Magnetic Field Sensor Adaptive Sampling for Precision and Power
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Solution Overview
Problem
Conventional magnetic field sensors, such as circular vertical Hall (CVH) sensing elements, are limited in their ability to adjust sampling rates and resolution in response to changes in the rotational speed of a target object, leading to decreased performance at higher speeds and increased power consumption.
Innovation Solution
A magnetic field sensor with programmable circuit elements and a processor that adjusts sampling rates and resolution based on the rotation speed of the target object, using a semiconductor substrate with multiple magnetic field sensing elements and a rotation speed sensing circuit to generate a module control signal for programming these characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sampling rate is increased to maintain accurate angle information at higher rotational speeds, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The patent implements dynamic adjustment of the sampling rate based on the detected rotational speed. When the rotational speed increases, the sampling rate is automatically increased to maintain measurement accuracy. When the rotational speed decreases, the sampling rate is reduced to lower power consumption. This dynamic adaptation resolves the contradiction between maintaining precision and reducing energy use.
Solution Approach 2:
The system changes the sampling rate parameter according to the rotational speed conditions. By adjusting this key parameter dynamically, the system optimizes the balance between measurement precision and power consumption, achieving high accuracy when needed and energy efficiency when possible.
2Measurement precision
If the sampling rate is increased to maintain resolution at higher rotational speeds, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent employs a processor that dynamically adjusts sampling parameters based on detected rotational speed. This software-controlled approach avoids the need for complex hardware switches or multiple dedicated circuits for different speed ranges, thereby maintaining measurement precision while limiting the increase in device complexity.
Solution Approach 2:
A single processor unit performs multiple functions: detecting rotational speed, determining appropriate sampling rates, controlling the sampling process, and processing the measured data. This multi-functionality approach maintains high resolution across varying speeds without requiring separate dedicated circuits for each function, thus limiting complexity growth.
3Measurement precision
If the sampling rate is kept high to maintain measurement accuracy, then measurement precision is improved, but power consumption increases
Solution Approach 1:
The magnetic field sensor dynamically adjusts its sampling rate based on the rotational speed of the target object. During high-speed rotation, the sampling rate is increased to maintain measurement accuracy. During low-speed operation, the sampling rate is reduced to minimize power consumption, thus resolving the contradiction between maintaining precision and reducing energy use.
Solution Approach 2:
The sensor performs periodic measurements at variable intervals based on rotational speed. Instead of continuous high-rate sampling, the system uses periodic sampling with adaptive timing, maintaining measurement accuracy when needed while allowing power consumption to decrease during periods of lower activity or lower speed requirements.
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 sensor automatically adjusts its characteristics to maintain accurate angle and speed information, even at higher rotational speeds, while reducing power consumption and maintaining high resolution at lower speeds.
Implementation Method 1
One type of current sensor uses a Hall Effect magnetic field sensing element in proximity to a current-carrying conductor. Planar Hall elements and vertical Hall elements are known types of magnetic field sensing elements.
Implementation Method 2
Like a vertical Hall element, a conventional magnetoresistance element tends to be responsive to magnetic field parallel to a surface of a substrate on which the magnetoresistance element is formed.
Data Source
Figure 1~1A
Figure 2
Figure 3A
AI summary
A magnetic field sensor and a method used therein provide a measured signal representative of an angular speed of rotation of a target object. The magnetic field sensor, in accordance with the measured speed of rotation, can automatically change various characteristics of the magnetic field sensor.