仿鸟扑翼试验平台控制器快速原型设计

介绍控制系统实时在线仿真平台dSPACE系统,研究了仿鸟扑翼试验平台控制方案,利用dSPACE系统构造了仿鸟扑翼试验平台伺服控制器,通过实时仿真对PID控制参数完成了优化,从而取得了满意的扑翼运动轨迹跟踪效果。设计过程表明：利用dSPACE在线仿真技术开发控制器原型可以大大节省时间和费用。     

Optimization‐based group performance deducing

Large‐scale group performance animation has been an important research topic because of its diverse range of applications including virtual rehearsal and film production. Animating hundreds of virtual actors as what the director wishes is a tough task. In this paper, we address this challenge by introducing an optimization method that generates large‐scale group performance by deducing a small‐scale one with fewer actors. We introduced group motion bigraph technique and transformed the motion‐deducing problem into a constrained optimization problem. A solving process is then presented to automatically obtain the motion of the large group with velocity constraints. Moreover, an interactive system of constructing the group motion bigraph has been implemented, which provides flexible edit and control on deducing group motion. The animation results show that our method is competent for deducing large‐scale group performance from only several motion clips performed by small groups. Copyright © 2013 John Wiley & Sons, Ltd.     

Complex models for animating synthetic actors

A classification of models for animating synthetic actors is proposed. The classification depends on the motion control method used (geometric, physical, or behavioral) and the type of actor interaction (single actor, actor-actor, actor-environment, and animator-actor). These interactions and models give rise to a classification array with four rows and three columns. Each case represents existing and potential approaches to animation control. The characteristics of each motion control method and interaction type are examined     

Path planning in GPS-denied environments via collective intelligence of distributed sensor networks

This paper proposes a framework for reactive goal-directed navigation without global positioning facilities in unknown dynamic environments. A mobile sensor network is used for localising regions of interest for path planning of an autonomous mobile robot. The underlying theory is an extension of a generalised gossip algorithm that has been recently developed in a language-measure-theoretic setting. The algorithm has been used to propagate local decisions of target detection over a mobile sensor network and thus, it generates a belief map for the detected target over the network. In this setting, an autonomous mobile robot may communicate only with a few mobile sensing nodes in its own neighbourhood and localise itself relative to the communicating nodes with bounded uncertainties. The robot makes use of the knowledge based on the belief of the mobile sensors to generate a sequence of way-points, leading to a possible goal. The estimated way-points are used by a sampling-based motion planning algorithm to generate feasible trajectories for the robot. The proposed concept has been validated by numerical simulation on a mobile sensor network test-bed and a Dubin’s car-like robot.     

Formal modeling of evolving self-adaptive systems

In this paper, we present a formal model, named PobSAM (Policy-based Self-Adaptive Model), for developing and modeling self-adaptive evolving systems. In this model, policies are used as a mechanism to direct and adapt the behavior of self-adaptive systems. A PobSAM model is a collection of autonomous managers and managed actors. The managed actors are dedicated to the functional behavior while the autonomous managers govern the behavior of managed actors by enforcing suitable policies. A manager has a set of configurations including two types of policies: governing policies and adaptation policies. To adapt the system behavior in response to the changes, the managers switch among different configurations. We employ the combination of an algebraic formalism and an actor-based model to specify this model formally. Managed actors are expressed by an actor model. Managers are modeled as meta-actors whose configurations are described using a multi-sorted algebra called CA. We provide an operational semantics for PobSAM using labeled transition systems. Furthermore, we provide behavioral equivalence of different sorts of CA in terms of splitting bisimulation and prioritized splitting bisimulation. Equivalent managers send the same set of messages to the actors. Using our behavioral equivalence theory, we can prove that the overall behavior of the system is preserved by substituting a manager by an equivalent one.     

多种动态模拟和复杂三维动画控制的框架结构

本文提出了一种新的适用于多种动态模拟和复杂三维动画控制的面向对象的框架结构，它采用混合层次模型，其角色按部件层次组织其静态结构，角色中包含有决定其形状、样式和行为变化的属性，它按类的层次结构定义，属性的动态赋值通过引进的动态约束机制实现.该框架结构已用于SIMUKIT──用于多种动态模拟视觉效果自动生成的集成工具环境中，并在SGI工作站上初步实现，实验表明该框架结构对解决多种动态模拟生成是可行的.     

SAM-animation software for simulating articulated motion

A collection of software used for interactive specification, motion control and graphics simulation of articulated objects of arbitrary complexity is described. While used primarily for simulating and evaluating robotic manipulators, it has also been applied to the animation of biological models. One of the key issues discussed involves a flexible and intuitive approach to the motion specification for that large class of objects which possess redundant degrees of freedom.     

交通干线无线传输链路性能仿真与实验研究

对交通干线无线宽带覆盖网络骨干链路的传输性能进行仿真与实验研究,在前期研究提出的无线Mesh网络骨干链路传输模型的基础上,基于NS2搭建了仿真实验床,并建立了实验测试网,对影响骨干链路传输性能的关键因素进行研究,仿真实验结果和实验网测试结果进一步论证了理论传输模型的正确性与有效性.     

Transport analysis and quality evaluation of MVC video streaming

This paper explores the performance of the emerging H.264/MVC standard for stereo video under various packetization schemes, encoding parameters and network conditions. An experimentation test-bed platform has been developed to support the multi session transmission approach for various video packetization options under various number of NAL units per frame. The paper presents measurements in terms of overhead as well as 3D video quality for sequences with different characteristics in terms of spatial resolution and motion. Extensive test-bed experiments indicate that the fragmentation of frames in more than one NAL units improves the perceived video quality measured objectively in terms of PSNR, VQM, SSIM for both base and non-base view as well as, subjectively in terms of 3D MOS.     

人体行为动作的形状轮廓特征提取及识别

将傅里叶变换与边缘小波矩描述子相结合,提出一种人体行为动作的识别方法。凹凸复杂图像的质心到轮廓为非单一直线,据此,给出一种多段定向距离轮廓描述矩阵,实现轮廓特征的提取。分别对2类人体和4种行为动作进行仿真实验,结果表明,边缘小波矩描述子能较好地体现人体行为动作的形状轮廓局部特征,具有较高的识别率。     

变循环航空发动机半物理仿真研究

变循环发动机数字控制系统属于较新的研究方向,基于此设计变循环发动机半物理仿真平台,通过半物理仿真试验可以及早发现系统设计中的缺陷,确定最佳的设计方案,大大降低试验风险,减少试验成本.搭建了变循环航空发动机半物理仿真平台主要包括五部分:实时发动机模型、油门杆、状态开关、I/O接口箱和数字电子控制器.     

车速台智能仪表的设计与实现

车速表试验台是汽车安全性能检测线以及汽车维修必不可少的测试设备,在借鉴传统车速表试验台智能仪表的基础上,结合现代电子信息技术发展的最新成果,设计了一种性价比高、通用、多功能的新型智能仪表;该仪表可以和多种测速传感器相配．既可作为单机智能仪表检测,也可以和上位机采用RS232／RS485通信,实现联网自动检测;该仪表已投入实际使用,效果良好。     

Analysis of dynamometry scheme for semi-physical simulation platform of space docking mechanism

The semi-physical simulation platform of space docking mechanism is one of the main ground testing equipments for study of docking mechanism, and is used to simulate docking procedure. In order to demonstrate test-bed schemes, analysis for the semi-physical simulation platform must be carried out. First, impacting model of docking mechanism and mathematic model of two spacecrafts motion are set up in this paper. Then, determination methods of passive spacecraft impacting torques are analyzed when adopting single-sensor scheme. Finally, representative conditions are simulated adopting single-sensor and double-sensor schemes separately. Simulation results indicate that the declinations of position, velocity of two spacecrafts and that of two docking mechanisms are less, so the single-sensor scheme for the semi-physical simulation platform is presented in this paper.     

Simulating the task-level control of human motion: a methodology and framework for implementation

A task-level control framework is proposed for providing feedback control in the simulation of goal-directed human motion. An operational space approach, adapted from the field of robotics, is used for this purpose. This approach is augmented by a significant new extension directed at addressing the control of muscle-driven systems. Task/posture decomposition is intrinsically exploited, allowing human musculoskeletal properties to direct postural behavior during the performance of a task. This paper also describes a simulation architecture for generating musculoskeletal simulations of human characters. The evolving capabilities of the collective environment are directed toward autonomously generating realistic motion control for virtual actors in interactive computer graphics applications, as well as synthesizing the control of human-like motion in robotic systems.     

Bearing-only Cooperative Localization

In cooperative localization a group of robots exchange relative position measurements from their exteroceptive sensors and their motion information from interoceptive sensors to collectively estimate their position and heading. For the localization errors to be bounded, it is required that the system be observable, independent of the estimation technique being used. In this paper, we develop a test-bed of three ground robots, which are equipped with wheel encoders and omnidirectional cameras, to implement the bearing-only cooperative localization. The simulation and experimental results validate the observability conditions, derived in Sharma et al. (IEEE Trans Robot 28:2, 2011), for the complete observability of the bearing-only cooperative localization problem.     

Towards an extensible simulator of real motion platforms

The limitations of a real motion platform will not normally be discovered until it is completely built and tested. Late identification of its limitations imposes the necessity of a redesign of the motion platform. This, in turn, incurs important and significant economic costs for the manufacturer. Note that any change in the original design of the motion platform requires an investment in resources, money and time in order to perform the re-design of the platform. The main contribution of this paper is to address this problem by creating a virtual motion platform (VMP). This virtual motion platform is a computer-based simulation of a real motion platform which produces the same outputs as the real platform when it receives the same inputs. The VMP has been designed to easily replace the real platform in order to avoid damage to the real system, avoid the potential for human injuries and reduce costs, among other advantages. The model is extensible, enabling the simulation of different kinds of real motion platforms in real-time. The VMP has been validated against a real system implementation. This prototype has been validated against two real motion platforms that we have in our labs: a T3R3 (6DoF) and a T1R2 (3DoF) platform. Extensive empirical tests have been performed and the results show that the VPM exhibits a deviation of less than 3% with respect to the real motion platform, which is a really reasonable result considering the complexity of the simulation. We have also demonstrated that our simulation is capable of running faster than real-time being able to perform batch simulations on many different design iterations.     

Kinematic Discussion and Development of a Multi-Legged Planetary Exploration Rover with an Isotropic Leg Arrangement

This study deals with a multi-legged planetary rover with a spherically isotropic leg arrangement. The legged rover is a reliable rover system for exploration on rough terrains, because it can continue walking even after overturning. Moreover, the legged rover can also show a rotational motion by utilizing its isotropic shape. This paper discusses the walking performance of two types of rover shapes: one has a six-leg arrangement based on a regular octahedron and the other has an eight-leg arrangement based on a regular hexahedron. The design procedure of the proposed rover is explained, and a test-bed system, which is developed to demonstrate the fundamental motions, is also presented.     

Animation of Human Diving

The motion of a human platform diver was simulated using a dynamic model and a control system. The dynamic model has 32 actuated degrees of freedom and dynamic parameters within the range of those reported in the literature for humans. The control system uses algorithms for balance, jumping, and twisting to initiate the dive, sequences of desired values for proportional-derivative servos to perform the aerial portion of the dice, and a state machine to sequence the actions throughout the dice. The motion of the simulated diver closely resembles video footage of dices performed by human athletes. The control and simulation techniques presented in this paper are useful for providing realistic motion for synthetic actors in computer animations and virtual environments and may some day be useful for analysis of sports performance.     

Maze exploration behaviors using an integrated evolutionary robotics environment

This paper presents results generated with a new evolutionary robotics (ER) simulation environment and its complementary real mobile robot colony research test-bed. Neural controllers producing mobile robot maze searching and exploration behaviors using binary tactile sensors as inputs were evolved in a simulated environment and subsequently transferred to and tested on real robots in a physical environment. There has been a considerable amount of proof-of-concept and demonstration research done in the field of ER control in recent years, most of which has focused on elementary behaviors such as object avoidance and homing. Artificial neural networks (ANN) are the most commonly used evolvable controller paradigm found in current ER literature. Much of the research reported to date has been restricted to the implementation of very simple behaviors using small ANN controllers. In order to move beyond the proof-of-concept stage our ER research was designed to train larger more complicated ANN controllers, and to implement those controllers on real robots quickly and efficiently. To achieve this a physical robot test-bed that includes a colony of eight real robots with advanced computing and communication abilities was designed and built. The real robot platform has been coupled to a simulation environment that facilitates the direct wireless transfer of evolved neural controllers from simulation to real robots (and vice versa). We believe that it is the simultaneous development of ER computing systems in both the simulated and the physical worlds that will produce advances in mobile robot colony research. Our simulation and training environment development focuses on the definition and training of our new class of ANNs, networks that include multiple hidden layers, and time-delayed and recurrent connections. Our physical mobile robot design focuses on maximizing computing and communications power while minimizing robot size, weight, and energy usage. The simulation and ANN-evolution environment was developed using MATLAB. To allow for efficient control software portability our physical evolutionary robots (EvBots) are equipped with a PC-104-based computer running a custom distribution of Linux and connected to the Internet via a wireless network connection. In addition to other high-level computing applications, the mobile robots run a condensed version of MATLAB, enabling ANN controllers evolved in simulation to be transferred directly onto physical robots without any alteration to the code. This is the first paper in a series to be published cataloging our results in this field.     

半实物仿真综合实验台控制系统方案

构建半实物仿真综合实验台,能够模拟再现2个飞行器的空间交会动力学过程。在此基础上,提出半实物仿真综合实验台控制系统方案。控制系统包括中央控制单元、测控单元、模型计算单元、驱动装置以及六维力传感器,实现对整个实验的控制和管理、在线监视以及驱动机构的动作。该系统设计具有控制实时性以及良好的用户界面,经过实验验证,证明其是稳定、可靠的。