scholarly journals Wheel load transfer in high-speed unmanned vehicles

2009 ◽  
Author(s):  
John R. Rogers
Keyword(s):  
High Speed ◽  
Load Transfer ◽  
Unmanned Vehicles ◽  
Wheel Load

scholarly journals Observation and analysis of diving beetle movements while swimming

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Debo Qi ◽  
Chengchun Zhang ◽  
Jingwei He ◽  
Yongli Yue ◽  
Jing Wang ◽  
...  
Keyword(s):  
Swimming Speed ◽  
High Speed ◽  
Kinematic Model ◽  
Movement Pattern ◽  
Unmanned Vehicles ◽  
Power Stroke ◽  
Cross Sectional ◽  
Motion Data ◽  
The Cross ◽  
Diving Beetle

AbstractThe fast swimming speed, flexible cornering, and high propulsion efficiency of diving beetles are primarily achieved by their two powerful hind legs. Unlike other aquatic organisms, such as turtle, jellyfish, fish and frog et al., the diving beetle could complete retreating motion without turning around, and the turning radius is small for this kind of propulsion mode. However, most bionic vehicles have not contained these advantages, the study about this propulsion method is useful for the design of bionic robots. In this paper, the swimming videos of the diving beetle, including forwarding, turning and retreating, were captured by two synchronized high-speed cameras, and were analyzed via SIMI Motion. The analysis results revealed that the swimming speed initially increased quickly to a maximum at 60% of the power stroke, and then decreased. During the power stroke, the diving beetle stretched its tibias and tarsi, the bristles on both sides of which were shaped like paddles, to maximize the cross-sectional areas against the water to achieve the maximum thrust. During the recovery stroke, the diving beetle rotated its tarsi and folded the bristles to minimize the cross-sectional areas to reduce the drag force. For one turning motion (turn right about 90 degrees), it takes only one motion cycle for the diving beetle to complete it. During the retreating motion, the average acceleration was close to 9.8 m/s2 in the first 25 ms. Finally, based on the diving beetle's hind-leg movement pattern, a kinematic model was constructed, and according to this model and the motion data of the joint angles, the motion trajectories of the hind legs were obtained by using MATLAB. Since the advantages of this propulsion method, it may become a new bionic propulsion method, and the motion data and kinematic model of the hind legs will be helpful in the design of bionic underwater unmanned vehicles.

scholarly journals Prototype Design and Experimental Evaluation of Autonomous Collaborative Communication System for Emerging Maritime Use Cases

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3871
Author(s):  
Jiri Pokorny ◽  
Khanh Ma ◽  
Salwa Saafi ◽  
Jakub Frolka ◽  
Jose Villa ◽  
...  
Keyword(s):  
Communication System ◽  
Autonomous Vehicles ◽  
High Speed ◽  
High Capacity ◽  
Workplace Safety ◽  
Unmanned Vehicles ◽  
Use Cases ◽  
Automated Systems ◽  
Collaborative Communication ◽  
Wide Range

Automated systems have been seamlessly integrated into several industries as part of their industrial automation processes. Employing automated systems, such as autonomous vehicles, allows industries to increase productivity, benefit from a wide range of technologies and capabilities, and improve workplace safety. So far, most of the existing systems consider utilizing one type of autonomous vehicle. In this work, we propose a collaboration of different types of unmanned vehicles in maritime offshore scenarios. Providing high capacity, extended coverage, and better quality of services, autonomous collaborative systems can enable emerging maritime use cases, such as remote monitoring and navigation assistance. Motivated by these potential benefits, we propose the deployment of an Unmanned Surface Vehicle (USV) and an Unmanned Aerial Vehicle (UAV) in an autonomous collaborative communication system. Specifically, we design high-speed, directional communication links between a terrestrial control station and the two unmanned vehicles. Using measurement and simulation results, we evaluate the performance of the designed links in different communication scenarios and we show the benefits of employing multiple autonomous vehicles in the proposed communication system.

Dynamic Performance Analysis on High-Speed Railway Continuous Girder Bridge

2011 ◽  
Vol 280 ◽  
pp. 186-190
Author(s):  
Shou Tan Song ◽  
Ji Wen Zhang ◽  
Xin Yuan
Keyword(s):  
High Speed ◽  
Moving Load ◽  
Damping Ratio ◽  
Dynamic Performance ◽  
Wheel Load ◽  
Dynamic Coefficients ◽  
Bridge Structures ◽  
Continuous Girder Bridge ◽  
Girder Bridge ◽  
Dynamic Performance Analysis

The dynamic performance of continuous girder under the train in a series of speed is studied through examples, and the main conclusions are given in the following. The resonance mechanism of continuous girder is similar to simply supported beam. The vehicle wheel load forms regular moving load series, which induces periodical action and resonance of the bridge. The damping ratio of bridge itself has less effect on the amplitude at the loading stage, but significant effects appear when the load departs from the bridge. The count of continuous spans also has less impact on the dynamic coefficients, so three continuous spans can be adopted for calculation and analysis. Span and fundamental frequency have significant influence on dynamic coefficients of bridge structures. To extend the span of the bridge structure can reduce the dynamic coefficient while keeping its frequency invariant. The fundamental frequencies of different bridges are corresponding to certain resonant speeds, which calls for the attention in the design.

Prospects for the Application of the Global High-speed, Low Latency Broadband Satellite Internet in the Field of Road Transport

2021 ◽  
pp. 254-264
Author(s):  
Anatoliy Soltus ◽  
◽  
Maksym Rud ◽  
Keyword(s):  
Antenna Arrays ◽  
Communication Systems ◽  
High Speed ◽  
Electromagnetic Compatibility ◽  
Emerging Market ◽  
Satellite Communications ◽  
Road Transport ◽  
Unmanned Vehicles ◽  
Low Latency ◽  
Current State

The article examines the problems of navigation and communication with the use of satellite technologies in road transport in the context of the growth of globalization processes in the world economy and the transformations of freight transport technologies caused by a large-scale transition to transport with zero emissions and the development of unmanned vehicles. The paper discusses the principles of building a global high-speed broadband satellite Internet with low latency. Potential capabilities of technologies such as digital antenna arrays and laser communication channels used in such systems are analyzed. Also considered are the existing and potential problems, both technical with electromagnetic compatibility with existing satellite communication systems and between systems under construction or planning, and legal caused by changes in the principles of information transfer at the interstate level. The main players in the emerging market of high-speed satellite communications are considered and the parameters of the systems declared by them are described. The comparison of the current state of building satellite constellations of individual projects is carried out and the ability to implement the announced plans by individual companies is analyzed. The disadvantages that create obstacles for the introduction of high-speed satellite communications in road transport at the moment and the directions of their overcoming are highlighted. Considering the potential of satellite Internet systems, the current state of construction, as well as existing technical and legal restrictions, the introduction of reliable satellite communications will significantly speed up the transition to autonomous unmanned vehicles. In this regard, the most successful opportunities for the new communication technology will be able to realize the transport companies, which will simultaneously update the fleet of vehicles towards zero emissions and with unmanned technologies.

Stability control for high speed tracked unmanned vehicles

2005 ◽  
Author(s):  
Olivier Pape ◽  
Joel G. Morillon ◽  
Philippe Houbloup ◽  
Stephane Leveque ◽  
Cecile Fialaire ◽  
...  
Keyword(s):  
High Speed ◽  
Stability Control ◽  
Unmanned Vehicles

scholarly journals On the creation of the Intelligent multimodal transport system of Russia and the project “Intelligent container chain“

2020 ◽  
Vol 79 (5) ◽  
pp. 276-281
Author(s):  
B. M. Lapidus
Keyword(s):  
Transport System ◽  
High Speed ◽  
Road Transport ◽  
Unmanned Vehicles ◽  
High Tech ◽  
Railway Transport ◽  
Russian Science ◽  
Multimodal Transport ◽  
The Creation ◽  
Transport Complex

In the article, the ideas for the development of unmanned freight vehicles and the construction of high-speed railways are transformed into an innovative resource-efficient and high-tech solution — the creation of an Intelligent Multimodal Transport System of Russia, and the development of projects and structures for unmanned vehicle freight traffic — into the “Intelligent Container Chain” project. The proposals put forward are based on an analysis of the potential of the Russian railways and its implications for the spatial development of the Russian Federation. The trends in the development of unmanned vehicles are analyzed and it is concluded that its implementation in Russia will require the construction of specialized road, energy and digital infrastructure with the appropriate allocation of land allocation and supply of energy, communications and other technological communications. The need to search for new scientific, technological and organizational solutions is shown to achieve synergy between the demand for container road transport and the infrastructural and technological capabilities available in the railway transport system. As such a decision, the expediency of developing a new Intelligent Multimodal Transport System under the auspices of the Russian Railways was substantiated. Priority directions for the development of this system, as well as technical and investment solutions and scientific and technological tasks necessary for its implementation, have been determined. At the same time, questions have been formulated that require scientific study. The advantages of the proposed system for increasing the efficiency of using the transport space and developing a breakthrough competitive infrastructure business of the Russian Railways are disclosed. The prospect of the formation on this basis of unique high-tech groundwork is shown, which makes it possible to realize the potential of Russian science and the transport complex and has a high export potential.

Development of variable-configuration wheeled driving system for enhancing the obstacle-crossing ability of unmanned vehicles

2020 ◽  
pp. 095440622095160
Author(s):  
Wen-Hao Wang ◽  
Xiao-Jun Xu ◽  
Hai-Jun Xu ◽  
Cheng-Liang Sun
Keyword(s):  
Unmanned Vehicles ◽  
System Configuration ◽  
Wheel Load ◽  
Obstacle Crossing ◽  
Driving System ◽  
Crossing Experiment ◽  
Lift Height ◽  
Calculation Results ◽  
Optimal Adjustment ◽  
Variable Configuration

A variable-configuration wheeled driving system is proposed to improve the obstacle-crossing abilities of unmanned vehicles. The effects of the wheel load on the wheels’ obstacle-crossing abilities are analysed using statics theory. Similarly, the effects of the suspension’s stiffness and the adhesion coefficient on the vehicle’s obstacle-crossing ability are analysed. Numerical calculation results show that a higher wheel lift height leads to improved obstacle-crossing abilities. A strategy to adjust the system configuration during obstacle crossing is designed with the wheel lift height acting as the optimisation target. The variable-configuration strategy is verified and the optimal adjustment of the middle axle is determined through simulations. An obstacle-crossing experiment shows that a vehicle can cross a 1-m step obstacle when the proposed variable-configuration strategy is applied. The obstacle-crossing ability of the unmanned vehicle can thus be greatly enhanced.

Influence of Conversion Deviation on Dynamic Performance of High-Speed Railway Turnout

2011 ◽  
Vol 474-476 ◽  
pp. 1599-1604 ◽  
Author(s):  
Rong Chen ◽  
Wang Ping ◽  
Xian Kui Wei
Keyword(s):  
High Speed ◽  
Detection System ◽  
Structural Characteristics ◽  
Dynamic Responses ◽  
Normal Operation ◽  
Foreign Matter ◽  
Wheel Load ◽  
High Speed Railway ◽  
Lateral Displacements ◽  
Railway Turnout

Railway turnout, an integrated mechatronics equipment of track technology, is one of key equipments that control the running speed of high-speed railway. During the conversion of turnout, the friction, inclusion of foreign matter and deficient displacement of conversion caused by its own structural characteristics may lead to severe wheel/rail impact. In order to study the influence of conversion deviation on safety and comfort of a train during passing the turnout, train/turnout dynamic model was applied. Taking No.18 turnout on a Passenger Dedicated Line (PDL) with 350km/h as a case study, when the train passed it, the influences of its deficient displacement and inclusion of foreign matter on the following dynamic responses were studied, i.e. wheel load distribution, wheel flange force, dynamic stress of rail, wheel unloading rate, derailment coefficient, as well as the lateral displacements of switch rail and nose rail, etc. Result shows that: (1) the deficient displacement and the inclusion of foreign matter will severely influence the normal operation of the turnout, so the safety and comfort during the train passing through turnout may be affected; (2) During the conversion of turnout, its deficient displacement should be controlled properly, and the foreign matter should be removed during routine maintenance, moreover, a reliable detection system should be set.

Dynamic Performance of Vehicle-Turnout-Bridge Coupling System in High-Speed Railway

2011 ◽  
Vol 50-51 ◽  
pp. 654-658
Author(s):  
Rong Chen ◽  
Wang Ping ◽  
Shun Xi Quan
Keyword(s):  
Relative Position ◽  
High Speed ◽  
Dynamic Performance ◽  
Dynamic Responses ◽  
Continuous Beam ◽  
Analysis Model ◽  
Wheel Load ◽  
System A ◽  
Coupling System ◽  
Contact Relation

In order to study dynamic behavior of vehicle-turnout-bridge coupling system, a vehicle-turnout-bridge dynamic analysis model is established by employing the dynamic finite element method (FEM). When No.18 crossover turnouts(with a speed of 350km/h) are laid symmetrically on the 6×32m continuous beam, influences of turnout/bridge relative position and wheel/rail contact relation in turnout zone on the system dynamic responses are analyzed. The result shows that: wheel/rail contact of turnout zone (especially the frog) has great effect on dynamic responses of turnout on bridge, thus the nose rail height of frog should be optimized to mitigate the wheel load transition and its longitudinal gradient. In terms of the 32m-span continuous beam, the best relative position is frog part of turnout arranged in the range of 1/8 and 1/4 of span.

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