bluuebunny/crossref_metadata_2025 huggingface dataset:
Force Control Command Synthesis for Constrained Hybrid Dynamic Systems with Friction
Authors: Austin David J. , McCarragher Brenan J.
Published: July 2003

A new hybrid dynamic controller synthesis methodology for the successful convergence of force-controlled assembly tasks with friction is presented. Hybrid dynamic modeling has been shown to be a very effective strategy to incorporate both the continuous-time and discrete-event natures of an assembly task. Previously, hybrid dynamic controllers have used velocity control. This paper develops a hybrid dynamic controller that uses force control, the accepted paradigm for constrained motion systems such as assembly tasks. Frictional forces present a significant problem for force control and cannot be neglected in the development of a controller. Constraints on the control command are developed for each type of single-contact transition, and then further constraints are developed to ensure that superposition can be used for multicontact situations. Experimental results are presented for the new controller synthesis method performing an assembly task with a 0.8 mm tolerance and requiring four degrees of freedom for completion. These experiments demonstrate the effectiveness of the combination of hybrid dynamic control and force control for assembly tasks, successfully completing the assembly with positioning errors of up to 50 mm and orientation errors of up to 10 degrees.
Force Tracking Impedance Control for Robot Manipulators with an Unknown Environment: Theory, Simulation, and Experiment
Authors: Jung Seul , Hsia T. C. , Bonitz R. G.
Published: July 2003

In impedance control for force tracking, it is well known that the reference trajectory of the robot is calculated from known environmental stiffness. The authors present a simple technique for determining the reference trajectory under the condition that the environment is unknown. The technique is developed based on the replacement of the unknown stiffness with a function of the measured force. Combining this technique with the impedance function yields the force tracking impedance function. Robot dynamic uncertainties are assumed to be compensated by a robust position control method based on time-delayed control. The local stability at equilibrium points is analyzed with respect to uncertainty in environmental position. Computer simulation studies demonstrate that force tracking using the proposed technique is excellent for unknown environment and dynamics uncertainty. The practicality of the technique is also verified experimentally using a PUMA 560 manipulator.
Distributed Coordination in Modular Precision Assembly Systems
Authors: Rizzi Alfred A. , Gowdy Jay , Hollis Ralph L.
Published: July 2003

A promising approach to enabling the rapid deployment and reconfiguration of automated assembly systems is to make use of cooperating, modular, robust robotic agents. Over the past 5 years, the authors have been constructing just such a system suitable for assembly of high-precision, high-value products. Within this environment, each robotic agent executes its own program, coordinating its activity with that of its peers to produce globally cooperative precision behavior. To simplify the problems associated with deploying such systems, each agent adheres to a strict notion of modularity, both physically and computationally. The intent is to provide an architecture within which it is straightforward to specify strategies for the robust execution of potentially complex and fragile cooperative behaviors. The underlying behaviors use a runtime environment that includes tools to automatically sequence the activities of an agent. Taken together, these abstractions enable a designer to rapidly and effectively describe the high-level behavior of a collection of agents while relying on a set of formally correct control strategies to properly execute and sequence the necessary continuous behaviors.
The Acceleration Vector of a Rigid Body
Authors: Featherstone Roy
Published: July 2003

This paper explains the relationship between two existing representations of rigid-body acceleration in a 6-D vector: conventional acceleration, which is the concatenation of two 3-D acceleration vectors, and spatial acceleration, which is the time derivative of a 6-D velocity vector. The two are materially different and obey different composition rules. In particular, spatial accelerations behave like true vectors, and conventional accelerations do not. This paper shows that the conventional acceleration of a rigid body is its apparent spatial acceleration in a moving coordinate system. This implies that both vectors describe the same physical phenomenon but in different coordinate systems. It also implies that rigid-body acceleration really is a vector. The paper concludes with some examples showing how 6-D accelerations are used.
Application of Motion-Based Visual Servoing to Target Tracking
Authors: Crétual Armel , Chaumette François
Published: July 2003

In this paper, the classical task of mobile target tracking using a pan-and-tilt camera is considered. The authors use recent results in motion-based visual servoing to deal with complex targets for which shape and texture are unknown. The first method consists of designing a control law directly from the estimated image motion. This leads to the computation of the pan-and-tilt acceleration necessary to reduce the tracking error. A second method, more efficient for target tracking, consists of retrieving the target position in the image from its estimated motion. This leads to classical image-based visual servoing. For both methods, experimental results obtained at video rate are presented and discussed.
Torso Force Feedback Realistically Simulates Slope on Treadmill-Style Locomotion Interfaces
Authors: Hollerbach John M. , Mills Rose , Tristano David , Christensen Robert R. , Thompson William B. , Xu Yangming
Published: July 2003

This paper investigates whether torso force feedback on treadmillstyle locomotion interfaces can substitute for treadmill tilt to simulate walking on smooth inclines. The experimental platform is the Sarcos Treadport, whose active mechanical tether can apply horizontal forces to the user to simulate the gravity forces experienced in slope walking. The authors show that users are extremely sensitive to slope while walking, being able to discriminate a 0.5 degree slope change. Comparisons are then made between walking on a tilted treadmill platform versus walking on a level platform but with tether force application. Psychophysical experiments show that users select tether forces that are predicted by the gravity forces, although at a 65% fractional force level. These results demonstrate definitively that torso force feedback can realistically simulate gravity forces during smooth slope walking.
Suboptimal Multiple Model Filter for Mobile Robot Localization
Authors: Oussalah Mourad
Published: July 2003

The problem of mobile robot localization by using sensor information appeals to different communities since the need for accurate position has become crucial for many robot subtasks. The Kalman filter (KF) has been acknowledged as an appropriate tool for a suitable dynamic combination of the different measurements using the state and measurement models. However, when there are discrete uncertainties about the models, without additional restrictions, the performance of KF degrades drastically as the predicted estimate tends to be updated by a wrong measurement. This paper focuses on a suboptimal multiple model filter to deal with the associated measurement/model. Experimental and simulated results are achieved, which prove the feasibility of the proposal. The experimental setup consists of a structured environment constituted of elementary features such as walls and corners, while a possibly unmodeled obstacle may be encountered. The robot is equipped with odometry and a set of ultrasonic sensors.
Robust Mapping and Localization in Indoor Environments Using Sonar Data
Authors: Tardós Juan D. , Neira José , Newman Paul M. , Leonard John J.
Published: July 2003

In this paper we describe a new technique for the creation of feature-based stochastic maps using standard Polaroid sonar sensors. The fundamental contributions of our proposal are: (1) a perceptual grouping process that permits the robust identification and localization of environmental features, such as straight segments and corners, from the sparse and noisy sonar data; (2) a map joining technique that allows the system to build a sequence of independent limited-size stochastic maps and join them in a globally consistent way; (3) a robust mechanism to determine which features in a stochastic map correspond to the same environment feature, allowing the system to update the stochastic map accordingly, and perform tasks such as revisiting and loop closing. We demonstrate the practicality of this approach by building a geometric map of a medium size, real indoor environment, with several people moving around the robot. Maps built from laser data for the same experiment are provided for comparison.
Deformable Free-Space Tilings for Kinetic Collision Detection†
Authors: Agarwal Pankaj K. , Basch Julien , Guibas Leonidas J. , Hershberger John , Li Zhang
Published: July 2003

We present kinetic data structures for detecting collisions between a set of polygons that are moving continuously. Unlike classical collision detection methods that rely on bounding volume hierarchies, our method is based on deformable tilings of the free space surrounding the polygons. The basic shape of our tiles is that of a pseudo-triangle , a shape sufficiently flexible to allow extensive deformation, yet structured enough to make detection of self-collisions easy. We show different schemes for maintaining pseudo-triangulations as a kinetic data structure, and we analyze their performance. Specifically, we first describe an algorithm for maintaining a pseudo-triangulation of a point set, and show that the pseudo-triangulation changes only quadratically many times if points move along algebraic arcs of constant degree. In addition, by refining the pseudo-triangulation, we show triangulations of points that only change about O(n7 /3 ) times for linear motion. We then describe an algorithm for maintaining a pseudo-triangulation of a set of convex polygons. Finally, we extend our algorithm to the general case of maintaining a pseudo-triangulation of a set of moving or deforming simple polygons.
Model-based Feedforward Control in Industrial Robotics
Authors: Grotjahn Martin , Heimann Bodo
Published: July 2003

Simple linear joint controllers are still used in typical industrial robotic systems. The use of these controllers leads to non-negligible dynamic path deviations for applications that require high path accuracy. These deviations result from the strong influence of nonlinearities, such as multi-body dynamics and gear friction. Sophisticated nonlinear control algorithms, known from the literature, are still not used because they usually require an expensive change of the control architecture. Therefore, different compensation methods are compared in this paper which reduce the path deviations by correction of the desired trajectory. This means that no torque interface is required, only an interface for path corrections is necessary. Such an interface normally exists so that the methods can simply be implemented within standard industrial controls. Using the industrial robot Siemens manutec-r15 the methods are experimentally compared with respect to their efficiency and practical applicability. Starting from this, one method is chosen for application to the state-of-the-art industrial robot KUKA KR15 . The algorithm is based on a complete nonlinear dynamic model of the robot. It is integrated into the standard control KRC1. The experimental results prove the efficiency and the industrial applicability of the method.
Singularity Loci of a Special Class of Spherical Three-degree-of-freedom Parallel Mechanisms with Revolute Actuators
Authors: Gosselin Clément M. , Jing Wang
Published: July 2003

In this paper, we study the singularity loci of a special class of spherical three-degree-of-freedom parallel manipulators. The concise analytical expressions describing the singularity loci are obtained in the joint and in the Cartesian spaces by using the direct and inverse kinematic solutions of these manipulators, respectively. As mentioned elsewhere, there are three different types of singularities for parallel manipulators, each having a different physical interpretation. These types are considered and it is shown that, for the manipulators considered here, the three types of singularities coincide. Moreover, for the two types of manipulators studied here, there are only four singular configurations in the Cartesian space. In addition, the three-dimensional graphical representations of the singularity loci in the joint and in the Cartesian spaces are illustrated. The description of the singular configurations provided here has great significance for robot trajectory planning and control.
Bipedal Locomotion: Stopping and the Standing/Balance Gait
Authors: Reisinger Kim D. , Moskowitz Gordon D.
Published: July 2003

A bipedal locomotion system is synthesized to characterize some of the previously overlooked aspects of the locomotion process, specifically standing/balance and initiation and stopping. The locomotion system is described by a three-element three-dimensional model consisting of two lower limbs and an upper body. The system equations of motion are derived using variational methods, and are retained in their nonlinear form. The impulsive contact events of impact of the swing limb with the ground and transfer of support are incorporated into the model. Bipedal locomotion is synthesized through numerical simulations. Several control inputs are studied for establishing and sustaining the standing/balance gait. Subsequent motion is analyzed via phase-space portraits. It is shown that an impulsive torque is sufficient for establishing and controlling the standing/balance gait as well as steady locomotion.
Handling Sensing Failures in Autonomous Mobile Robots
Authors: Murphy Robin R. , Hershberger Dave
Published: July 2003

This article details the SFX-EH architecture for handling sensing failures in autonomous mobile robots. The SFX-EH uses novel extensions to the generate-and-test method to classify failures with only a partial causal model of the sensor/environment/task interactions for the robot. The generate-and-test methodology exploits the ability of the robot as a physically situated agent to actively test assumptions about the state of sensors, condition of the environment, and validity of task constraints. The SFX-EH uses the type of failure to determine the appropriate recovery strategy: reconfiguration of the logical sensor or logical behavior, recalibration of the sensor or actuator, and corrective actions. The system bypasses classification if all hypotheses lead to the same recovery strategy. Results of the SFX-EH running on two robots with different sensor suites and tasks are presented, demonstrating intelligent failure recovery within a modular, portable implementation.
Inverse Kinematic Solutions for a Fully Parallel Robot with Singularity Robustness
Authors: Perng Ming-Hwei , Hsiao Lin
Published: July 2003

In this paper, two inverse-kinematic solutions with singularity robustness for a fully parallel robot manipulator are proposed. First, two inverse-kinematic solution sare presented based on the damped least squares method, where the first solution (OSVC) is derived using a velocity constraint, and the other (OSFC) uses a force constraint. It can be shown that both solutions are special cases of a general damped least-squares method (GIKS). Next, under the assumption that direct position measurement is available, a feedback-correction term is introduced into the general damped least-squares method to eliminate positioning error in resolved-rate control. It can be shown that both solutions are stable with bounded errors, but each has its own relative merits and shortcomings. Illustrative examples are also given to show their effectiveness in practical applications.
Test Bed Robot Development for Cooperative Submunitions Clearance
Authors: Pook Polly K. , DeBolt Christopher K.
Published: July 2003

This paper describes the development of a team of small autonomous robots that are designed to clear a field of unexploded submunitions. The ultimate application goals are to remove the explosive ordnance disposal (EOD) technician from hazards associated with submunitions; to perform the mission efficiently, reliably, and inexpensively; and to record pertinent mission information, such as area searched and location of submunitions found. Four robots coordinate to search for, pick up, and safely deposit submunitions lying on the ground surface using a control strategy of supervised autonomy. A remote Pentium laptop that communicates with the robot team via wireless radio serves two purposes: (1) as an off-board processor to dispatch the robots effectively, track their performance, and record data for postprocessing and (2) as an operator control unit to permit an EOD technician to monitor the mission and intervene as necessary from a safe distance.
From Laboratory to Warehouse: Security Robots Meet the Real World
Authors: Everett H. R. , Gage Douglas W.
Published: July 2003

The Mobile Detection Assessment and Response System robotic security program has successfully demonstrated simultaneous control of multiple robots navigating autonomously within an operational warehouse environment. This real-world warehouse installation required adapting a navigational paradigm designed for highly structured environments such as office corridors (with smooth walls and regularly spaced doorways) to a semistructured warehouse environment (with no exposed walls and within which odd-shaped objects unpredictably move about from day to day). A number of challenges, some expected and others unexpected, were encountered during the transfer of the system first to a beta-test/demonstration site and then to an operational warehouse. This paper examines these problems (and others previously encountered) in a historical context of the evolution of navigation and other needed technologies, and the transition of these technologies from the research lab to an operational warehouse environment. A key lesson is that system robustness can only be ensured by exhaustively exercising the system’s operational capabilities in a number of diverse environments. This approach helps to uncover latent system hardware deficiencies and software implementation errors not manifested in the initial system hardware or initial development environment, and to identify sensor modes or processing algorithms tuned too tightly to the specific characteristics of the initial development environment.
The Defense Advanced Research Projects Agency (DARPA) Tactical Mobile Robotics Program
Authors: Krotkov Eric , Blitch John
Published: July 2003

Today’s regional military conflicts are increasingly likely to occur in populated urban areas, in, around, over, and under unknown buildings. This places land forces in dangerous and unpredictable situations, and in many instances the conflicts also threaten noncombatants. To address this need, the Defense Advanced Research Projects Agency (DARPA) Tactical Mobile Robotics program is researching and developing the capability to perform urban reconnaissance with teams of small, low-cost, semiautonomous mobile robots. Easily transportable by individuals, these robot teams will be capable of working together to perform a variety of reconnaissance functions. The program develops enabling technologies (machine perception, autonomous operation, and robotic locomotion) and integrates them into tactical systems for urban operations.
Mechanically Implementable Accommodation Matrices for Passive Force Control
Authors: Goswami Ambarish , Peshkin Michael
Published: July 2003

Robot force control implemented by means of passive mechanical devices has inherent advantages over active implementations with regard to stability, response rapidity, and physical robustness. The class of devices considered in this paper consists of a Stewart platform-type mechanism interconnected with a network of adjustable mechanical elements such as springs and dampers. The control law repertoire of such a device, imagined as a robot wrist, is given by the range of admittance matrices that it may be programmed to possess. This paper focuses on wrists incorporating damper networks for which the admittance matrices reduce to accommodation or inverse-damping matrices.

We show that a hydraulic network of fully adjustable damper elements may attain any diagonally dominant accommodation matrix. We describe the technique of selecting the individual damping coefficients to design a desired matrix. We identify the set of dominant matrices as a polyhedral convex cone in the space of matrix entries, and show that each dominant matrix can be composed of a positive linear combination of a fixed set of basis matrices.

The overall wrist-accommodation matrix is obtained by projecting the accommodation matrix of the damper network through the wrist kinematics. The linear combination of the dominant basis matrices projected through the wrist kinematics generates the entire space of mechanically implementable force-control laws. We quantify the versatility of mechanically implementable force-control laws by comparing this space to the space of all matrices.
A Divide-and-Conquer Articulated-Body Algorithm for Parallel O(log(n)) Calculation of Rigid-Body Dynamics. Part 2: Trees, Loops, and Accuracy
Authors: Featherstone Roy
Published: July 2003

This paper is the second in a two part series describing a recursive, divide and conquer algorithm for calculating the forward dynamics of a robot mechanism, or a general rigid body system, on a parallel computer. This paper presents the general version of the algorithm. The derivation begins with an algorithm for kinematic trees, which is then extended to closed loop systems. The general algorithm achieves O(log(n)) time complexity on O(n) processors for all kinematic trees and a large subset of closed loop systems.

This paper also presents a more accurate version of the algorithm and the results of some numerical accuracy tests that compare both versions with the standard articulated body algorithm. The tests use rigid body systems containing up to 1024 bodies, and they show that the divide and conquer algorithm is substantially less accurate than the best serial algorithm but still accurate enough to be useful.
Determination of 6D Workspaces of Gough-Type Parallel Manipulator and Comparison between Different Geometries
Authors: Merlet J -P.
Published: July 2003

We consider in this paper a Gough-type parallel robot whose leg length values are constrained to lie within some fixed ranges and for which there may be mechanical limits for the motion of the passive joints.

The purpose of this paper is to present algorithms to determine:

• the constant orientation workspace: all the possible locations of the center of the platform that can be reached with a fixed orientation

• thetotal orientation workspace: all the possible locations of the center of the platform that can be reached with any orientation in a set defined by three ranges for the orientation angles (the dextrous workspace is an example of total orientation workspace case, the three ranges being T [0,360] degree1)

• the inclusive orientationworkspace: all the possible locations of the center of the platform that can be reached with at least one orientation among a set defined by three ranges for the orientation angles (the maximal or reachableworkspace is an example of inclusive orientation workspace, the three ranges being [0,360])

Most of these algorithms are based on a basic method: approximation of the result by a set of 3D or 6D boxes obtained from an initial estimation through a bisection process. The boxes in the result will either fully or partially lie inside the workspace: the bisection stops as soon as all the boxes that do not lie fully inside the workspace have a size that is lower than a fixed threshold.

A companion algorithm enables to verification that any 6D workspace (i.e., a continuous set of poses) lies within the reachable workspace of the robot. The paper includes a comparison between the workspace volumes of four different robot geometries, which shows that for robots of similar dimensions the joints layout has a large influence on the workspace volume.
Stabilization of Lateral Motion in Passive Dynamic Walking
Authors: Kuo Arthur D.
Published: July 2003

Passive dynamic walking refers to a class of bipedal machines that are able to walk down a gentle slope with no external control or energy input. The legs swing naturally as pendula, and conservation of angular momentum governs the contact of the swing foot with the ground. Previous machines have been limited to planar motions. We extend the planar motions to allow for tilting side to side (roll motion). Passive walking cycles exist, but the roll motion is unstable, resembling that of an inverted pendulum. The instability is due to mismatching of roll velocity with the ground contact conditions. Several strategies are presented for stabilizing this motion, of which the quasi-static control of step width is determined to be both simple and efficient.
A Force Commanded Impedance Control for a Robot Finger with Uncertain Kinematics
Authors: Doulgeri Zoe , Arimoto Suguru
Published: July 2003

We consider the problem of impedance control for the physical interaction between the soft tip of a robot finger, where the nonlinear characteristics of the reproducing force and the finger dynamic parameters are unknown, and a rigid object or environment under kinematic uncertainties arising from both uncertain contact point location and uncertain rigid object geometry. An adaptive controller is proposed, and the asymptotic stability of the force regulation problem is shown for the planar case even when finger kinematics and rigid surface orientation are uncertain. Confirmation of the theoretical findings is done through simulation of a 3-degree-of-freedom planar robotic finger.
Robotics Research toward Explication of Everyday Physics
Authors: Arimoto Suguru
Published: July 2003

It is commonly recognized now at the end of the 20th century that a general 6- or 7-degree-of-freedom robot equipped with an endeffector with simple structure is clumsy in performing a variety of ordinary tasks that a human encounters in his or her everyday life. In this paper, it is claimed that the clumsiness manifests the lack of our knowledge of everyday physics. It is then shown that even dynamics of a set of dual fingers grasping and manipulating a rigid object are not yet formulated when the fingers’ ends are covered by soft and deformable material. By illustrating this typical problem of everyday physics, it is pointed out that explication of everyday physics in computational (or mathematical) languages is inevitable for consideration of how to endow a robot with dexterity and versatility. Once kinematics and dynamics involved in such everyday tasks are described, it is then possible to discover a simple but fine control structure without the need of much computation of kinematics and dynamics. Simplicity of the control structure implies robustness against parameter uncertainties, which eventually allows the control to perform tasks with dexterity and versatility by using visual or tactile sensing feedback. Thus, a key to uncover the hidden secret of dexterity is to characterize complicated dynamics of such a robotic task as seen when a set of multifingers with multijoints covered by deformable material interacts physically with objects or an environment. It is pointed out throughout the paper that some of the generic characteristics of dynamics that everyday physics encounters must be “passivity,” “approximate Jacobian matrix of coordinates transformation,” “feedback loops from sensation to action,” “impedance matching,” and “static friction.”
Advances in Robotics: The DLR Experience
Authors: Hirzinger Gerd , Fischer Max , Brunner Bernhard , Koeppe Ralf , Otter Martin , Grebenstein Markus , Schäfer Ingo
Published: July 2003

Key items in the development of a new smart robot generation are explained in light of DLR’s recent activities in robotics research. These items are the design of articulated hands, ultra-lightweight links, and joint drive systems with integrated joint torque control, sensory feedback including real-time 3-D vision, learning and skill-transfer, modeling the environment using sensorfusion, and new sensor-based off-line programming techniques based on teaching by showing in a virtual environment.
Motion Planning: A Journey of Robots, Molecules, Digital Actors, and Other Artifacts
Authors: Latombe Jean-Claude
Published: July 2003

During the past three decades, motion planning has emerged as a crucial and productive research area in robotics. In the mid-1980s, the most advanced planners were barely able to compute collision-free paths for objects crawling in planar workspaces. Today, planners efficiently deal with robots with many degrees of freedom in complex environments. Techniques also exist to generate quasioptimal trajectories, coordinate multiple robots, deal with dynamic and kinematic constraints, and handle dynamic environments. This paper describes some of these achievements, presents new problems that have recently emerged, discusses applications likely to motivate future research, and finally gives expectations for the coming years. It stresses the fact that nonrobotics applications (e.g., graphic animation, surgical planning, computational biology) are growing in importance and are likely to shape future motion-planning research more than robotics itself.
Estimating First-Order Geometric Parameters and Monitoring Contact Transitions during Force-Controlled Compliant Motion
Authors: de Schutter Joris , Bruyninckx Herman , Dutré Stefan , de Geeter Jan , Katupitiya Jayantha , Demey Sabine , Lefebvre Tine
Published: July 2003

This paper uses (linearized) Kalman filters to estimate first-order geometric parameters (i.e., orientation of contact normals and location of contact points) that occur in force-controlled compliant motions. The time variance of these parameters is also estimated. In addition, transitions between contact situations can be monitored. The contact between the manipulated object and its environment is general, i.e., multiple contacts can occur at the same time, and both the topology and the geometry of each single contact are arbitrary.

The two major theoretical contributions are 1) the integration of the general contact model, developed previously by the authors, into a state-space form suitable for recursive processing; and 2) the use of the reciprocity constraint between ideal contact forces and motion freedoms as the “measurement equation” of the Kalman filter. The theory is illustrated by full 3-D experiments.

The approach of this paper allows a breakthrough in the state of the art dominated by the classical, orthogonal contact models of Mason that can only cope with a limited (albeit important) subset of all possible contact situations.
Robot Visor Research: Past and Future Roles
Authors: Shirai Yoshiaki
Published: July 2003

This paper describes what I have done and learned in robot-vision research, and speculates what is necessary and promising in the future. In early artificial intelligence research, it was proved in the context of recognition of polyhedra that a hierarchical method in which a higher process assumes an ideal output of lower processes has limitations. A similar approach has been effective for vision processes that use the result of color segmentation, stereo vision, optical flow, or correspondence between multiple images. It is often more effective for recognition of difficult scenes to increase available input data than to try to make a clever procedure. There was an attempt to approach more flexible vision systems like human vision, which include reliable stereo vision and integration of multiple visual cues. Now a tightly coupled perception-action paradigm is an important issue, where significant research themes are person tracking and recognition, flexible real-time vision processors, and planning of perception-action considering the planning cost.
Criminal Psychological Profiling of Serial Arson Crimes
Authors: Kocsis Richard N. , Cooksey Ray W.
Published: July 2003

The practice of criminal psychological profiling is frequently cited as being applicable to serial arson crimes. Despite this claim, there does not appear to be any empirical research that examines serial arson offence behaviors in the context of profiling. This study seeks to develop an empirical model of serial arsonist behaviors that can be systematically associated with probable offender characteristics. Analysis has produced a model of offence behaviors that identify four discrete behavior patterns, all of which share a constellation of common nondiscriminatory behaviors. The inherent behavioral themes of each of these patterns are explored with discussion of their broader implications for our understanding of serial arson and directions for future research.
Diagnosing Sexual Sadism in Sexual Offenders: Reliability across Diagnosticians
Authors: Marshall W. L. , Kennedy Pamela , Yates Pamela , Serran Geris
Published: July 2003

On the basis of detailed accounts of offences committed by 12 dangerous sexual offenders and of descriptions of their life histories, their responses to various tests, self-reports of offenders’sexual interests and activities, and results of phallometric evaluations, 15 expert forensic psychiatrists diagnosed whether each offender met the criteria for sexual sadism. The psychiatrists also indicated their confidence in the diagnoses they made and rated the relevance to the diagnosis of sexual sadism for various features of the offence and the offender. Results revealed unsatisfactory levels of diagnostic agreement among the psychiatrists. On the other hand, they agreed quite well on the importance for the diagnosis of several of the offence features described. Suggestions are offered for clinical practice.
Alcohol and Drug Use among Rural and Urban Incarcerated Substance Abusers
Authors: Leukefeld Carl G. , Narevic Egle , Hiller Matthew L. , Staton Michele , Logan T. K. , Gillespie Wayne , Webster J. Matthew , Garrity Thomas F. , Purvis Rick
Published: July 2003

A number of prisoners use drugs. Limited information is available about the extent to which urban and urban substance abusers differ in their drug use in criminal justice settings. In addition, many believe that rural areas are protected from drug use. However, findings from this study show only marginally statistical significant differences in drug use between incarcerated rural and urban drug users. It was expected that urban drug users would be more drug career involved with consistently higher levels of drug use and associated problems. Specifically, rural drug users in this study were older at age of first use of marijuana and cocaine; report fewer years of cocaine, hallucinogen, and heroin use; and report more alcohol and sedative use. Findings from this study suggest that rural and urban drug users are similar and that rural areas may be protective from some drug use but risky for other drug use.
Does the Group Conductor Make a Difference? Communication Patterns in Group-Analytically and Cognitive-Behaviourally Oriented Therapy Groups
Authors: Sandahl Christer , Lindgren Annika , Herlitz Kristina
Published: July 2003

This article focuses on a research study analysing communication patterns in groups and how the group conductor may influence these. Videotapes from five group-analytically oriented and five cognitive-behaviourally oriented time-limited group therapies with moderately alcohol-dependent patients were analysed by means of the System for Analysing Verbal Interaction (SAVI). The most striking finding was the similarities in communication patterns in the groups and between the therapists. There were, however; also some significant differences. More empathic verbal acts were expressed in the group analytically oriented groups, while there were more verbal signs of competition in the cognitive behavioral groups. The group analytically oriented therapists were actively influencing the process in the beginning of therapy. The other therapists were more stable in their communication pattern during the whole therapy. It seemed that the therapists influenced the communication pattern during the initial and middle phases of therapy, but that the group as whole determined the communication pattern during the later phases of therapy.
The Self-Relatedness Construct: Empirical Verification via Observation in the Context of Inpatient Group Therapy
Authors: Seidler Gunter H.
Published: July 2003

The article outlines the empirical verification of a self-relatedness construct theoretically elaborated elsewhere for its suitability as a way of describing changes achieved in the framework of inpatient psychotherapy. The study centres on two hypotheses: (1) during inpatient therapy lasting 12 weeks, patients display identifiable changes in the form of an increase in self-referentiality; (2) an increase in self-referentiality correlates with a decrease in symptomatology. The study was conducted in a practice-near design involving 76 patients in the framework of a multi-level approach. The article presents the findings gained with newly devised instruments for the identification of features of (a) self-relatedness and (b) of symptomatology and the experience of illness. First, it was again possible to show that these instruments satisfy various quality criteria. Of the two hypotheses, the first may safely be said to stand confirmed. Assessment of the second hypothesis calls for a differentiation regarding the increase of self-referentiality and symptom change in that this increase differs according to symptom area: whereas the increase of self-referentiality is bound up with a reduction of somatic and social symptoms, there is no demonstrable connection of this kind with regard to psychic symptoms, although the individual scales also show a reduction. The findings are interpreted with all due caution as indicating that the new instruments may have touched on, or indeed identified, a `capacity for symbolization `factor underlying both structure formation and symptomatology.
24th S.H. Foulkes Annual Lecture
Authors: deMendelssohn Felix
Published: July 2003

Group analytic work serves as a prism through which the aesthetic dimensions of political life can be differentiated and appreciated as forming a complex creative human activity akin to art, science and psychoanalysis itself. The perspective on the unconscious processes permits a fuller view of what politics is about, as a medium for creating a world of relationships. The increasing experience of transcultural small and large group settings reflects and focuses this development. Group analytic process allows us glimpses of the inherent beauty and the concomitant violence of political activity as the expression of a basic `aesthetic conflict' (D. Meltzer).
The Compound I: The Group Self and the Poetic Self
Authors: Maher Michael
Published: July 2003

This article starts with a consideration of `The Poetic Self' (1992), an essay written by Ted Hughes as a centenary tribute to TS. Eliot. In this Hughes argues that the voice of poetry from ancient times came from contact with higher, external creative powers, and it was this connection with sacred meaning that gave poetry its power He also proposes the idea that this is something that has changed, that the poetic self underwent a mutation, dated around the early years of this century, and the work of Freud had a significant part in this change; in fact, that human consciousness itself had mutated, and Freud was part instigator; part secretary to the change. From a metaphysical universe centred on God we moved to a new kind of reality, without the consolation and the persecutions of the supernatural world, but with a new terror, that of meaninglessness. (By `we' in this context I take Hughes to mean something like the dominant perception of the age, the sense by which the majority of people within a culture make sense of their experience of living.) It is Hughes's argument that the previously sacralized outer landscape was translated by Freud into an interior landscape in which new ways of discovering meaning could be found, but that this was an incomplete translation which left an emptiness, a void, which has been in itself the distinctive tone and central preoccupation of Modernism, and the centre of the tradition since then. In this article I will attempt to consider these arguments, and take the discussion on from that point into a consideration of what group analysis can offer from this perspective. This will take me to a consideration of what connections there might be between this idea of the poetic self, in its mutated and pre-mutated forms, and the concept of the group self, in order to see if there is an area of connectedness between the two that might be one of mutual enrichening.
A Psychotherapy Group as a Sociopolitical Context: The Case of the `Silent Majority'
Authors: Ettin Mark
Published: July 2003

Group psychotherapy can be conceived as a sociopolitical context, wherein participants (as citizens) struggle to balance personal needs and rights against the collective requirements of the group to which they belong. Potential conflicts arise between: (1) a member's right to privacy and the group's need to know about its members; and (2) the will of the majority and the protection of the minority. Psychotherapeutic groups also face constituency problems that arise from inequality of opportunity, skills or feelings of self-worth that affect what members give and get. This article explores the relationship between individual and group needs, membership and leadership, and the evolution of an enabling group culture in the case of the `silent majority'.
`Proper Time' in the Matrix
Authors: Bradbury Sue
Published: July 2003

Assuming twice weekly and block group analysis have the same outcome within different time frames, this article examines what makes this possible. Using the metaphorical concept of `proper time' I propose that our understanding must be that this is a property of the group matrix and the unconscious. Whilst using the general theory of relativity, this article draws on physical measurements of time and the concept of time-space to describe `proper time' as a concept without numbers.
Notes on the Technique of Psychoanalytic Infant Observation: A Group-Analytic Training Perspective
Authors: Winship Gary
Published: July 2003

Recent developments in the field of psychoanalytic infant observation are considered as a basis for extending the dyadic focus of the technique to encompass a group orientated perspective. A provisional method of `group-as-a-whole infant observation' is presented using illustrative material and is accompanied by a contextualizing analysis. It is posited that group observation of infants and children may highlight group dynamics in unrefined forms and may therefore be a useful resource not only in the training of group practitioners but also as a way of deepening group and social theory.
Chaos and Desire: The Simple Truth of the Unconscious in the Psychoanalytic Group
Authors: Giraldo Macario
Published: July 2003

Beginning with metaphorical comparison to a barber's shop, where patients in group-analytic psychotherapy may be `customers' or `the barber', this article explores the changing group dynamics where two small groups are merged to make one larger group. Some aspects of work with the unconscious in the psychoanalytic group are highlighted, documenting those aspects which changed in the course of the merger and with references to some of the concepts of Jacques Lacan and his view of the function of analysis.
Henry Ezriel - A Personal Account
Authors: (Bill) Blomfield O. H.D.
Published: July 2003

Presented to a Meeting of Supervisors, Australian Association of Group Psychotherapists (Victorian Branch) Melbourne, 1 May 2000.
Silence and the Use of Objects Brought to the Session as a Resistance in a Group with Adolescents
Authors: Ghirardelli Roberto
Published: July 2003

Containment and waiting are the instruments needed by the conductor of a teenager group. It is in fact necessary to make room for silences, strange objects and non-verbal language: these should not always be interpreted as provocations, but rather as transitional objects.
Towards a Group-Analytic Approach to Individual Psychotherapy
Authors: Nitsun Morris
Published: July 2003

Is there a distinctive group-analytic approach to individual psychotherapy? In seeking an answer to this question, the social context of psychotherapy is examined and the need for a psychotherapy of connectedness proposed. The group frame that group analysts inherently adopt in their psychotherapeutic work is seen as a valid basis for such an enterprise. A recasting of the therapeutic relationship and the transference-countertransference configuration in individual psychotherapy in line with this aim is proposed, in a way that draws on contemporary relational theories, including self psychology and the intersubjective school. It is likely that much of this is implicit in the way group analysts work with individuals. The challenge is to develop this as an explicit medium of individual therapy.
Working Intersubjectively: What Does it Mean for Theory and Therapy?
Authors: Weegmann Martin
Published: July 2003

This article describes some exciting developments in self psychology and intersubjectivity theory, particularly the work of Robert Stolorow. This is contrasted with classical psychoanalysis and some implications for group analysis are explored.
Group-Analytic Training Conducted through a Language Interpreter: Are We Understanding Each Other?
Authors: Kennard David , Roberts Jeff , Elliott Barbara
Published: July 2003

In 1995 the authors ran an Introductory Course in Group Analysis in St Petersburg, using language interpreters in the small experiential groups. The effectiveness of simultaneous translation was evaluated using daily rating scales completed by trainees, conductors and interpreters, examples of mistranslations and audiotapes of sessions. The evidence obtained suggests that a high level of mutual understanding is possible. The most comnmon difficulties concern the omission of potentiallv significant material during rapid exchanges, and gaps and misunderstandings of cultural significance. The work is hard and stressful for interpreters. Our experience suggests some guidelines to maximize the effectiveness of the interpretation process. This article complements another article (Kennard et al., 2002) that explores evidence from group members about whether the groups were effective as therapeutic and as group-analytic experiences.
Group-Analytic Training Conducted through a Language Interpreter: Is the Experience Therapeutic? is it Group-Analytic?
Authors: Kennard David , Elliott Barbara , Roberts Jeff , Evans Chris
Published: July 2003

Three of the authors ran an Introductory Course in Group Analysis in St Petersburg, using language interpreters in the small experiential groups. The members identified the most important event in the group at the end of each day. These responses were used to explore two questions: Were the groups therapeutic? Were they group-analytic? Using Yalom's model of group therapeutic factors indicated that similar therapeutic factors were operating as in outpatient therapy groups, although a large proportion of responses could not be coded within this format. Using our own group-analytic markers suggested that the group sessions could also be rich in group-analytic qualities. While the data is inferential, a combination of quantitative results and illustrative examples provides convincing support for the view that the group members were engaged in an experience that was both therapeutic and group-analytic.