bluuebunny/crossref_metadata_2025_split huggingface dataset:
Appropriate lengths between phalanges of multijointed fingers for stable grasping
Authors: Okada Tokuji , Kanade Takeo 
Published: July 2007

AbstractAn appropriate arrangement of finger joints is very important since the stability of grasping an object greatly depends on that arrangement. Multijointed fingers can grasp an object with many points of contact each of which is pressed against the object as if wrapping up that object. The amount of the wrapped up area and the form of the finger when an object is grasped are therefore important factors for determining the stability of grasping. We propose the wrapping factor to be used for the evaluation of the stability of grasping by using these factors. We consider 28 models for the finger having three joints, and perform a simulation of their ability to grasp various shapes stably. Based on the simulation results, an appropriate arrangement of lengths between phalanges for a multijointed finger is presented.
Evaluation of a grey scale tactile array sensor pad for robotic applications
Authors: Driels M. R. , Michael K. M. , Cholakis P. N. 
Published: July 2007

AbstractSince sensory feedback is an important part of robot control and the acquisition, manipulation, and recognition of objects, incorporating a sense of touch into a robotic system can greatly enhance the performance of that system. This article describes the evaluation of a recently developed low‐resolution tactile array sensor pad system for use in robotic applications. Computer algorithms are developed which acquire data from the sensor pad and display the data on a CRT screen. Vision algorithms are implemented in order to extract the necessary information from the tactile data which will aid in the acquisition, manipulation, and recognition of objects. An object's pose is estimated by calculating its center of gravity (position) and principal axis (orientation). Recognizing an object and distinguishing between different objects is accomplished by implementing algorithms which estimate an object's perimeter (shape) and area (size). This work demonstrates that a low‐resolution tactile array sensor is capable of providing the information that is required for many robotic applications in which objects must be acquired, manipulated, and recognized. Such a system provides a low‐cost alternative to more conventional vision‐based systems.
Mathematical modeling of a robot collision with its environment
Authors: Zheng Yuan‐Fang , Hemami Hooshang 
Published: July 2007

AbstractIn this article the collision of a robot with its environment is studied. In normal applications of a robot arm, a collision takes place because of the velocity of the end effector relative to the object at the time of contract. The collision has effects on the velocities and internal forces of the robotic system. Firstly, the generalized velocities representing joint rates have abrupt changes at the moment of collison with the environment. The mathematical model is derived to establish the quantitative relationship between this abrupt change and the severity of the collision. The latter is represented by either an external impulsive force or the instantaneous change of the linear velocity of the contact point. Secondly, internal to the system, large impulsive forces and torques of constraint may develop at each joint because of the collision. These impulses cause possible damages to the system. The mathematical model is also derived to establish a quantitative relation between the impulsive forces and torquest of constraint and the collision. These two models are applied to a Stanford Arm designed to pick up an object by its end effector, and the consequences of the collision are analyzed.
A kinematics and dynamics simulation of the IBM‐7565 robot using AML
Authors: Goldenberg A. A. , Kelly A. 
Published: July 2007

AbstractThis article presents a kinematics and dynamics simulation of the IBM‐7565 robot using its AML programming language. The kinematics and dynamics models are formulated according to the Denavit‐Hartenberg convention and a recursive Newton‐Euler algorithm, respectively. The simulation is integrated in a CAD software package (CATIA) which is used in robot offline programming and collision/interference analysis. The CAD package software which runs on an IBM 3033 main frame also emulates the AML for automatic programming. The simulation models can be run on the IBM 3033 using the emulator or on the robot's dedicated Series‐1 computer to where the programs are downloaded for execution and control of robot motion.
Improving the absolute positioning accuracy of robot manipulators
Authors: Hayati S. , Mirmirani M. 
Published: July 2007

AbstractThe absolute positioning accuracy of robot manipulator can be increased substantially by updating the nominal link parameters in the control software. This paper presents a general method to estimate the link parameter errors for any serial link manipulator (i.e., n links, and any combination of revolute and prismatic joints). The parameters are estimated through a linear kinematic model which relates the link bias errors to the end‐effector positioning error. Only end‐effector measurements are required instead of individual link measurements to implement this method.
Reliable real‐time robot operation employing intelligent forward recovery
Authors: Smith Richard E. , Gini Maria 
Published: July 2007

AbstractModern computer‐controlled robots typically fail at their tasks whenever they encounter an error, no matter how minor. The physical environment of a typical assembly robot is too unstructured to benefit from conventional software approaches to reliability. We present an approach which interfaces the real‐time operation of the robot with an intelligent subsystem that performs error analysis and forward recovery if a failure occurs. Our approach involves a special representation of the robot's program that efficiently tracks the robot's operation in real time and is easy to modify to include automatically generated recovery procedures.
Subminiature binary camera design for inspection and robotic assembly applications
Authors: Driels M. R. , Collins E. 
Published: July 2007

AbstractThe article describes the design and utilization of a small, lightweight digital camera intended to assist in robot assembly tasks and to provide a low cost visual inspection tool. The main operational features of the design are outlined together with some sample applications involving the identification of integrated circuit devices, and the location of assembly sites on a printed wiring board.
Robust discrete nonlinear feedback control for robotic manipulators
Authors: Neuman Charles P. , Tourassis Vassilios D. 
Published: July 2007

AbstractNonlinear feedback control algorithms for manipulators utilize a complete (coupled and nonlinear) dynamic robot model to decouple the robot joints. In the companion article1 we outlined the practical problems introduced by modeling inaccuracies, unmodeled dynamics and parameter errors. We then introduced the α‐computed‐torque nonlinear feedback control algorithm which is robust in the presence of the aforementioned error sources. In this article, we apply the insight gained from the α‐computed‐torque algorithm to design a robust discrete‐time (accelerometer‐free) computed‐torque robot‐control algorithm founded upon our discrete dynamic robot model.2 Numerical experiments with the cylindrical robot confirm both the robust disturbance rejection characteristics and the practical applicability of our discrete‐time computer‐torque control algorithm.
A new approach to improve absolute positioning accuracy of robot manipulators
Authors: Ishii M. , Sakane S. , Kakikura M. , Mikami Y. 
Published: July 2007

AbstractThis article describes a new calibration system for robot manipulators which improves their absolute positioning accuracy by using parameter‐estimation algorithms based on the Newton method. When 3D position data of the specified points on a manipulator and the joint encoder values are input to the calibration system, the system estimates the offset values of joint encoders, link lengths, and position and orientation of the manipulator base coordinate system with respect to the world coordinate system which is difficult to obtain by conventional calibration methods. This calibration system can be applied to various manipulator types by just changing the basic kinematic equations. The system employs an algebraic programming system called REDUCE to automatically reduce the manipulator kinematic equation and partial differential calculus in the Newton method. For efficiency, first only the arm part with three degrees of freedom and then the hand part are calibrated. The experimental results demonstrate the effectiveness of this system by reducing the robot's absolute positioning errors to the order of repeatability errors.
Information‐control aspects of sensor systems for intelligent robotics
Authors: Nevins J. L. 
Published: July 2007

AbstractIn order to discuss sensor systems in intelligent robotics or manufacturing systems, it is necessary to classify tasks, controller requirements, as well as the information‐control aspects. This paper classifies tasks as deterministic (principally driven by geometry considerations) and non‐deterministic. The latter are the problems done by people requiring skill involving processes whose process models either do not exist or are poorly understood. Other non‐deterministic tasks involve inspection or data interpretation. The process tasks require adaptive‐learning type control systems and are rich in sensor needs. Automated inspection tasks can be implemented by Engineering‐Based Expert systems with more modest sensor system requirements.
On trajectory generation for flexible robots
Authors: Bayo E. , Paden B. 
Published: July 2007

AbstractA trajectory based on a Gaussian velocity profile is presented as an alternative to the double square pulse acceleration profile. The new trajectory leads to the fast positioning of the tip of a flexible robot with a minimal excitation of high‐frequency modes. The torques necessary to move the robot according to this trajectory show a very smooth behavior. The absence of high‐frequency content, present when double square pulse accelerations are considered, eliminates the Occurrence of undesired residual vibrations produced by modeling uncemnties at high frequencies. The excellent results obtained suggest the use of this new trajectory for fast and precise positioning of flexible robots.
Issues and approaches of automatic focusing algorithms for intelligent robot eye‐in‐hand system
Authors: Luo Ren C. , Lin Min‐Hsiung 
Published: July 2007

AbstractThe new, fast, automatic focusing algorithms, namely Energy Maximization and Histogram Variance Maximization, for computer vision systems have been presented in this article. These two focusing algorithms have greatly reduced the arithmetical operations needed to perform an automatic focusing operation. Experimental evaluations and comparisons to previously developed algorithms have been performed and the results presented. The improved performance in accuracy and speed of our new algorithms will certainly benefit applications such as distance measurement, target tracking, and scene analysis by the use of computer vision techniques.
General‐purpose inverse kinematics transformations for robotic manipulators
Authors: Ang Marcelo H. , Tourassis Vassilios D. 
Published: July 2007

AbstractReal‐time robot control requires efficient inverse kinematics transformations to compute the temporal evolution of the joint coordinates from the motion of the end‐effector. The development of a coherent, general‐purpose framework, incorporating position, velocity and acceleration transformations, is the theme of this paper. In this framework, the computational requirements of a new inverse kinematic algorithm are delineated. The algorithm is applicable to serial (open‐chain) manipulators with arbitrary axes of motion. Comparative evaluations of the computational cost of the algorithm demonstrate its efficacy and feasibility for real‐time applications.
Adaptive control strategies for cooperative dual‐arm manipulators
Authors: Seraji H. 
Published: July 2007

AbstractThe article describes three strategies for adaptive control of cooperative dual‐arm robots. In the position‐position control strategy, the adaptive controllers ensure that the end‐effector positions of both arms track desired trajectories in Cartesian space despite unknown time‐varying interaction forces exerted through the load. In the position‐hybrid control strategy, the adaptive controller of one arm controls end‐effector motions in the free directions and applied forces in the constraint directions; while the adaptive controller of the other arm ensures that the end‐effector tracks desired position trajectories. In the hybrid‐hybrid control strategy, the adaptive controllers ensure that both end‐effectors track reference position trajectories while simultaneously applying desired forces on the load. In all three control strategies, the coupling effects between the arms through the load are treated as “disturbances” which are rejected by the adaptive controllers while following desired commands in a common frame of reference. The adaptive controllers do not require the complex mathematical model of the arm dynamics or any knowledge of the arm dynamic parameters or the load parameters such as mass and stiffness. The controllers have simple structures and are computationally fast for on‐line implementation with high sampling rates. Simulation results are given to illustrate the proposed adaptive control strategies.
Visual control of autonomous mobile robot based on self‐organizing model for pattern learning
Authors: Suzuki Hisashi , Arimoto Suguru 
Published: July 2007

AbstractThis article proposes a self‐organizing model for pattern learning together with an application to an autonomous mobile robot system. The self‐organizing model consists of a processing rule prescribed and a memory part being blank at the initial stage. To an input signal, the model searches for a similar signal in the memory, and recalls its related information. If the information accompanied with the input signal differs from the recalled information, the model adds the new information to the memory. It influences the subsequent operations. Thus, the model constructs successively a data‐base in a self‐organizing way. This model can universally learn and reproduce any pattern of input‐output response desired. Two principal functions in autonomous movement, i.e., position identification and obstacle avoiding movement were realized based on the self‐organizing model. Furthermore, a camera type autonomous mobile robot system for indoor was made up. The size of the robot is about 0.7 × 0.7 × 0.7 m, and the weight is about 30 kg. The speed of movement is less than 3 km/h. A small computer that has a 16 bit microprocessor and a 1Mbyte RAM controls the motion of the robot with an extendedClanguage.
An alternative algebra for deriving equations of motion of flexible manipulators
Authors: Everett Louis J. 
Published: July 2007

AbstractAn alternative means for deriving equations of motion of complex systems is demonstrated. Since the method is energy based, it is useful for elastic systems. Because the method can handle vectors expressed relative to rotating coordinate systems, it does not require the introduction of coordinate transformations and thereby produces equations in a simple form. The article shows that Kane's method for rigid body systems is a special case of this alternative method. Two example problems show how the algebra can be applied to rigid and flexible nonholonomic systems.
Engineering design of a multirate nonlinear controller for robot manipulators
Authors: Machado J. A. Tenreiro , Martins Carvalho J. L. De 
Published: July 2007

AbstractA new multirate nonlinear controller for robot manipulators is described. The algorithm stems from the computed torque method, but has several modifications on its structure, resulting in a more robust controller.The main philosophy behind those improvements resides on a sound engineering and management of the system resources. Consequently, the use of multirate sampling, memory tables, and predictive action arises naturally from that methodology.The resulting controller is easy to tune using standard industrial engineering practice; moreover, by alleviating the computational burden its implementation is feasible with present day microprocessors.
Variable structure control of a robotic arm in the presence of uncertainty
Authors: Singh Sahjendra N. , Zakharia Youssef N. 
Published: July 2007

AbstractBased on the theory of variable structure systems (VSS), control system design for the trajectory control of robotic systems is presented. It is assumed that the parameters of the system are uncertain and unknown frictional torques are acting at the various joints of the arm. For simplicity, the control of a three‐link PUMA arm is considered. For trajectory following, two control laws, CH and Cθ, based on the choice of coordinates of the end effector or joint angles as the controlled outputs, respectively, are derived. It is seen that whereas control Cθ has no singularity, certain singular surfaces arise where feedback elements of CH become infinity. These singular surfaces describe the boundary of the reachable region (workspace). Digital simulation results are presented to show that accurate trajectory following can be accomplished using the control CH or Cθ for large maneuvers of the arm in spite of the uncertainty in the system.
Inversion techniques for trajectory control of flexible robot arms
Authors: De Luca A. , Lucibello P. , Ulivi And G. 
Published: July 2007

AbstractA general framework is given for computing the torques that are needed for moving a flexible arm exactly along a given trajectory. This torque computation requires a dynamic generator system, as opposed to the rigid case, and can be accomplished both in an open‐ or in a closed‐loop fashion. In the open‐loop case, the dynamic generator is the full or reduced order inverse system associated to the arm dynamics and outputs. In order to successfully invert the arm dynamics, the torque generator should be a stable system. The stability properties depend on the chosen system output, that is on the robot variables (e.g., joint or end‐effector) to be controlled. The same inversion technique can be applied for closed‐loop trajectory control of flexible robots. A simple but meaningful nonlinear dynamic model of a one‐link flexible arm is used to illustrate different feasible control strategies. Simulation results are reported that display the effects of the system output choice on the closed‐loop stability and on the overall tracking performance.
On the motion of oblique bevel geared robot wrists
Authors: Ma R. , Gupta K. C. 
Published: July 2007

AbstractIn this article, we show that the principle of superposition can be applied for analyzing the spatial motion of a bevel geared three‐roll wrist with nonzero oblique angle. The total motion of the wrist is decomposed into three independent component motions, which are easier to analyze. A superposition tabulation is then constructed to derive the relations among the three wrist joint variables and three coaxial actuation variables. The displacement solution for the wrist joint variables is found by using the zero reference position method.
Stability analysis of wave‐crab gaits of a quadruped
Authors: Zhang Chang‐De , Song Shin‐Min 
Published: July 2007

AbstractCrab walking is as important as forward walking as applied to walking machine control. Crab walking is especially important to a quadruped since a quadruped has a similar leg geometric layout in both longitudinal and lateral directions. In the studies of forward walking gaits, the wave gait was found to be the optimally stable. In this article, the wave gait is applied to the crab walking of a quadruped and it is modified into four types of wave‐crab gaits according to the range of crab angle. The stability formulae of these wave‐crab gaits are then derived analytically based on the following three stability measurements: stability margin (Sm), body‐longitudinal (or lateral) stability margin (Sbl or Sbt) and crab longitudinal stability margin (Scl). Sm is the true stability index under quasi‐static walking condition. However, the equations are more complicated. Sbl (or Sbt) is simpler and can be used as a good approximation of Sm. Scl was commonly adopted as the stability index in the previous gait studies. Nevertheless, Scl is found to be misleading for a large portion of crab angle range. The analytical results derived in this paper are useful to the geometric design and to the real‐time control of a quadruped.
Sensor integration and data fusion
Authors: Thomopoulos Stelios C. A. 
Published: July 2007

AbstractThe problem of sensor integration and data fusion is addressed. We consider the problem of combining information from diversified sources in a coherent fashion. We assume that information from various sensors may be available in different forms at the fusion. For example, data from infrared (IR) sensors may be combined with range radar (RR) data and further combined with visual images. In each case, data and information from different sensors are presented in a different format which may not be directly compatible for all sensors. Part of the available information may be in the form of attributes and part in the form of dynamical measurements. A generalized evidence processing theory and an architecture for sensor integration and data fusion that accommodates diversified sources of information are presented. Data (or, more generically, information) fusion may take place at different levels, such as the level of dynamics, the level of attributes, and the level of evidence. The common and different aspects of fusion at the different levels are investigated and several practical examples of real world data fusion problems are discussed.
Multiple sensor data association and fusion in aerospace applications
Authors: Blackman S. S. , Broida T. J. 
Published: July 2007

AbstractThis article presents a summary of some of the issues and methods encountered in the use of multiple sensors for surveillance and tracking problems that arise in aerospace and defense. Applications include air traffic control using multiple internetted ground‐based radar sensors, ship‐based air defense systems, and air‐to‐air systems for drug interdiction and for air combat. During the past decade signal and data processing technology has evolved quickly, in terms of computing power, cost, size, and weight. As a result, the automatic fusion of data from multiple sensors has become a viable way of increasing the capabilities and performance of multiple target surveillance and tracking systems, while simultaneously reducing operator or pilot workload. The design, implementation, and performance of automated single sensor systems are fairly well understood, but the same cannot be said of systems that involve fusion of data from multiple sensors. A number of fundamental issues in this area remain unresolved, and the general problem is an area of active research in both the aerospace and the academic communities.