Skip Fire Engine Control for Vibration Suppression
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Solution Overview
Problem
Skip fire engine control technologies face challenges in vibration control, leading to rough engine operation and hindering widespread adoption due to the inability to satisfactorily address vibration concerns, which affects passenger comfort and limits commercial success.
Innovation Solution
A firing control unit that dynamically determines firing sequences to deliver a desired engine output by detecting and suppressing frequency components causing vibrations, using feedback signals filtered through band-pass filters and sigma-delta converters, with variable frequency characteristics that adapt to engine speed and gear ratios to minimize undesirable vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If skip fire engine control is implemented to improve fuel economy, then fuel efficiency is improved, but vibration increases causing rough engine operation
Solution Approach 1:
The patent implements feedback control by monitoring engine vibrations and dynamically adjusting firing sequences to suppress unwanted frequency components. The system continuously measures vibration levels and modifies skip fire patterns in real-time to maintain fuel efficiency while reducing harmful vibrations, directly resolving the contradiction between fuel economy improvement and vibration control.
Solution Approach 2:
The system dynamically changes operating parameters including firing sequences, cylinder selection, and timing to optimize both fuel economy and vibration characteristics. By varying these parameters based on real-time conditions, the system achieves fuel efficiency improvements while maintaining acceptable vibration levels through adaptive control.
2Productivity
If skip fire operation is used to reduce displacement and improve efficiency, then fuel consumption is reduced, but engine smoothness deteriorates
Solution Approach 1:
The feedback mechanism monitors engine smoothness metrics and adjusts skip fire patterns accordingly, ensuring that fuel efficiency gains do not come at the expense of excessive roughness. The system learns from operational data to optimize the balance between displacement reduction and smoothness maintenance.
Solution Approach 2:
The system employs dynamic adjustment of firing patterns rather than fixed skip fire schedules. By adapting cylinder selection and firing timing based on real-time engine conditions, the system maintains smooth operation while achieving fuel efficiency improvements through variable displacement control.
3Object-affected harmful factors
If vibration suppression control is added to skip fire system, then passenger comfort is improved, but control system complexity increases
Solution Approach 1:
The control system incorporates self-learning and adaptive capabilities that allow it to automatically optimize vibration suppression without requiring extensive manual calibration or complex external control systems. The system serves itself by learning from operational data and autonomously adjusting parameters to maintain comfort while managing complexity.
Solution Approach 2:
The system manages complexity by dynamically changing control parameters such as feedback gains, filtering characteristics, and firing patterns based on operating conditions. This adaptive parameter adjustment allows effective vibration suppression across diverse scenarios without requiring a prohibitively complex control architecture for every possible condition.
Data Source
AI summary
A variety of methods and arrangements for controlling the operation of an internal combustion engine in a skip fire variable displacement mode are described. In general, a firing control unit determines working chamber firings during operation of the engine that are suitable for delivering a desired engine output. In one aspect, the firing control unit is arranged to isolate the generation of firing sequences having frequency components in a frequency range of concern and to alter the firing sequence in a manner that reduces the occurrence of frequency components in the frequency range of concern. In another aspect, a filter is arranged to filter a feedback signal to provide a filtered feedback signal that is used in the determination of the working chamber firings. In preferred embodiments, the frequency characteristics of the filter are variable.