Engine Control Device Transient Acceleration Shock Suppression
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Solution Overview
Problem
Existing engine control devices fail to accurately detect transient acceleration states in engines, leading to excessive ignition timing advancement and resulting in acceleration shocks, particularly in two-wheeled vehicles where slight engine output variations cause discomfort due to quicker vehicle response and drive chain extension/shortening.
Innovation Solution
An engine control device with an electronically-controlled throttle unit, ignition-timing control unit, transient-state determination-processing unit, and transient-state correction-processing unit that calculates a target throttle opening degree and retards ignition timing based on the deviation between actual and target throttle opening degrees to prevent acceleration shocks.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If ignition timing is advanced during acceleration state to increase engine power output, then engine power is improved, but acceleration shock occurs due to excessive timing advancement
Solution Approach 1:
The control device determines transient state in advance based on throttle valve opening degree changes before full acceleration occurs. By detecting the transient state early (when throttle opening increases by a predetermined amount or more), the system can preemptively adjust ignition timing to prevent excessive advancement and resulting acceleration shocks.
Solution Approach 2:
The system continuously monitors the throttle valve opening degree and compares it with reference values to determine whether the engine is in a transient state. This feedback mechanism allows real-time adjustment of ignition timing based on actual operating conditions, preventing both over-advancement (acceleration shock) and under-advancement (power loss).
2Object-affected harmful factors
If ignition timing is retarded during transient state to suppress acceleration shock, then acceleration shock is reduced, but engine power output decreases
Solution Approach 1:
The ignition timing control is made dynamic by adjusting the timing based on real-time detection of transient states. During transient states (when throttle opening changes rapidly), the system retards ignition timing to suppress acceleration shock. During steady-state acceleration, the system allows normal or advanced timing to maintain power output. This dynamic adjustment resolves the contradiction between shock suppression and power maintenance.
Solution Approach 2:
The system changes the ignition timing parameter based on the detected operating state. When transient state is detected (throttle opening degree change exceeds threshold), the timing parameter is adjusted to retard the ignition timing. When in steady state, the timing parameter returns to normal values. This parameter change strategy allows the system to optimize for different operational priorities.
3Device complexity
If ignition timing control is simplified to reduce computational complexity, then device complexity is reduced, but transient state detection precision deteriorates
Solution Approach 1:
The control system extracts only the essential parameter (throttle valve opening degree) needed to detect transient states, rather than monitoring multiple parameters simultaneously. By focusing on the throttle opening degree and comparing it with reference values, the system achieves precise transient state detection without requiring complex multi-parameter analysis or additional sensors.
Data Source
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AI summary
To provide an engine control device including a transient-state determination-processing unit 24a that determines whether an operating state of an engine is in a transient state of shifting to an acceleration state based on a change amount of a target throttle opening degree, and a transient-state correction-processing unit 24b that retards an ignition timing by a predetermined amount set by the change amount when the transient-state determination-processing unit determines that the operating state of the engine is in the transient state.