Accelerator Pedal Rotation Angle Detection Using Dual Hall IC Voltage Ratios
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Solution Overview
Problem
Existing accelerator apparatuses fail to accurately determine abnormal rotation angles of the pedal, leading to potential misinterpretation of normal and abnormal operation states, which can result in incorrect throttle valve control.
Innovation Solution
The apparatus includes a support device, a shaft, an operation device, a biasing device, a magnetism generation device, and plural magnetism detection devices, with an abnormality check device that determines abnormal rotation angles based on voltage differences between output voltages from the magnetism detection devices, using predetermined relational expressions to define normal and abnormal operation conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If voltage difference checking is used to determine abnormal operation, then the accelerator apparatus can detect power supply issues, but it cannot accurately determine abnormal pedal rotation angles exceeding full-closure limits
Solution Approach 1:
The patent changes the parameter used for abnormality detection from voltage difference alone to a combined parameter that includes the relationship between voltages from multiple magnetism detection devices. By establishing predetermined relational expressions between these voltage parameters, the system can accurately determine when the pedal rotation angle exceeds the full-closure limit, resolving the inability to detect abnormal rotation angles while maintaining reasonable system complexity.
2Ease of operation
If the accelerator apparatus determines normal operation based on voltage difference within predetermined range, then it can operate the throttle valve normally, but it misinterprets abnormal states where the pedal rotates beyond full-closure angle
Solution Approach 1:
The patent implements feedback by continuously monitoring the voltages from multiple magnetism detection devices and comparing them against predetermined relational expressions. This feedback mechanism allows the system to distinguish between normal operation (where the pedal is within the valid rotation range) and abnormal operation (where the pedal exceeds full-closure angle), thereby improving measurement precision without compromising ease of operation.
Solution Approach 2:
The system changes from using a single voltage difference parameter to using multiple voltage parameters from different magnetism detection devices. By establishing relational expressions between these parameters, the system achieves more precise measurement of pedal rotation angle, enabling accurate detection of abnormal states while maintaining normal throttle valve control operation.
3Device complexity
If only two magnetism detection devices are used, then the device complexity is reduced, but the ability to accurately determine abnormal rotation angles is compromised
Solution Approach 1:
The patent transforms the limitation of using only two magnetism detection devices into an advantage by establishing specific relational expressions between their voltage outputs. Instead of adding more devices to improve precision, the system changes the parameter relationship analysis method, using the predetermined mathematical relationships between the two voltage parameters to accurately detect abnormal rotation angles, thus maintaining low device complexity while achieving high measurement precision.
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 solution enables precise detection of abnormal pedal rotation angles, preventing misinterpretation and ensuring accurate throttle valve control, thereby maintaining vehicle engine stability and performance.
Implementation Method 1
a magnetism generation device for generating magnetic flux
Implementation Method 2
plural magnetism detection devices, which rotate relatively to a magnetism generation device provided on a shaft, convert changes in magnetic density into voltages
Data Source
AI summary
A rotation angle sensor detects a rotation angle of a pedal by its first Hall IC and second Hall IC, which are disposed between two magnets and output voltages varying with magnetic flux changes. When the rotation angle of the pedal is an accelerator full-closure rotation angle or more, the first Hall IC generates a first voltage V1, which is twice as large as a second voltage V2 of the second Hall IC. When the rotation angle is less than 0°, the first Hall IC fixes the first voltage irrespective of the rotation angle. An ECU determines that the rotation angle is abnormal indicating that the pedal rotates in an accelerator closing direction beyond an accelerator full-closure position, when an output difference G1 calculated as G1=V1/2−V2 is more than a predetermined value.