Yawei Wang, Weihu Zhou, Xiaoquan Han, Zhongyu Wang and Jinbin Ding
The purpose of this paper is to describe a strap‐down image stable strategy for multi‐load optoelectronic imaging platform hung below a tethered aerostat.
Abstract
Purpose
The purpose of this paper is to describe a strap‐down image stable strategy for multi‐load optoelectronic imaging platform hung below a tethered aerostat.
Design/methodology/approach
Four two dimension pods, each with a visible light camera, are fixed on the optoelectronic platform. A POS (Position and Orientation System) is used to acquire the attitude rate data of optoelectronic platform, while the data can be coupled to the pods' servo systems through corresponding coordinate rotation, then the motors of pods will adjust the line of sight to the opposite way to keep the stabilization of image exported by visible light camcorders. Simultaneously, two rate gyros are installed at the inner frame of each pod, which are used as a backup to avoid the failure of POS.
Findings
Using one attitude and position measurement system can realize the stabilization of multi optoelectronic pods, which is same as or even better than the ratio gyro stabilization.
Research limitations/implications
As the tethered aerostat is a flexible body, it is affected a lot by the wind speed and wind direction at the low height (<1,000 m), which leads to the motors of pods always adjust the line of sight to the mechanical limiting of pods.
Practical implications
Strap‐down stabilization technology has been successfully used in the tethered aerostat monitoring platform to surveillance Shanghai World EXPO site. Long time experiments verify the feasible and effective of the multi‐load stabilization technology. The impact on the image by the adjustment of servos is less than 10 percent of the whole view of sight.
Originality/value
The paper introduces a strap‐down stabilization technology for multi‐load tethered aerostat platform, which is more suitable to be applied in the platform of relatively minor attitude change, like the airborne multi‐load platform and multi‐load UAV (unmanned aerial vehicle) platform.
Details
Keywords
Cheng Jiang, Ying Yang, Xuequn Cheng, Jinbin Zhao and Xiaogang Li
This study aims to study the effect of Sn on the corrosion behavior of weathering steel (WS) in a simulated tropical marine atmosphere.
Abstract
Purpose
This study aims to study the effect of Sn on the corrosion behavior of weathering steel (WS) in a simulated tropical marine atmosphere.
Design/methodology/approach
Indoor alternate immersion tests, electrochemical measurements and real-time current-monitoring technology based on the galvanic corrosion principle were used and the scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy and electron probe microanalyzer were used to analyze the morphology and component of the rust layer.
Findings
The results indicated that Sn has a positive influence on the corrosion process. Sn participated in the composition of the rust layer in the form of SnO2 and is enriched in the inner rust layer. SnO2 participated in the coprecipitation process with iron oxides and oxyhydroxides, which promoted further transformation of γ-FeOOH to α-FeOOH. As a result, the rust layer of Sn-containing steel was continuous, compact and effectively blocked the invasion of aggressive Cl−. Therefore, the additive of Sn enhanced the corrosion resistance of WS in a simulated tropical marine atmosphere.
Originality/value
The corrosion behaviors of WS were researched by the real-time current-monitoring technology which was rarely used.