Temperature Compensated Torque Sensor Using Feedback Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Magnetostrictive torque sensors face inaccuracies due to temperature-induced changes in magnetic properties of materials, leading to deviations in torque measurements independent of applied torque.
Innovation Solution
Incorporating a temperature sensor positioned to avoid interference with the magnetic flux while ensuring accurate temperature measurement, allowing for compensation of torque measurements based on temperature variations, thereby enhancing measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a magnetostrictive torque sensor is used to measure torque, then torque measurement capability is provided, but measurement precision deteriorates due to temperature-induced changes in magnetic properties
Solution Approach 1:
The patent implements a feedback mechanism by measuring the actual temperature of the shaft or sensor head with a temperature sensor, comparing it to a reference temperature, and using the temperature difference to generate a compensation signal that adjusts the torque measurement output. This closed-loop feedback system continuously corrects for temperature-induced magnetic property changes, thereby maintaining measurement precision across varying temperature conditions.
Solution Approach 2:
The patent changes the operational parameters of the magnetostrictive sensor by adjusting its magnetic properties based on temperature conditions. A temperature-dependent compensation mechanism modifies the sensor's magnetic characteristics (such as permeability or coercivity) to counteract the adverse effects of temperature variations, effectively transforming the sensor's parameters to maintain optimal performance across different temperatures.
2Measurement precision
If a temperature sensor is added to compensate for temperature effects, then measurement accuracy improves, but device complexity increases
Solution Approach 1:
The patent merges the temperature compensation function with the existing torque sensing mechanism by integrating a temperature sensor into the sensor head assembly. The temperature sensor, compensation circuitry, and torque measurement system are combined into a single integrated unit, allowing temperature compensation to be implemented without requiring a completely separate system, thereby limiting the increase in device complexity.
Solution Approach 2:
The patent introduces a temperature sensor as an intermediary element that mediates between the physical temperature conditions and the torque measurement system. This intermediary device converts temperature information into an electrical signal that can be processed by the compensation circuitry, providing a simple and effective bridge that adds minimal complexity while enabling accurate temperature compensation.
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 improves the accuracy of torque measurements by accounting for temperature effects on magnetic permeability, resulting in more reliable control of rotating machine components.
Implementation Method 1
A magnetostrictive torque sensor can generate magnetic flux that permeates a shaft and it can sense the magnetic flux as it interacts with the shaft
Implementation Method 2
magnetostriction is a property of ferromagnetic materials that characterizes changes in shape (e.g., expansion or contraction) of the material in the presence of a magnetic field. Conversely, magnetic properties of a ferromagnetic material, such as permeability (the capability to support development of a magnetic field within the material) can change in response to torque applied to the material
Implementation Method 3
the sensor head includes a temperature sensor disposed on the sensor head
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A temperature compensated torque sensing system and methods (700) for using the same are provided. The system can include a sensor head (202,300) in electrical communication with a controller (114,204). The sensor head (202,300) can contain a torque sensor including a core, a driving coil (212) and a sensing coil (214,502). The sensor head (202,300) can also include a temperature sensor (112,216,400,500) coupled to the sensor head (202,300). The torque sensor can be configured to measure torque applied to a selected portion of a target (222) based upon magnetic flux passing through the target (222), while the temperature sensor (112,216,400,500) can be configured to concurrently measure the target temperature. The temperature sensor (112,216,400,500) can be positioned for avoiding interference with sensed magnetic flux. The controller (114,204) can adjust the determined torque using the temperature measurements to compensate for changes in magnetic properties of the target (222) due to variation in target temperature. In this manner, the accuracy of the torque measurements can be increased.