Hybrid Vehicle Ignition Timing Control for Knock Prevention
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Solution Overview
Problem
In hybrid vehicles, the existing control systems for preventing knocking during power generation in idle states are ineffective when the ignition timing is advanced, leading to delayed retardation and continued knocking upon sudden accelerator pedal depression.
Innovation Solution
A control device that includes a knock control mechanism to prevent excessive advancement of ignition timing when the accelerator pedal is not depressed, allowing for quick retardation of ignition timing when the pedal is pressed, thereby avoiding knocking during power generation in idle states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the ignition timing is advanced to stabilize idle state during power generation, then the idle stability is improved, but knocking occurs when the accelerator pedal is suddenly depressed
Solution Approach 1:
The control device performs preliminary action by detecting the operator's intention to accelerate before knocking occurs. When the accelerator pedal is depressed, the control device immediately retards the ignition timing in advance, preventing knocking before it can happen during the transition from idle to acceleration state
Solution Approach 2:
The control device uses feedback from the accelerator pedal position sensor to continuously monitor the operator's input. When pedal depression is detected, the feedback signal triggers immediate ignition timing retardation, creating a closed-loop control system that responds dynamically to operating conditions
2Power
If the knock control mechanism allows ignition timing advancement, then combustion efficiency is improved, but the response time for retardation becomes delayed
Solution Approach 1:
The control device performs preliminary action by detecting the operator's intention to accelerate before knocking occurs. When the accelerator pedal is depressed, the control device immediately retards the ignition timing in advance, preventing knocking before it can happen during the transition from idle to acceleration state
Solution Approach 2:
The control device applies preliminary anti-action by preemptively retarding the ignition timing when accelerator pedal depression is detected. This counteracts the tendency toward knocking before it can occur, eliminating the harmful effect in advance rather than reacting after knocking begins
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 control device effectively prevents knocking by limiting ignition timing advancement during idle states and enabling quick retardation upon accelerator pedal depression, ensuring stable engine operation and reduced knocking occurrences.
Implementation Method 1
an internal combustion engine serving as a traveling source of the vehicle
Implementation Method 2
operating a power generator by the internal combustion engine
Implementation Method 3
an engine including a spark plug, ignition timing control is performed
Data Source
AI summary
An engine ECU executes a program including a step of detecting an opening degree of an accelerator pedal and a state of a power generation command to MG, if a KCS feedback execution condition is met, and a step of detecting a KCS feedback correction amount eakcs, if the accelerator is off and if during power generation load operation, and then substituting a constant AKCSI for eakcs, if eakcs is larger than a threshold value and the ignition timing is on the advance side. Since the KCS feedback correction amount eakcs is adjusted not to be excessively on the advance side, the ignition timing can be retarded promptly at the time of accelerator on, thereby avoiding occurrence of knocking.