Engine Starter Current Sensor Speed Detection
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Solution Overview
Problem
Existing engine rotational speed determining devices face challenges in accurately detecting engine rotational speed during starting operations due to the influence of battery State of Charge (SOC) and deterioration, which affects the change in terminal voltage.
Innovation Solution
An engine rotational speed determining device that inputs a signal indicating current supplied to an electric motor, performs a relaxation process to eliminate electrical noise, and resets the process when the current decreases, allowing for accurate determination of rotational speed based on the signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If terminal voltage change is used to determine engine rotational speed, then the measurement method is simple, but the measurement precision deteriorates due to battery SOC and deterioration influence
Solution Approach 1:
The patent introduces current change as an intermediary parameter to indirectly determine engine rotational speed. Instead of directly measuring voltage change (which is affected by battery conditions), the system measures current change through a current sensor, which serves as a more reliable mediator that is not influenced by battery SOC or deterioration, thereby improving measurement precision while maintaining relatively simple device complexity
Solution Approach 2:
The patent replaces the electrical measurement approach (voltage sensing) with a current-based measurement approach. By substituting voltage measurement with current measurement, the system eliminates the harmful influence of battery internal resistance changes on the measurement accuracy, achieving more precise rotational speed detection without significantly increasing system complexity
2Measurement precision
If current signal is used to determine rotational speed, then the measurement precision improves, but the difficulty of detecting and measuring increases due to electrical noise
Solution Approach 1:
The patent applies preliminary action by performing a relaxation process on the current signal before using it for rotational speed determination. This preprocessing step eliminates electrical noise and other interfering factors in advance, making the subsequent measurement and detection easier and more accurate. The relaxation process prepares the signal in advance, reducing the difficulty of detecting and measuring the actual rotational speed information
Solution Approach 2:
The system uses feedback by continuously monitoring the current signal and applying relaxation processing based on the detected signal characteristics. The feedback mechanism allows the system to adaptively process the current signal, eliminating noise while preserving the essential rotational speed information, thereby improving measurement precision without permanently increasing device complexity
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 solution enables precise determination of engine rotational speed and predicts the possibility of successful engine starting, improving accuracy and reliability in engine operation control.
Implementation Method 1
an electric motor, which starts an internal combustion engine
Implementation Method 2
a battery that powers the starter
Data Source
AI summary
An engine rotational speed determining device is disclosed which includes a signal inputting means and a rotational speed determining means. The signal inputting means inputs a signal that indicates current supplied to an electric motor, which starts an internal combustion engine, during a starting operation of the engine by the motor. The rotational speed determining means determines a rotational speed of the engine in the starting operation based on a change in the current indicated by the signal input by the signal inputting means.