Vibrating Beam Nodal Point Alignment for Gyro Mounting Sensitivity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current Coriolis Vibratory Gyros (CVG) face challenges in minimizing vibration energy coupling to the mounting base, which reduces the high Q resonant frequency and increases sensitivity to mechanical impedance variations, limiting their performance in high-performance vibrating beam gyros.
Innovation Solution
The solution involves a vibrating beam with altered mass content in the center area, aligning the nodal points with the flexures, which are coupled to the mounting points, to minimize vibration energy coupling to the mounting base, thereby maintaining high Q and reducing mounting sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the beam is supported at the nodal points to minimize vibration energy coupling to the mounting base, then the Q of the resonant frequency is improved, but the nodal point location must be precisely controlled which increases manufacturing complexity
Solution Approach 1:
The patent changes the physical parameters of the beam by adding mass to the center area, which directly alters the nodal point location. This allows the nodal points to be positioned at the flexure mounting points without requiring precise manufacturing tolerances, as the mass addition actively adjusts the nodal point positions to match the mounting locations.
Solution Approach 2:
The patent performs preliminary action by adding mass to the beam's center area during manufacturing, before the beam is assembled and mounted. This pre-adjustment ensures that the nodal points are correctly positioned at the flexure locations prior to installation, eliminating the need for post-assembly adjustments or extremely tight manufacturing tolerances.
2Loss of energy
If the beam is supported at the nodal points to minimize vibration energy coupling to the mounting base, then energy loss is reduced, but the system becomes more sensitive to mechanical impedance variations which worsens reliability
Solution Approach 1:
By adding mass to the center area of the beam, the patent changes the dynamic parameters of the system, specifically shifting the nodal point locations. This parameter change allows the beam to be supported at the flexure mounting points while maintaining minimal vibration energy coupling, as the modified mass distribution ensures the nodal points coincide with the mounting locations, reducing sensitivity to impedance variations.
3Reliability
If mass is added to the center area to align nodal points with flexures, then mounting sensitivity is reduced, but the beam mass increases which may affect the gyroscopic performance
Solution Approach 1:
The patent applies local quality by adding mass specifically to the center area of the beam rather than uniformly increasing the entire beam's mass. This localized mass addition selectively alters the nodal point positions while minimizing the overall mass increase, thereby reducing mounting sensitivity without significantly affecting the gyroscopic performance that depends on the beam's total mass and moment of inertia.
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 effectively reduces vibration energy coupling to the mounting structure, maintaining high Q and low mounting sensitivity, enhancing the performance of vibrating beam gyros for accurate angular rate sensing.
Implementation Method 1
a beam having at least first and second mounting points that are operatively coupled to first and second flexures; the beam having first and second nodal points; the beam having a center area; and an altered mass content in a vicinity of the center area, the altered mass content being such that the first and second nodal points are substantially aligned with the first and second flexures
Implementation Method 2
An angular rate of the vibrating beam and the first oscillation induce a Coriolis force on the vibrating beam. For example, the angular rate is about the longitudinal axis of the vibrating beam. The Coriolis force causes a second oscillation of the vibrating beam. The second oscillation is substantially perpendicular to the first oscillation.
Data Source
AI summary
The apparatus in one embodiment may have: a beam having at least first and second mounting points that are operatively coupled to the beam by first and second flexures, respectivly; the beam having first and second nodal points; the beam having a center area; and an altered mass content in a vicinity of the center area, the altered mass content being such that the first and second nodal points are substantially aligned with the first and second flexures. The beam is therefore supported at the nodal points for the fundamental mode of vibration.