bluuebunny/crossref_metadata_2025_split huggingface dataset:
An integrated programming environment for a generic robotic workcell
Authors: Carayannis G. , Freedman P. , Malowany A. 
Published: July 2007

AbstractThe complexity of modern robotic workcells, consisting of many cooperating elements (e.g., robots, sensing systems) makes programming applications enormously difficult. Even when the application can be easily decomposed into workcelll operations, the tight coupling among these operations due to constraints on precedence and resource sharing makes it difficult to identify and take advantage of possible concurrency. Since robotic workcells are typically configured to repetitively perform an application, we seek to minimize the ‘cycle’ time required, by optimizing the order in which operations take place. Eventually, a sequential program must be written for each workcell element, and they must then execute concurrently. Commercial robot languages and systems provide neither the necessary tools for programming such a distributed collection of elements nor a mechanism for inter‐element communication. In this article the authors propose a two‐part solution to this workcell programming problem: SAGE/WRAP. A graphics interface is provided to the user in order to define the application. Then, from the user's input, SAGE builds a Petri Net description of the workcell application; this is used to obtain a time‐optimal sequence of operations for each workcell element. The time‐optimal sequence then becomes the basis of the runtime program that performs the application. This program is interpreted and executed by the hierarchical workcell runtime environment called WRAP. An example is provided to illustrate the approach.
Hamiltonian description and dynamic control of flexible robots
Authors: Nicosia S. , Tomei P. , Tornambé A. 
Published: July 2007

AbstractThe article is concerned with the problem of modeling and control of flexible robots. This problem is faced by using the Hamiltonian approach and the assumed modes method to obtain an approximate finite dimensional model of the robot dynamics. The pseudo‐linearization method is then applied to design a nonlinear control law that is effective in the neighborhood of the operating points. The article ends with an application to a single‐link robot arm.
Solution schemes for the system equations of flexible robots
Authors: Low K. H. 
Published: July 2007

AbstractIn this work, a method for generating the dynamic equations of flexible robots with open‐chain linkage mechanisms is developed. A general transformation matrix associated with the elastic deformation is introduced. In determining the elastic response, a method of separation of variables and the Galerkin's approach are suggested for the boundary‐value problem with time‐dependent boundary conditions. Besides the formulation scheme, the present work also studies the difficulty of dealing with the inverse kinematic problem, in which the unknowns involve the rigid‐body displacements and the elastic deflections. Finally, the ideas presented here have been implemented in a computer simulation, and the formulation of the boundary‐value problem has been employed to obtain the equations of motion of a flexible robot. Simulation results are presented.
Decentralized adaptive control of robot manipulators
Authors: Oh B. J. , Jamshidi M. 
Published: July 2007

AbstractA decentralized adaptive control scheme is proposed for the trajectory tracking of a general n‐degree‐of‐freedom robot manipulator. The robot is considered as a set of decoupled second‐order systems with disturbances. The controller consists of feedforward from the desired trajectory based on the “inverse system” of the model, PID feedback from the actual trajectory, and auxiliary input for the compensation of the neglected terms in modeling in each subsystem. The gain is derived in diagonal matrix form, and is adjusted by the model reference adaptive control theory based on the Lyapunov's direct method. The result is high accuracy in path tracking despite the high speed, load change, and sudden torque disturbances. Numerical simulations on.a planar two‐link robot manipulator are presented to show the performance under various practical considerations.
A generalized kinematic modeling method for modular robots
Authors: Benhabib B. , Zak G. , Lipton M. G. 
Published: July 2007

AbstractModular robots can be defined as reconfigurable mechanical arms which can be automatically controlled using suitable motion control software. In this article, a generalized kinematic modeling method is presented for such modular robots. This method can be used to derive the individual kinematic models of all the mechanical elements that make up the inventory of modular units, independently of their geometry and sequence of assembly into a robot. A general procedure is also presented to derive a global kinematic model of any robot configured using these modular units. The kinematic modeling technique of the units is based on Denavit‐Hartenberg (D‐H) parameter notation. A provision is also presented for converting “non D‐H” parameter transformations, obtained in assembling the kinematic chain, into D‐H transformations. This D‐H conversion feature allows the modeling technique to preserve its generality when a kinematic model is obtained for the specific robot configuration at hand. The conceptual design of modular robot units that is under development in the Computer Integrated Manufacturing Laboratory (CIML) is also presented to show the feasibility of a modular approach to robot design and to clarify some of the mathematical for mulations developed in the article.
A holdsite method for parts acquisition using a laser rangefinder mounted on a robot wrist
Authors: Roth Gerhard , O'Hara Dave , Levine Martin D. 
Published: July 2007

AbstractParts acquisition by a robot is an important industrial problem. Our method makes possible the acquisition of various types of parts which are jumbled together in a pile. An intensity image along with selected range data is used to guide a robot to a location, called a holdsite, at which it can grasp a part. The intensity image gives a rough indication of an area of interest and a laser rangefinder mounted on the robot wrist collects range data in its vicinity. This data is processed using spatial planning methods to find a good holdsite according to safety and stability criteria. The robot is then directed to the holdsite and the part is grasped. The algorithms are simple, fast, and have been successfully tested on a variety of parts.
A local solution with global characteristics for the joint torque optimization of a redundant manipulator
Authors: Nedungadi A. , Kazerouinian K. 
Published: July 2007

AbstractIn this article, a stable local solution with global characteristics is developed for the joint torque optimization problem in redundant robotic manipulators. It is shown that the local optimization of the inertia inverse weighted dynamic torque corresponds to the global kinetic energy minimization problem. The proposed local‐global alternative to the joint torque optimization problem is compared for stability and torque optimality with five different methods used for redundancy resolution of robotic manipulators at the acceleration level. The proposed local‐global solution has been implemented and tested on a planar four‐DOF kinematically redundant lab robot which was designed and built at Southwest Research Institute (SWRI). Several numerical simulations confirm the positive advantages of solutions which have a local as well as a global interpretation. In addition, a “dynamic manipulation index” is introduced to monitor the stability of an optimization problem in a kinematically redundant robot.
Redundancy resolution through local optimization: A review
Authors: Nenchev Dragomir N. 
Published: July 2007

AbstractKinematically redundant manipulator arms and other robotic mechanisms provide a means for solving sophisticated motion tasks but require complex research on both mechanical and control problems. So far, many works have been published on kinematic redundancy, however, a systemization is missing. In this article an attempt for such a systemization is presented. It has been limited to methods for redundancy resolution through local optimization. Until now, these methods are most widely used, and it is expected also that they will prevail in the near future. A classification is suggested and the performance capabilities of the methods are discussed and compared. Two reference tables are provided; One of them lists references for different problems on kinematic redundancy as: mechanical design, dexterity measures, multicriteria optimization, global optimization, control design and computational considerations. The other table displays existing publications classified according to the application area of redundant robotic‐mechanisms.
A global approach for the optimal path generation of redundant robot manipulators
Authors: Mayorga R. V. , Wong A. K. C. 
Published: July 2007

AbstractIn this article the optimal path generation of redundant robot manipulators is considered as an optimization problem, with given kinematics and subject to the robot requirements and a singularities avoidance constraint. This problem is formulated as a constrained continuous optimal control problem, which allows to consider joints and velocities constraints and/or manipulator dynamics. This approach is exemplified for a planar redundant manipulator and the resultant state constrained problem is solved by an efficient iterative numerical technique.
An efficient algorithm for finding a collision‐free path among polyhedral obstacles
Authors: Fu Li‐Chen , Liu Dong‐Yueh 
Published: July 2007

AbstractThe use of graph search algorithms on a so called “visibility graph” is a common approach to finding a minimum‐distance collision‐free path among polyhedral obstacles in a 2D environment. Complexity of the search can be greatly reduced by reducing the size of the graph. The focus of this article is to provide an algorithm aimed at constructing asubvisibilitygraph using only “necessary” obstacles, i.e., excluding as many obstacles as possible whose vertices are never via points of the shortest collision‐free path.
Robot arm‐wrist coordination. Part 2. Design guidelines
Authors: Ang Marcelo H. , Tourassis Vassilios D. 
Published: July 2007

AbstractIn the companion article (Part 1), we developed a mathematical framework that provides for the analysis and quantitative rating of arm‐wrist coordination. The objective of this article is to exploit this framework and formulate manipulator design guidelines for effective arm‐wrist coordination and task execution. We explore various arm and wrist designs and quantify their performance in terms of meeting the two design objectives of efficient arm‐wrist coordination and robot flexibility. Numerical simulation experiments highlight the measurable effects of both the fixed manipulator geometry and changing robot configuration on arm‐wrist coordination and demonstrate the impact of the design guidelines on robot performance.
Significance of observation strategy on the design of robot calibration experiments
Authors: Driels Morris R. , Pathre Uday S. 
Published: July 2007

AbstractThis article examines the factors influencing the identification and observability of kinematic parameters during robot calibration. A generalized calibration experiment has been simulated using two different identification techniques. Details of the identification techniques and considerations for implementing them using standard IMSL routines are presented. The factors considered during the simulations include: initial estimates of parameters, measurement accuracy and noise, encoder resolution and uncertainty, selection of measurement configurations, number of measurements, and range of motion of the joints during observations. Results are tabulated for the various cases and suggestions are made for the design of robot calibration experiments.
Behavioral knowledge in sensor/data fusion systems
Authors: Pau L. F. 
Published: July 2007

AbstractThis article proposes a behavioral control formalism to explain situations often encountered in complex sensor/data fusion (eventually decentralized) information acquisition, command and control systems, it involves making the input‐output relations of each actor involved in the fusion process conditional on selected behavioral classes, with error creation and repair options. For each behavioral class, the input‐output relations are modified by concurrent behavioral rules, while the class itself has visible and hidden attributes. A formalism is also given for interactions between actors. This approach allows to describe and analyze such situations as: indirect observations, ambiguous controls, hysterisis, deadlocks, initiation of attention mechanisms. Finally, the engineering use of this approach is illustrated by three concrete designs involving humans operating indoors.
Logical behaviors
Authors: Henderson Thomas C. , Grupen Rod 
Published: July 2007

AbstractIn this article we describe an approach to high‐level multisensor integration organized around certain egocentric behaviors. The task itself determines the sequence of sensing, the sensors used, and the responses to the sensed data. This leads to the encapsulation of robot behavior in terms of logical sensors and logical actuators. A description of this approach is given as well as some examples for dextrous manipulation and mobile robots.
Feature space mapping for sensor fusion
Authors: Flachs G. M. , Jordan J. B. , Beer C. L. , Scott D. R. , Carlson J. J. 
Published: July 2007

AbstractIn the context of a random process scene environment model, a method is presented for fusing data from multiple sensors into a simplified, ordered space for performing electronic vision tasks. The method is based on a new discriminating measure called the tie statistic that is introduced to quantify sensor/feature performance and to provide a mapping from sensor/feature measurement space to a simplified and ordered decision space. The mapping process uses the tie statistic to measure the closeness of an unknown sample probability density function (pdf) to a known pdf for a decision class. Theorems presented in this article relate the tie statistic to minimum probability of error decision making and to the well known Kolmogorov‐Smirnov distance. As examples of the sensor/feature fusion method, the tie mapping process is applied to the object location (cueing) and the texture recognition problems.
Automatic generation of forward and inverse kinematics for a reconfigurable modular manipulator system
Authors: Kelmar Laura , Khosla Pradeep K. 
Published: July 2007

AbstractTraditional industrial and research manipulators have a fixed configuration and are thus suited for a certain class of tasks. In order to make manipulators flexible and suited for a larger class of tasks we have proposed the concept of a Reconfigurable Modular Manipulator System (RMMS). The RMMS consists of a set of modular links and joints of various sizes; reconfigurable manipulators are designed and built from this system as appropriate for a given task. In order to effectively utilize such a system, one needs algorithms for automatically generating the kinematic descriptions for an arbitrary manipulator configured from the RMMS. Previous research on the kinematics of robotic manipulators has addressed fixed configuration manipulator systems. In this article, we propose an algorithm for automatically generating both the forward and inverse kinematics of a serial linkNdegrees‐of‐freedom reconfigurable manipulator. Generation of the kinematic equations that govern a modular manipulator starts with geometric descriptions of the units, or modules, as well as their sequence in the manipulator. Using this geometric information, we determine the Denavit‐Hartenberg parameters of a reconfigurable manipulator. The Denavit‐Hartenberg kinematic parameters are then used to obtain the forward kinematic transformation of the system. We also address the problem of otaining the inverse kinematics of reconfigurable manipulators. In order to automate the inverse kinematics and to make the procedure as general as possible, we have proposed the idea of scaling a manipulator. We use the efficient numerical approach and in the case of a redundant manipulator, we exploit the extra degrees of freedom to achieve singularity avoidance. We have implemented our algorithms on an Ironies 68020 based single board computer that is used to control the prototype Reconfigurable Modular Manipular System (RMMS) which is being developed in our laboratory.
Solving the inverse kinematics problem via the principle of self‐support
Authors: Novaković Zoran R. 
Published: July 2007

AbstractA new way of treating various phenomena and processes, called “the principle of selfsupport,” is implemented for solving the inverse kinematics problem. This approach does not use cause/effect philosophy, but is based instead on the concurrency of all kinematic variables involved in the process of executing the desired task. Control action is then seen as a circular and not as a hierarchical process. Such a methodology brings simple numerical algorithms that guarantee stability (tracking). They are realistic from the engineering standpoint and can be implemented using current microprocessor technology. If advanced sensor equipment is available, they appear to be even superior to the analytical solution of the problem.
Model‐based control of industrial manipulators: An experimental analysis
Authors: Leahy M. B. 
Published: July 2007

AbstractModel‐based control techniques for industrial robotic manipulators were experimentally analyzed. The case study for the analysis was the first three joints of a PUMA‐560. Development of an advanced control evaluation environment removed the computational restrictions of previous studies. The specific issues of: incomplete and/or asynchronous dynamic compensation, feedback paradigm selection, payload sensitivity, and drive systems effects were experimentally analyzed. Evaluation results clearly demonstrate that the performance improvement capability of model‐based control is not restricted to research robots. A model‐based controller with complete feedforward compensation and sliding mode feedback reduced the maximum tracking error by at least a factor of five when compared to feedback alone. End‐effector payload invariant tracking only requires mass information. Tracking performance is not dependent on dynamic compensation at the servo rate. Evaluation results provide insight for adaptive control law design and a baseline to compare their performance against.
An adaptive scheme for robot joint trajectory generation
Authors: Hsia T. C. , Guo Z. Y. , Li L. 
Published: July 2007

AbstractIt has been shown recently that robot inverse kinematic transformation can be easily carried out by using a nonlinear dynamic system called “joint space command generator.” In this paper, an adaptive version of the command generator is proposed. The main feature of this command generator is that the inverse Jacobian is estimated on‐line (using least‐squares algorithms), thus the explicit form of the inverse Jacobian is not required. Since the Jacobian is dependent on the end‐effector orientation representation, the adaptive command generator is then inherently flexible in accommodating any choice of orientation representation during Cartesian trajectory planning. The only knowledge required is the forward kinematics of the robot. Thus inverse kinematic transformation of robot trajectories can be carried out with a minimum amount of kinematic information. Extensive simulation studies of the proposed scheme have been carried out which showed that the adaptive command generator is computationally feasible and highly accurate. Different orientation representations have been tested with equal success. Some typical simulation results are presented to illustrate the performance of the adaptive command generator.
A case study of two‐robot‐arm workcell material handling
Authors: Hemami A. , Ranjbaran F. , Cheng R. M. H. 
Published: July 2007

AbstractMore problems are involved in collaborating multi‐robot‐arm systems than in single robot arms. These problems stem from mutual dynamic and kinematic effects between the arms. This work is confined to only the kinematics of two robot arms; other problems like control, force distribution, and so on are not addressed here. A particular case of a material handling problem with two collaborating robot arms loading/unloading long objects from a conveyor is studied. The feasibility of the task from a kinematics point of view, and the necessary conditions and constraints for the relative set‐up of the two manipulators are discussed. These conditions originate from the working envelope of the two arms which depends on three factors: the working envelope of each individual arm, the spacing between them, and the dimensions of the workpiece. To assist this study, an efficient algorithm for determining the two‐dimensional contours of the workspace of a single arm is included.
Linearized dynamic models of robot manipulators in cartesian space
Authors: Li Chang‐Jin 
Published: July 2007

AbstractThis article presents development of the linearized dynamic models of robot manipulators in Cartesian space. A clever method is proposed to formulate the linearized dynamic models of robot manipulators in Cartesian space. Efficient methods are developed to compute various matrices involved in the models (or the manipulator sensitivity matrices in Cartesian space), such as the Jacobian matrix and the first and second derivatives of it with respect to time as well as the manipulator sensitivity matrices in joint space. The proposed methods are simple and systematic and have computational complexity of the order O(n2) only, where n is the number of degrees‐of‐freedom of the manipulator.
Hybrid control: A constrained motion perspective
Authors: Mills James K. 
Published: July 2007

AbstractControl of manipulators during execution of tasks that require the end‐effector to come into contact with objects in its work environment represents an important class of control problem. Hybrid control, a concept which defines the architecture of a class of control laws has been proposed as a method with which to solve this control problem. One interpretation of the hybrid control method is within the framework of constrained motion control. Constrained motion occurs during contact by the manipulator end‐effector with rigid objects in the workplace, hence the motion of the manipulator is kinematically constrained. Papers have appeared in the robotics control literature addressing hybrid control within the constrained motion context which do not explicitly use the constrained dynamic formulation that correctly describes the dynamic behaviour of the manipulator. This article serves to link results from constrained motion control and the existing literature on the hybrid control method. In this article a formulation of the constrained manipulator dynamics is presented in which the hybrid control design is most naturally carried out. This formulation of the manipulator dynamics, previously proposed in the robotics literature, is such that the generalized force and position coordinates to be controlled are mutually orthogonal. Hence, the hybrid selection matrices, a key element of the hybrid control design philosophy, are implicit in this coordinate representation. A hybrid control design methodology is then formulated based on this development. Two hybrid control laws are proposed. For each hybrid control law, the global asymptotic stability is readily established due to the natural coordinate representation. One of these hybrid control laws, a constrained motion control law already proposed in the literature, is given to illustrate the equivalence of the hybrid control design and certain existing constrained motion control methods. Finally, a concrete example of a three‐degree‐of‐freedom robotic manipulator illustrates the hybrid design methodology proposed.