Dynamic Crank Angle Interval for Engine Combustion Estimation
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Solution Overview
Problem
Conventional methods for estimating the combustion state of internal combustion engines require a fixed crank angle interval, leading to increased calculation processing load due to the need to account for varying operating conditions, without providing a method to adjust the angle interval accordingly.
Innovation Solution
A controller and control method that dynamically sets the estimation crank angle interval based on operating conditions, using an angle information detection unit, estimation angle interval setting unit, gas pressure torque calculation unit, and combustion state estimation unit to adjust the interval and reduce unnecessary calculations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed wide crank angle interval is used to cover all operating conditions, then the combustion state estimation can be performed for all conditions, but the calculation processing load increases
Solution Approach 1:
The patent applies the dynamics principle by making the crank angle interval dynamic rather than fixed. The estimation crank angle interval is adjusted according to operating conditions, specifically based on the burning angle interval which varies with engine speed and load. This allows the system to cover all operating conditions adaptively while minimizing calculations by using narrower intervals when appropriate
Solution Approach 2:
The patent applies parameter changes by modifying the crank angle interval parameter based on operating conditions. The estimation crank angle interval is changed according to the burning angle interval, which itself changes with engine speed and load conditions. This parameter adaptation enables the system to maintain estimation accuracy across all conditions while reducing unnecessary calculations
2Productivity
If a fixed narrow crank angle interval is used to reduce calculation load, then the calculation processing load decreases, but the combustion state estimation accuracy deteriorates under varying operating conditions
Solution Approach 1:
The system dynamically adjusts the estimation crank angle interval based on the burning angle interval which varies with operating conditions. During rapid combustion phases, a narrower interval captures the critical changes accurately, while during slower phases, a wider interval reduces unnecessary calculations. This dynamic adaptation maintains estimation accuracy while optimizing calculation load
Solution Approach 2:
The patent changes the estimation crank angle interval parameter according to the burning angle interval under different operating conditions. By adapting this parameter to match the actual combustion characteristics at each operating point, the system ensures accurate combustion state estimation without performing excessive calculations
Data Source
AI summary
To provide a controller and a control method for internal combustion engine which can set appropriately an angle interval for estimating the combustion state in accordance with change of a burning angle interval, and can reduce calculation processing load for estimation of the combustion state. A controller for internal combustion engine changes the estimation crank angle interval based on an operating condition of the internal combustion engine; calculates an increment of gas pressure torque by burning at each crank angle of the estimation crank angle interval; and estimates the combustion state of the internal combustion engine, based on the increment of gas pressure torque by burning in the estimation crank angle interval.