Extreme 3D Image Navigation in Mobile Robotics

2021 ◽  
Vol 22 (11) ◽  
pp. 594-600
Author(s):  
V. P. Noskov ◽  
D. V. Gubernatorov

The actual problem of determining all six coordinates of the current position of a mobile robot (unmanned aerial vehicle) from 3D-range-finding images (point clouds) generated by an onboard 3D laser sensor when moving (flying) in an unknown environment is considered. An extreme navigation algorithm based on using multidimensional optimization methods is proposed. The rules for calculating the difference between 3D images of the external environment used for optimization of the functional are described. The form of the functional of the difference of 3D images for different environments (premises, industrial-urban environment, rugged and wooded areas) has been investigated. Requirements for the characteristics of the sensor and the geometry of the external environment are formulated, the fulfillment of which ensures the correct formulation and solution of the problem of extreme navigation. The optimal methods of scanning the surrounding space are described and the conditions are substantiated, the fulfillment of which ensures the solution of the navigation problem by the proposed algorithm in real time (at the rate of movement) when processing 3D images formed by modern 3D laser sensors. In particular, the dependence between the frequency of formation of 3D images and the angular and linear velocities of motion is described, which ensures that the functional of the difference of 3D images falls into the multidimensional interval of unimodality, which guarantees a direct search of global minimum in real time. Various methods of direct search for the global minimum of the functional are tested and the  fastest for the case under consideration are selected. The accuracy of solving the navigation problem is estimated and a method is proposed to reduce the accumulated error, based on using an older 3D image for correcting the calculated value of the current coordinates, which has an intersection of the view area with the current view area. The proposed method, which is a modification of the reference image method, allows reduce the total error, which grows in proportion to the number of cycles of solving the extreme navigation problem, to values that ensure the autonomous functioning of transport robots and UAVs in previously unprepared and unknown environments. The effectiveness of the proposed algorithmic and developed software and hardware for extreme navigation is confirmed by field experiments carried out in real conditions of various environments.

2021 ◽  
Vol 8 ◽  
pp. 109-117
Author(s):  
Artem L. Pazoev ◽  
Sergey A. Shoydin

When holographic information is transmitted through communication channels, a problem arises associated with the large capacity of holograms. In the patent of the Russian Federation No. 2707582, the possibility of compressing holographic information was shown, similar to the transmission on one sideband known in radio electronics. The experimental transmission of such compressed information over a Wi-Fi wireless communication channel with a frame rate of more than 25 frames per second is shown in this paper. The experiment of transmitting holographic information of 3D images over a wireless Wi-Fi communication channel to simulate 3D video using the FTP protocol was carried out. In accordance with the RF patent No. 2707582, each transmitted frame of a 3D image was the sum of two 2D frames-a texture (2000x2000 pixels) and a mask (1000x1000 pixels). To simulate the transmission of a video sequence, packets of 500 double frames were transmitted simultaneously. The transmission times of these frame packets measured in real time by FileZilla showed that the transmission of full holographic information about a 3D object in real time with a frame rate greater than 25 frames / sec. quite feasible.


2021 ◽  
Vol 15 ◽  
Author(s):  
Zhan Cao ◽  
Daolong Yang ◽  
Xiaolei Ma ◽  
Yanxiang Wang ◽  
Songquan Wang ◽  
...  

Background: Concrete pavers are self-propelled units used in concrete pavement construction that have of paving, vibrating, and leveling functions. The existing concrete pavers have a large size, making it difficult for them to enter underground roadways, and it is difficult to adjust the paving equipment in real time when the width of the underground roadway is deformed. Objective: To realize intelligent concrete paving in coal mine roadways, based on the analysis of recent concrete paver patents, this paper proposes an intelligent virtual paving system based on 3D infrared scanning imaging. Method: The intelligent virtual paving system, which uses multiple groups of 3D infrared scanners and signal processing systems, can collect and analyze 3D images in the roadway and perform virtual paving in the computer. This system can obtain the required parameters of roadway paving, such as the feeding amount, driving speed, limiter height, and width of the synovium, as well as give the initial paving parameters. Results: In the actual paving process, through virtual paving parameters, the feeding amount and accelerator can be regulated in real time, and the difference between the actual paving and virtual paving can be judged to change the paving width in real time. Conclusion: Intelligent virtual paver systems have a guiding significance for the improvement of existing paver systems.


2013 ◽  
Vol 25 (2) ◽  
pp. 364-374 ◽  
Author(s):  
Ayaka Kume ◽  
◽  
Toshihiro Maki ◽  
Takashi Sakamaki ◽  
Tamaki Ura

Autonomous Underwater Vehicles (AUVs) are often used for seafloor exploration, and some AUVs are now being deployed to obtain detailed photomosaics of the seafloor. However, it is difficult for the results to be evaluated on-site, so the image maps obtained often have unscanned areas caused by occlusions, disturbances, etc. In order to improve the coverage of a map, operators have to plan a new path and then redeploy the AUV. This process is quite timeconsuming and troublesome. The authors propose a new method for an AUV to obtain a full-coverage 3D image of a rough, unknown seafloor in a single deployment. First, the AUV observes the seafloor by following a pre-determined path. Second, the AUV calculates the following on-site and based on the data obtained: 3D bathymetry map, unscanned areas on the map, and the next path that can be taken to image the unscanned areas effectively. Then, the AUV follows the new path to obtain better results. The performance of this proposed method is verified in both tank experiments and by simulation. In the experiments, the AUV “Tri-TON” succeeds in generating a route for a second observation, and the coverage increases from 73% to 82%. The performance of the method on the actual seafloor is verified using the results of the tank experiments and the bathymetry data on a chimney in Kagoshima Bay, Japan.


2020 ◽  
Vol 2020 (2) ◽  
pp. 100-1-100-6
Author(s):  
Takuya Omura ◽  
Hayato Watanabe ◽  
Naoto Okaichi ◽  
Hisayuki Sasaki ◽  
Masahiro Kawakita

We enhanced the resolution characteristics of a threedimensional (3D) image using time-division multiplexing methods in a full-parallax multi-view 3D display. A time-division light-ray shifting (TDLS) method is proposed that uses two polarization gratings (PGs). As PG changes the diffraction direction of light rays according to the polarization state of the incident light, this method can shift light rays approximately 7 mm in a diagonal direction by switching the polarization state of incident light and adjusting the distance between the PGs. We verified the effect on the characteristics of 3D images based on the extent of the shift. As a result, the resolution of a 3D image with depth is improved by shifting half a pitch of a multi-view image using the TDLS method, and the resolution of the image displayed near the screen is improved by shifting half a pixel of each viewpoint image with a wobbling method. These methods can easily enhance 3D characteristics with a small number of projectors.


2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 370-377
Author(s):  
Edward Chaum ◽  
Ernő Lindner

ABSTRACT Background Target-controlled infusion anesthesia is used worldwide to provide user-defined, stable, blood concentrations of propofol for sedation and anesthesia. The drug infusion is controlled by a microprocessor that uses population-based pharmacokinetic data and patient biometrics to estimate the required infusion rate to replace losses from the blood compartment due to drug distribution and metabolism. The objective of the research was to develop and validate a method to detect and quantify propofol levels in the blood, to improve the safety of propofol use, and to demonstrate a pathway for regulatory approval for its use in the USA. Methods We conceptualized and prototyped a novel “smart” biosensor-enabled intravenous catheter capable of quantifying propofol at physiologic levels in the blood, in real time. The clinical embodiment of the platform is comprised of a “smart” biosensor-enabled catheter prototype, a signal generation/detection readout display, and a driving electronics software. The biosensor was validated in vitro using a variety of electrochemical methods in both static and flow systems with biofluids, including blood. Results We present data demonstrating the experimental detection and quantification of propofol at sub-micromolar concentrations using this biosensor and method. Detection of the drug is rapid and stable with negligible biofouling due to the sensor coating. It shows a linear correlation with mass spectroscopy methods. An intuitive graphical user interface was developed to: (1) detect and quantify the propofol sensor signal, (2) determine the difference between targeted and actual propofol concentration, (3) communicate the variance in real time, and (4) use the output of the controller to drive drug delivery from an in-line syringe pump. The automated delivery and maintenance of propofol levels was demonstrated in a modeled benchtop “patient” applying the known pharmacokinetics of the drug using published algorithms. Conclusions We present a proof-of-concept and in vitro validation of accurate electrochemical quantification of propofol directly from the blood and the design and prototyping of a “smart,” indwelling, biosensor-enabled catheter and demonstrate feedback hardware and software architecture permitting accurate measurement of propofol in blood in real time. The controller platform is shown to permit autonomous, “closed-loop” delivery of the drug and maintenance of user-defined propofol levels in a dynamic flow model.


Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 627
Author(s):  
David Marquez-Viloria ◽  
Luis Castano-Londono ◽  
Neil Guerrero-Gonzalez

A methodology for scalable and concurrent real-time implementation of highly recurrent algorithms is presented and experimentally validated using the AWS-FPGA. This paper presents a parallel implementation of a KNN algorithm focused on the m-QAM demodulators using high-level synthesis for fast prototyping, parameterization, and scalability of the design. The proposed design shows the successful implementation of the KNN algorithm for interchannel interference mitigation in a 3 × 16 Gbaud 16-QAM Nyquist WDM system. Additionally, we present a modified version of the KNN algorithm in which comparisons among data symbols are reduced by identifying the closest neighbor using the rule of the 8-connected clusters used for image processing. Real-time implementation of the modified KNN on a Xilinx Virtex UltraScale+ VU9P AWS-FPGA board was compared with the results obtained in previous work using the same data from the same experimental setup but offline DSP using Matlab. The results show that the difference is negligible below FEC limit. Additionally, the modified KNN shows a reduction of operations from 43 percent to 75 percent, depending on the symbol’s position in the constellation, achieving a reduction 47.25% reduction in total computational time for 100 K input symbols processed on 20 parallel cores compared to the KNN algorithm.


2021 ◽  
pp. 174498712110161
Author(s):  
Ann-Marie Cannaby ◽  
Vanda Carter ◽  
Thomas Hoe ◽  
Stephenson Strobel ◽  
Elena Ashtari Tafti ◽  
...  

Background The association between the nurse-to-patient ratio and patient outcomes has been extensively investigated. Real time location systems have the potential capability of measuring the actual amount of bedside contact patients receive. Aims This study aimed to determine the feasibility and accuracy of real time location systems as a measure of the amount of contact time that nurses spent in the patients’ bed space. Methods An exploratory, observational, feasibility study was designed to compare the accuracy of data collection between manual observation performed by a researcher and real time location systems data capture capability. Four nurses participated in the study, which took place in 2019 on two hospital wards. They were observed by a researcher while carrying out their work activities for a total of 230 minutes. The amount of time the nurses spent in the patients’ bed space was recorded in 10-minute blocks of time and the real time location systems data were extracted for the same nurse at the time of observation. Data were then analysed for the level of agreement between the observed and the real time location systems measured data, descriptively and graphically using a kernel density and a scatter plot. Results The difference (in minutes) between researcher observed and real time location systems measured data for the 23, 10-minute observation blocks ranged from zero (complete agreement) to 5 minutes. The mean difference between the researcher observed and real time location systems time in the patients’ bed space was one minute (10% of the time). On average, real time location systems measured time in the bed space was longer than the researcher observed time. Conclusions There were good levels of agreement between researcher observation and real time location systems data of the time nurses spend at the bedside. This study confirms that it is feasible to use real time location systems as an accurate measure of the amount of time nurses spend at the patients’ bedside.


2018 ◽  
Vol 108 (2) ◽  
pp. 145-150
Author(s):  
James M. Mahoney ◽  
Vassilios Vardaxis ◽  
Noreen Anwar ◽  
Jacob Hagenbucher

Background: This study examined the differences between faculty and trained standardized patient (SP) evaluations on student professionalism during a second-year podiatric medicine standardized simulated patient encounter. Methods: Forty-nine second-year podiatric medicine students were evaluated for their professionalism behavior. Eleven SPs performed an assessment in real-time, and one faculty member performed a secondary assessment after observing a videotape of the encounter. Five domains were chosen for evaluation from a validated professionalism assessment tool. Results: Significant differences were identified in the professionalism domains of “build a relationship” (P = .008), “gather information” (P = .001), and share information (P = .002), where the faculty scored the students higher than the SP for 24.5%, 18.9%, and 26.5% of the cases, respectively. In addition, the faculty scores were higher than the SP scores in all of the “gather information” subdomains; however, the difference in scores was significant only in the “question appropriately” (P = .001) and “listen and clarify” (P = .003) subdomains. Conclusions: This study showed that professionalism scores for second-year podiatric medical students during a simulated patient encounter varied significantly between faculty and SPs. Further consideration needs to be given to determine the source of these differences.


Artful Noise ◽  
2020 ◽  
pp. 107-117
Author(s):  
Thomas Siwe

With the end of World War II came the rebirth of European radio. Government stations in both France and Germany established experimental studios for research, from which arose a new kind of music, “electronic music.” The station in France, Office de Radiodiffusion Télevision Française (ORTF), was directed by the engineer/composer Pierre Schaeffer and his partner, Pierre Henry, who called their musical creations musique concrète. In Germany the Westdeutscher Rundfunk (WDR) studio produced music through the process of “synthesis.” This chapter will explain the difference between the two approaches used to create electronic music with examples from the percussion solo and ensemble repertoire. Early experiments using wire recorders, test records, and tape recorders by composers Halim El-Dabh, John Cage, and Edgard Varèse precede the major electronic works of Karlheinz Stockhausen, Mario Davidovsky, and the American composer Stephen Everett, whose use of computers in “real time” brings the reader into the next century.


Sign in / Sign up

Export Citation Format

Share Document