Orientation Control of an Object on a Rotating Base by Using a Two-Stage Electric Drive

Journal of Computer and Systems Sciences International - In this paper, we study the process of controlling the rotation of an object relative to a rotating base using a two-stage electric drive...     

基于多通道的移动目标监控协同仿真技术研究

多通道虚拟现实仿真技术是1种支持大场景、具有高度沉浸感的仿真支撑技术,系统研究了多通道技术实现的数学模型基础、基于移动目标空间模型构建和协同仿真技术、选择合适的多通道技术应用方案、构建实验室仿真平台并实现了基于空间六自由度的多通道移动目标监控仿真。实践证明,所采用的多通道目标监控仿真技术具有较强的实用性,结合移动目标空间模型与协同仿真技术的优势,能够解决目标观测的大范围、真实感、沉浸感要求。     

Shock Isolation with Anticipating Control for External Disturbances of Various Shapes

Limiting performance analysis is performed for isolation of an object on a movable base from short-duration impact excitations by means of an active shock isolator with anticipating control. The external disturbance (excitation) is modeled by the time history of the absolute acceleration of the base. The control is performed by a force that acts between the base and the object to be protected. The absolute value of the control force is subject to a constraint. A procedure is proposed for constructing optimal anticipating controls that minimize the peak magnitude of the displacement of the object relative to the base for external disturbances from a certain class. For a number of types of external disturbances, the solution of the optimal control problem is obtained in closed form. The controls that are constructed in closed form are modified to be applicable for the disturbances for which closedform solutions are absent.     

Adaptive Control of an Object with a Delayed Control and Scalar Input-Output Signals

A problem is considered for the synthesis of an adaptive control system with the use of an augmented error signal when scalar input-output signals are accessible for measurement. A quadratic criterion of the absolute stability of nonlinear systems is used for the synthesis.     

应用程序与驱动程序间的事件同步

由于驱动程序运行于操作系统内核，所以应用程序与驱动程序间的事件同步不同于两个应用程序的线程同步。本介绍一种应用程序和驱动程度共享一个事件对象的方法，实现二的同步。     

基于询问-回答模式的对象控制模型的实现

在诸多系统设计中，系统需要管理大量具有内在关联性相似性的对象系统（通常表现为对象树或对象图的形式）。通常采用的方法是系统集中管理和控制，根据对象的互异性特征，选取指定的对象和决定对象如何访问。这种集中控制的弊端是管理复杂、成本高，容易造成错误，并且可扩充性差。文章介绍了一种基于询问-回答模式的对象控制模型，有效地解决了这个问题。     

基于SQL Server浅谈ADO对象编程

数据库应用程序与数据库的数据访问接口有多种类型.最新的是ADO技术.本文以VB与SQL Server为平台,研究ADO对象编程技术.     

Design of Integral Sliding Mode Control Using Decoupled Disturbance Compensator with Mismatched Disturbances

This paper deals the problem of integral sliding mode control using decoupled disturbance compensator for discrete-time systems with mismatched disturbances. The proposed method allows the disturbance compensation to be modified separately from the control input, since the two inputs of system are completely decoupled. In the developed method, the actual disturbance is estimated by the decoupled disturbance compensator (DDC) method to design the control input and stabilize the system. Integral sliding mode control with DDC scheme minimizes the control effort and improves the system performance. Main advantage of this method is to eliminate the reaching phase and reduce the control effort, simultaneously. Finally, simulation results are shown to demonstrate the usefulness of the presented methodology.

     

Game Control of a Random Jump Structure of an Object in Mixed Strategies

Journal of Computer and Systems Sciences International - The problem of the optimal control of a random jump-like structure of an object under counteraction conditions is considered. The change in...     

基于模糊控制的电梯群控系统的研究与设计

本文对电梯群控系统输入的交通数据进行了分析,通过模糊识别把输入的交通特征量区分出四种交通模式。本文对厅层信号控制进行了重点的研究,对系统中的输入变量的选择进行了对比、分析,从而选择出了比较恰当的隶属函数。在算法的设计中还考虑到交通模式对本文提出的三个程度函数权重的影响,最终提出了基于模糊控制的电梯群控方法。设计了一个综合评价函数来衡量电梯群控系统的运行。通过控制相应的三个程度函数(平均等待时间、平均乘梯时间和能量消耗),达到乘客满意,系统节能的目的。论文最后对所设计的电梯群控算法进行计算机仿真,仿真结果验证了算法的可行性。     

Optimal Control of Rotation of a Rigid Body by a Movable Internal Mass

Journal of Computer and Systems Sciences International - The two-dimensional problem on the fastest turn of a rigid body by moving an internal mass is considered. It is assumed that the rigid body...     

Object Detection Using the Statistics of Parts

In this paper we describe a trainable object detector and its instantiations for detecting faces and cars at any size, location, and pose. To cope with variation in object orientation, the detector uses multiple classifiers, each spanning a different range of orientation. Each of these classifiers determines whether the object is present at a specified size within a fixed-size image window. To find the object at any location and size, these classifiers scan the image exhaustively.Each classifier is based on the statistics of localized parts. Each part is a transform from a subset of wavelet coefficients to a discrete set of values. Such parts are designed to capture various combinations of locality in space, frequency, and orientation. In building each classifier, we gathered the class-conditional statistics of these part values from representative samples of object and non-object images. We trained each classifier to minimize classification error on the training set by using Adaboost with Confidence-Weighted Predictions (Shapire and Singer, 1999). In detection, each classifier computes the part values within the image window and looks up their associated class-conditional probabilities. The classifier then makes a decision by applying a likelihood ratio test. For efficiency, the classifier evaluates this likelihood ratio in stages. At each stage, the classifier compares the partial likelihood ratio to a threshold and makes a decision about whether to cease evaluation—labeling the input as non-object—or to continue further evaluation. The detector orders these stages of evaluation from a low-resolution to a high-resolution search of the image. Our trainable object detector achieves reliable and efficient detection of human faces and passenger cars with out-of-plane rotation.     

Fractional Control of a Humanoid Robot Reduced Model with Model Disturbances

There is an open discussion between those who defend mass-distributed models for humanoid robots and those in favor of simple concentrated models. Even though each of them has its advantages and disadvantages, little research has been conducted analyzing the control performance due to the mismatch between the model and the real robot, and how the simplifications affect the controller’s output. In this article we address this problem by combining a reduced model of the humanoid robot, which has an easier mathematical formulation and implementation, with a fractional order controller, which is robust to changes in the model parameters. This controller is a generalization of the well-known proportional–integral–derivative (PID) structure obtained from the application of Fractional Calculus for control, as will be discussed in this article. This control strategy guarantees the robustness of the system, minimizing the effects from the assumption that the robot has a simple mass distribution. The humanoid robot is modeled and identified as a triple inverted pendulum and, using a gain scheduling strategy, the performances of a classical PID controller and a fractional order PID controller are compared, tuning the controller parameters with a genetic algorithm.     

Trajectory Control of a Quadrotor Subject to 2D Wind Disturbances

The paper addresses the flight control of a quad-rotor subject to two dimensional unknown static/varying wind disturbances. A model separation is proposed to simplify the control of the six-degrees-of-freedom (6DOF) nonlinear dynamics of the flying robot. Such approach allows to deal with quad-rotor’s 3D-motion via two subsystems: dynamic (altitude and MAV-relative forward velocity) and kinematic (nonholonomic-like navigation) subsystems. In terms of control, a hierarchical control is used as the overall control structure to stabilize the kinematic underactuaded subsystem. A control strategy based on sliding-mode and adaptive control techniques is proposed to deal with slow and fast time-varying wind conditions, respectively. This choice not only provides well tracking control but also improves the estimation of unknown disturbance. The backstepping technique is used to stabilize the inner-loop heading dynamics, such recursive design takes into account a constrained heading rate. Promising simulations results show the validity of the proposed control strategy while tracking a time-parameterized straight-line and sinusoidal trajectory.     

基于全方位视觉的运动目标检测与定位方法

针对全方位视觉的运动目标检测,存在背景非常复杂,光照变化等噪声干扰明显等难点;在进行运动目标定位时,也需要消除当目标发生一定分裂时对定位结果的影响.为了滤出噪声,对目标准确定位,提出一种采用改进的背景消减法和区域成长法的运动目标检测与定位方法.本文首先采用背景消减法分割运动目标,在背景消减时利用最大方差比阈值法来滤除噪声,然后利用改进的区域成长法定位出目标.实验结果表明方法简单有效,能准确检测与定位出全方位视觉复杂背景下的运动目标.     

旋转体圆周角位置控制方法

针对旋转导向钻井工具稳定平台的角位置姿态控制系统,分析了角位置系统控制中圆周旋转运动各动 态参数之间的关系和旋转角度控制的特点．介绍了满足这类特殊控制要求的控制算法．提出一种在极坐标系中描述 动态响应曲线的方法,非常适用于旋转角位置控制系统．设计了一个钻井工具稳定平台模糊控制系统,它以角位置 和角速度为输入、以控制电流的增量为输出,不仅可以解决角位置与旋转方向间的关系问题,而且具有比常规控制 方法更好的鲁棒性及抗干扰能力,因此也更适合于钻井工程中的井下工作环境．     

Bernstein多项式推广及其所生成的拟Bézier曲线

文章对Bernstein多项式进行推广,用函数f(t)代替变量t,所生成的拟Bézier曲线不仅拥有与Bézier曲线相类似的性质,而且能产生一些好的特性,如通过调节因子可以改变拟Bézier曲线的次数,使拟Bézier曲线拼接时有更大的自由度和灵活性,有一定的应用和研究价值。     

Comparison of the Two Methods of Identification under Unknown-but-Bounded Disturbances

Considered are stable linear SISO plants subjected to unknown-but-bounded disturbances. For such plants, the potentials of the two methods of active identification are Compared—the instrumental variable method and the finite-frequency identification method. The relation between these methods is established in the situation where the measurable input is represented by a test signal in the form of the sum of harmonics, whose number is equal to the state space dimension of the plant. The advantages of the finite-frequency method are twofold: it reduces both the sensitivity of the estimates of the plant coefficients to the errors in experimental data and the effect of the dependence between the measurable input and exogenous disturbance on the accuracy of identification. These extra capabilities are provided by the self-tuning of the frequencies of the test signal.