Pressure Cylinder Position Sensing With Trinary Code Tracks
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing measuring systems for determining the absolute position of a piston rod in a pressure medium cylinder are cumbersome, requiring a large number of components and increased costs due to their extensive length, which limits the usable stroke of the piston.
Innovation Solution
A measuring system with a trinary code track formed by grooves and plateaus on the piston rod, scanned by a stationary sensor system with radially arranged Hall sensors, utilizing a De Bruijn sequence to reduce the length of the code track and sensor system, thereby minimizing component count and installation space while maximizing piston stroke.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a binary code track with stationary sensor is used to determine absolute position, then measurement precision is achieved, but the length of the sensor and code track becomes very large, reducing productivity
Solution Approach 1:
The patent changes the coding system from binary (two states) to trinary (three states), represented by grooves at three different depths. This parameter change in the code element structure allows for more information to be encoded in a shorter track length, directly resolving the contradiction between measurement precision and usable stroke length
Solution Approach 2:
Instead of using only lateral variations in the code track, the patent introduces a third dimension by varying the groove depth radially into the piston rod. This dimensional addition creates trinary code elements that provide higher information density, enabling accurate position measurement over a shorter axial length
2Measurement precision
If a long sensor is mounted on a special flange to achieve accurate position measurement, then measurement precision is improved, but the number of components increases, leading to higher costs
Solution Approach 1:
The patent merges the code track directly onto the piston rod surface, eliminating the need for a separate special flange mounting structure. The trinary code elements are formed by grooves cut into the piston rod itself, integrating the encoding function with the existing piston rod structure and reducing component count
Solution Approach 2:
The patent extracts the unnecessary intermediate flange component from the system by directly implementing the code track on the piston rod. This removal of the special mounting flange simplifies the overall structure while maintaining the ability to achieve accurate position measurements
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 significantly reduces the length of the sensor system and code track, halving the costs and increasing the usable piston stroke, while ensuring high accuracy and stability through redundant detection channels and plausibility checks.
Implementation Method 1
A stationary sensor system with a plurality of sensor elements arranged parallel to and radially spaced from the piston rod is a component of the measuring system. The sensor elements each scan a limited number of code elements.
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a measuring system and a pressure medium cylinder comprising a measuring system.