MIVAS: A Multi-Modal Immersive Virtual Assembly System

2004 ◽  
Author(s):  
Huagen Wan ◽  
Shuming Gao ◽  
Qunsheng Peng ◽  
Guozhong Dai ◽  
Fengjun Zhang
Keyword(s):  
Virtual Environments ◽  
Large Scale ◽  
Force Feedback ◽  
User Interaction ◽  
Virtual Assembly ◽  
Research Area ◽  
Optimization Techniques ◽  
Assembly System ◽  
Assembly Operations ◽  
Assembly Constraints

Evaluation and planning of assembly processes in virtual environments have become an active research area in engineering community. However, planning of complex assemblies in virtual environments, especially large-scale virtual environments, is still hindered by limitations like unnatural user interaction, insufficient frame rates, and deficiencies in processing of assembly constraints. In this paper, we present MIVAS, a Multi-modal Immersive Virtual Assembly System. By viewing the virtual assembly system as a finite state machine, we incorporate tracked devices, force feedback dataglove, voice commands, human sounds, fully immersive 4-sided CAVE, together with optimization techniques for both complex assembly models and assembly operations to provide for engineers an intuitive and natural way of assembly evaluation and planning. Testing scenarios on disassembling different components of an intelligent hydraulic excavator are described. Special attention is paid upon such technical issues as interface between CAD packages and the CAVE virtual environment, natural and intuitive user interaction including realistic virtual hand interaction and force feedback, intelligent navigation for assembly operations, and real-time display of complex assemblies.

OPTIMIZATION TECHNIQUES FOR ASSEMBLY PLANNING OF COMPLEX MODELS IN LARGE-SCALE VIRTUAL ENVIRONMENTS

2003 ◽  
Vol 03 (02) ◽  
pp. 379-398 ◽  
Author(s):  
HUAGEN WAN ◽  
SHUMING GAO ◽  
QUNSHENG PENG ◽  
YIYU CAI
Keyword(s):  
Virtual Environments ◽  
Real Time ◽  
Large Scale ◽  
User Interaction ◽  
Detection Algorithm ◽  
Optimization Techniques ◽  
Assembly Planning ◽  
Complex Models ◽  
Assembly Operations ◽  
Assembly Constraints

Evaluation and planning of assembly processes in virtual environments, especially large-scale virtual environments, have attracted much attention in the engineering community. However, the planning of complex assemblies in virtual environments is still hindered by limitations like insufficient frame rates, unnatural user interaction, as well as deficiencies in the processing of assembly constraints. This paper discusses some optimization techniques for the assembly planning of complex assemblies in a large-scale virtual environment such as CAVE. Specifically, the real-time display of complex assemblies, the natural and intuitive assembly operations, and a real-time collision detection algorithm for the assembly applications are presented.

scholarly journals AN EFFICIENT Hybrid Swarm Intelligence Technique for Solving Integer Programming

2013 ◽  
Vol 10 (4) ◽  
pp. 1531-1538
Author(s):  
Mahmoud M. Ismail ◽  
Ibrahim M. El-henawy
Keyword(s):  
Integer Programming ◽  
Large Scale ◽  
Hybrid Approach ◽  
Optimal Solution ◽  
Research Area ◽  
Optimization Techniques ◽  
Computational Time ◽  
Hybrid Swarm ◽  
Integer Programming Problems ◽  
Scale Optimization

In this paper, a hybridization of two different swarm intelligent approaches, stochastic diffusion search, and particle swarm optimization techniques is presented  for solving integer programming problems. The hybrid implementation allows us to avoid certain drawbacks and weaknesses of each algorithm, which means that we are able to find an optimal solution in an acceptable computational time. Our hybrid implementation allows the IP algorithm to reach the optimal solution in a considerably shorter time than is needed to solve the model using the entire dataset directly within the model. Our hybrid approach outperforms the results obtained by each technique separately. It is able to find the optimal solution in a shorter time than each technique on its own, and the results are highly competitive with the state-of-the-art in large-scale optimization. Furthermore, according to our results, combining the PSO with SDS approach for solving IP problems appears to be an interesting research area in combinatorial optimization. 

Study on Desktop Virtual Assembly System for Interactive Assembly Process Planning

2010 ◽  
Vol 426-427 ◽  
pp. 371-375
Author(s):  
Dan Zhang ◽  
Guang Ming Jiao ◽  
Dun Wen Zuo ◽  
Jian Xie ◽  
J.P. Li ◽  
...  
Keyword(s):  
Process Planning ◽  
Process Design ◽  
Virtual Assembly ◽  
Data Conversion ◽  
Assembly System ◽  
Assembly Process ◽  
Assembly Process Planning ◽  
Key Technologies ◽  
Assembly Operations ◽  
Assembly Models

Aiming at the shortcomings of traditional assembly process design and immersive virtual assembly system, the architecture of Desktop Virtual Assembly System (DVAS) for interactive assembly process planning is presented. The key technologies such as data conversion and reconstruction of assembly models, assembly intention recognition and assembly control navigation are studied. The lightweight storage of assembly models’ data and the intelligent constraints recognition are realized. The problem of assembly operations resulted from the lack of immersion is solved by movement navigation. The algorithms were proposed and applied to the DVAS prototype, and an application case is studied to demonstrate the effectiveness of the system.

Research on Exact Placement Technology of Virtual Assembly for Large-Scale Products

2007 ◽  
Vol 10-12 ◽  
pp. 460-465 ◽  
Author(s):  
Yue Dong Lang ◽  
Ying Xue Yao ◽  
Ping Jun Xia ◽  
G.H. Liu
Keyword(s):  
Large Scale ◽  
Virtual Assembly ◽  
Recognition Algorithm ◽  
Assembly Planning ◽  
Assembly Process ◽  
Hierarchical Assembly ◽  
Complex Process ◽  
Set Up ◽  
The Cost ◽  
Assembly Operations

Due to big structure and complex process for some large-scale products (such as planes and rockets), the workers have to try many times and move around in the products to accomplish the assembly operations for high-precision requirements. Thus, the efficiency is low and the cost is high in the assembly process. To deal with that, the virtual assembly (VA) system for large-scale products is developed in this paper. First a new VA environment considering human activity is set up, and then a hierarchical assembly process list (HAPL) model and a dynamic constraint recognition algorithm is proposed to realize exact placement for large-scale products in VA system. Finally, the method is verified by the development VA system which successfully applied in the process of satellite assembly. Moreover, the method can be used in the common VA systems for assembly planning.

A force rendering model for virtual assembly of mechanical parts with clearance fits

2018 ◽  
Vol 38 (2) ◽  
pp. 173-181
Author(s):  
QingHui Wang ◽  
Zhong-Dong Huang ◽  
JingRong Li ◽  
Jia-Wu Liu
Keyword(s):  
Force Feedback ◽  
Virtual Assembly ◽  
Geometric Constraints ◽  
Prototype System ◽  
Content Type ◽  
Mechanical Parts ◽  
Proposed Model ◽  
Physics Simulation ◽  
Realistic Force ◽  
Assembly Operations

Purpose Realistic force sensation can help operators better feel and manipulate parts for virtual assembly (VA). Moreover, for VA of mechanical parts, it is necessary to consider their tolerance levels so as to apply proper assembly forces. Out of the three common assembly fit types, the type of clearance fit is the focus of virtual manual assembly, as parts with such fit type require precise force feedback to assist users’ assembly operations. Design/methodology/approach This study proposes a novel force rendering model for VA of mechanical parts with clearance fits. By decomposing an actual assembly operation into three consecutive states, the corresponding forces are formulated. Findings A prototype system is designed and developed to implement the model, and comparative case studies are conducted to investigate the users’ performance with the other three common approaches, namely, a typical WIMP (window-icon-menu-pointer) interface with CAD software, a physics simulation with collision detection and the approach that combines physics simulation and geometric constraints restriction. The results have shown that the proposed model is more realistic by providing continuous and realistic force feedback to the users. Originality/value The users’ feeling of immersion and their operational efficiency are greatly enhanced with the force sensation provided.

scholarly journals Formation of Morphable 3D­model of Large Scale Natural Sites by Using Image Based Modeling and Rendering Techniques

2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Rabinarayan Sathpathy ◽  
Rajani Kanta Chhotray ◽  
Sabyasachi Pattnaik
Keyword(s):  
Virtual Environments ◽  
Large Scale ◽  
3D Models ◽  
Optimization Techniques ◽  
Global Registration ◽  
Image Based Modeling ◽  
Geometric Reconstruction ◽  
Interactive Frame ◽  
The Individual ◽  
3D Virtual Environments

No global 3D model of the environment needs to be assembled, a process which can be extremely cumbersome and error prone for large scale scenes e.g. the global registration of multiple local models can accumulate a great amount of error, while it also presumes a very accurate extraction of the underlying geometry. On the contrary, neither any such accurate geometric reconstruction of the individual local 3D models nor a very precise registration between them is required by our framework in order that it can produce satisfactory results. This paper presents an application of LP based MRF optimization techniques and also we have turned our attention to a different re­ search topic: the proposal of novel image based modeling and rendering methods, which are capable of automatically reproducing faithful (i.e. photorealistic) digital copies of complex 3D virtual environments, while also allowing the virtual exploration of these environments at interactive frame rates.

Research on Force Feedback-Based Tool Operation in Virtual Assembly

2010 ◽  
Vol 29-32 ◽  
pp. 1046-1050 ◽  
Author(s):  
Cheng Jun Chen ◽  
Yun Feng Wu ◽  
Niu Li
Keyword(s):  
Force Feedback ◽  
Virtual Assembly ◽  
Assembly System ◽  
Assembly Operation ◽  
Motion Constraints ◽  
Operation Method ◽  
Initial Stage

To verify the accessibility and workspace of tool operation in virtual assembly system, this paper presented a tool-part operation method based on force feedback. According to characters of common tool-part operations, standard fastening tools and parts were modeled using features and parameters at initial stage. Then operator was enabled to conduct different kinds of fastening and unfastening operations in virtual assembly system by three steps namely identification, interactive positioning and operation. With feedback force, the operator can feel corresponding motion constraints of tool during virtual fastening and unfastening operation, so the immersion of virtual assembly operation is promoted.

scholarly journals Solving the Real Power Limitations in the Dynamic Economic Dispatch of Large-Scale Thermal Power Units under the Effects of Valve-Point Loading and Ramp-Rate Limitations

2021 ◽  
Vol 13 (3) ◽  
pp. 1274
Author(s):  
Loau Al-Bahrani ◽  
Mehdi Seyedmahmoudian ◽  
Ben Horan ◽  
Alex Stojcevski
Keyword(s):  
Large Scale ◽  
Thermal Power ◽  
Optimization Technique ◽  
Economic Dispatch ◽  
Pso Algorithm ◽  
Search Space ◽  
Economic Benefits ◽  
Optimization Techniques ◽  
Ramp Rate ◽  
Dynamic Economic Dispatch

Few non-traditional optimization techniques are applied to the dynamic economic dispatch (DED) of large-scale thermal power units (TPUs), e.g., 1000 TPUs, that consider the effects of valve-point loading with ramp-rate limitations. This is a complicated multiple mode problem. In this investigation, a novel optimization technique, namely, a multi-gradient particle swarm optimization (MG-PSO) algorithm with two stages for exploring and exploiting the search space area, is employed as an optimization tool. The M particles (explorers) in the first stage are used to explore new neighborhoods, whereas the M particles (exploiters) in the second stage are used to exploit the best neighborhood. The M particles’ negative gradient variation in both stages causes the equilibrium between the global and local search space capabilities. This algorithm’s authentication is demonstrated on five medium-scale to very large-scale power systems. The MG-PSO algorithm effectively reduces the difficulty of handling the large-scale DED problem, and simulation results confirm this algorithm’s suitability for such a complicated multi-objective problem at varying fitness performance measures and consistency. This algorithm is also applied to estimate the required generation in 24 h to meet load demand changes. This investigation provides useful technical references for economic dispatch operators to update their power system programs in order to achieve economic benefits.

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