scholarly journals An Infinite-Norm Algorithm for Joystick Kinematic Control of Two-Wheeled Vehicles

Electronics ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 164 ◽  
Author(s):  
Alejandro Said ◽  
Yasser Davizón ◽  
Rogelio Soto ◽  
Carlos Félix-Herrán ◽  
Carlos Hernández-Santos ◽  
...  
Keyword(s):  
Computer Simulations ◽  
Research Work ◽  
Geometrical Model ◽  
Radius Of Curvature ◽  
Kinematic Control ◽  
Infinity Norm ◽  
Real Robot ◽  
Infinite Norm ◽  
Wheeled Vehicles ◽  
Traction Power

In this paper, we propose an algorithm based on the mathematical p-norm which has been applied to improve both the traction power and the trajectory smoothness of joystick-controlled two-wheeled vehicles. This algorithm can theoretically supply 100% of available power to each of the actuators if the infinity-norm is used, i.e., when the p-norm tends to infinity. Furthermore, a geometrical model using the radius of curvature has been developed to track the effect of the proposed algorithm on the vehicle’s trajectory. Findings in this research work contribute to the kinematic control and path planning algorithms for vehicles actuated by two wheels, such as tanks and electric wheelchairs, both of vital importance for the security and heath industry. Computer simulations and experiments with a real robot are performed to verify the results.

Assisting the Teleoperation of an Unmanned Underwater Vehicle Using a Synthetic Subsea Scenario

1999 ◽  
Vol 8 (5) ◽  
pp. 520-530 ◽  
Author(s):  
Qingping Lin ◽  
Chengi Kuo
Keyword(s):  
Virtual World ◽  
Research Work ◽  
Underwater Vehicle ◽  
Geometrical Model ◽  
Remotely Operated Vehicle ◽  
Science And Engineering ◽  
Orientation Data ◽  
Underwater Positioning ◽  
Position And Orientation ◽  
Domain Concept

Virtual reality (VR) systems serve as a tool for users to become immersed in a virtual world, navigate through it, and interact with the synthetic objects in real time. Successful applications of VR can be found in many fields outside entertainment ranging from science and engineering to education. In this paper, we present our research work on using a synthetic subsea scenario to assist the navigation of a remotely operated vehicle (ROV) in and around an offshore installation. Our approach takes the ROVs position and orientation data from a sonar-based underwater positioning unit and generates a 3-D synthetic subsea navigation scenario that is based on a geometrical model of the offshore installation. It incorporates the “ROV safety domain” concept to ensure that the synthetic subsea scenario conveys sufficient accuracy for ROV navigation. Our research results have positively demonstrated the feasibility of assisting ROV navigation using a synthetic subsea scenario in combination with the ROV safety domain.

scholarly journals Measurement and Simulation of Flow in a Section of a Mine Gallery

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4894
Author(s):  
Jakub Janus ◽  
Jerzy Krawczyk
Keyword(s):  
Cross Sections ◽  
Laser Scanning ◽  
Model Building ◽  
Research Work ◽  
Geometrical Model ◽  
Building Process ◽  
Model Geometry ◽  
Simulation Results ◽  
Model Building Process

Research work on the air flow in mine workings frequently utilises computer techniques in the form of numeric simulations. However, it is very often necessary to apply simplifications when building a geometrical model. The assumption of constant model geometry on its entire length is one of the most frequent simplifications. This results in a substantial shortening of the geometrical model building process, and a concomitant shortening of the time of numerical computations; however, it is not known to what extent such simplifications worsen the accuracy of simulation results. The paper presents a new methodology that enables precise reproduction of the studied mine gallery and the obtaining of a satisfactory match between simulation results and in-situ measurements. It utilises the processing of data from laser scanning of a mine gallery, simultaneous multi-point measurements of the velocity field at selected gallery cross-sections, unique for mine conditions, and the SAS turbulence model, recently introduced to engineering analyses of flow issues.

scholarly journals The influence of geometry of primary air channels in standard retort burners on dust emission

2019 ◽  
Vol 254 ◽  
pp. 04009 ◽  
Author(s):  
Bartosz Ciupek ◽  
Jarosław Bartoszewicz
Keyword(s):  
First Generation ◽  
Research Work ◽  
Dust Emission ◽  
Geometrical Model ◽  
Technical Parameters ◽  
Work Settings ◽  
Air Supply ◽  
Air Channels ◽  
The Impact ◽  
Power Boiler

The article presents the analysis of dust emissions from a low power boiler fired with various solid fuels. The boiler, presented for testing, met the emission conditions for boilers made in the third class in accordance with the PN-EN 303-5: 2012 standard. The solid fuel boiler was equipped with two different retort burners with automatic fuel supply. For the test were used a first generation retort burner with a fixed rim and the next were used second generation retort burner provided with a rotary rim. Both constructions differ in the geometrical model of the primary air supply system to the furnace. During the tests, the work of the burners was controlled using a microprocessor temperature controller. During the research, the rotation time of the screw supplying the fuel through the retort to the furnace was changed, as well as the rotational speed of the blast fan impeller responsible for supplying the combustion air. The purpose of the tests was to check whether the boiler will meet the highest environmental class regardless of the technical parameters of the burner and fuel used. The article describes the research methodology and analysis of the results obtained. The effect of the tests carried out is a comparison of average dust emission values depending on the fuel used and the work settings of a given burner. The test results are a prerequisite for further research work in terms of the impact of primary air supply on the emission of harmful substances.

A simple biologically inspired algorithm for collision-free navigation of a unicycle-like robot in dynamic environments with moving obstacles

Robotica ◽  
2013 ◽  
Vol 31 (6) ◽  
pp. 993-1001 ◽  
Author(s):  
Andrey V. Savkin ◽  
Chao Wang
Keyword(s):  
Computer Simulations ◽  
Dynamic Environments ◽  
Rigorous Analysis ◽  
Biologically Inspired ◽  
Moving Obstacles ◽  
Real Robot

SUMMARYWe present a simple biologically inspired strategy for the navigation of a unicycle-like robot towards a target while avoiding collisions with moving obstacles. A mathematically rigorous analysis of the proposed approach is provided. The performance of the algorithm is demonstrated via experiments with a real robot and extensive computer simulations.

Experimental Investigations into Electrochemical Milling of Ti6Al4V During Generation of Three-Dimensional Features

2021 ◽  
pp. 1-22
Author(s):  
Koushik Mishra ◽  
Biplab Ranjan Sarkar ◽  
B. Bhattacharyya
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Research Work ◽  
Three Dimensional ◽  
Side Wall ◽  
Performance Criteria ◽  
Radius Of Curvature ◽  
Layer Depth ◽  
Influence Of Process Parameters ◽  
Tool Rotation

This research work investigates the influence of process parameters e.g. feed rate and milling layer depth with tool rotation on various performance criteria e.g. overcut, machining depth, perpendicularity, radius of curvature of the side wall and surface roughness during electrochemical (EC) milling of Ti6Al4V with the indigenously developed setup. In this study, three most accepted multicriteria and decision-making (MCDM) techniques e.g. SAW, TOPSIS and MOORA are utilized for finding out the optimal parametric combination followed by fabrication of different three-dimensional complex features on Ti6Al4V at that optimal parametric combination. This study confirms that internal flushing with tool rotation improves the accuracy of the machined profile due to better removal of sludge from the machining zone. Developed milling setup is able to generate different complex and three- dimensional features on Ti6Al4V with desired accuracy. Using 1[Formula: see text]M of NaNO3 and NaCl mixed electrolyte, at 4.4[Formula: see text]mm/min of feed rate and 0.25[Formula: see text]mm of milling layer depth with tool rotation, best values of width overcut, average depth, side angle, radius of curvature and surface roughness ([Formula: see text] are achieved as 0.666[Formula: see text]mm, 1.538[Formula: see text]mm, 47∘, 2.091[Formula: see text]mm, and 1.462[Formula: see text][Formula: see text]m, respectively.

A High Resolution Study of G.P. Zones in Aluminum - 4.2 at % Silver

1982 ◽  
Vol 40 ◽  
pp. 722-723 ◽  
Author(s):  
R. Gronsky
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Computer Simulations ◽  
Structural Characteristics ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Resolution Study

The phenomenon of clustering in Al-Ag alloys has been extensively studied since the early work of Guinierl, wherein the pre-precipitation state was characterized as an assembly of spherical, ordered, silver-rich G.P. zones. Subsequent x-ray and TEM investigations yielded results in general agreement with this model. However, serious discrepancies were later revealed by the detailed x-ray diffraction - based computer simulations of Gragg and Cohen, i.e., the silver-rich clusters were instead octahedral in shape and fully disordered, atleast below 170°C. The object of the present investigation is to examine directly the structural characteristics of G.P. zones in Al-Ag by high resolution transmission electron microscopy.

Enumeration and Identification of Asbestos Fibres in Water

1974 ◽  
Vol 32 ◽  
pp. 526-527 ◽  
Author(s):  
O. Mudroch ◽  
J. R. Kramer
Keyword(s):  
Water Supply ◽  
Water Samples ◽  
Drainage Basin ◽  
Lake Superior ◽  
Research Work ◽  
List Type ◽  
The West ◽  
Asbestos Fibre ◽  
Amphibole Asbestos

Approximately 60,000 tons per day of waste from taconite mining, tailing, are added to the west arm of Lake Superior at Silver Bay. Tailings contain nearly the same amount of quartz and amphibole asbestos, cummingtonite and actinolite in fibrous form. Cummingtonite fibres from 0.01μm in length have been found in the water supply for Minnesota municipalities.The purpose of the research work was to develop a method for asbestos fibre counts and identification in water and apply it for the enumeration of fibres in water samples collected(a) at various stations in Lake Superior at two depth: lm and at the bottom.(b) from various rivers in Lake Superior Drainage Basin.

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