Actuator Load Path Failure Detection Using Vibration Strain Gauges
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing actuators lack effective means to detect and identify the failure of the primary load path, leading to potential uncontrolled loading on the secondary load path during failure scenarios.
Innovation Solution
A system comprising strain gauges mounted on the static and nut assemblies of the actuator to measure vibrations, with a processor comparing these measurements to identify primary load path failure, activating alarms or notifying users when necessary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a secondary load path is provided for backup, then reliability is improved, but the ability to detect primary load path failure deteriorates
Solution Approach 1:
The patent introduces strain gauges as intermediary sensing elements that detect vibrations in the primary and secondary load paths. These strain gauges serve as mediators between the mechanical load path and the electronic detection system, enabling indirect measurement of load path status through vibration analysis without interfering with the mechanical function of the load paths themselves.
Solution Approach 2:
The patent replaces direct mechanical monitoring of load path integrity with an electronic sensing and processing system. Instead of using mechanical switches or direct contact sensors that would interfere with the load path, the system uses strain gauges to convert mechanical vibrations into electrical signals, which are then processed electronically to detect failure conditions.
2Measurement precision
If vibration measurements are taken from both static and nut assemblies, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent divides the actuator into two functional segments for measurement purposes: the static assembly and the nut assembly. Each segment is equipped with its own strain gauge, allowing independent measurement of vibrations at different locations. This segmentation enables more precise failure detection by comparing measurements from both segments, while keeping each measurement system simple and modular.
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
Enables timely detection and notification of primary load path failure, ensuring safe transfer of load to the secondary path, thereby preventing damage and maintaining actuator functionality.
Implementation Method 1
a first strain gauge configured to be mounted to the static portion and to measure vibrations of the static portion and a second strain gauge configured to be mounted to the nut assembly and to measure vibrations of the nut assembly
Data Source
Figure 1
Figure 2
Figure 3
AI summary
There is provided a system for identifying a failure of the primary load path in an actuator (200). The actuator comprises a screw shaft (210), a static portion (202) fixedly attached to the screw shaft (210) and a nut assembly (400) moveable along the screw shaft (210). The nut assembly (400) is moveable relative to the static portion (202). The nut assembly (400) comprises a primary nut (420) for transmitting load through the actuator (200) along a primary load path, and a secondary nut (440) for transmitting load through the actuator (200) along a secondary load path. The nut assembly (400) is configured such that, in normal operation, the secondary nut (440) is not engaged with the screw shaft (210) and load is transmitted through the actuator (200) along the primary load path, and such that, upon failure of the primary load path, the secondary nut (440) is configured to engage the screw shaft (210) and transmit load through the actuator (200) along the secondary load path. The system comprises a first strain gauge (480a) configured to be mounted to the static portion (200) and to measure vibrations of the static portion (200) and a second strain gauge (480b) configured to be mounted to the nut assembly (400) and to measure vibrations of the nut assembly (420). The system comprises a processor configured to identify a failure of the primary load path by comparing the measured vibrations of the static portion (200) and the measured vibrations of the nut assembly (400). There is also provided a method for identifying a failure of the primary load path in an actuator (200).