ACG Starter Crankshaft Reverse Rotation Control Against Sensor Noise
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Solution Overview
Problem
Existing engine start control systems for saddle-ride vehicles may prematurely stop reverse rotation drives due to noise interference, leading to inadequate crankshaft positioning and reduced startability.
Innovation Solution
An engine start control system that uses an integrated starter generator and a control unit to maintain reverse rotation of the crankshaft for a predetermined time period, incrementing or decrementing a rotation-direction signal based on motor angle sensor output, ensuring accurate positioning despite noise interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the reverse rotation drive is stopped immediately when a forward rotation signal is detected from the motor angle sensor, then the control responsiveness is improved, but the reverse rotation drive may be stopped prematurely due to noise before the piston reaches the predetermined position ATDC on compression
Solution Approach 1:
The control unit requires multiple forward rotation signals to be detected within a predetermined time period before stopping the reverse rotation drive. This preliminary condition checking prevents premature stopping due to noise while ensuring the drive is stopped in time when genuine forward rotation occurs, thus maintaining both reliability and timing accuracy.
2Reliability
If the reverse rotation drive is maintained for a long period to ensure adequate approach run, then the startability is improved, but the power consumption increases and the control complexity increases
Solution Approach 1:
The control unit periodically checks for forward rotation signals at predetermined intervals during the reverse rotation drive. By requiring multiple signals detected within a specific time window, the system maintains the reverse rotation drive for the necessary duration to ensure adequate approach run and improve startability, while automatically stopping the drive when genuine forward rotation is detected, thus avoiding excessive power consumption.
3Device complexity
If the motor angle sensor output is directly used to control the reverse rotation drive stopping, then the control simplicity is maintained, but the measurement precision is affected by noise
Solution Approach 1:
The control unit continuously monitors the motor angle sensor output and requires multiple forward rotation signals to be detected within a predetermined time period before stopping the reverse rotation drive. This feedback mechanism filters out noise signals while responding to genuine forward rotation, maintaining control simplicity without sacrificing detection accuracy.
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
This approach ensures continuous reverse rotation until the crankshaft reaches the desired position, improving startability and minimizing power consumption by accurately determining the rotation state and adjusting the drive accordingly.
Implementation Method 1
a motor angle sensor (29) for detecting a rotation angle of the integrated starter generator (70)
Implementation Method 2
an integrated starter generator (70) rotating in synchrony with a crankshaft (51) of an engine (E) and driving a forward rotation and a reverse rotation of the crankshaft (51)
Data Source
Figure 1
Figure 2
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AI summary
In an engine start control system of a saddle-ride type vehicle configured such that a control unit (80) causes an ACG starter motor (70) to drive a reverse rotation of a crankshaft (51) to a predetermined position ATDC on compression after an engine € stops, the control unit (80) determines on the basis of sensor output of a motor angle sensor (29) detecting a rotation angle of the ACG starter motor (70) whether the crankshaft (51) is in a reverse rotation state or a forward rotation state. After the start of the reverse rotation drive of the crankshaft (51) by the ACG starter motor (70), three signals indicating the reverse rotation of the crankshaft (51) are successively detected, thereby setting a compression detection permission flag. While the flag is on, upon detection of a forward rotation signal of the crankshaft (51), the reverse rotation drive is stopped.