bluuebunny/crossref_metadata_2025_split huggingface dataset:
Robotic force control for deburring using an active end effector
Authors: Bone G. M. , Elbestawi M. A. 
Published: March 2009

SUMMARYAn active force control system for robotic deburring based on an active end effector is developed. The system utilizes a PUMA-560 six axis robot. The robot's structural dynamics, positioning errors, and the deburring cutting process are examined in detail. Based on ARMAX plant models identified using the least squares method, a discrete PID controller is designed and tested in real-time. The control system is shown to maintain the force within l N of the reference, and reduce chamfer depth errors to 0.12 mm from the 1 mm possible without closed-loop control.
Nonlinear control robot: A phenomenological approach to linearization by static feedback
Authors: Verdier M. , Rouff M. , Fontaine J. G. 
Published: March 2009

SUMMARYThis paper presents a linearization by static feedbacks in the robotic field, i.e. by feedback depending on the whole state space. A phenomenological approach is considered, which by using the derivation with respect to time, leads to the major results of the method. Simulation results are presented, and some aspects of the correction of the effect of the characteristic numbers are also discussed.
A parameter identification method for robot dynamic models using a balancing mechanism
Authors: Lim T. G. , Cho H. S. , Chung W. K. 
Published: March 2009

SUMMARYAccurate modeling of robot dynamics is a prerequisite for the design of model-based control schemes and enhancement of the performance of the robot. The dynamic parameters associated with a pseudo-inertia matrix are often difficult to identify accurately because the inertia torques are small in comparison to gravity loadings, thus creating signal processing problem. The identification method presented in this paper utilizes a balancing mechanism which increases the estimation accuracy of the dynamic parameters. The balancing mechanism has the effect of amplifying the inertia-related torque signal by eliminating gravity loadings acting on the robot joints. A series of motion data were experimentally obtained through sequential test steps. By incorporating the measured information about joint torques, angular positions, velocities and accelerations the least square algorithm was used to identify the dynamic parameters. The estimated values were converted to those of the original robot model to obtain its dynamic model parameters. The identified robot dynamic model was shown to be accurate enough to predict the actual robot motions.
Effect of joint stiffness on the dynamic stability of a one-link force-controlled manipulator
Authors: Chiou Bing C. , Shahinpoor M. 
Published: March 2009

SUMMARYStudies are the effects of joint flexibility on the dynamic stability of a one-link force-controlled manipulator. The closed-loop dynamic equation with the explicit force controller and the damping force controller are first derived. Stability analysis is then carried out by computing the system eigenvalues. Results indicate a conditionally stable system. Due to the presence of discontinuous contacts with the environment during the interaction process, the system exhibits a stable limit cycle when the force feedback gain goes beyond the critical value.
Recursive formulation for the analytical or numerical application of the Gibbs-Appell method to the dynamics of robots
Authors: Desoyer K. , Lugner P. 
Published: March 2009

SUMMARYTo derive the equations of motion for a multibody system using the Gibbs-Appell calculus – the partial derivatives of the Gibbs function G = 1/2 ∫ a2 dm with respect to the generalized accelerations equal the generalized forces-shows special advantages. Describing the kinematics with Jacobi matrices and local terms, these equations can be written in such a way that the partial derivations need not be performed explicitly. Kinetic effects of fast rotating driving devices attached to the moving links can be included in a similar way. Though an analytical formulation of the equations of motion is especially desirable with respect to its application for industrial robots, such a formulation becomes too extended and susceptible to errors for systems with more than 3 or 4 bodies. Therefore an approach is developed for tree structured robots with rotational or translational joints for calculating the Jacobi matrices and the local terms without employing any differentiation process. So it is possible to use the Gibbs-Appell method numerically in a recursive way e.g. for calculating the torques of the actuators of a robot with 6 or more degrees of freedom for a given motion.
An interactive robotic device with progress monitoring
Authors: Widmer Neal S. , Nof Shimon Y. , Karlan George R. 
Published: March 2009

SummaryThe purpose of this paper is to describe a system which utilizes an interactive robotic device to help in the educational process of very young disabled children. Within the System the child's performance is monitored and evaluated on line, providing a current prescription for progress to more or less advanced learning levels. The robotic Systems developed at Purdue University during research on this concept are described as well as the prototype Systems to monitor progress of the students
Dynamic characteristics of balanced robotic manipulators with joints flexibility
Authors: Lee S. B. , Cho H. S. 
Published: March 2009

SummaryThe mass balancing of robotic manipulators has been shown to have favorable effects on their dynamic characteristics. In actual practice, however, since conventional manipulators have flexibility at their joints, the improved dynamic properties obtainable for rigid manipulators may be influenced by those joints flexibilities. This paper investigates the effects of the joints flexibility on the dynamic properties and the controlled performance of a balanced robotic manipulator. The natural frequency distribution and damping characteristics were investigated through frequency response analyses. To evaluate the dynamic performance a series of simulation studies of the open-loop dynamics were made for various trajectories, operating velocities, and joint stiffnesses. These simulations were also carried out for the balanced manipulator with a PD controller situated inside the motor control loop. The results show that, at low speed, the joints flexibility does but little influence the performance of the balanced manipulator, but at high speed it tends to render the balanced manipulator susceptible to vibratory motion and yields large joints deformation errors.
Hermies-III: A step toward autonomous mobility, manipulation and perception
Authors: Weisbin C. R. , Burks B. L. , Einstein J. R. , Feezell R. R. , Manges W. W. , Thompson D. H. 
Published: March 2009

SUMMARYHERMIES-III is an autonomous robot comprised of a seven degree-of-freedom (DOF) manipulator designed for human scale tasks, a laser range finder, a sonar array, an omnidirectional wheel-driven chassis, multiple cameras, and a dual computer system containing a 16-node hypercube expandable to 128 nodes. The current experimental program involves performance of human-scale tasks (e.g., valve manipulation, use of tools), integration of a dexterous manipulator and platform motion in geometrically complex environments, and effective use of multiple cooperating robots (HERMIES-IIB and HERMIES-III). The environment in which the robots operate has been designed to include multiple valves, pipes, meters, obstacles on the floor, valves occluded from view, and multiple paths of differing navigation complexity. The ongoing research program supports the development of autonomous capability for HERMIES-IIB and III to perform complex navigation and manipulation under time constraints, while dealing with imprecise sensory information.
Closed loop trajectory control of walking machines
Authors: Gardner J. F. , Srinivasan K. , Waldron K. J. 
Published: March 2009

SUMMARYThe global trajectory control of walking machines is addressed here with particular attention paid to the consequences of actuator redundancy for control and to the inclusion of actuator dynamics in trajectory controller design. Redundancy of actuation, typical of walking machines, results in the trajectory control problem being formulated perforce in a global coordinate frame, instead of the joint space, as in nonredundant manipulators. This lack of one-to-one correspondence between the degrees of freedom of motion in the global coordinate frame and the actuators results in coupling between the different trajectory control loops. A mechanism for reducing this coupling effect is proposed here, along with a procedure to take into account approximately the effect of actuator dynamics in designing the trajectory controllers. The proposed methods are evaluated by simulation for an example problem in legged locomotion and are shown to be effective.
Formulation of manipulator Jacobian using the velocity similarity principle
Authors: Gupta K. C. , Ma R. 
Published: March 2009

SUMMARYVelocity similarity principle V(θ.,ṡ, ub, Qb) = DabV (θ.,ṡ, ua, Qa)Dab–1is presented and used to derive several useful forms of the Jacobian matrix for the manipulator from its basic kinematic equations in 4 X 4 matrix form. The zero reference position representation is used and, therefore, the base system is the only coordinate system utilized in the derivations. For manipulators with a spherical wrist, a modified form of the Jacobian is presented in which the Jacobian columns corresponding to the regional structure are completely decoupled from those corresponding to the wrist structure.
Derivation of optimal walking motions for a bipedal walking robot
Authors: Channon P. H. , Hopkins S. H. , Pham D. T. 
Published: March 2009

SUMMARYThe problem of determining energy optimal walking motions for a bipedal walking robot is considered. A full dynamic model of a planar seven-link biped with feet is derived including the effects of impact of the feet with the ground. Motions of the hip and feet during a regular step are then modelled by 3rd order polynomials, the coefficients of which are obtained by numerically minimising an energy cost function. Results are given in the form of walking profiles and energy curves for the specific cases of motion over level ground, motion up and down an incline, and varying payload.
DELTA: a simple and efficient parallel robot
Authors: Pierrot F. , Reynaud C. , Fournier A. 
Published: March 2009

SummaryThe DELTA parallel robot, designed by an EPFL (Ecole Polytechnique Fédérale de Lausanne) research team, is a mechanical structure which has the advantage of parallel robots and ease of serial robots modeling. This paper presents solutions for a complete modeling of the DELTA parallel robot (direct and inverse kinematics, inverse statics, inverse dynamics), with few arithmetic and trigonometric operations. Our method is based on a satisfactory choice of kinematic parameters and on a few restricting hypotheses for the static and dynamic models. We give some details of each model, we present some computation results and we put the emphasis on some particular points, showing the capabilities of this mechanical structure.
Payload capacity of balanced robotic manipulators
Authors: Lim T. G. , Cho H. S. , Chung W. K. 
Published: March 2009

SummaryThe payload capacity of a conventional robot is usually limited as compared to the mass of the robot body. This is because a payload adds additional gravity loadings to the robot joints resulting in large input joint torques. To reduce the required input joint torques, the authors have proposed a mechanical balancing mechanism. Basically, the mechanism was designed to exactly balance the first three links of an articulated robot by adjusting the positions of counter-balancing masses so as to eliminate the gravity loading terms. Since the input joint torques are greatly reduced by adopting balancing mechanisms, a balanced robot is expected to carry heavier payload and move with higher speed and acceleration. This paper further investigates the possibilities of improving the payload capacity as well as speed and acceleration capabilities. These features were investigated under various operating conditions involving payload, maximum angular velocity, and acceleration period. Based upon the simulation results, the performances of the balanced robot are compared in detail with those of a unbalanced conventional robot.
An approach to the modeling of the highest control level of flexible manufacturing cell
Authors: Jocković M. , Vukobratović M. , Ognjanović Z. 
Published: March 2009

SummaryThe paper considers the highest control level organization of a flexible manufacturing cell (FMS). The indeterminancy problem in Petri nets is discussed as well as a method for overcoming it by two control levels. The net is decomposed into individual robot nets and machines. A simple language for defining robot activation conditions is developed and used for defining knowledge base contents. A method for linking it with other control modules is given. Also, the solution performance is analysed.
Trajectory planning of redundant robots by maximizing the moving acceleration radius
Authors: Kim Ki-Kap , Yoon Yong-San 
Published: March 2009

SUMMARYThe moving acceleration radius (MAR) is proposed as a local performance index quantifying the dynamic uniformity of a redundant robot. MAR can be calculated by a simple sequential algorithm, and the resolution of the redundant joint angles is obtained by maximizing MAR locally. In addition, the reduction of the joint torques is achieved by maximizing the acceleration bound in the direction of work path, while MAR is being kept at a maximum. Also a new differentiation algorithm for angular acceleration is suggested for numerical efficiency as well as accuracy, using a null space operator.A three degrees of freedom planar robot with one degree of redundancy, simulated using these algorithms for various situations, showed a marked improvement in dynamic characteristics.
A Real-time Algorithm for Obstacle Avoidance of Autonomous Mobile Robots
Authors: Han-Pang Huang , Pei-Chien Lee 
Published: March 2009

SUMMARYA real-time obstacle avoidance algorithm is proposed for autonomous mobile robots. The algorithm is sensor-based and consists of a H-mode and T-mode. The algorithm can deal with a complicated obstacle environment, such as multiple concave and convex obstacles. It will be shown that the algorithm is more efficient and more robust than other sensor-based algorithms. In addition, the algorithm will guarantee a solution for the obstacle avoidance problem. Since the algorithm only takes up a small computational time, it can be implemented in real time.
Application-oriented robotic vision – a review
Authors: Jarvis R. A. 
Published: March 2009

SUMMARYComputer Vision is essentially concerned with emulating the process of seeing, naturally manifested in various higher biological systems,1–4 on a computational apparatus, and is consequently part of the Artificial Intelligence field within the sub-category of Machine perception. Seeing has to do with making sense of image data acquired through an optical system and subsequently dealt with at increasing levels of abstraction and association with known facts about the world. The spectrum of interest in Computer Vision ranges from attempting to answer basic questions concerning the functionality of biological vision systems, particularly human, at one end, all the way to enhancing the reliability, speed and cost effectiveness of specific industrial operations, particularly component inspection and vision driven robotic manipulation. The main bulk of interest is in the middle, where the quest for generality pushes interest towards biological vision systems with their demonstrated effectiveness in a wide range of environments, some hostile, whilst the need for economic viability and timeliness in relation to particular application pushes interest towards finding workable algorithms which function reliably at high speed on affordable apparatus.This paper is addressed, in somewhat tutorial style, at clarifying, by examples of work in the area, the issues surrounding application oriented robotic vision systems, their assumptions, strengths, weaknesses and degree of generality, and at the same time putting them in the context of the overall field of Computer Vision. In addition, the paper points to directions of development which promise to provide powerful industrial vision tools at an acceptable price.
Special computer architectures for image analysis
Authors: Fu K. S. 
Published: March 2009

SUMMARYWith the recent advances of VLSI technology, it has become possible to realize parallel architectures for image processing which are more efficient than the customary sequential processors. The paper discusses general architectural requirements for parallel processing and then the existing systems architectures. This is followed by a description of VLSI devices for image processing in three examples. The paper emphasizes VLSI architectures for image feature extraction, classification and structure (syntax) analysis.
Automated assembly by reference measurement
Authors: Francois C. , Artigue F. 
Published: March 2009

SUMMARYThis paper describes an automatic assembly method by reference searching followed by workpiece repositioning. In such a case, the adjustment of the piece to be assembled to its relative location is obtained before the final insertion phase.The efficiency of the method is shown in the case of the automatic fitting of a car suspension triangle. The main elements of the prototype designed for this task are described and their principles are developed. Considerations regarding less specific devices lead to a possible improvement of the flexibility of the assembly method.
Inference of Automata by dialectic learning
Authors: Richetin M. , Naranjo M. 
Published: March 2009

SUMMARYAn algorithm for the inference of the external behaviour model of an automaton is given. It uses a sequential learning procedure based on induction-contradiction-correction concepts. The induction is a generalization of relationships between automaton state properties, and the correction consists in a more and more accurate discrimination of the automaton state properties. These properties are defined from the input/output contradictory sequences which are discovered after the observed contradictions between successive predictions and observations.
International cooperation and trends in the field of industrial robots
Authors: Yonemoto Kanji 
Published: March 2009

SUMMARYAfter discussing the advent of the Age of Automation, the author considers the number of robots in operation throughout the world and the forecasts of their manufacture for each country. Attention is then drawn to the international exchange of research and technological information, in particular to the frequent symposia on industrial robots (ISIR). In addition to ISIR, international conferences on advanced robotics are also envisaged (ICAR). Finally, some details are given of international cooperation in the realm of industrial research.
Robot vision as a problem of picture analysis optimization
Authors: Bereznaya I. Y. , Granovskaya R. M. 
Published: March 2009

SUMMARYSome principles of information processing in the right and left cerebral hemispheres are used to construct effective algorithms for the recognition of handwritten characters and for processing complex grey-level pictures, viz, photographs of human faces. These algorithms reduce to a considerable extent the exhaustive search for pixels being analysed. A quantitative estimate of the thus obtained gain is given.
A method for the generation and recording of industrial robots continuous trajectories
Authors: Couderc Robert , Fannechère Georges , Poiraudeau Jean-François , Roux Serge 
Published: March 2009

SUMMARYThe need to store the trajectory information required by industrial robots, so that they may carry out tasks such as painting, has led to various data compression methods. The method proposed, simple to implement and adaptable to low cost systems, enables a best compromise to be reached for a given application between the detailed description of a complex movement and the use of as little memory as possible. This method was first used on a hydraulic prototype for the French Master-Slave firm PHAREMME.
Extended kinematic path control of robot arms
Authors: Krustev Evgeny , Lilov Ljubomir 
Published: March 2009

SUMMARYPath planning a robot arm motion essentially requires that the constraints of the joint variables and the vector of the joint motion rates are taken into account. In order to satisfy the constraints of the joint variables a sliding mode is being employed together with the developed kinematic path control method. The extended form of the kinematic path control method, here proposed, treats simultaneously the constraints of the joint variables and the vector of joint motion rates in path planning a robot arm motion.
Dynamics of redundant robots – inverse solutions
Authors: Huston Ronald L. , King Timothy P. 
Published: March 2009

SUMMARYThe dynamics of “simple, redundant robots” are developed. A “redundant” robot is a robot whose degrees of freedom are greater than those needed to perform a given kinetmatic task. A “simple” robot is a robot with all joints being revolute joints with axes perpendicular or parallel to the arm segments. A general formulation, and a solution algorithm, for the “inverse kinematics problem” for such systems, is presented. The solution is obtained using orthogonal complement arrays which in turn are obtained from a “zero-eigenvalues” algorithm. The paper concludes with an assertion that this solution, called the “natural dynamics solution,” is optimal in that it requires the least energy to drive the robot.
Time-optimal Trajectories for Robot Manipulators
Authors: Dissanayake M. W. M. G. , Goh C. J. , Phan-Thien N. 
Published: March 2009

SUMMARYA computational technique for obtaining minimum-time trajectories for robot manipulators is described in this paper. In the analysis, limitations to link movements due to design constraints are taken into consideration. Numerical examples based on a two-link planar robot arm shows the feasibility of the technique proposed. A physical explanation for the general characteristics of the observed trajectories is also presented. The importance of appreciating optimal control issues in designing robot manipulators and in planning robot workstation layouts is emphasised.
Constrained Motion Control of Manipulation Robots – A Contribution
Authors: Stokić Dragan M. 
Published: March 2009

SUMMARYThe problems concerning the control of constrained motion of manipulation robots are discussed in the paper. Two general problems of hybrid position/force control are considered: the problem of interaction between position and force control and the problem of contact between a robot and an environment. Some promising solutions to these problems are identified. It is shown that adaptive control is necessary to solve these problems. A new control scheme is proposed and results of computer simulations are presented
Task-Driven Extraction of Object Contour by Human Haptics: Part 2
Authors: Lederman Susan J. , Klatzky Roberta L. , Balakrishnan J. D. 
Published: March 2009

SUMMARYThe extraction of contour information from subjects is essential for purposes of grasping and manipulation. We proposed that human haptic exploration of contours, in the absence of vision, would reveal specialized patterns, or “contour exploration procedures,” that are directly related to task goals and intrinsic system capacities. Our general assumptions, method, and initial results were described in Part 1. Part 2 provides an analysis of the relation between contour extraction procedures and processing constraints. These theoretical assumptions are supported by empirical findings, and implications are discussed for issues of importance to robotic exploration and manipulation.