Double Piston Rod Position Detection Using Electromagnetic Phase Difference
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Solution Overview
Problem
Existing distance measuring devices in fixed-pipe process plants, such as those in the food and pharmaceutical industry, are complex to install, prone to mechanical wear, and require additional space, making them inefficient for accurately detecting the position of pneumatic valves.
Innovation Solution
A distance measuring apparatus using a sensor device with antennas to transmit and receive electromagnetic waves, determining the position of reflection bodies within a line structure by evaluating the phase difference between transmitted and received waves, which can be integrated into the valve or line structure without contact and with high precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional sensors (potentiometers, LVDTs, reed switches) are used to detect valve position, then position detection function is achieved, but device complexity increases and installation becomes complex
Solution Approach 1:
The patent replaces mechanical sensors (potentiometers, LVDTs, reed switches) with an electromagnetic field-based measurement system. The system uses a sensor device that generates an electromagnetic field and detects changes in the field caused by the position of conductive components in the piston rod, thereby eliminating mechanical contact and complex mechanical sensor assemblies.
Solution Approach 2:
The sensor device serves multiple functions: it generates the electromagnetic field for detection, acts as the measurement probe, and integrates directly into the existing valve structure. The evaluation electronics process the electromagnetic signals to determine position, combining sensing and evaluation in a unified system that replaces multiple separate mechanical components.
2Measurement precision
If mechanical sensors are used for position detection, then position information is obtained, but mechanical wear and tear occurs reducing reliability
Solution Approach 1:
The patent eliminates mechanical contact between the sensor and the piston rod by using electromagnetic field interaction. The sensor device generates an electromagnetic field that penetrates the guide pipe wall and interacts with conductive components on the piston rod, allowing position detection without physical contact and thus preventing mechanical wear.
Solution Approach 2:
The electromagnetic field acts as an intermediary between the sensor device and the piston rod position. Instead of direct mechanical contact, the electromagnetic field carries information about the piston rod position back to the sensor, enabling non-contact measurement and improving reliability.
3Measurement precision
If external sensors are mounted on valves for position detection, then position measurement is possible, but additional external space is required
Solution Approach 1:
The sensor device is integrated directly into the valve structure, specifically utilizing the guide pipe as part of the sensor assembly. The evaluation electronics are incorporated into the valve's existing electronic components, merging the measurement function with the valve structure and eliminating the need for separate external sensor mounting space.
Solution Approach 2:
The guide pipe serves dual functions: it provides mechanical guidance for the piston rod and simultaneously acts as part of the electromagnetic sensing structure. The evaluation electronics also serve dual purposes by processing both valve control signals and position measurement signals, eliminating the need for dedicated external measurement equipment.
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 solution provides a precise, wear-resistant, and space-efficient method for detecting the position of pneumatic valve components, enabling accurate positioning without mechanical contact and additional external space requirements, suitable for various valve configurations.
Implementation Method 1
a sensor device, which has at least one antenna for feeding a transmission signal as an electromagnetic wave into the line structure and for receiving the electromagnetic wave reflected on the reflection body
Implementation Method 2
evaluation electronics which are configured to determine the position of the reflection body from the phase difference between the transmitted and the received wave
Data Source
AI summary
A distance measuring apparatus for detecting the position of a reflection body in a line structure is provided that includes a sensor device, which has at least one antenna for feeding a transmission signal as an electromagnetic wave into the line structure and for receiving the electromagnetic wave reflected on the reflection body. The sensor device also includes evaluation electronics which are configured to determine the position of the reflection body from the phase difference between the transmitted and the received wave.