Mansell power lifter actuator failure analysis

Bailey, Donald (2016) Mansell power lifter actuator failure analysis. [USQ Project]

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The Mansell Power Lifter is a critical component of the Mansell Infant Retrieval System. It functions as an electrically powered stretcher which can be raised or lowered through the use of two independant DC-motor driven linear actuators. The Mansell Infant Retrieval System is a key piece of medical equipment used widely to transport critically ill infants. Over a number of years there have been reports of the linear actuators used in the Mansell Power Lifter failing unexpectedly. Due to the high reliability requirements of the Mansell Power Lifter as a medical device any failures are unacceptable, and as a result the manufacturer of the Mansell Power lifter has sought to identify the cause of the failures. The aim of this project was to attempt to identify the mechanism and cause of the actuator failures and if possible propose a potential solution.

In order to identify the failure mechanism and root cause, it was determined that data would need to be collected about the usage and operational characteristics of the linear actuators. After analysis of the situation, it was decided to construct an autonomous data collection device to collect real world usage data from the actuators. An integrated, microcontroller based, data logger device was designed and developed which could be placed on a Mansell Power Lifter and record operational data without interfering with normal operation. Analysis of the collected data was performed to identify any operational characteristics which might lead to failures. While an actual failure of the linear actuators was not observed during the testing period, the data obtained showed that the actuators were being subjected to a large number of short, sharp movements on a regular basis, which could be contributing to the limit switches in the actuators jamming. Since the definitive cause of the actuator failures could not be confirmed, given the data obtained, it was not possible to propose a guaranteed solution to the problem. Despite this, a number of potential solutions were proposed, which given further testing and analysis, could be implemented to help prevent actuator failures in the future.

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Item Type: USQ Project
Item Status: Live Archive
Additional Information: Bachelor of Engineering (Honours) Major Computer Systems Engineering project
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering (1 Jul 2013 - 31 Dec 2021)
Supervisors: Leis, John; Grant-Thomson, John
Date Deposited: 19 Jul 2017 01:18
Last Modified: 19 Jul 2017 05:50
Uncontrolled Keywords: electrically powered stretcher; mansell power lifter; actuator; failure analysis
Fields of Research (2008): 09 Engineering > 0913 Mechanical Engineering > 091302 Automation and Control Engineering
Fields of Research (2020): 40 ENGINEERING > 4007 Control engineering, mechatronics and robotics > 400799 Control engineering, mechatronics and robotics not elsewhere classified

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