Accelerometer Protective Housing for Radiation Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Accelerometer systems using electromagnetic forces to counteract proof mass displacement are affected by hysteresis, which is exacerbated by adhesive materials with different thermal expansion coefficients and the presence of magnets in the magnetic circuit assembly.
Innovation Solution
The use of a magnetic circuit assembly with fewer boundaries between dissimilar materials and the removal of magnets from the magnetic flux pathway can mitigate hysteresis effects. Additionally, an excitation ring with a recess houses electronic circuitry to protect it from harmful environments and reduce hysteresis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive materials are used to connect pieces of metal alloy material in the magnetic circuit assembly, then the structural integrity is improved, but hysteresis effect increases due to different coefficients of thermal expansion
Solution Approach 1:
The patent removes magnets from the magnetic circuit assembly to eliminate the source of hysteresis. By extracting the magnetic components that cause the problem, the system achieves better reliability without hysteresis effects while maintaining structural integrity through alternative design configurations.
Solution Approach 2:
The patent changes the material parameters of the magnetic circuit assembly by using pieces of metal alloy material with matched coefficients of thermal expansion. This parameter change reduces thermal expansion differences at boundaries, thereby reducing hysteresis effects while maintaining structural strength through proper material selection.
2Power
If magnets are present along the flux path in the magnetic circuit assembly, then the electromagnetic functionality is improved, but hysteresis effect increases
Solution Approach 1:
The patent extracts magnets from the magnetic circuit assembly, removing them from the flux path entirely. This eliminates the hysteresis effect caused by magnetic materials while maintaining electromagnetic functionality through alternative configurations that do not rely on permanent magnets in the flux path.
3Device complexity
If electronic circuitry is exposed to the external environment, then the device complexity is reduced, but the circuitry is vulnerable to harmful environments such as radiation and high temperatures
Solution Approach 1:
The patent nests electronic circuitry within the magnetic circuit assembly structure. By placing the circuitry inside the assembly and using the assembly's housing as protection, the design shields sensitive components from harmful environments like radiation and extreme temperatures while avoiding the need for separate protective structures.
Solution Approach 2:
The magnetic circuit assembly serves multiple functions: it provides the magnetic flux path for accelerometer operation, structural support, and simultaneously acts as a protective housing for the electronic circuitry. This multi-functionality reduces overall device complexity while protecting sensitive components.
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 approach improves the performance of accelerometer systems by reducing hysteresis, thereby enhancing accuracy and reliability, especially in environments with high temperatures and harmful radiation.
Implementation Method 1
hysteresis may be present when a change in one electromagnetic parameter lags behind a change in another magnetic parameter such that a behavior of the system depends on the history of the system. One example of hysteresis is when a change in magnetic flux lags behind a change in magnetic force.
Implementation Method 2
a change in magnetic flux lags behind a change in magnetic force. This means that magnetic flux does not immediately disappear from a material when magnetic force is removed from the material.
Implementation Method 3
A magnetic circuit assembly may include an excitation ring that forms a recess and is configured to be assembled from multiple pieces, such that the electronic circuitry may be placed within the recess. The excitation ring may be made of materials that protect the electronic circuitry from harmful environments
Implementation Method 4
electrically conductive material (e.g., a capacitor plate) may be deposited on the upper surface of the proof mass, and similar electrically conductive material may be deposited on the lower surface of the proof mass. An acceleration or force applied along the sensitive axis of the accelerometer causes the proof mass to deflect either upwardly or downwardly causing the distance (e.g., a capacitive gap) between the pick-off capacitance plates and upper and lower non-moving members to vary.
Implementation Method 5
Accelerometers function by detecting a displacement of a proof mass under inertial forces.
Implementation Method 6
The change in the capacitance may be used as a displacement signal, which may be applied to a servo system that includes one or more electromagnets (e.g., a force-rebalancing coil) to return the proof mass to a null or at-rest position.
Data Source
AI summary
In some examples, an accelerometer system includes a first excitation ring comprising: a first housing; and a first cover removably attached to the first housing, wherein the first housing and the first cover define a first recess. The accelerometer system also includes a second excitation ring comprising: a second housing; and a second cover removably attached to the second housing, wherein the second housing and the second cover define a second recess. The accelerometer system also includes a proof mass assembly; and processing circuitry located within one or both of the first recess and the second recess, wherein the first excitation ring and the second excitation ring shield the processing circuitry from harmful levels of radiation existing outside of the accelerometer system, and wherein the processing circuitry is configured to maintain a proof mass of the proof mass assembly in a null position.