Influence of motion characteristics of dual stealth aircraft on monopulse radar performance

This paper studies the measurement of motion parameters of a parachute scanning platform. The movement of a parachute scanning platform has fast rotational velocity and a complex attitude. Therefore, traditional measurement methods cannot measure the motion parameters accurately, and thus fail to satisfy the requirements for the measurement of parachute scanning platform motion parameters. In order to solve these problems, a method for measuring the motion parameters of a parachute scanning platform based on a combination of magnetic and inertial sensors is proposed in this paper. First, scanning motion characteristics of a parachute-terminal-sensitive projectile are analyzed. Next, a high-precision parachute scanning platform attitude measurement device is designed to obtain the data of magnetic and inertial sensors. Then the extended Kalman filter is used to filter and observe errors. The scanning angle, the scanning angle velocity, the falling velocity, and the 2D scanning attitude are obtained. Finally, the accuracy and feasibility of the algorithm are analyzed and validated by MATLAB simulation, semi-physical simulation, and airdrop experiments. The presented research results can provide helpful references for the design and analysis of parachute scanning platforms, which can reduce development time and cost.

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Coupled motion characteristics of a large-scale tunnel element suspended by immersion rigs in the vicinity of seabed

Tunnelling and Underground Space Technology ◽

10.1016/j.tust.2020.103804 ◽

2021 ◽

Vol 110 ◽

pp. 103804

Author(s):

Yue Song ◽

Nian-Zhong Chen ◽

Ningchuan Zhang

Keyword(s):

Large Scale ◽

Coupled Motion ◽

Motion Characteristics

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Seed motion characteristics and seeding performance of a centralised seed metering system for rapeseed investigated by DEM simulation and bench testing

Biosystems Engineering ◽

10.1016/j.biosystemseng.2020.12.017 ◽

2021 ◽

Vol 203 ◽

pp. 22-33

Author(s):

Xiaolong Lei ◽

Hongji Hu ◽

Wencheng Wu ◽

Hongnan Liu ◽

Liyang Liu ◽

...

Keyword(s):

Dem Simulation ◽

Motion Characteristics ◽

Bench Testing

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A reciprocating permanent magnetic actuator for driving magnetic micro robots in fluids

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/09544062211014547 ◽

2021 ◽

pp. 095440622110145

Author(s):

Chuan Qu ◽

Yong-Chen Pei ◽

Qing-Yuan Xin ◽

Zhen-Xing Li ◽

Long Xu

Keyword(s):

Permanent Magnet ◽

Analytical Calculation ◽

Magnetic Actuator ◽

Cross Sectional ◽

Permanent Magnetic Actuator ◽

Element Simulation ◽

Micro Robot ◽

Analytical Formulas ◽

Motion Performance ◽

Motion Characteristics

Magnetic-based driving applications are receiving increasing attention. This study proposed a novel reciprocating permanent magnetic actuator (PMA) to manipulate magnetic micro robots to impact and clear blockages inside fluid pipes in a linear path. The PMA consisted of a cylindrical permanent magnet and a crank slider structure. A straight pipe with a circular cross-sectional area was located in front of the actuator to study the driving performance of PMA. A micro permanent magnet with a cylinder shape was employed as a working robot for manipulation inside the pipe. Firstly, analytical formulas were derived to obtain the magnetic driving force acting on the micro robot and determine the most suitable magnet configuration. The finite element simulation verified the analytical calculation. The developed reciprocating PMA prototype was then introduced, and the PMA and micro robot’s motion performance was analysed. Lastly, preliminary experiments were carried out for evaluating the micro robot’s motion characteristics. Performance tests for different excitation frequencies, flow rates, viscosities, and axial distances, indicating that PMA could manipulate the magnetic micro robot inside the pipe. The results confirmed that the developed PMA could effectively drive the micro robot with the advantage of consecutive magnetic driving. Especially, the micro robot featured good flexibility, rapid response, and a simple structure, suggesting that this micro robot may play an important role in industrial and medical applications, such as blockage elimination and thrombus clearance.

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