Severity: Warning
Message: file_get_contents(https://...@gmail.com&api_key=61f08fa0b96a73de8c900d749fcb997acc09&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 197
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 197
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 271
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3165
Function: getPubMedXML
File: /var/www/html/application/controllers/Detail.php
Line: 597
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 511
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 317
Function: require_once
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As the core component of aviation optoelectronic equipment, vibration isolator plays a crucial role in attenuating high frequency mechanical vibrations from airborne platforms, thereby ensuring the clarity and stability of the optoelectronic imaging system. This paper presents what we believe to be a novel six degrees of freedom vibration isolator (SDFVI) and introduces its forward design methodology tailored to meet the high frequency attenuation requirements all six degrees of freedom in aviation optoelectronic system. Initially, a SDFVI is proposed based on the Stewart platform principle, which exhibits elastic characteristics in both translational and rotational directions. Subsequently, the relationship between the characteristic parameters (stiffness and damping) of the SDFVI and its design parameters is established. Furthermore, the dynamic equation of six degrees of freedom isolation system, comprising the aviation optoelectronic device and the SDFVI, is derived by using the Newton-Euler formula. This derivation constructs a comprehensive mapping from the isolator design parameters to the isolation performance characteristics. Additionally, a forward design methodology for the SDFVI is summarized, enabling the rapid determination of isolator design parameters within specified constrains domain. Finally, a practical example is given and the effectiveness of the method proposed in the paper is validated through dynamic experiment. The results show that the SDFVI achieves a linear vibration isolation rate of about 97% above 15 Hz, while the RMS values of the coupled angular responses about the other two axes are 7.4 µrad and 8.1 µrad. This indicates that the SDFVI can meet the requirements with a single production run and improve the design efficiency. The methodology outlined in this paper offers a valuable reference for the design of vibration isolator in aviation optoelectronic platform.
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http://dx.doi.org/10.1364/OE.564911 | DOI Listing |