Inductive Sensor Coil Feedback for Temperature-Stable Distance Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inductive sensor units face challenges in accurately determining the distance of metallic objects due to temperature-related inductance changes and other environmental influences, which affect the reliability of distance measurements and require additional sensors for temperature monitoring.
Innovation Solution
An inductive sensor unit that monitors the inductance and effective resistance of the sensor coil, providing these values via an interface to correct for environmental influences and use them for temperature profiling and system monitoring, eliminating the need for separate temperature sensors, and enabling the detection of mechanical loads and magnetic fields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temperature compensation is implemented using additional temperature sensors, then temperature monitoring accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The sensor coil serves dual purposes: detecting metallic objects through inductance changes and monitoring temperature through resistance changes. This multi-functionality eliminates the need for separate temperature sensors, reducing device complexity while maintaining measurement accuracy
Solution Approach 2:
The sensor coil's inherent resistance property is utilized to provide temperature information without requiring additional measurement components. The existing sensor infrastructure serves itself by providing both object detection and temperature monitoring functions
2Measurement precision
If additional temperature sensors are installed for monitoring, then temperature measurement capability is improved, but space requirements and cost increase
Solution Approach 1:
The sensor coil performs both object detection and temperature monitoring functions, eliminating the need for additional temperature sensors that would occupy extra space in the sensor housing or mounting area
3Measurement precision
If inductance monitoring is added to correct environmental influences, then distance measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The system continuously monitors inductance changes and uses this feedback to compensate for environmental influences such as temperature variations. The measured inductance values are used to correct distance measurements, improving accuracy while utilizing existing sensor components
Solution Approach 2:
Inductance measurements serve as an intermediary parameter that links environmental conditions to distance measurement corrections. By monitoring inductance changes caused by temperature and other environmental factors, the system can compensate for these influences without directly measuring them
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 solution provides accurate distance measurements and additional monitoring capabilities, reducing costs and space requirements, while allowing for automatic system condition analysis and fault detection, and enabling the creation of temperature profiles without additional sensors.
Implementation Method 1
The magnetic field generated by the coil via the current pulse or the oscillation of the resonant circuit induces eddy currents in the object from a sufficiently small distance of an approaching metallic object.
Implementation Method 2
The induced eddy currents, due to the magnetic coupling between the metallic object and the resonant circuit or coil, lead to a change in the frequency and/or amplitude of the resonant circuit or the pulse response signal received by the coil.
Data Source
Figure 1
Figure 2a~2c
Figure 3a~3b
AI summary
An inductive sensor unit for detecting a distance to a metallic object, comprising a sensor coil, wherein the sensor coil has an inductance and a resistance, and the sensor coil is supplied with an excitation signal, an evaluation unit for determining the distance, wherein the evaluation unit provides an evaluation signal depending on the determination, a circuit unit for determining an actual value of the inductance of the sensor coil and/or an actual value of the resistance of the sensor coil and/or a derived quantity functionally related to the actual value of the inductance or the actual value of the resistance, and an interface to provide, in addition to the evaluation signal, the actual value of the resistance and/or the actual value of the inductance and/or the derived quantity via the interface.