基于ARcode的移动增强现实系统研究

为解决移动设备多用户、大数据量目标的识别和跟踪问题,提出一种基于改进二维码的新型移动增强现实系统。通过C/S框架保证模型的更新,在客户端分离出识别和渲染过程,分析基于快速响应矩阵码的跟踪注册方法,针对其存在的跟踪范围小、跟踪不稳定的问题给出解决方案,从而完善系统。实验结果表明,与基于常规标志点和利用自然特征的方法相比,该系统方便实用、便于推广,且条码容易被手机使用,能识别出更多的信息。     

Combination of augmented Lagrangian technique and ST preconditioner for saddle point problems

For symmetric indefinite linear systems, we introduce a new triangular preconditioner based on symmetric and triangular (ST) decomposition. A new (1, 1) block is obtained by augmented Lagrangian technique. The new ST preconditioner is introduced by the combination of the new (1, 1) block and symmetric and triangular (ST) decomposition. Then a preconditioned system can be obtained by preconditioning technique, which is superior to the original system in terms of condition number. We study the spectral properties of preconditioned system, such as eigenvalues, the estimation of condition number and then give the quasi-optimal parameter. Numerical examples are given to indicate that the new preconditioner has obvious efficiency advantages. Finally, we conclude that the new ST preconditioner is a better option to deal with large and sparse problems.     

Simultaneous stabilization of a set of nonlinear port-controlled Hamiltonian systems

This paper investigates simultaneous stabilization of a set of nonlinear port-controlled Hamiltonian (PCH) systems and proposes a number of results on the design of simultaneous stabilization controllers for the PCH systems. Firstly, the case of two PCH systems is studied. Using the dissipative Hamiltonian structural properties, the two systems are combined to generate an augmented PCH system, with which some results on the control design are then obtained. For the case that there exist parametric uncertainties in the two systems’ Hamiltonian structures, an adaptive simultaneous stabilization controller is proposed. When there are external disturbances and parametric uncertainties in the two systems, two simultaneous stabilization controllers are designed for the systems: one is a robust controller and the other is a robust adaptive one. Secondly, the case of more than two PCH systems is investigated, and a new result is proposed for the simultaneous stabilization of the systems. Finally, two illustrative examples are studied by using the results proposed in this paper. Simulations show that the simultaneous stabilization controllers obtained in this paper work very well.     

Augmented Lagrange方法在钢丝绳捻制成形摩擦接触数值模拟中的应用

钢丝绳中金属线间接触摩擦会影响捻制成形加工应力和结构强度。在经典的Coulom摩擦理论的基础上,本文采用AugmentedLagrange方法计算钢丝绳捻制过程中的法向接触力和摩擦接触力,并应用radial return径向回映法修正摩擦接触力试算值。以钢丝绳一次捻制成形过程为例,分析并讨论了摩擦系数和自扭转系数对接触应力和加工应力应变的影响,为钢丝绳成形工艺和结构强度的合理设计提供依据。     

An augmented reduced mechanism for the reburning process

A skeletal and an augmented reduced mechanisms (ARM) describing the reburning process have been obtained. The full chemistry is taken from the detailed kinetic model of Glarborg et al. (1998) which consists of 438 elementary reactions and 65 chemical species. The mechanisms have been obtained by means of the application of sensitivity and reaction rate analysis, as well as the application of the quasi-steady-state approximation. The ARM finally obtained in this work consists of 19 species and 15 lumped reaction steps. It has been validated by comparing the calculated concentrations of CH₄, CO₂, CO and NO, with those calculated with the detailed mechanism in a wide range of operating conditions, with emphasis in those conditions directly applicable to a reburn environment. Compared to the detailed mechanism, both the skeletal and the reduced mechanisms show very good predictions in a wide range of operating conditions, and therefore should be appropriate for their implementation in CFD calculations describing reburn environments.     

Interactive robot trajectory planning and simulation using Augmented Reality

Human-robot interaction in industrial robotics has largely been confined to finding better ways to reconfigure or program the robots. In this paper, an Augmented Reality based (RPAR-II) system is proposed to facilitate robot programming and trajectory planning considering the dynamic constraints of the robots. Through the various simulation capabilities provided in the proposed AR environment, the users are able to preview the simulated motion, perceive any possible overshoot, and resolve discrepancies between the planned and simulated paths prior to the execution of a task. By performing the simulation, the performance of the trajectory planning and the fitness of the selection of the robot controller model/parameters in the robot programming process can be visually evaluated. Practical issues concerning the system implementation are also discussed.     

Assessing continuity and compatibility in augmented reality systems

Integrating computer-based information into the real world of the user is becoming a crucial challenge for the designers of interactive systems. The Augmented Reality (AR) paradigm illustrates this trend. Information is provided by an AR system to facilitate or to enrich the natural way in which the user interacts with the real environment. We focus on the output of such systems and, in particular, on the smooth integration of additional information in the real environment of the user. We characterize the integration of the computer-provided entities with the real ones using two new properties: compatibility and continuity. After defining the two properties, we provide factors and an analytical method needed for assessing them. We also empirically study the two properties to highlight their impact on interaction. The CASPER system, developed in our teams, is used to illustrate the discussion. Published online: 14 May 2002     

Tangled reality

Leonardo da Vinci was a strong advocate for using sketches to stimulate the human imagination. Sketching is often considered to be integral to the process of design, providing an open workspace for ideas. For these same reasons, children use sketching as a simple way to express visual ideas. By merging the abstraction of human drawings and the freedom of virtual reality with the tangibility of physical tokens, Tangled Reality creates a rich mixed reality workspace. Tangled Reality allows users to build virtual environments based on simple colored sketches and traverse them using physical vehicles overlayed with virtual imagery. This setup allows the user to “build” and “experience” mixed reality simulations without ever touching a standard computer interface.     

Material light: exploring expressive materials

The control of material appearance has become richer than before, giving designers new expressive freedom. Designers need tools and techniques to handle this freedom when designing products. We present a simple but powerful technique to explore material expression in the conceptual phase of the design process. Colours and patterns are projected on foam and paper models to enable designers to quickly visualise and judge materials in context of the products shape. This paper is part of the 3AD design colloquium creative connections.