Engine Idle Stop Control with Backup Crank Angle Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing engine control devices for saddle-straddling vehicles, such as those described in JP 2005-291143 A, face issues with spark discharge timing accuracy due to electromagnetic pickup failures, leading to poor engine startability during idle stop and re-start scenarios.
Innovation Solution
An engine system with an ignition device, a first detection subject, a first detector, a controller, and an abnormality detector that maintains engine control in a normal mode even if the first detector experiences operational abnormalities, ensuring proper spark discharge timing and quick re-start by detecting the first detection subject before switching from idle stop to normal mode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a crank angle detection device using electromagnetic pickup is used to detect spark discharge timing, then engine control precision is improved, but reliability deteriorates due to electromagnetic pickup failures
Solution Approach 1:
The detection function is segmented into two independent systems: a primary crank angle detection device using electromagnetic pickup for normal operation, and a secondary detection mechanism using the rotation sensor for backup. This segmentation ensures that failure of one detector does not compromise overall system reliability.
Solution Approach 2:
The rotation sensor acts as an intermediary backup detection mechanism. It detects rotor rotation to determine crankshaft position when the primary electromagnetic pickup fails, serving as a mediator to maintain detection functionality without requiring complete system redesign.
2Productivity
If quick re-start is implemented by generating first explosion based on detected crank angle, then productivity is improved, but measurement precision deteriorates when detector malfunctions
Solution Approach 1:
The system performs preliminary detection of crankshaft rotation using the rotation sensor before initiating the re-start sequence. This preliminary action ensures that detection is already underway and data is available, enabling immediate spark discharge timing control without waiting for primary detector initialization.
Solution Approach 2:
The abnormality detector continuously monitors the operational status of the electromagnetic pickup and provides feedback to the controller. When malfunction is detected, the system switches to using rotation sensor data, maintaining accurate spark discharge timing control through adaptive feedback-based detector selection.
3Reliability
If abnormality detection and mode switching control are implemented, then reliability is improved, but device complexity increases
Solution Approach 1:
The rotation sensor serves multiple functions: it acts as a backup crank angle detection mechanism, provides rotational speed data for abnormality detection, and enables the controller to determine when to switch between normal and abnormal modes. This multi-functionality reduces the need for separate dedicated components.
Solution Approach 2:
The abnormality detection function is merged with the existing rotation sensor system rather than requiring a completely separate detection mechanism. The controller integrates monitoring of both the electromagnetic pickup and rotation sensor signals, combining multiple detection functions into a unified control logic that manages detector selection and mode switching.
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
Prevents deterioration in engine startability by ensuring accurate spark discharge timing and quick re-starts, even when the crank angle detection device malfunctions, and maintains optimal air-fuel ratios during mode transitions.
Implementation Method 1
The electromagnetic pickup is provided in the vicinity of the outer peripheral surface of the rotor, and generates a crank angle pulse signal indicating that the front end and the rear end of each convex portion has passed through the vicinity
Implementation Method 2
at the time of the engine start-up, spark discharge (the ignition) of the ignition plug is generated
Data Source
AI summary
An engine is controlled in a normal mode or an idle stop mode. The ignition of a fuel-air mixture is performed in the normal mode, and the ignition of the fuel-air mixture is not performed in the idle stop mode. A detection subject that is rotated together with a crank shaft is provided at the crank shaft. At the time of the re-start of the engine, the ignition of the fuel-air mixture compressed in a first compression stroke is performed based on the detection of the detection subject by a reference angle sensor. When the operation abnormality of the reference angle sensor is detected, the change from the normal mode to the idle stop mode is not performed.