Acceleration Sensor Circuit Frequency-Selective Signal Extraction
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Solution Overview
Problem
The acceleration sensors used in reflection seismic prospecting require a dynamic range of 120 dB for accurate detection, which is beyond the capabilities of current sensors like those used in vehicle control, necessitating a low-cost and high-performance solution for improved sensitivity without relying on high-performance amplifier or filter circuits.
Innovation Solution
An acceleration sensor circuit that applies a sinusoidal AC signal of a predetermined frequency to capacitors, extracts the corresponding frequency component using an arithmetic circuit, and eliminates unwanted frequencies to enhance detection sensitivity, thereby reducing costs and complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If high-performance amplifier circuits or filter circuits are used to improve detection sensitivity, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces complex analog amplifier and filter circuits with a digital signal processing approach. A simple AC signal is applied to the capacitor, and the acceleration signal is extracted digitally by detecting the frequency component matching the applied AC signal frequency, thereby eliminating the need for high-performance analog amplifiers and filters
Solution Approach 2:
The patent changes the operating parameters of the capacitor by applying an AC signal at a specific frequency rather than using DC or broadband signals. This frequency-selective approach allows the acceleration signal to be distinguished from noise through frequency matching, improving detection sensitivity without requiring complex analog filtering
2Measurement precision
If high-performance amplifier circuits or filter circuits are used to improve detection sensitivity, then measurement precision is improved, but cost increases
Solution Approach 1:
The patent substitutes expensive high-performance analog amplifier and filter circuits with a low-cost digital processing approach. By applying a simple AC signal and using frequency-based signal extraction in the digital domain, the system achieves high detection sensitivity while significantly reducing component costs and manufacturing complexity
3Measurement precision
If the dynamic range is expanded to 120 dB for reflection seismic prospecting, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent achieves a 120 dB dynamic range by changing the signal excitation method to use AC signals at a predetermined frequency. This frequency-selective measurement approach allows the system to distinguish acceleration signals from noise across a wide dynamic range without requiring complex analog circuitry, as the frequency matching provides inherent signal separation
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 enables a high-performance acceleration sensor circuit at a lower cost, increasing detection sensitivity and expanding the dynamic range without the need for high-performance amplifiers or filters, while simplifying the circuit configuration and reducing noise interference.
Implementation Method 1
an acceleration sensor including a first capacitor C1 whose capacitance changes according to a position of a first movable electrode Pm1, and a second capacitor C2 whose capacitance changes as opposed to the first capacitor according to a position of a second movable electrode Pm2
Data Source
AI summary
An acceleration sensor circuit 1 of the invention includes an acceleration sensor 11 having a first capacitor C1 whose capacitance changes according to a position of a first movable electrode and a second capacitor C2 whose capacitance changes as opposed to the first capacitor according to a position of a second movable electrode moved together with the first movable electrode, a first circuit 15A for generating a sinusoidal AC signal of a predetermined frequency, a second circuit 12 for generating a signal according to the positions of the movable electrodes, and an arithmetic circuit 14 for analyzing data in which a signal generated by the second circuit 12 is encoded and outputting data of acceleration.