Engine Control Apparatus Knocking Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing internal combustion engine control systems fail to accurately detect knocking tendency due to environmental and fuel-related factors, leading to inadequate timing in switching injection modes.
Innovation Solution
A control apparatus with an electronic control unit that switches between injection modes based on ignition timing, adjusting injection frequency in the compression stroke and using sensors to monitor engine speed, intake air, and cooling water temperature to optimize fuel injection timing and frequency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If knocking tendency is detected based on engine speed and output torque, then the injection mode can be switched, but the knocking tendency cannot be accurately detected due to environmental and fuel factors
Solution Approach 1:
The patent introduces a knock sensor as an intermediary device to directly detect knocking in the combustion chamber. This mediator provides accurate knocking detection independent of environmental and fuel variations, resolving the contradiction between detection accuracy and adaptability.
Solution Approach 2:
The patent replaces the indirect mechanical parameter-based detection (engine speed and torque) with a direct acoustic/knock signal detection system using a knock sensor. This substitution enables accurate knocking detection despite varying operating conditions and fuel types.
2Reliability
If the injection mode is switched based on inaccurate knocking detection, then the control response is delayed, but the knocking suppression timing is off
Solution Approach 1:
The patent implements a feedback control system where the knock sensor continuously monitors knocking and provides real-time signals to the control unit. This feedback mechanism enables precise and timely injection mode switching based on actual knocking conditions, eliminating timing errors.
Solution Approach 2:
The control unit performs preliminary actions by switching the injection mode in advance based on predicted knocking tendency from the knock sensor signals. This preliminary action ensures optimal timing for knocking suppression before actual knocking occurs.
3Measurement precision
If multiple sensors are added to improve detection accuracy, then the knocking tendency can be detected more accurately, but the device complexity increases
Solution Approach 1:
The patent employs a knock sensor that utilizes the engine's own combustion process and acoustic field to detect knocking. The sensor serves itself by using the existing combustion chamber environment rather than requiring external complex measurement systems, maintaining simplicity while achieving high accuracy.
Data Source
AI summary
An internal combustion engine control apparatus including an electronic control unit having a microprocessor and a memory. The microprocessor is configured to perform switching an injection mode between a first injection mode in which the fuel is injected in a range including an intake stroke and a compression stroke of an internal combustion engine and a second injection mode in which the fuel is injected in the range so that an injection frequency in the compression stroke in the second injection mode is greater than an injection frequency in the compression stroke in the first injection mode; and determining whether the injection mode needs to be switched based on an ignition timing of the ignitor.