A microprocessor based trainer for both single-site and two-site myoelectric prostheses

Electronic training aids are essential in preparing an amputee for the use of a myoelectric prosthesis. Those presently available are often complicated in use and never flexible enough to handle a wide variety of possible myoelectric control strategies. By the judicial application of microprocessor technology, the Bio-Engineering Institute of the University of New Brunswick has designed a ‘high-tech’ training device, which overcomes these drawbacks. The new trainer interacts with a therapist via a 2 × 40 character liquid crystal display and two key switches. It is completely menu driven, and as such can be used immediately by an inexperienced person. By using low power circuitry throughout the design, the instrument can be run continually for up to 8 h off a set of five standard D-type cells. In addition, the instrument can be easily adapted to any new control strategy by an update to read-only-memory based software.     

Adaptive control strategies for cooperative dual-arm manipulators

The article describes three strategies for adaptive control of cooperative dual-arm robots. In the position-position control strategy, the adaptive controllers ensure that the end-effector positions of both arms track desired trajectories in Cartesian space despite unknown time-varying interaction forces exerted through the load. In the position-hybrid control strategy, the adaptive controller of one arm controls end-effector motions in the free directions and applied forces in the constraint directions; while the adaptive controller of the other arm ensures that the end-effector tracks desired position trajectories. In the hybrid-hybrid control strategy, the adaptive controllers ensure that both end-effectors track reference position trajectories while simultaneously applying desired forces on the load. In all three control strategies, the coupling effects between the arms through the load are treated as “disturbances” which are rejected by the adaptive controllers while following desired commands in a common frame of reference. The adaptive controllers do not require the complex mathematical model of the arm dynamics or any knowledge of the arm dynamic parameters or the load parameters such as mass and stiffness. The controllers have simple structures and are computationally fast for on-line implementation with high sampling rates. Simulation results are given to illustrate the proposed adaptive control strategies.     

Control of laparoscopic instrument motion in an inanimate bench model: implications for the training and the evaluation of technical skills

Computer-assisted analysis of wrist movement has recently emerged as an objective laparoscopic performance evaluation method. The first purpose of this study was to assess the differences in motion characteristics between the tip of the instrument and the wrist. The second purpose was to describe the control strategies used to move laparoscopic instruments. During a bead transfer task, motions of a laparoscopic needle driver's tip, heel, and the participants' wrist were monitored. Results showed that large amplitude movements were best described by movements of the wrist, and small amplitude movements were evidenced by motions of the instrument tip. Thus, for describing expertise, and for evaluation and feedback, motion of the tip of the laparoscopic instrument should be quantified, in addition to motion of the wrist. The motions of the instrument were controlled by utilizing the flexibility of the skin of the laparoscopic trainer in addition to using the fulcrum, and sliding through the trocar. In order to increase fidelity, virtual reality trainers should simulate the flexibility of the real structures around the insertion of the instrument.     

一种新型电子胶带秤控制仪表的设计

针对传统的电子胶带秤控制仪表采用单片机实现累积运算,存在闭环控制效果差、通信功能不强等问题,提出了一种基于ARM的电子胶带秤控制仪表的设计方案,详细介绍了该仪表的硬件及软件设计。该仪表由数据采集器和基于ARM的显示控制器组成,采用分离式的仪表结构形式,数据采集器安装在现场,显示控制器安装在监控室,两者通过RS485接口通信。实验结果表明,该仪表的计量精度优于0.2%,设计合理。     

Convergence properties of a class of pointwise control strategies

In recent years, a number of nonlinear power system stabilization problems have been approached using techniques termed "velocity-matching" or "optimal-aiming" strategies. At each instant of time, these strategies require that the velocity of the system be adjusted through instantaneous control action such that the state moves in some "preferred" direction subject to constraints imposed by an admissible input set, the choice of a preferred direction producing the different control strategies. In this paper, we show that for any such control strategy σ and independent of preferred direction choices, there will be a controllable linear time-invariant system which is rendered unstable under σ, even if arbitrarily large inputs and nonlinear dependence of σ on its arguments is permitted.     

Analytical and design aspects of magnetically suspended vehicles

This paper presents some theoretical and experimental results concerning the dynamics and control of vehicles suspended by controlled direct current electromagnets. Due to multi-degrees of freedom of such vehicles, interaction of the various control loops through the dynamics of the vehicle is an important factor in the formulation of overall control strategies. This interaction is first demonstrated through the behaviour of a two-degree of freedom suspension system and methods of influencing such interaction illustrated. The effect of the vehicle centre of mass not coinciding with its geometric centre is studied, and it is shown that the weight of a multimagnet suspension system can be advantageously distributed to obtain a large area free from any coupling between the natural modes of the system. Various methods of controlling a multimagnet suspension system are discussed in the context of simulation and experimental results and the design constraints due to magnetic circuit nonlinearities are outlined, and the effectiveness of linear analysis illustrated.     

钢坯加热炉计算机控制动态数学模型的开发

本文论述了一个应用于加热炉计算机控制和优化操作的离散状态空间模型的开发.模型 基于描述钢坯不稳定导热的两维偏微分方程的相应的边界条件,应用系统分解和离散化方法, 最终转化为由一系列相互关联的子系统组成的大规模离散状态方程.根据加热炉的可测炉段 温度和钢坯的几何尺寸、钢种、移动速度等有关操作条件,模型实时地给出钢坯在炉内任意位 置温度分布的动态响应. 由大型加热炉工业试验数据表明,模型的精度能满足工程应用的要求. 本文还提出了应用数学模型实现加热炉递阶计算机空子的策略.     

基于ActiveX控件的网络虚拟频谱分析仪的设计

该文提出了一种利用ActiveX控件构建网络虚拟频谱分析仪系统的方法。整个系统基于浏览器,服务器构架,首先在VC6．0环境下采用ActiveX控件技术设计出虚拟仪器,然后将其制作成网页的形式并通过Internet向外发布,最后用户通过浏览器向服务器发送命令以远程控制频谱分析仪,并获取实时测试结果。实践证明,ActiveX控件在搭建虚拟仪器软件平台方面具有形象逼真的显示效果、更好的通用性、更强的灵活性等优点。     

太阳辐照度监测仪主动热控测试系统设计

太阳辐照度监测仪（SIM）作为某卫星的有效载荷,每个轨道周期从背阴区到光照区环境温度变化剧烈,而太阳辐照度监测仪的精密测量需要仪器处于稳定的温度环境下。为保证仪器在轨测量时工作在正常温度下,设计了太阳辐照度监测仪主动热控测试系统。根据热分析的结论,确定仪器测温点和加热区。以单片机和FPGA为硬件平台,完成各测温点温度的采集、处理和分析,从而控制各加热区的加热状态,实现仪器在背阴面时对仪器各加热回路的主动加热控制,并通过上位机进行实时监控。实验结果表明：在主动热控系统的控制下,仪器各测温点在模拟外热流环境下能够维持在目标温度平均误差小于0．1℃水平,该系统设计能够达到维持温度稳定的效果,满足太阳辐照度监测仪主动热控的设计要求。     

仿真环境中智能化控制语言的研究

智能化控制语言可控制仿真系统中的实体,使其表现出智能化行为。本文定义了一种智能化控制脚本语言ICSL(Intelligent Control Scripting Language),并实现了ICSL的解释器。ICSL支持基本的控制语句和核心对象,针对领域特征,对仿真领域的语义进行编码,并提供语义扩展机制,为控制策略的制定者提供一种灵活表达策略的手段。ICSL语言的解释器将智能化策略映射为仿真系统中实体的行为序列,实现了对仿真实体的智能化控制。最后,本文通过把ICSL语言用于战场仿真系统对其实用性进行了系统的实验研究,结果表明,基于ICSL语言定义的控制策略可以有效地映射到仿真系统中,从而完成对仿真实体的智能化控制。     

User-Tailored Planning of Mixed Initiative Information-Seeking Dialogues

Intelligent dialogue systems usually concentrate on user support at the level of the domain of discourse, following a plan-based approach. Whereas this is appropriate for collaborative planning tasks, the situation in interactive information retrieval systems is quite different: there is no inherent plan-goal hierarchy, and users are known to often opportunistically change their goals and strategies during and through interaction. We need to allow for mixed-initiative retrieval dialogues, where the system evaluates the user's individual dialogue behavior and performs situation-dependent interpretation of user goals, to determine when to take the initiative and to change the control of the dialogue, e.g., to propose (new) problem-solving strategies to the user. In this article, we present the dialogue planning component of a concept- oriented, logic-based retrieval system (MIRACLE). Users are guided through the global stages of the retrieval interaction but may depart, at any time, from this guidance and change the direction of the dialogue. When users submit ambiguous queries or enter unexpected dialogue control acts, abductive reasoning is used to generate interpretations of these user inputs in light of the dialogue history and other internal knowledge sources. Based on these interpretations, the system initiates a short dialogue offering the user suitable options and strategies for proceeding with the retrieval dialogue. Depending on the user's choice and constraints resulting from the history, the system adapts its strategy accordingly.     

基于虚拟仪器机械动力参数自动测试系统的开发

本文介绍了一种基于虚拟仪器的机械动力参数的微机自动测试测试系统，并对该系统的工作原理、硬件结构及软件编程进行了阐述。该系统综合采用了虚拟仪器技术和现代测控技术来实现对机械动力参量的的在线监测和管理。实践表明该系统性能良好。     

基于终端监控的仪器管理系统服务器设计与实现

针对高校实验室科研仪器存在的种类繁多、使用人员流动性大、仪器地点分散等情况,设计了一个采用C/S架构的仪器监控管理系统。系统终端采用ARM架构的嵌入式处理器,通过霍尔电流传感器检测其所监控的仪器的电流变化情况,将仪器状态、使用人的卡号以及非法操作的报警照片实时地通过网络发送给服务器,同时应用网络数据库技术设计了实验室监控仪器网上查询列表,实现了可在网页直接地查询当前各个房间的仪器使用情况、任何时间段的使用记录信息和所有时间段的报警记录照片以及实验室仪器的预约。     

Motion control analysis of a parallel robot assisted minimally invasive surgery/microsurgery system (PRAMiSS)

This paper presents motion control architectures for a parallel robot assisted minimally invasive surgery/microsurgery system (PRAMiSS) that enable it to achieve milli/micro-manipulations under the constraint of moving through a fixed penetration point or so-called remote centre-of-motion (RCM) point without any mechanical constraint. Two control structures suitable for minimally invasive surgery operations with submillimeter accuracy and for minimally invasive microsurgery operations with the desired accuracy in micron range are proposed. The control algorithm also applies orientation constraints preventing the tip from orienting around the instrument axis due to the robot movements as well as a minimum displacement constraint to minimise the movements of the parallel micropositioning robot. Experiments were performed and the results are analysed in this paper to verify accuracy and effectiveness of the proposed control algorithm for both cases of minimally invasive surgery and microsurgery operations. The experimental results present good accuracy and performance of the control algorithm. The numerical modelling and graphical simulations were also carried out and the results are also provided that demonstrate the correlation between the experimental results and physical responses.     

A new approach to dynamic input-output models

A new discrete-time dynamic input-output economic model is proposed. A control system formulation is undertaken in which the rates of change of capital stock and production are used in the control (policy or instrument) vector. The model is a supply-demand disequilibrium model, allowing excess demand to exist at any time. The exogenous final demand is modeled as a disturbance input.     

A Problem of Control of Markovian Processes on a Graph

The paper deals with the control of Markovian processes on a graph, provided that the control can be transferred from one node to another (neighboring) node at any time. The sufficient conditions of existence of optimal stationary nonrandomized Markovian strategies are obtained.     

Self-tuning controllers for nonlinear systems

Two new self-tuning control (STC) strategies for nonlinear control problems are proposed. These strategies are applicable to a broad class of nonlinear single-input, single-output systems which can include arbitrary nonlinear functions of the output and the old inputs as well as the products of these functions and any power of the most recent input. Simulation results for a stirred-tank chemical reactor demonstrate that the new nonlinear STC strategy provides significant improvement over conventional STCs based on linear models.     

Model reduction and controller design for a nonlinear heat conduction problem using finite element method

The mathematical models for dynamic distributed parameter systems are given by systems of partial differential equations. With nonlinear material properties, the corresponding finite element (FE) models are large systems of nonlinear ordinary differential equations. However, in most cases, the actual dynamics of interest involve only a few of the variables, for which model reduction strategies based on system theoretical concepts can be immensely useful. This paper considers the problem of controlling a three dimensional profile on nontrivial geometries. Dynamic model is obtained by discretizing the domain using FE method. A nonlinear control law is proposed which transfers any arbitrary initial temperature profile to another arbitrary desired one. The large dynamic model is reduced using proper orthogonal decomposition (POD). Finally, the stability of the control law is proved through Lyapunov analysis. Results of numerical implementation are presented and possible further extensions are identified.     

基于MATLAB的仪表通信控件的设计

针对仪表数据处理能力和控制算法方面的不足,提出了一种基于MATLAB的仪表通信接口设计方案。通过MATLAB仪器控制工具箱所封装的串口对象,编程实现了MATLAB与仪表通信,并使用MATLAB COM Builder生成DLL文件,然后在C＋＋环境下调用并以通用控件的形式加以封装。通过实验测试证明该接口稳定有效,为充分发挥MATLAB强大的数据处理能力,拓展传统仪表在工业控制系统的应用提供了新方案,为智能仪表的设计开发提供了新思路。     

基于GPS/DR组合的新型车辆导航仪

为了实现车辆的动态监控，介绍一种基于GPS(Global Positioning System)和DR(Dead Reckoning System)组合的新型车辆导航仪。系统采用C8051F005单片机作为控制单元组合GPS和DR信号对车辆进行连续定位，并把位置信息传输给监控中心；监控中心以车辆当前位置为中心截取地图并传输给车载终端，车载终端利用彩色液晶显示屏LCM(LCD Module)显示地图，并通过GPRS通信模块实时刷新地图。利用该导航仪进行跑车实验，结果表明该装置有较高的精度和良好的实时性。该导航仪适用于公交车、出租车等车辆的监控系统。