MEMS Shock Sensor Digital Signal Processing for False Alarm Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing shock sensors, typically using piezo bimorphs, are ineffective in accurately detecting attacks due to their inability to sense three-dimensional shock signals and are prone to false alarms and instability caused by noise and complex analog circuits.
Innovation Solution
A shock sensor system incorporating a microprocessor, microelectromechanical system (MEMS) for sensing three-dimensional shock signals, a microchip for analyzing signals, and an output device for generating alarms, with adjustable sensitivity settings and communication options via serial peripheral interface or wireless connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a piezo bimorph is used as the sensing device, then the shock sensor can sense shock signals, but it can only sense shock in one direction and the output signal is easily interfered by noise and power supply, leading to false alarms and instability
Solution Approach 1:
The patent replaces the piezo bimorph (analog mechanical sensing element) with a microelectromechanical system (MEMS) acceleration sensing device that outputs digital signals. This substitution eliminates the need for complex analog circuits, reduces sensitivity to noise and power supply interference, and improves both measurement precision and alarm stability.
Solution Approach 2:
The patent changes the output parameter type from analog voltage (prone to interference) to digital signal (immune to noise). The MEMS device converts acceleration into digital data that can be processed by a microprocessor, fundamentally changing how shock signals are captured and analyzed, thereby reducing false alarms.
2Measurement precision
If a piezo bimorph is used as the sensing device, then the shock sensor can detect shock signals, but it requires complicated analog electrical circuits, causing the shock sensor to be unstable
Solution Approach 1:
The patent replaces the piezo bimorph with a MEMS acceleration sensing device that directly outputs digital signals. This eliminates the need for complex analog electrical circuits including amplifiers, filters, and signal conditioners, significantly reducing device complexity while maintaining detection capability.
Solution Approach 2:
The patent introduces a microprocessor as an intermediary between the sensing device and the alarm system. The microprocessor digitally processes shock signals, replacing the need for complex analog circuitry and providing a simpler, more stable system architecture.
3Reliability
If the shock signal detected by the shock sensor is compared with a threshold value with additional judgment conditions, then false alarm and missing alarm can be decreased, but the shock signal sensed by the piezo bimorph may not describe really the real attack, causing the shock sensor to be ineffective
Solution Approach 1:
The patent replaces the piezo bimorph with a MEMS acceleration sensing device that accurately captures three-dimensional shock signals. This substitution ensures that the sensed signals truly represent real attacks, making threshold comparison and judgment conditions effective in reducing false alarms while maintaining high detection accuracy.
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 provides a reliable and simple means to detect real attacks, reducing false alarms by accurately analyzing shock signals and adjusting sensitivity for specific applications, enhancing the stability and effectiveness of the shock sensor.
Implementation Method 1
a micro electromechanical system (MEMS) in communication with the microprocessor, the micro electromechanical system being integrated with a shock sensing device adapted to sense a shock generated by the attack in any direction and a microchip adapted to receive and store at least one parameter from the microprocessor and to analyze a shock signal generated by the shock based on the at least one parameter
Data Source
AI summary
Disclosed is a shock sensor for detecting an attack on a facility equipped with the shock sensor, comprising: a microprocessor; a micro electromechanical system in communication with the microprocessor, the micro electromechanical system being integrated with a shock sensing device adapted to sense a shock generated by the attack in any direction and a microchip adapted to receive and store at least one parameter from the microprocessor and to analyze a shock signal generated by the shock based on the at least one parameter; and an output device connected with the microprocessor and adapted to output information based on an analysis result of the shock signal. According to the invention, the shock sensor can detect reliably any attack and has a simple circuit arrangement.