Adjustable Magnetic Field Angle Sensor Using Bias Current Control
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Solution Overview
Problem
Existing angle sensors for measuring magnetic field directions in a plane lack the ability to adjust sensitivity direction dynamically and efficiently determine the angle describing the magnetic field direction, leading to inaccuracies and inefficiencies.
Innovation Solution
A magnetic field sensor system comprising two sensors with adjustable biasing currents and electronic circuitry to rotate the sensitivity direction until the scalar product of the sensitivity vector and magnetic field is zero, allowing for precise determination of the angle by adjusting biasing currents according to specific equations and using amplifiers and summing junctions to deliver a zero signal.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetic field sensor with fixed sensitivity direction is used, then the device structure is simple, but the measurement precision of magnetic field angle is insufficient
Solution Approach 1:
The patent applies dynamics by making the sensitivity direction of the magnetic field sensor adjustable rather than fixed. The sensor's sensitivity vector can be rotated to different orientations, allowing the measurement system to adapt its sensing direction dynamically. This is achieved through a sensor array with controllable current sources that can redirect the sensitivity vector to align with or perpendicular to the magnetic field direction, thereby improving angle measurement precision without requiring a mechanically complex rotating sensor structure.
Solution Approach 2:
The patent segments the measurement function by using multiple magnetic field sensors arranged in an array rather than a single sensor. Each sensor contributes to the overall measurement capability, and their combined outputs are processed to determine the magnetic field angle. This segmentation allows the system to achieve precise angle measurement through computational processing of multiple sensor readings, avoiding the need for a single complex sensor with mechanically adjustable sensitivity direction.
2Measurement precision
If the sensitivity direction is rotated by mechanical means, then the measurement accuracy improves, but the measurement speed decreases
Solution Approach 1:
The patent replaces the mechanical rotation system with an electrical control system. Instead of physically rotating the sensor to change its sensitivity direction, the invention uses controllable current sources to electronically adjust the sensitivity vector orientation. This substitution eliminates mechanical inertia and friction, allowing instantaneous reorientation of the sensitivity direction and enabling fast angle measurements without the speed limitations of mechanical rotation systems.
Solution Approach 2:
The patent implements dynamic control of the sensitivity direction through electrical means. The current sources can rapidly change the orientation of the sensor's sensitivity vector in response to control signals, enabling the system to track and measure magnetic field angles at high speeds. This dynamic electrical control replaces slow mechanical adjustment mechanisms, achieving both high measurement accuracy and fast response times.
3Reliability
If multiple magnetic field sensors are used to determine sensitivity direction, then the measurement reliability improves, but the device complexity increases
Solution Approach 1:
The patent makes the magnetic field sensor array multi-functional by enabling it to perform both magnetic field strength measurement and angle determination functions. The same sensor elements that detect magnetic field components are also used to calculate the field direction through computational processing. This universality allows the system to achieve reliable angle measurement without adding separate dedicated angle sensing hardware, thereby improving measurement reliability while limiting the increase in device complexity.
Solution Approach 2:
The patent merges the angle measurement function with the existing magnetic field sensing capability. By processing the outputs of multiple magnetic field sensors in combination, the system simultaneously obtains both field strength and direction information. This merging of functions allows the sensor array to determine sensitivity direction and measure angles using the same hardware infrastructure, improving reliability through redundant measurement paths while avoiding the complexity of separate angle sensing subsystems.
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
Enables fast and reliable measurement of the magnetic field angle by rotating the sensitivity direction to align with the magnetic field, ensuring accurate determination of the angle by achieving a zero scalar product, thereby improving measurement precision and efficiency.
Implementation Method 1
A magnetic field sensor comprising a horizontal Hall element capable of measuring a magnetic field pointing in a direction parallel to a surface of the Hall element
Data Source
AI summary
The invention concerns an angle sensor and a method of measuring an angle of a magnetic field. The angle sensor is configured to measure a direction of a magnetic field in a plane, comprising a first magnetic field sensor having a first sensitivity direction and delivering a first voltage, a second magnetic field sensor having a second sensitivity direction and delivering a second voltage, a first current source supplying a first biasing current to the first magnetic field sensor, a second current source supplying a second biasing current to the second magnetic field sensor (2), and electronic circuitry configured to adjust the first biasing current and the second biasing current in such a manner that a sum of the first voltage and the second voltage equals 0.