Piston Cylinder Position Sensing with RF Collimator Accuracy
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Solution Overview
Problem
Existing piston-cylinder units in work machines require complex and expensive magnetostrictive sensors for precise piston position detection, which is technically challenging and costly.
Innovation Solution
A piston-cylinder unit with a collimator integrated into the piston position detection unit using high-frequency technology, where the collimator improves signal quality by converting non-parallel beams into parallel beams for precise position detection, allowing for accurate measurement of piston position without significant structural changes or material addition.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If magnetostrictive sensors are used for piston position detection, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces complex magnetostrictive sensors with a simplified radio-frequency measurement system consisting of an antenna, collimator, and evaluation unit. This substitution eliminates the need for magnetostrictive materials and complex sensor structures while achieving comparable or superior measurement precision through electromagnetic wave-based distance measurement.
Solution Approach 2:
The patent changes the measurement approach from magnetostrictive effect-based to radio-frequency wave-based measurement. By transmitting RF signals and analyzing their reflection from the piston, the system achieves precise position detection without requiring complex magnetostrictive sensor structures, thereby reducing device complexity while maintaining measurement accuracy.
2Device complexity
If radio-frequency technology is used for position detection, then device complexity is reduced, but measurement precision deteriorates due to signal quality issues at larger distances
Solution Approach 1:
The patent introduces a collimator as an intermediary component between the antenna and the piston. The collimator focuses and directs the radio-frequency beams, improving signal quality and measurement precision at larger distances. This intermediary element enables the simple RF-based system to achieve high measurement accuracy by optimizing the electromagnetic wave propagation and reflection characteristics.
3Measurement precision
If a collimator is added to improve signal quality, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The collimator serves as a simple intermediary optical component that focuses RF beams without requiring complex electronics or processing. By adding only this passive focusing element, the system achieves improved signal-to-noise ratio and measurement precision while maintaining relatively simple device architecture. The collimator's straightforward geometric design minimizes the increase in device complexity.
Solution Approach 2:
The collimator utilizes curved or lens-like geometric structures to focus and direct radio-frequency beams. This geometric approach to beam focusing achieves improved signal quality and measurement precision without requiring complex electronic control or processing systems. The curved geometry of the collimator naturally directs the RF waves toward the piston, improving measurement accuracy with minimal added 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
The solution enhances measurement accuracy and reduces structural complexity and cost by filtering out unwanted signals and amplifying direct signals, improving signal-to-noise ratio, especially at larger distances, while maintaining the existing installation space and avoiding overloading of the piston-cylinder unit.
Implementation Method 1
The piston position detection unit serves to detect the axial position of the piston in the cylinder using radio-frequency technology and, for this purpose, has an antenna for transmitting and receiving radio-frequency signals
Implementation Method 2
A collimator is arranged in the beam path of the antenna. The collimator improves the precision of the piston position detection unit in several ways and therefore leads to improved measurement results when determining the piston's position
Data Source
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AI summary
A piston-cylinder unit (1) of a working machine, e.g., a wheel loader, excavator, dump truck, crane, forklift, or lifting platform, serves to steer, support, extend, tilt, lift, or otherwise move the working machine or a tool or other part of the working machine. The piston-cylinder unit (1) comprises a cylinder (2), a piston (7) axially movably mounted in the cylinder (2) along a longitudinal central axis (54), and a piston position sensing unit (28). The cylinder (2) has a mounting bore (27) extending radially within the cylinder (2). The piston position sensing unit (28) is arranged in the mounting bore (27) and detects the axial position of the piston (7) in the cylinder (2) using high-frequency technology. The piston position sensing unit (28) has an antenna (46) for transmitting and receiving high-frequency signals. A collimator (57) is arranged in the beam path of the antenna (46).The antenna (46) has a main beam direction (63) which extends parallel to the longitudinal central axis (54).