Self-Powered Sensor Using Piezoelectric Vibration Harvesting
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Solution Overview
Problem
Existing battery-less sensor systems for monitoring parameters like temperature and vibrations are costly and power-consuming due to the need for additional devices such as accelerometers or microphones.
Innovation Solution
A self-powered sensor system that utilizes a piezoelectric power source to generate power based on vibrations, a charge management circuit to control data transmission rates, and a processor to identify changes in vibration profiles without requiring separate vibration sensing devices, thereby detecting variations in mechanical properties of equipment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a separate vibration sensing device such as an accelerometer is used to sense vibrations, then vibration sensing capability is improved, but system cost and power consumption increase
Solution Approach 1:
The piezoelectric device is designed to perform multiple functions: it generates electrical power from vibrations and simultaneously enables vibration sensing through monitoring its own power generation characteristics. This eliminates the need for separate vibration sensing devices while maintaining sensing capability and reducing power consumption.
Solution Approach 2:
The system uses the piezoelectric device's own power generation output to detect vibration changes. By monitoring the electrical power generated by the piezoelectric element, the system can infer vibration profile changes without requiring additional sensing components, making the system self-sufficient for both power and sensing needs.
2Measurement precision
If a separate vibration sensing device such as an accelerometer is used to sense vibrations, then vibration sensing capability is improved, but system cost increases
Solution Approach 1:
The piezoelectric device serves dual purposes as both a power source and a vibration sensing mechanism. By monitoring the electrical characteristics of the piezoelectric element itself, the system achieves vibration sensing functionality without adding expensive separate sensors, thereby reducing overall system cost.
Solution Approach 2:
The invention merges the power generation function and vibration sensing function into a single piezoelectric device. The electrical power output from the piezoelectric element contains information about vibration characteristics, allowing the system to combine both functions in one component rather than using separate devices.
3Device complexity
If the charge cycle time is used to detect vibration changes, then additional vibration sensing devices are eliminated, but the system requires careful management of charge cycles to ensure accurate detection
Solution Approach 1:
The controller monitors the charge cycle time of the capacitor and uses this feedback to detect changes in vibration profile. By continuously measuring how long it takes to charge the capacitor to a threshold voltage, the system can infer vibration changes and adjust its operation accordingly, maintaining accuracy while managing 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
Enables cost-effective and power-efficient monitoring of vibrations and temperature without additional power consumption, allowing for real-time detection of potential equipment failures through changes in transmission rates.
Implementation Method 1
A self-powered sensor system that utilizes a piezoelectric power source to generate power based on vibrations
Data Source
AI summary
A self-powered sensor system and sensing method includes a power source generating power which is a function of a first parameter such as vibration. A charge management circuit is responsive to the power output by the power source and is configured to provide, every charge cycle, a supply signal to a controller which activates it to control a transmitter to transmit data at a transmission rate which is a function of the charge cycle. The data and the transmission rate are processed and used to identify a variation in the first parameter by a variation in the transmission rate beyond a predetermined threshold.