Sensor Adaptive Switching Frequency for Interference Filtering
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Solution Overview
Problem
Existing sensors face challenges in effectively filtering out-of-band interference signals due to overlapping harmonic components, which affects their accuracy and reliability in safety-critical applications.
Innovation Solution
The sensor employs a switching cycle to periodically turn on and off components, allowing for selective sampling of analog signals only during active periods, and adjusts the switching frequency to stagger harmonic components away from interference signals, enabling aggressive filtering and improved signal quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the sensor uses continuous sampling of analog signals, then the signal quality and measurement precision are improved, but the power consumption increases and out-of-band interference signals cannot be effectively filtered
Solution Approach 1:
The patent implements periodic switching of sensor components between active and low-power states. The analog signal is sampled only during active periods, creating a periodic sampling pattern that reduces average power consumption while maintaining measurement capability. This periodic action allows the sensor to achieve energy efficiency without completely sacrificing signal acquisition.
Solution Approach 2:
The patent changes the sampling parameter by introducing a switching cycle that modulates the sampling rate. By varying the duty cycle and switching frequency, the system optimizes the balance between power consumption and measurement precision. The sampling occurs at specific intervals rather than continuously, transforming the sampling regime from continuous to periodic.
2Measurement precision
If the sensor samples analog signals during all periods, then the measurement precision is improved, but out-of-band interference signals overlap with harmonic components reducing reliability
Solution Approach 1:
The patent converts the harmful effect of switching-induced harmonic components into a beneficial filtering mechanism. By intentionally introducing periodic switching, the system creates harmonic components at known frequencies. These harmonics serve as reference points that enable the filtering circuitry to identify and remove out-of-band interference signals that would otherwise overlap with the measurement signal.
Solution Approach 2:
The periodic switching acts as an intermediary mechanism between the analog signal source and the digital processing stage. It introduces a controlled modulation pattern that separates the signal spectrum into distinct frequency regions, allowing interference signals to be distinguished from legitimate signal components through frequency-domain analysis and filtering.
3Use of energy by moving object
If the sensor transitions components between on and off states periodically, then power consumption is reduced and interference filtering is enabled, but the device complexity increases
Solution Approach 1:
The switching control circuit performs multiple functions simultaneously: it manages power consumption by enabling periodic on/off transitions, generates the sampling clock signal for synchronized data acquisition, and creates the harmonic reference pattern needed for interference filtering. This multi-functionality reduces the need for separate dedicated circuits for each function, thereby limiting the increase in overall 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
This approach effectively reduces overlap between harmonic components and out-of-band interference signals, enhancing the sensor's ability to filter and produce accurate output signals, thereby improving its performance and reliability in noisy environments.
Implementation Method 1
Some sensors include one or more magnetic field sensing elements, such as a Hall effect element or a magnetoresistive element, to sense a magnetic field associated with proximity or motion of a target object
Implementation Method 2
Some sensors include one or more magnetic field sensing elements, such as a Hall effect element or a magnetoresistive element, to sense a magnetic field associated with proximity or motion of a target object
Data Source
AI summary
A method is provided for use in a sensor, the method comprising: selecting a switching cycle for the sensor; transitioning the sensor into a state in which at least one component of the sensor is periodically turned on and off in accordance with the switching cycle; sampling an analog signal to generate a sampled signal, the analog signal being generated by at least one sensing element, the analog signal being sampled only during periods in which the at least one component of the sensor is turned on; and generating an output signal based, at least in part, on the sampled signal and outputting the output signal.