Magnetic Field Sensor Output Encoding for Higher Angular Resolution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional magnetic field sensors for detecting the rotation and direction of ferromagnetic objects provide limited angular resolution, which is insufficient for applications requiring higher precision, such as automatic parking assist systems in vehicles.
Innovation Solution
A magnetic field sensor system that includes multiple magnetic field sensing elements and electronic circuits to generate output signals with multiple state transitions within each magnetic field signal period, providing higher resolution of angular accuracy by incorporating additional signal pulses between conventional speed pulses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional magnetic field sensors use single state transition output signals, then the device complexity is low, but the angular resolution and measurement precision are insufficient
Solution Approach 1:
The output signal is segmented into multiple distinct state transitions within each magnetic field period, where each state transition provides discrete angular position information. This segmentation of the continuous angular measurement into discrete states enables higher resolution without requiring a completely different sensing mechanism.
Solution Approach 2:
The patent transitions from a single-state output signal to a multi-state output signal format, adding an additional dimension of information encoding. By utilizing multiple state transitions (e.g., rising edges, falling edges, mid-point transitions) within each period, the system encodes angular position information in multiple dimensions, thereby achieving higher angular resolution.
2Measurement precision
If multiple state transitions are implemented within each magnetic field signal period, then angular accuracy is improved, but the processing complexity increases
Solution Approach 1:
The patent replaces complex mechanical or hardware-based high-resolution encoding mechanisms with a signal processing approach that generates multiple state transitions through electronic circuitry. This substitution allows achieving high angular accuracy through software or digital signal processing rather than through mechanically complex structures.
3Measurement precision
If conventional rotation detectors use peak-to-peak percentage detectors, then the circuit implementation is simple, but the angular resolution remains limited
Solution Approach 1:
The detector circuit dynamically generates multiple state transitions within each magnetic field period based on the instantaneous position of the ferromagnetic object. Rather than using a static threshold comparison, the system adapts its output states dynamically throughout the signal period, with each state transition occurring at a specific phase angle to provide incremental angular position information.
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 system offers enhanced angular resolution and position identification of rotating ferromagnetic objects, enabling more precise tracking and control in applications like automatic parking systems by providing additional high-resolution pulses between speed pulses.
Implementation Method 1
one or more magnetic field sensing elements operable to generate a respective one or more magnetic field signals proportional to a magnetic field associated with a ferromagnetic object
Data Source
AI summary
An apparatus and a method provide an output signal indicative of a speed of rotation and/or a direction of movement of a ferromagnetic object having ferromagnetic features and capable of moving. A variety of signal formats of the output signal are described, each of which have pulses at a rate faster than the ferromagnetic features pass by the magnetic field sensor.