bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distributed positioning for redundant robotic systems
Authors: Potkonjak Veljko 
Published: March 2009

SUMMARYA new approach to redundant robots is presented. The problem of the multiple solutions of the inverse kinematic is solved by making a special distribution of robot external motions to the redundant number of joint motions. The distribution is made in such a way to separate the smooth transport motion from the relative motion which could be fast and have high acceleration.
Tracking control of flexible robot manipulators with active inertia links
Authors: Jumarie Guy 
Published: March 2009

SUMMARYThe flexible structure of a robot multi-links manipulator can be either a side effect or, on the contrary, an essential feature. We present a fairly general model to derive the corresponding dynamic equations in quite a systematic and simple way. To this end, we use the Lagrange formulation with strain energy potential and Raleigh (dissipation) functions. The approach can incorporate torsional deformation and aerodynamic friction, and it applies easily to robots working in the sea. The trajectory control appears to be one in the presence of model imprecision, and a slightly modified version of the classical sliding control technique is utilized to design the tracking control of the manipulator. Then we introduce the time-varying inertia link device (carried out by means of sliding masses) which we suggested in earlier work, and we show how it can be used to improve the tracking control scheme above. This paper contributes new ideas concerning flexible multi-links arms and active inertia links.
Collision-free motion planning for two articulated robot arms using minimum distance functions
Authors: Chang C. , Chung M. J. , Bien Z. 
Published: March 2009

SummaryThis paper presents a collision-free motion planning method of two articulated robot arms in a three dimensional common work space. Each link of a robot arm is modeled by a cylinder ended by two hemispheres, and the remaining wrist and hand is modeled by a sphere. To describe the danger of collision between two modeled objects, minimum distance functions, which are defined by the Euclidean norm, are used. These minimum distance functions are used to describe the constraints that guarantee no collision between two robot arms. The collision-free motion planning problem is formulated as a pointwise constrained nonlinear minimization problem, and solved by a conjugate gradient method with barrier functions. To improve the minimization process, a simple grid technique is incorporated. Finally, a simulation study is presented to show the significance of the proposed method.
Deriving complex location data from simple movement sensors
Authors: Gordon J. L. , Williams D. , Hobson C. A. 
Published: March 2009

SummaryBuilding Management Systems and Home Automation are, at present, active areas of research and development. One of the unsolved problems within this field is that of Occupant Location within a premises. Computer vision systems are, as yet, too expensive and still not entirely adequate to monitor occupation from every room in a building. The use of existing movement sensors is a cost effective solution but has the disadvantages of not detecting people who are stationary for some time, or giving any indication of how many people are in a room.This paper addresses the problem of using the collaborative sum of these simple movement sensors in a temporal reasoning scheme to deduce room occupation.
Tactile image computation using a feature extraction algorithm
Authors: Mehdian M. 
Published: March 2009

SUMMARYA binary tactile image feature extraction algorithm using image primitive notation and perceptrons is presented. The basic image segments are defined as geometric factors by which the image structure is described so that effective feature values such as image shape, image size, perimeter and texture may be extracted on the basis of local image computation. The local property of the tactile image computation is evaluated by the concept called order of the perceptrons and based on this feature extraction algorithm, an efficient tactile image recognition system is realised.
Kinematic control of planar redundant manipulators by extended motion distribution scheme
Authors: Chung W. J. , Chung W. K. , Youm Y. 
Published: March 2009

SUMMARYThe kinematic control of a planar manipulator with several-degrees of redundancy has been a difficult problem because of the heavy computational burden and/or lack of appropriate techniques. The extended motion distribution scheme, which is based on decomposing a planar redundant manipulator into a series of nonredundant/redundant local arms (referred to as subarms) and distributing the motion of an end-effector to subarms at the joint velocity level, is proposed in this paper. The configuration index, which is defined as the product of minors corresponding to subarms in the Jacobian matrix, is used to globally guide the redundant manipulators. To enhance the performance of the proposed scheme, a self-motion control, which handles the internal joint motion that does not contribute to the end-effector motion, can be used optionally to guarantee globally optimal manipulation. The repeatability problem for the redundant manipulators is discussed using the proposed scheme. The results of computer simulations are shown and analyzed in detail for planar 8-DOF and 9-DOF manipulators, as examples.
A geometric approach to manipulator path planning in 3D space in the presence of obstacles
Authors: Kirćanski Manja , Timčenko Olga 
Published: March 2009

SUMMARYThe paper presents a geometric method for collision-free manipulator path planning in 3D Euclidean space with polyhedral obstacles. It ensures that none of the links nor the manipulator tip collide with the objects. The method is computationally very cheap and it does not require intensive off-line preprocessing. Hence, it is real-time applicable if the information about obstacles positions and shapes is obtained from a higher control level. The trajectories generated lie within the reachable workspace. The method is implemented on a VAX 11/750 computer and the simulation results are included.
Design of robots driven by linear servo systems
Authors: Minotti P. , Pracht P. 
Published: March 2009

SUMMARYThe performance of robotic manipulators is limited by the nature of the control systems which do not satisfactorily integrate the non-linear phenomena associated with the dynamic behavior of the mechanisms. The significant variations in the axial inertias lead to control problems and require an optimization of the mechanical structures in order to improve the stability of the manipulators. This paper proposes mechanical solutions in the domain of dynamic decoupling of robots and demonstrates, using numerical simulations the value of these solutions in terms of control.
The geometry of machining for computer-aided manufacture
Authors: Stacey T. W. , Middleditch A. E. 
Published: March 2009

SummaryA geometrical methodology for automatic machine tool command generation is introduced. The geometric entities relevant to machine tool operation are unambiguously defined by volume models. A vector sum operator is used to determine regions of the configuration space of the machine tool which correspond to undesired collisions, cavity access and material removal. Some indication of how cutter paths are generated is given and a practical implementation for the case of machining two and a half dimensional components under two and a half axis control is discussed in more detail.
Kinematic path control of robot arms
Authors: Krustev Evgeny , Lilov Ljubomir 
Published: March 2009

SUMMARYPath planning of the end effector motion is here treated from the viewpoint of the path invariance under the transformations of its parametrical representation. Thus, a new method for path planning of the robot arm motion is being developed. Both the problems of finding the end effector time optimal motion and the end effector motion with a prescribed velocity profile along a preplanned path are being solved by the employment of this method. Simulation results are presented and some aspects of implementation are also discussed.
A sealing robot system with visual seam tracking
Authors: Sawano Susumu , Ikeda Junichi , Utsumi Noriyuki , Ohtani Yukio , Kikuchi Akira , Ito Yoshimasa , Kiba Hiroshi 
Published: March 2009

SUMMARYA new robot system has been introduced which was designed to seal the seams of car body panels. The system has nine degrees of freedom, and includes the following features: (1) A seam tracking servo using a solid-state TV camera is mounted at the robot hand to compensate for the seam deviations. (2) The robot arm is equipped with a flexible mechanism at the wrist to provide a wide working range for the seal nozzle. (3) A two axis orthogonal robot carrier is provided to make the robot follow the work on an indexed conveyor during the sealing operation. This paper deals with the structure and operation of the system and presents test results obtained on a sealing line.
Automated manipulating system for an industrial robot for arc-welding
Authors: Shivarov Nedko , Yanakiev Kostadin 
Published: March 2009

SUMMARYAn automated manipulating system, which performs the task of loading, positioning and holding of parts in the working area of an industrial robot is discussed in this paper. The system feeds component parts for the lifting mechanisms of electric trucks to be arc-welded by the robot and then removes them, thus completing a predetermined cycle. It is a part of an actual assembly line in a standard workshop for manufacturing electric trucks. The system's operation is described in detail, and the basic technological characteristics of the welding and peripheral equipment are given. Also, some features of an original welding torch cleaning device are described. The principal approach of planning, designing and implementing robotized cells for automatic arc-welding using a robot is also discussed.
Differential relationship of kinematic model and speed control strategies for a computer-controlled robot manipulator
Authors: Ho C. Y. , Jen Sriwattanathamma 
Published: March 2009

SummaryThis paper describes a new approach to obtaining a differential relationship of a robot manipulator via the Theoretical Kinematics method which may expedite computational efforts. The method involves a successive transformation of velocities from the end-effector to the base of the manipulator, link by link, using the relationship of moving coordinate systems. The equations obtained are written in the form suitable for programming on a digital computer. Furthermore, this paper also discusses the speed control model for general robot manipulators and together presents the Inverse Jacobian of cases of underdetermined and overdetermined of joint-controlled variables.
Special configurations of robot-arms via screw theory
Authors: Hunt K. H. 
Published: March 2009

SUMMARYPart 1 of the paper* was concerned with the Jacobian of serial robot-arms and its matrix of cofactors; part 2 emphasizes the end-effector's velocity characteristics as affected at special configurations. The displacement about a ‘fixture-point’ is extended dually to a ‘fixture-plane’, and then to a ‘fixture-line’. These fixture-elements serve to highlight the prolixity of special configurations. Reciprocal screws lead to a complete survey of how the end-effector can ‘twist’ when one freedom is lost; extension to loss of more freedoms is explained. Then the fixture-elements are given elementary displacements that allow common requirements to be studied with the minimum of complications. Further investigation is thought to have promise for robot-control.
Separability of pairs of polygons through single translations
Authors: Sack Jörg-Rüdiger , Toussaint Godfried T. 
Published: March 2009

SUMMARYLet P = {p1, …,pn} and Q = {q1,…,qm} be two simple polygons in the plane with non-intersecting interiors, the vertices of which are specified by their cartesian coordinates in order. The translation separability query asks whether there exists a direction in which P can be translated by an arbitrary distance without colliding with Q. It is shown that all directions that admit such a motion can be computed in O(nlogm) time, where n > m, thus improving the previous complexity of O(nm) established for this problem. In designing this algorithm a polygon partitioning technique is introduced that may find application in other geometric problems.The algorithm presented in this paper solves a simplified version of the grasping problem in robotics. Given a description of a robot hand and a set of objects to be manipulated, the robot must determine which objects can be grasped. The solution given here assumes a two-dimensional world, a hand without an arm, and grasping under translation only.
A three axis tactile sensor-probe for robotic use
Authors: Havlík Štefan 
Published: March 2009

SUMMARYThe paper deals with a three axis reaction force and displacement sensor. The design procedure of the strain gauges sensor for its intended application as a tactile proble is described. The deformable sensor body with strain gauges arrangement allows all three output voltage readings to be directly related with rectangular components of the force displacement vector in a remote contact reference system. The structural orthogonalisation that results in minimal cross component couplings is briefly outlined. The practical use of the designed probe is exemplified by seam following in a robotic welding system.
Adaptive control of an industrial robot
Authors: Karnik Ajit M. , Sinha Naresh K. 
Published: March 2009

SUMMARYFor the past several years, industrial robots are being used extensively. These robots are generally equipped with relatively simple control systems. Such control systems have proved adequate, but with increased demand on robot performance, there is need for advanced and sophisticated controllers. One of the probelms in the control of robots is that system dynamics change due to several factors such as the orientation of arms and their effective inertia.Adaptive controllers have the advantage that the system is continuously modelled and controller parameters are evaluated on-line, thus resulting in superior performance. Adaptive controllers can be realized in several ways.This paper describes the design and performance of an explicit self tuning regulator for a robot arm.
Numerical complexity of decentralized dynamic control laws for manipulator systems
Authors: Vukobratović M. , Kirćanski N. 
Published: March 2009

SUMMARYThe numerical complexity of robot dynamic models, inverse control structures and decentralized control laws is analyzed in a systematic fashion. Dynamic models of actuators (DC motors and hydraulic cylinders) are taken into account, too. The exact number of floating-point multiplications and additions/subtractions for an n−link manipulator is determined. The results are applied to several typical industrial manipulators. Measuring of computation time for various control structures is realized on an up-to-date 16-bit microcomputer, widely used in robot controllers. Thereby, the real-time applicability and effectively the “price” of different control laws are estimated.
A Distributed On-Line Trajectory Generator for Intelligent Sensory-Based Manipulators
Authors: Zalzala A. M. S. , Morris A. S. 
Published: March 2009

SUMMARYAn algorithm is presented for the on-line generation of minimum-time trajectories for robot manipulators. The algorithm is designed for intelligent robots with advanced on-board sensory equipment which can provide the position and orientation of the end-effector. Planning is performed in the configuration (joint) space by the use of optimised combined polynomial splines, along with a search technique to identify the best minimum-time trajectory. The method proposed considers all physical and dynamical limitations inherent in the manipulator design, in addition to any geometric path constraints. Meeting the demands of the heavy computations involved lead to a distributed formulation on a multiprocessor system, for which an intelligent control unit has been created to supervise its proper and practical implementation. Simulation results of a proposed case study are presented for a PUMA 560 robot manipulator.
Dextrous Telerobotics with Force Feedback – An Overview. Part 1: Human Factors
Authors: Burdea Grigore , Zhuang Jiachen 
Published: March 2009

SUMMARYComplex tasks that need to be performed through teleoperation led to the development of multifinger robot hands. A dextrous master is a multi-DOF controller which is worn by the operator in order to teleoperate these anthropomorphic hands. Force feedback is very useful when there is interaction with the environment. Providing force feedback to dextrous masters is an area of active research. We outline some of the human factors that influence the design of such masters. Of obvious importance is the hand geometry and the desired number of degrees of freedom. Additional criteria relate to the force perception of the hand. Finally, the man-machine impedance is of importance, since at the man/machine interface there are two impedances acting in series. One is the effective impedance of the human operator holding the master controller, the second is the impedance of the master controller being manipulated.
A Variational Approach for Modeling Flexibility Effects in Manipulator Arms
Authors: Meghdari Ali 
Published: March 2009

SUMMARYThis paper presents a general technique to model flexible components (mainly links and joints flexibilities are considered) of manipulator arms based on Castigliano's theorem of least work. The robotic arms flexibility properties are derived and represented by the matrix of compliance coefficients. Such expressions can be used to determine the errors due to the robotic tip deformations under the application of a set of applied loads at the tip in a Cartesian space. Once these deformations are computed, they may be used to correct for the positional errors arisen from the robotic structural deformations in the motion control algorithms.
Optimizing motion trajectories of dextrous fingers by dynamic programming technique
Authors: Meghdari Ali , Sayyaadi Hassan 
Published: March 2009

SUMMARYAn optimization technique based on the well known Dynamic Programming Algorithm is applied to the motion control trajectories and path planning of multi-jointed fingers in dextrous hand designs. A three-fingered hand with each finger containing four degrees of freedom is considered for analysis. After generating the kinematics and dynamics equations of such a hand, optimum values of the joints torques and velocities are computed such that the finger-tips of the hand are moved through their prescribed trajectories with the least time or/and energy to reach the object being grasped. Finally, optimal as well as feasible solutions for the multi-jointed fingers are identified and the results are presented.
Generalized predictive control of a robotic manipulator with hydraulic actuators
Authors: Kotzev A. , Cherchas D. B. , Lawrence P. D. , Sepehri N. 
Published: March 2009

SUMMARYThis paper presents some aspects of the behavior of hydraulically actuated heavy duty manipulators. This category of manipulators is used extensively in large resource based industries and any improvement in efficiency may result in major financial benefits. In this paper an adaptive control algorithm is used for a two rigid link manipulator driven by hydraulic actuators. The dynamic model of the manipulator is derived as well as the models of the hydraulic actuators including compliance, dead time and full dynamics of the servo valves. An adaptive control algorithm is considered since changes occur on-line in the system's parameters. The adaptive algorithm used is Generalized Predictive Control (GPC). The GPC uses a controlled autoregressive integrated moving average (CARIMA) type model and a cost function that minimizes a predicted future output error and future weighted control inputs to the plant, resulting in a sequence of future control increments. The procedure, in this work, does not separate the hydraulic actuator and the link dynamics into separate sub-systems, but controls them as one system. The changes in the system's parameters due to the hydraulics or the link dynamics can be estimated and the coefficients of the model adjusted without the necessity of identifying the exact cause of the changes.It was found in this work that the variations of the GPC control horizon can lead to faster response during transients and significantly reduced overshoot in the nonlinear hydraulic actuation system. An on-line change of the maximum output horizon is also introduced.This work shows the analysis and results of a two link manipulator with hydraulic actuators. It can be implemented on any hydraulically actuated manipulator with any number of links and actuators.Numerical simulations are performed on a Vax 3200 computer and the results are presented.
A systemic approach to pattern recognition
Authors: Emptoz H. , Lamure M. 
Published: March 2009

SUMMARYWe suggest a new pretopological model for pattern recognition which was introduced to study complex economic systems. The model has its origin in the concept of “neighbour”, which is both primitive and fundamental in pattern recognition. Pretopology enables us to develop a perceptive and topological approach for patterns and to see that problems, apparently different, are in fact identical e.g. clustering and recognition, search of skeletons in image processing and search of an informative learning set. It should be noted that the suggeted model is more than a descriptive one.
Machine tool technology: an extended view
Authors: McKee Keith E. 
Published: March 2009

SUMMARYMany of the evolving technologies related to machining will expand the traditional concept of the machine tool industry. Preprocessing of materials into net or near-net shapes will reduce or even eliminate the need for machining operations. Conversion of particles into parts is one generic approach which, when automated, could be integrated into a machining center. Similarly diecasting or squeeze casting could become an integrated part of the machining center for volume production. The machine tool industry could automate die manufacturing so that dies could be made in real time and could justify net shape production for small quantities and rush jobs.Much and often most of the time and costs within a “machining” operation are generated by secondary operations such as heat treating, plating, and welding–operations done in different parts of or even at different plants. The concept of extending the machining center to include these secondary operations has been considered for several years and to a limited extent, has occurred. Laser extended machining centers provide one possibility for integrating several of the secondary operations with machines at a single site.Post processing of machined parts at the site of the machining center can result in parts oriented and appropriately presented or packaged for subsequent operations. When several machined parts subsequently become an assembly or subassembly, the concept of machining could be extended to include the assembly.When machining is considered in this broader context, the technology futures of the machine tool industry are considerably broadened. Smarter machine tools, improved support structures, and high speed machining are important, but competitors are looking at the same opportunities and the competitive advantage is likely to be limited. “Leap frog” improvement depends on some of the less conventional technologies considered in this paper. Broadening of the machine tool horizons is likely to offer the technology path for revitalization and growth of the machine tool industry.