scholarly journals Large-scale corn header design with adjustable line spacing and lifting cylinder motion simulation

2019 ◽  
Vol 1213 ◽  
pp. 052093
Author(s):  
Zijian Cao ◽  
Shukun Cao ◽  
Xiangqian Xu ◽  
Tao Han ◽  
Hejia Guo ◽  
...  
Keyword(s):  
Large Scale ◽  
Motion Simulation ◽  
Line Spacing ◽  
Header Design

scholarly journals Chirping for Large-Scale Maritime Archaeological Survey: A Strategy Developed from a Practical Experience-Based Approach

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ole Grøn ◽  
Lars Ole Boldreel
Keyword(s):  
Large Scale ◽  
Cost Effective ◽  
Practical Experience ◽  
Archaeological Sites ◽  
Archaeological Survey ◽  
Sea Floor ◽  
Mapping Strategy ◽  
Line Spacing ◽  
Definition Of ◽  
Subbottom Profiling

Archaeological wrecks exposed on the sea floor are mapped using side-scan and multibeam techniques, whereas the detection of submerged archaeological sites, such as Stone Age settlements, and wrecks, partially or wholly embedded in sea-floor sediments, requires the application of high-resolution subbottom profilers. This paper presents a strategy for cost-effective, large-scale mapping of previously undetected sediment-embedded sites and wrecks based on subbottom profiling with chirp systems. The mapping strategy described includes (a) definition of line spacing depending on the target; (b) interactive surveying, for example, immediate detailed investigation of potential archaeological anomalies on detection with a denser pattern of subbottom survey lines; (c) onboard interpretation during data acquisition; (d) recognition of nongeological anomalies. Consequently, this strategy differs from those employed in several detailed studies of known wreck sites and from the way in which geologists map the sea floor and the geological column beneath it. The strategy has been developed on the basis of extensive practical experience gained during the use of an off-the-shelf 2D chirp system and, given the present state of this technology, it appears well suited to large-scale maritime archaeological mapping.

scholarly journals Parallel Motion Simulation of Large-Scale Real-Time Crowd in a Hierarchical Environmental Model

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Xin Wang ◽  
Jianhua Zhang ◽  
Massimo Scalia
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Simulation Method ◽  
Crowd Simulation ◽  
Motion Path ◽  
Motion Simulation ◽  
Environmental Model ◽  
Parallel Methods ◽  
Parallel Motion ◽  
Methods Numerical

This paper presents a parallel real-time crowd simulation method based on a hierarchical environmental model. A dynamical model of the complex environment should be constructed to simulate the state transition and propagation of individual motions. By modeling of a virtual environment where virtual crowds reside, we employ different parallel methods on a topological layer, a path layer and a perceptual layer. We propose a parallel motion path matching method based on the path layer and a parallel crowd simulation method based on the perceptual layer. The large-scale real-time crowd simulation becomes possible with these methods. Numerical experiments are carried out to demonstrate the methods and results.

scholarly journals Experiential Learning in Vehicle Dynamics Education via Motion Simulation and Interactive Gaming

2009 ◽  
Vol 2009 ◽  
pp. 1-15 ◽  
Author(s):  
Kevin Hulme ◽  
Edward Kasprzak ◽  
Ken English ◽  
Deborah Moore-Russo ◽  
Kemper Lewis
Keyword(s):  
Postsecondary Education ◽  
Vehicle Dynamics ◽  
Large Scale ◽  
Physical Simulation ◽  
Traditional Classroom ◽  
Motion Simulation ◽  
Student Centered ◽  
Student Centered Learning ◽  
Upper Level ◽  
The Impact

Creating active, student-centered learning situations in postsecondary education is an ongoing challenge for engineering educators. Contemporary students familiar with visually engaging and fast-paced games can find traditional classroom methods of lecture and guided laboratory experiments limiting. This paper presents a methodology that incorporates driving simulation, motion simulation, and educational practices into an engaging, gaming-inspired simulation framework for a vehicle dynamics curriculum. The approach is designed to promote active student participation in authentic engineering experiences that enhance learning about road vehicle dynamics. The paper presents the student use of physical simulation and large-scale visualization to discover the impact that design decisions have on vehicle design using a gaming interface. The approach is evaluated using two experiments incorporated into a sequence of two upper level mechanical engineering courses.

A Practical Real-Time Motion Cueing Algorithm for Crane Simulator

2014 ◽  
Vol 532 ◽  
pp. 280-284
Author(s):  
Ze Zhu ◽  
Han Bin Xiao ◽  
Guo Xian Wang ◽  
Kan Hu
Keyword(s):  
Real Time ◽  
Large Scale ◽  
Computing Time ◽  
Reference Value ◽  
Simulation Models ◽  
Field Application ◽  
Operating Conditions ◽  
Motion Simulation ◽  
Time Motion ◽  
Motion Cueing

This paper addresses motion simulation issues involved in a crane simulator with a 6-Degree-Of-Freedom platform. The crane dynamical models in terms of a range of motion equations are built for the operator cab in various main operating conditions. The ways to make the motion to be reproduced are investigated and the corresponding real-time motion cueing algorithm is proposed based on a special curve-merging approach. The algorithm is of simplified form and the needed computing time is very short, which makes it very practicable. The crane simulation system with this algorithm being adopted has been successfully developed and put into practice. The field application showed that the algorithm is able to ensure achievement of satisfied motion cueing effects. The proposed motion simulation models and the corresponding algorithm will provide significant reference value for developing similar motion simulation systems for all types of large-scale cranes or construction machinery.

Large deployable network constructed by Altmann linkages

2016 ◽  
Vol 231 (2) ◽  
pp. 341-355 ◽  
Author(s):  
Xiaoke Song ◽  
Hongwei Guo ◽  
Bing Li ◽  
Rongqiang Liu ◽  
Zongquan Deng
Keyword(s):  
Theoretical Approach ◽  
Large Scale ◽  
Screw Theory ◽  
Motion Equation ◽  
Motion Simulation ◽  
Single Loop ◽  
Screw Motion ◽  
Revolute Joints ◽  
Constraint Graph ◽  
Mechanical Networks

This study proposes a large-scale modular deployable mechanical network constructed by networking Altmann linkages, which are spatial single-loop mechanisms with six revolute joints and four bars, and develops a theoretical approach to verify the feasibility of the networking method. First, the screw motion equation of the linkage is derived, and the deployability of the linkage is demonstrated through a motion simulation. Second, using the overlapping-unit method, a deployable mechanical network is constructed. The constraint graph of the mechanical network is deduced subsequently. The mobility of the mechanical network is proved by screw theory, which demonstrates the feasibility of the networking method. Then, the motion of the mechanical network is simulated and it is found to have excellent deployability. Finally, a prototype of the mechanical network is fabricated. Results show that spatial single-loop linkages can construct modular deployable mechanical networks with the overlapping-unit method under appropriate connections. This networking method can be verified with the theoretical approach proposed in this work.

The Design and Kinematics Analysis of an Underactuated Cable-Truss Mechanism

2014 ◽  
Vol 915-916 ◽  
pp. 256-263
Author(s):  
Nan Wu ◽  
Rong Qiang Liu ◽  
Hong Wei Guo
Keyword(s):  
Theoretical Analysis ◽  
Large Scale ◽  
Simple Structure ◽  
High Reliability ◽  
Light Weight ◽  
Motion Simulation ◽  
Kinematics Analysis ◽  
Precise Position ◽  
Underactuated Mechanism ◽  
Serial Mechanism

Although underactuated mechanism has been widely studied in recent years, little information is available on that with cable-truss. An underactuated cable-truss mechanism was presented in this paper. This serial mechanism consists of five quadrilateral cable-truss units and moves by changing the length of the cables. It can be extended to large-scale spatial gripper and has advantages like light weight, simple structure and high reliability. This mechanism can capture the object without its precise position and shape. The kinematics analysis was discussed considering the characteristics of different ways to capture and a numerical example was given. The results of motion simulation corresponding with the example were shown to verify the correctness of the theoretical analysis.

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

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