bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geometric model of the DCR-LAI compliant device
Authors: Jutard A. , Redarce T. , Fakri A. , Betemps M. 
Published: March 2009

SUMMARYIn this paper the authors present a mathematical model of geometric and kinematic behaviour of an original passive compliant device provided with two rotation centres, called DCR–LAI system. This device is designed for a robotic assembly of parts with very small tolerances including a chamfer at the hole. The given modélisation may be used as a decision aid for the choice of a compliant device with regard to characteristics of parts being assembled.
Efficient Sliding Mode Control for Robot Manipulator with Prescribed Tracking Performance
Authors: Lee Ju-Jang , Lee Jung-Hoon , Lee Jong-Soo 
Published: March 2009

SUMMARYIn this paper, we discuss the accurate and robust sliding mode tracking control for highly nonlinear robot manipulators using a disturbance observer. Due to the modeling error or environmental uncertainties, sliding mode control may present a significantchatteringproblem by using a conventional Sliding Mode Control (SMC) which can obtain the desired tracking performance, because the controller design is carried in the uncertainty space of the system parameters.To solve thischatteringproblem, the efficient compensation of the disturbance observer has been introduced. Thus the design of the proposed SMC is not influenced by the modeling error or parameter uncertainties.To ensure bounded stability, the proposed sliding mode controls have been analysed in a preliminary lemma and two main theorems. The stability of the proposed control method is proved in this paper, and the efficiency of the control algorithms has been demonstrated by simulations for a position tracking control of a two-link robot subject to parameter and payload uncertainties.
A Splines–Based Control Method for Robot Manipulators
Authors: Kanarachos A. , Sfantsikopoulos M. , Vionis P. 
Published: March 2009

SUMMARYIn this paper, a new splines–based control method for robot manipulators is presented and discussed. The above method can be effectively used for path planning and control of rigid and flexible robots. The computational simplicity of the proposed algorithm, together with its flexibility and its high–level intelligence built in, can be considered as promising tools for achieving the goals of modem robot manipulator design.
An Approach to Biped Control Synthesis
Authors: Borovac B. , Vukobratović M. , Surla D. 
Published: March 2009

SUMMARYA novel approach to control synthesis of biped locomotion mechanisms is suggested. The synthesis is carried out in two stages: the stage of nominal regimes (the synthesized control has to ensure the realization of gait in the absence of any disturbance), and the stage of perturbed regimes (the control has to eliminate deviations from the nominals under an additional condition of preserving the stability of the overall System). At the level of perturbed regimes, the proposed control synthesis should ensure the compensating movements such to bring the System ot its nominal during the gait. However, the compensating movements can, as a side–effect, induce the undesirable inertial forces which can influence the mechanism overall stability. To avoid this, it is suggested such a control which ensures that the acceleration of compensating movements does not exceed a value given in advance. In addition, the case is considered when an additional correction of the zero moment point ZMP position is accomplished by different mechanism joints.
Adaptive Control of Nonlinear Dynamic SCARA Type of Manipulators
Authors: Garg Devendra P. 
Published: March 2009

SUMMARYThis paper deals with an investigation of the relative importance of robotic characteristics typically associated with nonlinear manipulators. An IBM 7540 SCARA type of robot is used for simulation, and results are presented for decentralized proportional plus derivative control action applied to individual robot joints, and the use of an adaptive computed torque control strategy is illustrated. The influence of variations in payload and robot parameters on trajectory tracking is also shown.
Accuracy improvement: Modeling of elastic deflections
Authors: Yao Junjie 
Published: March 2009

SUMMARYActual positions of industrial robot end-effectors differ from those commanded off-line. Consequently, it is then difficult for robots to fulfill certain tasks, such as automated assembly sequences or tasks where high performance accuracy is required. This paper shows that the accuracy of robot performance can be improved by introducing deviation matrices which are functions of many possible error sources. As a first approach, an experiment was carried out where structural elastic deflections, one of the many error sources, of a robot ASEA Irb 6/2 were taken into account. The experiment showed that using the improved model, the positioning accuracy of an ASEA Irb 6/2 robot carrying a weight of 5.6kg was improved from 2.5mm to 0.25mm and the orientation accuracy was improved from 0·45° to 0·3°.
Automatic simulation of a robot program for a sequential manufacturing process
Authors: Jacak Witold , Rozenblit Jerzy W. 
Published: March 2009

SummaryThis paper presents a framework for the design of a hierarchical Simulator of a robotized sequential technological process. The framework employs concepts of discrerte event simulation modelling. The Simulator consists of two layers: the Simulator of a robot and technological process, and the interpreter and planner of robot tasks. A format specification of both layers is presented. The proposed simulation approach is expected to result in significant improvements in the robot task plan generation and in higher efficiency of a technological process.
A gait simulator for a quadruped walking robot
Authors: Stoner John , Davis Robert H. 
Published: March 2009

SummaryThe description is provided for the design and implementation of a system capable of simulating the motions of a quadruped walking robot. The system aims to investigate the feasibility of the robot's walking cycle. This is achieved by considering the robot's stability and more specifically the position of its centre of gravity in relation to its supporting legs. The robot is modelled as a solid body connected to four jointed limbs which are moved through a series of gaits, their positions being calculated at a set of discrete intervals. The resulting information is displayed using a graphical module to present an image of the moving robot and indicate its centre of gravity and support pattern. The complete system indicates the stability of the robot throughout a user-defined gait cycle and is both portable and adaptable.The system is implemented on a HLH Orion and an Atari 1040ST in the C programming language and is aimed at providing support for the Department of Mechanical Engineering at Edinburgh University where the particular robot is being built.
Automated planning and programming environments for robots
Authors: ElMaraghy H. A. , Rondeau J. M. 
Published: March 2009

SummaryTraditionally, most industrial robots are programmed by teaching. Automatic planning of robotic tasks has many potential benefits for flexible automation. It allows the user to describe a task to the robot programming system in a formal and natural manner, and reduces the time required to generate and update robot programs. Two main levels of abstraction in describing robot tasks can be identified.Robot-levelprogramming is based on robot movements and actions, as detailed by the programmer.Object-levelortask-levelprogramming allows the user to describe assembly tasks in terms of operations performed on objects being manipulated instead of specifying the individual motions of the robot end-effector. However, commercially available robot-level programming languages still fall short of the robot user's need to programme complex tasks and consequently are not widely used in industry. There is an increasing need for integrating sensors feedback into the robot system to provide better perception and for improving the capacity of the robot to reason and make decisions intelligently in real-time. Task-level programming represents the highest level of abstraction and is the most attractive, as it uses reasoning capabilities provided by Artificial Intelligence. To date, no system of this class has been completely implemented in industry. This paper reviews the progress made in robot programming and task planning systems in the last twenty years, and discusses the current research trends.
A model algorithmic learning method for continuous-path control of a robot manipulator
Authors: Oh Sang–Rok , Bien Zeungnam , Suh Il Hong 
Published: March 2009

SUMMARYA new type of an iterative learning control method is proposed for dynamic systems with uncertain parameters. The method, which employs the model algorithmic control concept in the iteration sequence, is shown to be convergent for linear time-varying systems. Then the method is shown to be applicable for continuous-path control of a robot manipulator.
Automatic robot program synthesis for assembly
Authors: ElMaraghy H. A. , Rondeau J. M. 
Published: March 2009

SUMMARYThis paper describes a revised version of ROBOPLAN, a goal-oriented robot task planning system for automatic generation, decomposition and execution of high-level robot plans for assembly. It emphasizes its new features, i.e., modularity, formal definition of the task, robust plan synthesis, and execution of each assembly step. A task definition language allows a formal description of the robot universe and the assembly task to be input to ROBOPLAN. The expert task planner is a non-linear backward chaining problem solver, using a goal driven depth-first strategy. The implemented search strategy has been tested in the assembly domain, but it could be used in other domains where planning is needed. The motion planner provides a non-optimal, safe robot trajectory; collision free path planning has not been included yet. A robot executable code is generated for each assembly step and monitored in real time. The error detection and recovery capability of the system is rather limited at present, since no sensors are used. The initial implementation of the system has been tested and evaluated on the assembly of a DC motor. The potential of extending this planning framework to other applications is also discussed.
Multivalue coding: application to autonomous robots
Authors: Pruski A. 
Published: March 2009

SUMMARYThe paper describes a free space modeling method by multivalue coding. Each code defines some numerical values representing a set of cells from a grid. The idea consists in using the grid as a Karnaugh board whose rows and columns are binary coded rather than Gray coded. This operating method allows to define, for each code, its grid location and allows numerical comparison in order to locate a code relatively to another. This aspect is helpful for path planning. The free space model is represented by a switching function or a tree to which boolean algebra rules and mathematic operations are applied. We describe an application to mobile robot path planning.
SYM-program environment for manipulator modeling, control and simulation
Authors: Timčenko Aleksandar , Kirćanski Nenad , Urošević Dragan , Vukobratović Miomir 
Published: March 2009

SUMMARYThis paper describes the structure of the program package for manipulator modeling, control law synthesis and simulation SYM. While the underlying algorithms have been explained elsewhere, this paper puts emphasis on SYM as a program environment with both research and educational purposes. The control law synthesis in symbolic form, as well as system simulation, are given in more details since those features have been introduced into SYM recently. As an illustration we present few instances of SYM outputs which depict main steps in manipulator control system creation process: manipulator structure as a 3D scheme, control law definition form and system simulation results as 2D plots.
An algebraic approach to collision-avoidance trajectory planning for dual-robot systems: Formulation and optimization
Authors: Suh Suk-Hwan , Kim Myung-Soo 
Published: March 2009

SUMMARYCollision-Avoidance is a key issue in planning trajectories for dual robots whose workspaces overlap. In this paper, we develop a new trajectory planning method by proposing a traffic control schemes. The traffic controller determines the next positions for each robot based on the motion priority and path direction subject to the collision-avoidance conditions and the robots' physical limits. The problem of determining the next positions is formulated and optimized. Algebraic expressions for collision avoidance between every-pair of links – one from the first robot and the other from the second robot – are derived inconfiguration space. These algebraic expressions are then used to solve the problem of determining “optimal” (in the sense of path direction and motion priority) robots' trajectories. A solution procedure is developed using a nonlinear programming (NLP) solver. The main advantage of our approach is that the two robots' trajectories can be determined simultaneously without requiring anya prioripath information. Several numerical examples are presented to demonstrate the validity and effectiveness of the proposed approach.
Tactile sensing of 3-dimensional surface features
Authors: Russell R. Andrew 
Published: March 2009

SummaryRobots will require some form of proximity sensing in order to perform many delicate exploration, assembly and manipulation tasks. This paper describes a novel articulated tactile probe which can locate and accurately measure the 3-dimensional surface contours of small objects. Although lacking the speed of data acquisition possible with vision and other non-contact sensors, the resulting data is easily processed to give useful information about an object.
Optimization of manipulator dynamics in non extreme design case
Authors: Youlun Xiong , Han Ding 
Published: March 2009

SummaryThis paper is concerned with the dynamic merit of robot manipulators and method for the optimization of manipulator dynamics in the case of an extremely bad design, which can be put into three categories: 1. Acceleration performance: minimize2. Velocity performance: minimize3. Comprehensive performance: minimize,andare the dynamics indices of API, VPI and CD PI under various conditions respectively.The exchange algorithm is presented and a procedure is developed to solve this kind of Minimax problem. An example is discussed to illustrate the application of the optimization method. The large uniform magnitude of a joint relative driving torque provided by this dynamics optimization procedure will be made into a large work space and large torques.
CAD of Devices for Gripping Prismatic Components
Authors: Pham D. T. , Tacgin E. 
Published: March 2009

SUMMARYThis paper describes the generation of profiles of jaws of robot grippers for holding parallel-sided workpieces. The profiles are effectively ruled surfaces. The line segments of the ruled surfaces are designed to contact workpieces of different thicknesses. The optimum design of these gripping surfaces is considered in this paper
Kinematics of a n–bay triangle–triangle variable geometry truss manipulator
Authors: Beiner L. 
Published: March 2009

SUMMARYVariable geometry truss manipulators (VGTM) are static trusses where the lengths of some members can be varied, allowing one to control the position of the free end relative to the fixed one. This paper deals with a planar VGTM consisting of a n–bay triangle-triangle truss with one variable length link (i.e. one DOF) per bay. Closed-form solutions to the forward, inverse, and velocity kinematics of a 3-DOF version of this VGTM are presented, while the forward and inverse kinematics of an n–DOF (redundant) one are solved by a recursive and an iterative method, respectively. A numerical example is presented.
A new wheel control system for the omnidirectional HERMIES-III robot
Authors: Reister D. B. 
Published: March 2009

SUMMARYWe have designed, built, and tested a new wheel control system for the HERMIES-III robot. HERMIES-III is a large mobile robot with omnidirectional steering that is designed for human scale experiments. During each cycle (at 20 Hz), the wheel control system moves the robot toward a goal and calculates the current position of the robot. The system has seven modes for moving to a goal and the goal may be changed during motion of the robot.
Planning of collision-free movements of a manipulator with dynamic constraints
Authors: Ozaki H. , Mohri A. 
Published: March 2009

SUMMARYIn this paper the joint trajectories of a manipulator, which avoids obstacles in the work space and follows given path, are planned considering the dynamics of the manipulator system. The planning problem has four types of constraints: collision-free conditions, structural joints movable ranges, joints velocity limits and actuators input limits. This problem is formulated using artificial potentials which give feasible joint movements under these constraints. An algorithm using the linear programming is given to solve the problem. This algorithm enables the successive adjustment of the weighting factors of artificial potentials and gives the desired joint trajectories. The algorithm is effectively applied to the planar movements of a manipulator with four links and four degrees of freedom.
Special configurations of robot-arms via screw theory
Authors: Hunt K. H. 
Published: March 2009

SUMMARYThe Jacobian of serial robot-arms is examined, and the matrix of cofactors of a singular Jacobian is presented as a means of explaining the physical nature of special configurations. Because the columns of both these matrices are screw coordinates, screw theory is central to proper understanding. ‘Realistic’ robot-arms are seen to behave in ways that can be explained not by particularizing from a general formulation but rather by carefully interpreting the relevant special screw systems from the outset. Higher singularities (with more than one freedom-loss) are then touched upon.
Robots in the construction industry
Authors: Warszawski A. 
Published: March 2009

SUMMARYRobots have a considerable potential of application on the building site; they can adapt to varying tasks, move and interact with environment. The building process may be restructured in such way that a majority of tasks would be performed by 4 configurations of robots: an assembling robot for handling of large structure components, a general purpose robot for interior finishing works, an exterior wall, and a floor finishing robot for finishing of large vertical and horizontal surfaces, respectively. A preliminary feasibility study reveals that such robots may be justified economically, especially under conditions which reduce human productivity or require high quality of work.
Resolved position control for two cooperating robot arms
Authors: Lim Joonhong , Chyung Dong H. 
Published: March 2009

SUMMARYThe problem of controlling two cooperating robot arms is investigated. The task is to move an object from one place to another by grasping it at two different points using two robot arms. The path of the object is determined first in the Cartesian coordinate system, and the corresponding joint variable trajectory is evaluated from the object path for each robot. Each robot is then position controlled so that it follows its joint variable trajectory. The method was successfully applied to two RHINO robot system.
On a human-arm-like mechanical manipulator
Authors: Hemami A. 
Published: March 2009

SUMMARYThis paper investigates the kinematics and motion of a human arm as a manipulator with seven degrees of freedom, and how to deal with the extra degree of freedom that exists. It proposes that a change of configuration be divided into a sequence of motions where each time one of the joints is locked. It then presents a general technique to solve inverse kinematic equations of the different reduced models that arise.
Automated Mobile Robots under the Influence of Random Disturbances
Authors: Hongler M. -O. 
Published: March 2009

SUMMARYThe dynamics of sensors operated devices such as Automated Mobile Robots and more generally automated target seeking devices is studied in presence of noise. We introduce a simple and analytically tractable class of dynamics which permits to classify qualitatively and somehow quantitatively also the approach to the targets when fluctuations corrupt the ideal trajectories. Our model constitute a first evaluation of the feasibility of an efficient approach when the parameters of the model (statistics of the noise, lengths of the path and progressing steps and heading velocity) are known.
An Efficient Computational Method of the Jacobian for Robot Manipulators
Authors: Li Chang-Jin , Hemami A. , Sankar T. S. 
Published: March 2009

SUMMARYIn this paper, an efficient method for computing the Jacobian matrix for robot manipulators on a single processor computer is developed. Compared with the existing methods, the number of required numerical operations is considerably smaller, making the proposed technique the fastest, or the least expensive, one for any general N degrees-of-freedom manipulator.
Learning Task Strategies in Robotic Assembly Systems
Authors: Ahn D. S. , Cho H. S. , Ide K. , Miyazaki F. , Arimoto S. 
Published: March 2009

SUMMARYThis paper presents a practical method for generating task strategies applicable to chamferless and high-precision assembly. The difficulties in devising reliable assembly strategies result from various forms of uncertainty such as imperfect knowledge on the parts being assembled and functional limitations of the assembly devices.In order to cope with these problems, the robot is provided with the capability of learning the corrective motion in response to the force signal through iterative task execution. The strategy is realized by adopting a learning algorithm and is represented in a binary tree-type database. To verify the effectiveness of the proposed algorithm, a series of experiments are carried out under simulated real production conditions. The experimental results show that sensory signal-to-robot action mapping can be acquired effectively and, consequently, the assembly task can be performed successfully.
Efficient computation of force distributions for walking machines on rough terrain
Authors: Gardner J. F. 
Published: March 2009

SUMMARYThe force distribution problem for legged vehicles on rough terrain is considered. A general formulation of the force distribution problem in which the feet contact the ground at arbitrary inclinations, is presented. Three techniques are used to solve the force distribution problem for three representative tasks. The Moore-Penrose pseudo-inverse, a numerical optimization scheme and an approximation to the optimal solution are described. The optimal scheme computes the forces which minimize the maximum ratio of tangential foot reaction force to foot normal force. The approximation is used to achieve certain desirable characteristics of the optimal scheme with considerably less computational resources.
A Knowledge-Based Approach to Modelling of Robotic Assembly Cells
Authors: Kim Dae-Won , Lee Bum-Hee , Ko Myoung-Sam 
Published: March 2009

SUMMARYIn this paper, an approach to modelling of a robotic assembly cell is proposed and a method for managing the cell operation is described using a knowledge base. Since the modelling structure is based on the concept of the state variable, the relationships between states are described by the state transition map (STM). The knowledge-bases for state transition and assembly job information are obtained from the STM and the assembly job tree (AJT), respectively. Using the knowledge-base, the System structure is discussed in relation to both managing the cell operation and evaluating the performances. Finally, a simulation algorithm is presented with the simulation results to show the significance of the proposed modelling approach.