Boat Engine Control Unit Shift Position Attenuation
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Solution Overview
Problem
Conventional engine control units for boat propulsion systems fail to accurately distinguish between forward and reverse shift positions, leading to engine stall and rotational speed fluctuations, especially during deceleration followed by brief acceleration, due to identical attenuation coefficients and time limits applied across all shift positions.
Innovation Solution
An engine control unit that includes a predicted boat speed value generator and control signal generator, which use detected signals from engine speed, intake pressure, lever position, and shift position to calculate and adjust fuel injection, air amount, and ignition timing, with varying attenuation and incremental coefficients for forward, neutral, and reverse shift positions to match actual boat speed, thereby improving attenuation and recovery rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If identical attenuation coefficients and time limits are applied to all shift operations, then the control system is simple, but engine stall and rotational speed fluctuations occur during deceleration followed by brief acceleration
Solution Approach 1:
The patent applies different attenuation coefficients and time limits to different shift positions (forward, neutral, reverse) based on their specific operational characteristics. This local differentiation ensures that each shift position receives optimized control parameters, preventing engine stall and rotational speed fluctuations while maintaining manageable system complexity through structured parameter variation.
2Device complexity
If the predicted boat speed is calculated using a single attenuation coefficient, then the computation is simple, but the predicted speed does not match the actual speed during deceleration
Solution Approach 1:
The patent implements different attenuation coefficients for different shift positions (forward shift, neutral shift, reverse shift) to accurately reflect the distinct deceleration characteristics of each position. This approach significantly improves boat speed prediction accuracy during deceleration by matching the actual speed more closely, while the computation remains organized and manageable through systematic parameter differentiation.
3Device complexity
If the same time limit is used for all shift operations, then the control logic is simple, but the control response is inaccurate during brief acceleration after deceleration
Solution Approach 1:
The patent sets different time limits for different shift positions based on their specific operational characteristics. This allows the control system to accurately respond to brief acceleration events following deceleration by applying appropriate time limits specific to the current shift position, improving control response accuracy while maintaining structured and manageable control logic.
Data Source
AI summary
A predicted boat speed value generator, in accordance with one or more embodiments, receives an engine rotation signal, an intake pressure value, and other detection signals including shift position, and provides a predicted boat speed value. A control signal generator determines the fuel injection amount, the amount of air, and the ignition timing based on the predicted boat speed to provide respective control signals. The predicted boat speed value generator includes a predicted boat speed mapped value extraction process to search through the predicted boat speed value map during the constant speed operation and acceleration, based on the rotational speed and the intake pressure, to extract the predicted boat speed mapped value “d” for output. A predicted decelerating boat speed value output process establishes the initial predicted boat speed value to provide the attenuated predicted boat speed value in every cycle.