Design and Development of a High-Speed UAS for Beyond Line-of-Sight Operation

2018 ◽  
Author(s):  
Matthew McCrink ◽  
James W. Gregory
Keyword(s):  
High Speed ◽  
Line Of Sight ◽  
Design And Development

scholarly journals Design and Development of a High Speed Sorting System Based on Machine Vision Guiding

2012 ◽  
Vol 25 ◽  
pp. 1955-1965 ◽  
Author(s):  
Wenchang Zhang ◽  
Jiangping Mei ◽  
Yabin Ding
Keyword(s):  
Machine Vision ◽  
High Speed ◽  
Design And Development ◽  
Sorting System

scholarly journals Controllers to Chase a High-Speed Evader Using a Pursuer with Variable Speed

2018 ◽  
Vol 8 (10) ◽  
pp. 1976 ◽  
Author(s):  
Jonghoek Kim
Keyword(s):  
Optical Flow ◽  
High Speed ◽  
Angular Rate ◽  
Relative Distance ◽  
Line Of Sight ◽  
Terminal Phase ◽  
Relative Speed ◽  
Variable Speed

This paper proposes a chasing controller to enable a pursuer to chase a high-speed evader such that the relative distance between the evader and the pursuer monotonically decreases as time passes. Our controller is designed to assure that the angular rate of Line-of-Sight joining the pair (the pursuer and the evader) is exactly zero at all time indexes. Assuming that the pursuee can readily observe optical flow, but only poorly detect looming, this pursuer’s movement is hardly detected by the pursuee. Consider the terminal phase when the pursuer is sufficiently close to the evader. As we slow down the relative speed of the pursuer with respect to the evader, we can reduce the probability of missing the high-speed evader. Thus, our strategy is to make the pursuer decrease its speed in the terminal phase, while ensuring that the distance between the evader and the pursuer monotonically decreases as time passes. The performance of our controller is verified utilizing MATLAB simulations.

scholarly journals Line of Sight Correction of High-Speed Liquid Crystal Using Overdriving Technology

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1477
Author(s):  
Hongyang Guo ◽  
Qing Li ◽  
Yangjie Xu ◽  
Yongmei Huang ◽  
Shengping Du
Keyword(s):  
Liquid Crystal ◽  
Response Time ◽  
High Speed ◽  
Pulse Width Modulation ◽  
Response Speed ◽  
Line Of Sight ◽  
Processing Unit ◽  
Driving Voltage ◽  
Light Modulator ◽  
Central Processing

In the line of sight correction system, the response time of the liquid crystal spatial light modulator under the normal driving voltage is too long to affect system performance. On the issues, an overdriving method based on a Field-Programmable Gate Array (FPGA) is established. The principle of the overdrive is to use a higher voltage difference to achieve a faster response speed of liquid crystal. In this scheme, the overdriving look-up table is used to seek the response time of the quantized phase, and the liquid crystal electrode is driven by Pulse–Width Modulation (PWM). All the processes are performed in FPGA, which releases the central processing unit (CPU) memory and responds faster. Adequate simulations and experiments are introduced to demonstrate the proposed method. The overdriving experiment shows that the rising response time is reduced from 530 ms to 34 ms, and the falling time is from 360 ms to 38 ms under the overdriving voltage. Typical light tracks are imitated to evaluate the performance of the line of sight correction platform. Results show that using the overdrive the −3 dB rejection frequency was increased from 1.1 Hz to 2.6 Hz. The suppression ability of the overdrive is about −20 dB at 0.1 Hz, however the normal-driving suppression ability is only about −13 dB.

Design and Development of Redeployable Underwater Data Communication Link for Defence Application

2017 ◽  
Vol 68 (1) ◽  
pp. 111
Author(s):  
Arun Kumar ◽  
L. Anjaneyulu
Keyword(s):  
High Speed ◽  
Data Communication ◽  
Video Camera ◽  
Physical Parameters ◽  
Communication Link ◽  
Fibre Optic ◽  
Time Data ◽  
Design And Development ◽  
Design Data ◽  
Fibre Optic Cable

<p class="p1">Testing of underwater system for defence application is carried out from submersible platform at specified depth. The underwater platform houses the article under test, equipment and instruments required to conduct the test and to control the platform. During development phase of defence systems, large numbers of sensors are mounted on the test article and data is collected to validate the design. Data acquisition system, video camera and high speed video cameras are positioned on the platform to record physical parameters and observe visually the performance of the article under evaluation. Since the data and video signals are parallely recorded on ship, the bandwidth demand for real-time data communication from underwater platform to control station is very high. The existing technology presently used for underwater communication has limitation of bandwidth and not suitable for defence application. This paper describes in detail the design and development of a re-deployable data communication link by laying a specially designed negatively buoyant fibre optic cable in high-sea from ship to underwater platform to provide higher bandwidth required for defence application. The link has been successfully used for sea state less than one during evaluation of underwater defence system. The availability of bandwidth from underwater platform to control system can be increased significantly by laying fibre optic cable in high sea. It also provides unlimited bandwidth for the above requirement.<span class="Apple-converted-space"> </span></p>

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