We utilize spatial and angular diversity to achieve speckle reduction in laser illumination. Both free-space imaging geometry configurations are considered. A fast two-dimensional scanning micromirror is employed steer the beam. simple experimental setup built demonstrate application of our technique a picture projection. Experimental results show that contrast factor can be reduced down 5% within integration time detector.

A Barker binary phase code of maximum length 13 has previously been used for speckle reduction in line-scan laser projectors, and a contrast factor decrease down to 13% achieved. In this Letter, Barker-like codes lengths longer than are at an intermediate image plane. It is shown by theoretical calculation that much better with up 6% can be achieved using other the code.

Speckle reduction by moving diffuser has been previously studied in display systems with coherent light sources, such as lasers. In this Letter, we propose a motionless diffractive optical element (DOE) for speckle reduction. The DOE was designed based on finite-element method simulations, fabricated using micromachining technology, and characterized despeckle efficiency. Experiments two gratings have indicated that the suppressed to 50%, which shows fair agreement theoretical analysis. With...

Unmanned Aerial Vehicle (UAV) navigation requires Machine Vision Systems to determine physical values of near distanced objects. These machine vision systems must respond in sufficiently amount time using less scanning data from the observed A novel Technical System (TVS), which uses DC motors and laser triangulation spatial coordinates these objects, is offered used for UAV navigation. Present paper thereby shows implementation open-loop control algorithm, position TVS ray Field View (FOV)....

Unmanned aerial vehicles can fly in an autonomic flight mode without any active radio control or passive navigation and they are almost invisible for radars. Only engines propellers acoustic emission (AE) may give lots of information their detection, recognition location. This paper discusses the experimental results testing classical detection direction finding methods by Bartlett, Capeon cross-correlation function method with use microphone array. Experiments include physical...

Information characteristics of small unmanned aerial vehicles (UAVs) sound signals are analyzed and their descriptions for a quadcopter monoplane presented. The difference between UAVs themselves noisy background becomes noticeable in the frequency domain. Research shows that energy spectra have significant region broadband noise harmonic components with frequencies multiples rotational propellers speed. Even averaging spectral estimates over ensemble samples, harmonics confidently observed....

In this paper, a method is proposed to create pair of one dimensional binary phase modulator matrices 1D-BPMs, which mathematically equivalent single two-dimensional matrix 2D-BPM based on Sylvester constructed Hadamard matrices. An advantage 1D-BPM over that the number drive electrodes can be reduced from <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">N</i> <sup xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> 2 for × matrix, thus simplifying...

Robotic group communication in a densely cluttered terrain is one of the main aid to optimize navigation and come through this sector efficiently. This paper describes basic set tasks need be solved for distributed robotic behavior. The transferring data obtained from technical vision system (TVS), which uses principles dynamic triangulation, given. Combination mentioned methods dovetailing with presented path planning method can improvement motion unknown terrain.

The paper is devoted to a reliable information extraction by passive sodar with microphone array. main attention paid the efficiency of target bearing estimation algorithms and targets resolution. investigation carried out in an experimental way described measuring set, which includes standard units linear array, for narrowband, broadband receiving acoustic signals different conditions. Such methods, as Bartlett's, Capone's cross-correlation function method are investigated presented their...

Review and analysis of methods for detection recognition unmanned aerial vehicles (UAVs) are carried out. The channels the UAVs - acoustic, optical, radar, infrared, radio channel discussed. advantages disadvantages used compared appreciated. In case small UAVs, there a number significant difficulties limitations. One directions in is acoustic observation. noise generated by UAV propulsion system air propeller damasking feature. Creating improving detecting, guiding recognizing reception...

Speckle suppression in projection displays with a laser light source can be achieved by imaging changing diffuser random phase cells onto the screen. Theoretical expressions for speckle contrast this method have been earlier obtained case when different realizations of produced statistically independent patterns field on In present paper, these are generalized produce partly correlated patterns. The possible structure motionless is presented. It includes dynamic diffractive optical element...

The results of comparison experimentally obtained information characteristics sound signals two types small unmanned aerial vehicles (UAVs) - a quadrocopter and monoplane are given. Studies have shown that the energy spectra significant region broadband noise pronounced harmonic components with frequencies multiple rotational speeds screw. Even averaging spectral estimates for ensemble samples, harmonics up to 8 ± 10 kHz confidently observed. With large difference in modes engines, maxima...

The features of acoustic spectrum UAVs, natural and industrial noise, noise automobile rail transport, human speech were investigated. method for recognition UAV sound based on the Mel-frequency cepstral coefficients was proposed. universal detecting characteristic proposed as well. Both methods tested using experimental recordings UAVs sounds got close well results. has some worse reliability false alarm probability, but does not need creation images base.

Paper covers the questions of informational entropy reduction and effectiveness improvement multi-robot systems (MRS) in densely cluttered terrain. The presented approach uses author's real-time laser technical vision (TVS) as main tool for environmental sensing. article proposes MRS collaboration during indoor environment digitalization while sharing information about detected obstacles.

The paper describes the research connected with motion detection of small unmanned air vehicles on a video stream. most comprehensive methods are analyzed and investigated real shooting. shows that differential method is more reliable in authenticity may be considered as base for practical systems.

A new Technical Vision System for target detection using a Laser Scanner and the Dynamic Triangulation measurement method was developed at engineering institute of UABC, which presents single-sensor, high-speed low-cost laser scanning system, to determine 3D spatial coordinates any object under observation. Previous research has shown existence serious disadvantages, when low-quality DC motors position ray in scanner field-of-view. Present paper introduces main issues implementation an...

Inertial navigation systems (INS) provide information about position and acceleration of a unmanned aerial vehicle (UAV) or airplanes. There are many types INS, but most them share the same principle operation. We in this paper basic regard accelerometers gyroscopes; then, we demonstrate effectiveness our method based on computational experiments to measure from INS. Finally introduce for frequency shift detection measurement pulse coincidence.

Abstract— The image quality of a laser projection display based on spatial light modulator with deformable polymer layer (SLMDPL) has been improved. Bias diffraction reduced by two methods: (1) filling the spacings between electrodes SiO 2 followed deposition slightly conductive thin film and (2) splitting electrodes. Both methods resulted in contrast ratio ≃1200:1, which is significantly better than 50:1 measured for an earlier type SLMDPL. Different reducing influence electrical‐charge...

Frequency domain sensors (FDS) are important elements in control, data acquisition and monitoring systems. Such have some outstanding characteristics like output of quasi-digital signals, high sensitivity, resolution, wide dynamic range, anti-interference capacity good stability. A FDS converts a physical variable (measurand) into frequency ouput. When the measurand changes, has proportional shift. In systems that use FDS, measuring shift is desirable. Accuracy most measurement techniques...

in this work described the basic idea of data transferring group robots while they move area with high density obstacles for increasing their movement speed by creating and synchronizing an map that made each robot separately. This paper provides a brief review existing robotic swarm projects definition problems teamwork, represents pathfinding methods there analysis, justificates technical vision system choice its obstacle detecting is based on dynamic triangulation. According to...