Magneto-elastic Force Sensor Distance Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magneto-elastic torque sensors are sensitive to distance changes between the sensor and the shaft, leading to measurement inaccuracies, especially in applications with large shafts, and require additional distance sensors that introduce adjustment errors.
Innovation Solution
A magneto-elastic force sensor with a transmitting coil and magnetic field sensors that records an electrical variable representing the inductance, allowing it to determine the distance to the measurement object and correct measurement results without an additional distance sensor, thereby compensating for distance-dependent fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magneto-elastic torque sensor is used to measure torque on shafts, then torque measurement capability is provided, but measurement precision deteriorates due to sensitivity to distance changes between sensor and shaft
Solution Approach 1:
The patent implements feedback by continuously monitoring the distance between the sensor and shaft using the same magneto-elastic sensor principle, then using this distance information to compensate for distance-dependent variations in the torque measurement signal. The evaluation unit dynamically adjusts the measurement based on real-time distance data, creating a closed-loop system that maintains measurement precision despite position changes.
Solution Approach 2:
The patent changes the operational parameters by recording not only the torque-related magnetic flux but also the inductance of the transmitting coil, which serves as a distance indicator. By analyzing changes in the inductance parameter, the system determines distance variations and uses this information to compensate for their effect on the torque measurement, thereby maintaining accuracy across varying positions.
2Measurement precision
If an additional distance sensor is added to compensate for distance changes, then measurement precision improves, but device complexity increases
Solution Approach 1:
The patent applies multi-functionality by enabling the magneto-elastic sensor to serve dual purposes: measuring both torque and distance. The same sensor head with transmitting coil and magnetic field sensors is used to detect both the torque-induced magnetic flux changes and the distance-induced inductance changes. This eliminates the need for a separate distance sensor, reducing system complexity while maintaining the ability to compensate for distance variations.
Solution Approach 2:
The patent merges the distance measurement function with the torque measurement function by combining the evaluation of magnetic flux (for torque) and inductance (for distance) within a single sensor system. The recording device captures both signals, and the evaluation unit processes them together, integrating what would traditionally be separate measurement systems into one unified device.
3Device complexity
If the sensor is positioned fixedly relative to the shaft, then device complexity is reduced, but measurement precision deteriorates due to inability to compensate for position changes
Solution Approach 1:
The patent introduces dynamics by enabling the sensor to adapt to position changes rather than maintaining a fixed rigid positioning system. The sensor continuously monitors its own position relative to the shaft through inductance changes and dynamically adjusts the torque measurement compensation accordingly. This allows the sensor to maintain measurement precision even when the physical position varies, eliminating the need for complex active positioning mechanisms.
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 configuration enables accurate force measurement without the need for additional sensors, reducing adjustment errors and enhancing the robustness of the magneto-elastic force sensor by using the same measuring head for force and distance measurement.
Implementation Method 1
A transmitting coil (9) which generates a magnetic field
Implementation Method 2
at least one magnetic field sensor (11) for measuring a magnetic flux caused by the magnetic field of the transmitting coil (9) in a measurement object
Implementation Method 3
The permeability of ferromagnetic materials is influenced by mechanical stresses. This physical effect which is known as the magneto-elastic effect can be used to measure forces which act on an item and cause stresses in this item
Data Source
AI summary
A magneto-elastic force sensor includes a sensor head (1) that has an emitting coil (9) which generates a magnetic field and at least one magnetic field sensor (11) for measuring a magnetic flux caused by the magnetic field of the emitting coil (9) in a measured object (13). The sensor head (1) also includes a recorder (14) for recording an electrical value that reflects the inductivity of the emitting coil (9) or that is clearly connected to the latter. The magneto-elastic force sensor allows for compensation of a distance dependency in the measurement signal by ascertaining the distance between the emitting coil (9) or the sensor head (1) and the measured object (13) based on the recorded electrical value and by compensating the distance dependency in the measurement signal based on the ascertained distance.