Microwave Piston Position Detection via Phase Analysis
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Solution Overview
Problem
Existing methods for determining the position of a piston in a piston cylinder lack high measurement accuracy and speed while also being minimally invasive, and they often require complex and invasive setups.
Innovation Solution
A method and device utilizing frequency-modulated microwave signals, where phase determination is carried out in both the baseband and sidebands, allowing for simultaneous fine and rough position determination, and bandpass filtering is used to filter signals based on fundamental and modulation frequencies, enabling high-precision distance measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex invasive measurement setups are used, then measurement accuracy may be improved, but device complexity and invasiveness increase
Solution Approach 1:
The patent replaces complex mechanical measurement systems with a microwave-based electromagnetic measurement system. By using microwave signals that propagate through the cylinder medium and reflect off the piston, the system achieves high measurement precision without requiring physical contact or invasive mechanical sensors on the piston itself
Solution Approach 2:
The patent introduces microwave signals as an intermediary medium to measure piston position indirectly. Instead of directly measuring piston position with complex sensors, the system uses microwave transmission and reflection characteristics, which are affected by the piston position, to determine position information through signal processing
2Productivity
If high measurement speed is achieved, then productivity is improved, but measurement precision may deteriorate
Solution Approach 1:
The patent employs periodic frequency modulation of microwave signals to enable high-speed measurements. By modulating the microwave carrier signal with a periodic modulation signal and analyzing the phase of the modulated signal, the system achieves both high measurement speed through rapid signal cycling and high precision through phase-based position determination
Solution Approach 2:
The patent uses dynamic frequency modulation techniques where the microwave signal frequency is continuously varied according to a modulation pattern. This dynamic approach allows the system to extract position information from phase changes at different modulation frequencies, enabling simultaneous high-speed operation and high measurement precision
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 allows for high-precision, high-speed absolute distance measurement with minimal invasive intervention, providing reliable and accurate piston position determination.
Implementation Method 1
a microwave transmission signal is emitted in the direction of the piston and microwaves reflected by the piston are detected
Implementation Method 2
the transmission signal comprising a modulated signal which has a fundamental frequency modulated sinusoidally with a modulation frequency
Implementation Method 3
an evaluation of the phase between transmission signals and reception signals is carried out
Data Source
Figure 1
Figure 2
Figure 3a~3b
AI summary
A method for detecting the position of a piston of a piston cylinder is provided. A microwave transmit signal is emitted in the direction of the piston and microwaves reflected from the piston are detected. The transmit signal is a modulated signal with a base frequency sinusoidally modulated at a modulation frequency. An evaluation of the phase between transmit signals and receive signals is performed. A phase determination at the baseband and a simultaneous phase determination at at least one sideband are also performed. The phase determination at the baseband is used for fine determination of the piston position and the phase determination at the at least one sideband is used for coarse determination of the piston position. Bandpass filtering on receive signals and evaluation transmit signals is performed with respect to the base frequency or an intermediate frequency. Bandpass filtering is performed with respect to the modulation frequency.