On a nonlinear problem of a sequential control with a parameter

The problem of evasion of a group of moving points from a nonlinear controlled object, whose goal is consecutively approach these points in a prescribed order, is analyzed. The movement of each point is defined uniquely by a scalar parameter chosen at the initial time instant. The controlled object minimizes a certain cost function, and the group of the points, acting cooperatively, maximize this cost function by choosing the parameters. Necessary optimality conditions for parameters are obtained. A model problem of an evasion of moving points from a vehicle is solved.     

Three-Link Mechanism as a Model of a Person on a Swing

Journal of Computer and Systems Sciences International - We model movements of a person swinging on a swing. We consider a flat three-link hinged mechanism as the main mechanical model of the...     

Design of a pH titrator as a component part of a personal computer

Personal computers are becoming almost as common as pocket calculators. In particular, their use in laboratories for measurement and control is growing. The next step after computer-controlled instruments is the development of a personal computer with an instrument as a component part. An automatic pH titrator has been designed. The system presented is based on an Apple Ile. Two plug-in cards are used. One card integrates analogue measurement and analogue-to-digital conversion. The other card controls a syringe driven by a stepper motor. The software control system for the personal pH meter is also described.     

Control of Motion of a Body in Formation of a Channel in a Fluid

Mechanics of the formation of a channel by a head of a bending body is considered. Equations are derived of the motion of the body in the channel with its simultaneous formation, which contain the positive feedback. Control is described of various modes of motion and also the transition from one mode to another, including the transition to the motion on account of the feedback. The clarified interrelation of the pressure of the body, its speed, and the responses of the fluid makes it possible to describe the mechanics of the formation and deformation of the channel, which denies the possibility of motion of the body on account of the positive feedback.     

A design of a controller as a component of a robotic manufacturing system

This paper specifies the functional design of a robot or machine tool controller suitable for inclusion in robotic manufacturing systems. The principle interest is the unmanned manufacturing cells which are being developed as major components of new manufacturing facilities. The functional specifications are motivated by recent experiences with the creation of a prototype cell for an open die forging process. There are two key technical design requirements. The first relates to the robot or machine tool being controlled. The controller must direct the machine actions, and, for unmanned operation, the controller must receive and process sensor information for process modification and for fault tolerance. The second relates to communication with the central cell computer (the host). The operation of an unmanned system requires a robot communication channel between the host and the controller; the controller must also respond to a variety of instructions transmitted from the host. Additional controller design requirements are imposed by economics. The proposed controller can be used today, and can develop in an evolutionary manner to meet the needs of future manufacturing systems. The evolutionary development is made possible by modular design, organized in a hierarchical manner.     

Motion control of a rotor with a cavity with a viscous fluid

A formulation and solution procedure of optimal control problems for perturbed relative uniform motion of a body with a cavity filled with a viscous incompressible fluid are proposed. In this paper, the case with a cylinder is considered; however, this approach is basically true for the a cavity of an arbitrary form. The formula for the angular velocity of perturbed motion depending on an external perturbing element is devised. After that, we have a possibility to set different optimal control problems and apply the formalism elaborated in the optimal control theory. Two illustrated problems are given.     

On the problem of a free drag of a rigid body with a tapered front in a resisting medium

The author constructs a nonlinear mathematical model of a plane-parallel impact of the medium on a rigid body with a front part of the outer surface shaped as a circular cone. Multivariable analysis of the dynamic equations of motion was performed. A new family of phase patterns on the phase cylinder of quasi-velocities has been obtained. This family consists of infinitely numerous topologically inequivalent phase patterns. The sufficient conditions for the stability of an important mode of motion, i.e., rectilinear translational drag, have been obtained, as well as conditions for the presence of the self-oscillatory modes in the system.     

非线性模型下的摄像机自标定

摄像机标定是从二维图像获取三维信息必不可少的步骤，线性（小孔）模型摄像机自标定，目前已成为计算机视觉领域的研究热点之一，对于非线性模型下摄像机的自标定，目前还未见到相关的研究报道，用于线性模型一般不能准确地描述真实像机的几何成像关系，因此对非线性模型摄像机自标定的研究具有十分重要的实际意义，该文主要探索非线性模型摄像机的自标定方法，基本原理是将非线性模型视为线性模型和畸变项的叠加，然后利用线性模型的基本矩阵或单应矩阵，给出非线性模型参数的约束方程，从而实现非线性模型摄像机的自标定，模拟和真实图像实验均表明该文所给的方法是可行的，具有一定的实用价值。     

Construction of a model of a continuous light source specified by a fixed set of rays

A physically correct model of a light source specified by a finite set of rays obtained either by processing the measured characteristics of the light source on the Radiant Imaging goniometric system or as a result of the forward stochastic ray tracing in a scene modeling the radiation of a complex light source is constructed. An algorithm for constructing a continuous emitting surface of a light source and its goniometric diagram given a finite set of rays is developed. The model preserves the spectral composition of the source rays in the surface luminance distribution of the radiation light source. An example of the photorealistic rendering of a scene illuminated by a finite set of rays obtained by the computer processing photometric measurement data.     

Algorithmic selection of a disassembly sequence of a component by a wave propagation method

The design of a product for its entire life-cycle is becoming more and more important. Nowadays, a product is designed with significant considerations for its manufacturability, serviceability, its functionality and even for its disassemblability. This is due to the fact that the modern consumers demand products that are not only functional, but also reliable, easy to repair and also environmentally friendly.For maintenance and re-use, the operation sequencing in disassembly process planning needs of reversible operation selecting.We present a new wave propagation disassembly algorithm of the determined component of a product; the given data are the immediate predecessors of each component.We show that the solution exists and that she is unique in the following conditions: the binary matrix of the immediate predecessors is non-symmetrical and the data does not contain a cycle. A tracked down cycle method in the data is also proposed.     

Markovianity of a subset of components of a Markov process

We consider the necessary and sufficient conditions for a group of the components of a stationary vector Gaussian Markov process to possess Markov property. The representation by a linear Itô stochastic differential equation is also given.     

Numerical Simulation of the Evolution of a Gas Bubble in a Liquid Near a Wall

A numerical technique based on the application of the boundary element method is proposed for studying the axially symmetric dynamics of a bubble in a liquid near a solid wall. It is assumed that the liquid is ideally incompressible and its flow is potential. The process of expansion and contraction of a spheroidal bubble is considered, including the toroidal phase of its movement. The velocity and pressure fields in the liquid surrounding the bubble are evaluated along with the shape of the bubble surface and the velocity of its displacement. The numerical convergence of the algorithm with an increase in the number of boundary elements and a refinement of the time step is shown, and comparison with the experimental and numerical results of other authors is performed. The capabilities of the technique are illustrated by solving a problem of collapse of a spheroidal bubble in water. The bublle is located a short distance from the wall.     

Constructing a committee of a system of linear inequalities

A representation of an arbitrary system of strict linear inequalities in R ⁿ as a system of points is proposed. The representation is obtained by using a so-called polarity. Based on this representation an algorithm for constructing a committee of a plane system of linear inequalities is given. A solution of two problems on minimal committee of a plane system is proposed. The obtained solutions to these problems can be found by means of the proposed algorithm. Kobylkin K.S. Born in 1977. Graduated from Ural State University in 2000. At the present time Kobylkin K.S. works at Institute of Mathematics and Mechanics of the Ural Division of the Russian Academy of Sciences. Scientific interests: pattern recognition, mathematical economics. Author of four publications. Member of the Russian Association for Pattern Recognition and Image Analysis and IAPR.     

On the Complexity of Searching for a Maximum of a Function on a Quantum Computer

We deal with the problem of finding a maximum of a function from the Hölder class on a quantum computer. We show matching lower and upper bounds on the complexity of this problem. We prove upper bounds by constructing an algorithm that uses a pre-existing quantum algorithm for finding maximum of a discrete sequence. To prove lower bounds we use results for finding the logical OR of sequence of bits. We show that quantum computation yields a quadratic speed-up over deterministic and randomized algorithms.     

Implementation of a model of a metainformation-controlled editor of information units with a complex structure

This paper describes the model and methods for implementing an extensible tool for editing information with a complex structure with different levels of abstraction and invariance to technological spaces (subject domains) in a common conceptual framework for carriers of this information; this makes it unnecessary to arrange specialized training for these carriers or involve professional intermediaries.     

On a Homomorphism of a Component Petri Net

A reduced Petri net model of a parallel distributed system is considered as a component Petri net (a CN) with a view to determining the adequacy between two models, namely, a detailed Petri model N and a component Petri model (CN model) of this distributed system. The concepts of a component relation χ and a component relation domain are introduced. A surjective homomorphism between the N and CN models and an isomorphism between the N / χ net, i.e., the factor model of N with respect to the relation χ, and CN are established.     

Finding a k-tree core and a k-tree center of a tree network inparallel

A k-tree core of a tree network is a subtree with exactly k leaves that minimizes the total distance from vertices to the subtree. A k-tree center of a tree network is a subtree with exactly k leaves that minimizes the distance from the farthest vertex to the subtree. In this paper, two efficient parallel algorithms are proposed for finding a k-tree core and a k-tree center of a tree network, respectively. Both the proposed algorithms perform on the EREW PRAM in O(log n log n) time using O(n) work (time-processor product). Besides being efficient on the EREW PRAM, in the sequential case, our algorithm for finding a k-tree core of a tree network improves the two algorithms previously proposed     

Dynamic behaviour of a mechanical system of which a part performs a prescribed relative motion

A method is presented to solve by means of a finite element analysis the problem of the dynamic behaviour of a mechanical system, a part of which performs a prescribed relative motion. The kinematic coupling of this part to the rest of the system and the derivation of the matrix equations of motion are discussed, as well as the applied condensation method. Moreover the results of a computation based on this method are compared to those obtained by neglecting the dynamic interactions of both the parts of such a mechanical system.     

Finite element mesh for a complete solution of a problem with a singularity

It is well known that the stress field at the tip of a crack in an elastic body exhibits a singularity. In this paper, a complete elastic solution for a center cracked plate loaded under uniform tension is obtained by a finite element plane-stress analysis using constant strain elements. No a priori assumptions about the form of the stress singularity are required. The numerical results are compared with the exact analytic solution. It is shown that a particular mesh arrangement in which the size of the elements decreases in a geometric series as the crack tip is approached yields stress and strain fields which are accurate over the entire plate, even at distances very close to the crack tip. The effects of changes in mesh arrangements on the accuracy of the solution are considered. The computations are carried out on the CRAY-1 computer and the advantages of vectorization are discussed for this problem.     

Derivation and analysis of a dynamic model of a robotic manipulator on a moving base

A dynamic model of a robotic manipulator mounted on a moving base is derived using the Euler-Lagrange approach. It is assumed that the base inertia is large enough not to be influenced by the manipulator motion and therefore can be treated as a time-varying parameter in the dynamic equations. The presented derivation is applied to a Mitsubishi PA10-6CE robotic manipulator mounted on a 2-DOF platform. The model is analysed by comparing simple closed-loop control results of the simulated model with experimental data from the manipulator mounted on the platform.