Electrostatic Capacitance Height Measurement via Frequency Sweeping
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Solution Overview
Problem
Existing height measuring apparatuses using ultrasonic sensors require the person to input their approximate height, which is inconvenient and may lead to inaccuracies.
Innovation Solution
A height measuring apparatus employing an electrostatic capacitance sensor with a variable frequency pulse generator to identify the frequency at which mutual capacitance is minimized, allowing for height measurement without user input, using a control apparatus to sweep the frequency of the pulse and determine the height based on the electrostatic capacitance measured between transmission and reception electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If ultrasonic sensor is used for height measurement, then height can be measured, but user input of approximate height is required
Solution Approach 1:
The system performs self-measurement by automatically determining height through capacitance sensing without requiring user input. The control apparatus autonomously sweeps frequency, measures capacitance values, identifies resonance frequency, and calculates height, making the system self-sufficient and eliminating the need for user-provided approximate height data
Solution Approach 2:
The system changes the frequency parameter of the pulse signal to sweep through a range of values. By measuring capacitance at different frequencies and identifying the resonance frequency where capacitance is maximized, the system translates a physical dimension (height) into an electrical parameter (resonance frequency) for automatic determination
2Measurement precision
If ultrasonic sensor receives reflected waves from multiple body portions, then measurement can be performed, but system complexity increases
Solution Approach 1:
The invention extracts the height measurement function from complex ultrasonic multi-point detection systems and implements it through a simplified capacitance sensing mechanism. Instead of using multiple ultrasonic receivers to detect reflected waves from different body parts, the system uses a single capacitance sensor to measure the resonant frequency of the human body, thereby achieving height measurement with reduced system complexity
Solution Approach 2:
The system replaces the mechanical ultrasonic wave transmission and reception mechanism with an electrical capacitance sensing mechanism. By substituting ultrasonic sensors with capacitance sensors that measure the resonant frequency of the human body through electrical fields, the system achieves simpler hardware configuration while maintaining measurement capability
3Ease of operation
If frequency sweeping is performed to identify resonance frequency, then user input is eliminated, but measurement time increases
Solution Approach 1:
The control apparatus continuously sweeps through a frequency range without interruption, measuring capacitance values at each frequency point. This continuous frequency sweeping process efficiently identifies the resonance frequency where capacitance is maximized, completing the height measurement automatically without user intervention while minimizing total measurement time through uninterrupted operation
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 accurate height measurement without user input, reducing operational time and power consumption, and simplifying the system configuration, while being less influenced by external factors like shoe soles or building thickness.
Implementation Method 1
allows an electrostatic capacitance sensor to measure a mutual capacitance between the transmission electrode and a reception electrode
Implementation Method 2
identify a frequency at which the measured mutual capacitance becomes a minimum value
Data Source
AI summary
An ultrasonic receiver receives ultrasonic waves reflected at a plurality of portions of the body of a person to be measured, and thus the person to be measured needs to input the approximate height of himself/herself. An electrostatic capacitance sensor includes a transmission electrode and a reception electrode. The electrostatic capacitance sensor measures a mutual capacitance between the transmission electrode and the reception electrode by a mutual capacitance method. A variable frequency pulse generator generates a pulse supplied to the transmission electrode. A control apparatus allows the variable frequency pulse generator to sweep the frequency of the pulse and allows the electrostatic capacitance sensor to measure the mutual capacitance to identify a frequency at which the measured mutual capacitance is minimized. The control apparatus obtains the height of a person to be measured on the basis of the identified frequency.