scholarly journals LAND UNMANNED COMPLEX WITH PASSIVE RANGE MEASUREMENT

Author(s):  
Volodymyr I. Mikitenko ◽  
Volodymyr M. Senatorov ◽  
Anatolii Gurnovych

The automatic robotic complex will obviously become one of the main subjects in the conduct of military actions in the near future. To control movement parameters, as well as search, target detection and aiming, the complex includes a technical vision system. The minimum sufficient configuration of such a system includes a television search camera with a wide field of view, television and thermal imaging sights, and a rangefinder. The use of laser rangefinders ensures high accuracy of aiming weapons, but generates a powerful unmasking feature. To ensure the secrecy of the functioning of the robotic complex, range finders can operate in a passive mode using information from on-board television cameras. But at the same time, the metrological characteristics of the information measuring channel are significantly deteriorated. Accuracy of five methods of passive distance measurement with application of TV-systems of land unmanned complex is assessed in paper. Classic method of TV-sight external-base range-finder with scale, designed on human height 1,65 m, is ensuring measurement accuracy 135 m on distance 1000 m. External base method, when a range finger scale is forming on remote display as variable length vertical line in process of target framing, is ensuring measurement accuracy 100,3 m on dis-tance 1000 m. Fixed-base range-finder method, when distance between entrance pupils of TV-sight and wide viewing field camera using as base, is ensuring measurement accuracy 76 m on distance 1000 m.  Distance measurement method due to displacement of land unmanned complex ensures a measurement accuracy up to 168 m on distance 1000 m. Measurement method due to using zoom-objective is not suitable for land unmanned complex. Proposals have been formulated for the spatial layout of the computer vision system, in which the method of the fixed-base rangefinder is implemented, which ensures the highest measurement accuracy.

2017 ◽  
Vol 14 (4) ◽  
pp. 172988141771598 ◽  
Author(s):  
De Xu ◽  
Qingbin Wang

A new vision measurement system is developed with two cameras. One is fixed in pose to serve as a monitor camera. It finds and tracks objects in image space. The other is actively rotated to track the object in Cartesian space, working as an active object-gazing camera. The intrinsic parameters of the monitor camera are calibrated. The view angle corresponding to the object is calculated from the object’s image coordinates and the camera’s intrinsic parameters. The rotation angle of the object-gazing camera is measured with an encoder. The object’s depth is computed with the rotation angle and the view angle. Then the object’s three-dimensional position is obtained with its depth and normalized imaging coordinates. The error analysis is provided to assess the measurement accuracy. The experimental results verify the effectiveness of the proposed vision system and measurement method.


2021 ◽  
Vol 11 (20) ◽  
pp. 9384
Author(s):  
Yan Liu ◽  
Zhendong Ge ◽  
Yingtao Yuan ◽  
Xin Su ◽  
Xiang Guo ◽  
...  

The stereo-vision system plays an increasingly important role in various fields of research and applications. However, inevitable slight movements of cameras under harsh working conditions can significantly influence the 3D measurement accuracy. This paper focuses on the effect of camera movements on the stereo-vision 3D measurement. The camera movements are divided into four categories, viz., identical translations and rotations, relative translation and rotation. The error models of 3D coordinate and distance measurement are established. Experiments were performed to validate the mathematical models. The results show that the 3D coordinate error caused by identical translations increases linearly with the change in the positions of both cameras, but the distance measurement is not affected. For identical rotations, the 3D coordinate error introduced only in the rotating plane is proportional to the rotation angle within 10° while the distance error is zero. For relative translation, both coordinate and distance errors keep linearly increasing with the change in the relative positions. For relative rotation, the relationship between 3D coordinate error and rotation angle can be described as the nonlinear trend similar to a sine-cosine curve. The impact of the relative rotation angle on distance measurement accuracy does not increase monotonically. The relative rotation is the main factor compared to other cases. Even for the occurrence of a rotation angle of 10°, the resultant maximum coordinate error is up to 2000 mm, and the distance error reaches 220%. The results presented are recommended as practice guidelines to reduce the measurement errors.


2016 ◽  
Vol 22 (3) ◽  
pp. 420-436 ◽  
Author(s):  
Karol Daliga ◽  
Zygmunt Kurałowicz

Interest in the influence of the incidence angle of a laser beam to distance measurements can be seen in many areas of science and technology: geodesy, glaciology, archaeology, machine automation, and others. This paper presents results of measurements of the effect of the incidence angle of a laser beam to distance measurements to the surfaces of different colour and roughness by Topcon's electro-optical total station with an accuracy of 3 mm. Measurement method and the method of elimination of test stand errors are presented. The results of measurements have been analysed and the influence of selected factors (surface colour and roughness, lack of instrument rectification) on the distance measurement have been discussed. It is also shown the critical incidence angle above which it can be impossible to measure distances to reflective foil with tested total station


2015 ◽  
Vol 135 (11) ◽  
pp. 1349-1350
Author(s):  
Kazuhiro Suzuki ◽  
Noboru Nakasako ◽  
Masato Nakayama ◽  
Toshihiro Shinohara ◽  
Tetsuji Uebo

2014 ◽  
Vol 536-537 ◽  
pp. 13-17
Author(s):  
Hong Long Cao ◽  
Fen Ju Qin ◽  
Xue Guan Liu ◽  
He Ming Zhao

In this paper, we designed an automatic system and automatic test software, and they can carry out Kunming rats bioelectromagnetic measurement in standard status and anesthesia automatically in anechoic chamber where the electromagnetic field outside is shielded, the reflection wave is absorbed, and the measurement accuracy will be improved. We get a great number of measurement data with frequency-sweep measurement method. The mean and standard deviation of amplitudes vs. frequencies is calculated and analyzed. The results show the measurement method is feasible. We have plotted the means of measured data as multiple sets of Y values in a series of bars with standard deviations bars included and distributed in the frequency axis of X. It is found that the fluctuation of the mean and standard deviation in some frequencies is not evident which may explain frequency window effects, while in other frequencies, such a fluctuation can be obviously observed, which may suggest that bioelectromagnetic signal is influenced by biological activities (standard and anaesthesia status) in these frequency points.


Author(s):  
Fenghui Lian ◽  
Qingchang Tan ◽  
Siyuan Liu

A method for measuring block thicknesses is proposed by the machine vision measurement. Equations of the measuring base plane and the light plane are formed by calibration. Then, the equation of the light strip image, that is, the image of the intersection between the base plane and light one, is established by the projection relation. Equation of the image of the light strip on the measured plane can be determined by the fitting. Since the light strip on the measuring base plane is parallel to one on the measured plane, the thickness of the measuring block is measured by using the two equations. The experiment evaluates the measurement accuracy of the measurement method and analyzes the influence of some factors on the measurement results.


Author(s):  
Kai Yue ◽  
Yongjian Niu ◽  
Xiaoming Guo ◽  
Xinxin Zhang

As one of the basic parameters characterizing the radiation heat transfer of material surface, the emissivity is of important significance to perform non-contact thermometry research. Comparing with the traditional measurement method, measurement method of spectral emissivity based on the Fourier spectrometer has many advantages such as high accuracy and fast measurement. However, the measurement accuracy is subject to the influence of the radiant energy and the spectrometer electromagnetic radiation noise resulted from the environment. In this study, the geometric factor of the sample was defined and the reflectance of the background radiation in the surface of the sample was applied to accurately determine the energy of the radiation received on the detector. An emissivity measurement model was established and a mathematical formula was derived in this study to eliminate the influence of the background radiation noise. To improve the measurement accuracy of the surface temperature of samples, a heat conduction model is established so that the radiation heat transfer of the sample surface can be calculated and the surface temperature of the sample was obtained by equilibrium calculation. Moreover, we conducted emissivity measurement of black paint samples with high emissivity using the Fourier spectrometer and the proposed model is proven valid. Comparing the experimental results modified by the eliminating calculation formula with the experimental data obtained by the monochromator, it was found that there was good qualitative agreement between two sets of results.


2014 ◽  
Vol 97 (8) ◽  
pp. 24-31
Author(s):  
Noboru Nakasako ◽  
Toshihiro Shinohara ◽  
Keiji Kawanishi ◽  
Tetsuji Uebo

Sign in / Sign up

Export Citation Format

Share Document