuel burning and engine performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If current estimation methods are used, then the system is simple, but the measurement precision of crankshaft angle is insufficient
Solution Approach 1:
The estimation system is divided into multiple independent modules: a combustion speed estimation module that calculates combustion speed based on engine operating parameters, and a crankshaft angle estimation module that uses the combustion speed along with engine speed and timing parameters to determine CA50. This segmentation allows each module to perform a specific function, improving overall measurement precision while keeping individual modules relatively simple.
Solution Approach 2:
The system performs preliminary estimation of combustion speed using readily available engine parameters (intake cam phaser angle, exhaust cam phaser angle, barometric pressure, air per cylinder, and engine speed) before calculating the final crankshaft angle. This preliminary action enables the system to account for combustion characteristics without requiring complex direct measurements, thereby improving precision without proportionally increasing device complexity.
2Productivity
If combustion parameters are monitored accurately, then engine efficiency is improved, but the loss of time for measurement and calculation increases
Solution Approach 1:
The system continuously monitors combustion speed and uses this feedback to dynamically estimate crankshaft angles in real-time. By establishing a feedback loop where combustion parameters are continuously measured and used to update angle estimates, the system maintains high engine efficiency without requiring time-consuming periodic measurements, as the estimation process uses current operating conditions to provide timely results.
Solution Approach 2:
The system replaces complex mechanical measurement devices with computational estimation based on sensor data from existing engine parameters. Instead of using additional mechanical sensors to directly measure crankshaft angle at combustion points, the system substitutes a calculation-based approach that uses readily available electronic sensor data (cam phaser angles, pressure, air flow) to derive the required information, significantly reducing measurement and calculation time.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system effectively estimates and controls crankshaft angles to improve engine efficiency by optimizing fuel burning, reducing turbocharger output, and minimizing exhaust temperature increases.
Implementation Method 1
Combustion of an air/fuel mixture within a cylinder begins when a spark plug generates spark within the cylinder
Implementation Method 2
Combustion of an air/fuel mixture within a cylinder begins when a spark plug generates spark within the cylinder
Data Source
AI summary
An engine control system of a vehicle includes an estimation module and an actuator module. The estimation module estimates a crankshaft angle where 50 percent of a mass of fuel is burned during a combustion event based on: a combustion speed when a crankshaft of an engine is at a predetermined position during the combustion event; an engine speed; a mass of air per cylinder (APC); a spark timing; and a predetermined spark timing. The actuator module controls an engine actuator based on the crankshaft angle where 50 percent of the mass of fuel is burned during the combustion event.