Three-dimensional Manipulation Research Articles

Three-dimensional scatter diagrams: application to surface analytical microscopy

Multivariate statistical techniques, such as principal component analysis and two-dimensional scatter diagrams, are increasingly being applied to multispectral images in analytical electron and X-ray microscopy. Combining data from different sources can often reveal more information than would be obtained if each image was processed separately. Three-dimensional data manipulation and visualisation tools are gaining popularity in many scientific fields. However, three-dimensional scatter diagrams are not yet being exploited much in analytical microscopy. This paper demonstrates the advantages of three-dimensional scatter diagrams and interactive correlation partitioning. An introduction to the methodology is included. Examples using multi-element Auger and topographic images from the York multispectral analytical electron microscope (MULSAM) are presented. Implementation issues are discussed briefly to help other workers who may wish to investigate the techniques. Some areas of future work are suggested.

Algorithm for Optimal Fingertip Force in Three-Dimensional Space.

In the previous report, we investigated the optimal fingertip force for 3-fingered robot hands in two-dimensional space. Generally robots manipulate objects in three-dimensional space. In this report, we consider three-dimensional space manipulation. As with the two-dimensional case. the problem is reduced to a linear programming problem, where the optimal solution is obtained via three-stage optimization solvable by the simplex method. However, in this paper a new criterion is introduced, which leads to a more desirable solution.

Laser manipulation and assembling of polymer latex particles in solution

Three-dimensional laser manipulation of polymer latex particles in solution was demonstrated. Polymer latex particles with a diameter of several microns were spatially aligned in arbitrary patterns (letters and geometrical figures) by respectively scanning a focused laser beam (1064 nm) under an optical microscope. Irradiation of nanosecond or picosecond 355-nm laser pulses on individual laser-trapped polymer particles is a sample solution containing polymerizable vinyl monomers and a photoinitiator brought about permanent fixation of the particles in three-dimensional structures

Three-dimensional cell manipulator by means of optical trapping for the specification of cell-to-cell adhesion

A cell manipulator capable of (1) trapping single living cells, (2) making a direct binary contact from a chosen direction, and (3) judging the formation of cell-to-cell adhesion is produced by means of optical trapping in combination with a fixed micropipette. The specificity of the cell adhesive capability is tested with isolated hydra cells, demonstrating a clear difference in adhesive properties between ectodermal and endodermal epithelial cells

Real-time path planning procedure for a whole-sensitive robot arm manipulator

SUMMARYWe consider the problem of sensor-based motion planning for a three-dimensional robot arm manipulator operating among unknown obstacles. When every point of the robot body is subject to potential collision. The corresponding planning system must include these four basic components: sensor hardware; real-time signal/sensory data processing hardware/software; a local step planning subsystem that works at the basic sample rate of the arm; and finally, a subsystem for global planning. The arm sensor system developed at Yale University presents a proximity sensitive skin that covers the whole body of the arm and consists of an array of discrete active infrared sensors that detect obstacles by processing reflected light. The sensor data then undergoes low level processing via a step planning procedure, which converts sensor information into local normals at the contact points in the configuration space of the robot. This paper presents preliminary results on the fourth component, a real-time algorithm that realizes the upper, global level of planning. Based on the current collection of local normals, the algorithm generates preferable directions of motion around obstacles, so as to guarantee reaching the target position if it is reachable. Experimental results from testing the developed system are also discussed.

Computer Imaging in Orthognathic and Facial Cosmetic Surgery

SUMMARY Computers will play an important role in providing information relevant to anticipated facial aesthetic changes for a wide range of surgery procedures. This article has reviewed interfacing computers with cephalometric data and the use of CT scanning for three-dimensional manipulation of images. A practical guide to the utilization of computer video imaging for orthognathic and facial cosmetic surgery has been presented. Within the limitations of its technology, computer imaging is seen as a valuable communication and diagnostic tool for facial surgery. Further investigations are needed to determine whether changes of soft tissues and hard tissues are sufficiently reproducible so that more meaningful predictive values can be established. A greater degree of interaction between surgery and computer technology can be expected as our level of sophistication grows in both fields.

A Unified Methodology for Motion Planning with Uncertainty for 2D and 3D Two-Link Robot Arm Manipulators

Most of the work on robot path planning revolves around two basic models: the model with complete information (often called the "Piano Mover's Problem") and the model with in complete information (called here the "South Pole Search Problem'). The approach of dynamic path planning intro duced in Lumelsky and Stepanov (1987) and Lumelsky (1987) is based on the latter model and produces nonheuristic (provable) algorithms for simple robot arm manipulators operating in an environment with unknown obstacles of arbi trary shapes. The algorithms assume local on-line input information coming from the arm sensors. Unfortunately, the existing techniques require that each kinematic configuration be considered separately, which results in different algo rithms for different kinematics. In this paper, a unified meth odology is presented for designing dynamic path planning algorithms for two- and three-dimensional two-link arm manipulators. The approach is independent of the specifics of the kinematic configuration and imposes no constraints on the shape of the arm links or obstacles in the environment. The methodology exploits some important topological char acteristics of the configuration space. However, no explicit computation of obstacles in the configuration space ever takes place, which results in fast real-time algorithms.

Proximity sensing in robot manipulator motion planning: system and implementation issues

Results of one effort to implement a motion planning system for a robot arm operating in an uncertain environment are discussed. It is known that path planning algorithms with proven convergence can be designed for some planar and three-dimensional robot arm manipulators operating among unknown obstacles of arbitrary shapes. The attractiveness of such systems lies in their ability to operate in a complex, perhaps even time-varying, unstructured environment. Implementation of these algorithms, however, presents a variety of hardware and algorithmic problems related to: covering the arm with arrays of sensors to form a sensitive skin; processing real-time sensor data; designing complementary algorithms for step-by-step motion planning based on limited local information; and integrating these components, together with global planning algorithms, in a single system. The authors discuss various tradeoffs and solutions implemented in the sensor-based planning system for a planar arm manipulator developed in their laboratory and present a summary of their experiments with it.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Computergraphic modeling and analysis II: three-dimensional reconstruction and interactive analysis

The analysis of human motion can be advanced by analyzing motion not only numerically, but also graphically. A new system is presented for the computergraphic analysis of human motion in three-dimensional space. The system allows the three-dimensional reconstruction, visualization, manipulation, and graphic editing of digitized movement trajectories. An entire sequence of the positions of the arm in three-dimensional space can be displayed simultaneously, or the actual motion can be recreated in real time. Along with the reconstruction of the spatial path, the temporal characteristics of the movement can be concurrently displayed. Graphic procedures for interactively examining couplings between spatial and temporal aspects of trajectories were developed. Finally, based on digitized trajectories, stimuli can be generated and sequenced in real time for studies of the perception of motion. In conjunction with new methods of three-dimensional movement tracking, the computergraphic methods presented here offer new approaches to the analysis of human movement and its underlying neural control.

Eigenfrequencies of three-dimensional n-element manipulator containing elastic and absolutely solid elements

Eigenfrequencies of three-dimensional n-element manipulator containing elastic and absolutely solid elements

Redundancy resolution of serial manipulators based on robot dynamics

Based on the minimization of the joint driving forces/torques, the classical Lagrangian technique is used to develop the governing equations for the computation ofthe joint accelerations in an N degree of freedom serial manipulator. Explicit equations for the computation of the joint accelerations are developed and used instead of numerical based solutions for pseudo inverses (e.g. singular value decompostion method). The developed solution is computationally three times more efficient than the comparable solutions in the literature. The problems of reliability and stability are discussed. Several modifications are introduced to make the algorithm rerliable and stable. An eleven degrees of freedom, three-dimensional robotic manipulator is used in a numerical example to test the developed algorithms.

Neuroanatomical digital image processing in CT-guided stereotactic operations.

In order to utilize computed tomography (CT) for functional neurosurgical procedures, a number of problems must be resolved. One such problem is the development of an appropriate technique for digital processing of neuroanatomical images. Our previous work concerned a numerical reproduction of a well-known stereotactic atlas and its three-dimensional manipulation. In order to efficiently utilize this information with CT images we propose a technique for data reduction that allows the reconstruction of anatomical structures from the atlas. The logic of implementing these data in CT-assisted stereotactic surgery is described.

A system for the three-dimensional construction, manipulation and display of microbiological models

A system is described for building up serial sections into a three dimensional structure, incorporating density, that can be displayed and then further manipulated by rotation about three orthogonal axes. The initial application was to produce a computer model of a protein structure and to compare the diverse images obtained from rotation with the two dimensional images observed in related electron micrographs. To obtain sufficient contrast in the electron microscope images of protein structures, the specimens need to be stained and since this can cause some deformation of the observed images, it is also necessary to simulate the possible effects of stain on the protein model. Because of the need to compare numerous orientations of the combined model, techniques are available either for speeding up the comparison or for obtaining better accuracy. The methods have been applied to the interpretation of electron micrograph images of microbiological specimens, where the three dimensional structure of the specimen is an important aid in understanding its biological function, but the techniques are also applicable to more general serial reconstruction requirements.

EXPLORATORY BEHAVIOR IN PATIENTS SUFFERING FROM SENILE DEMENTIA: A COMPARISON WITH CHILDREN

Thirty-seven patients with the diagnosis of senile dementia and 70 children aged 6 months to 4 years were observed in three tasks that stimulated exploratory behavior. The subjects were rated according to the frequencies of certain forms of behavior in 52 variables. It was assumed that certain behavior would be more frequent among children in specific age periods and for that reason a factor analysis of the children's behavior would generate factors characterizing clusters of behavior typical for certain periods. The factor analyses of the children's behavior yielded three factors, which were interpreted as an oral factor, a factor characterizing interest in three-dimensional relationships, and a factor regarding goal-directed manipulation. Indices of the three factors demonstrated that the oral factor had a very high frequency in the infants 6-11 months old; after that age it decreased steeply and disappeared at about 2 years of age. Activities involving three-dimensional relationships and goal-directed manipulation were scarcely displayed in the youngest infants but appeared at about 12 months. Both modes of exploratory behavior tended to disappear before the age of 4. Analyses were carried out to see if the behavior of the patients yielded similar factors, and to see if the distributions of the factor indices for the group of patients, when broken down according to the degree of mental deterioration, had forms similar to the distributions for the children in the different age groups. Similar factors were obtained for the patients, but the structures were less clear and less meaningful than those obtained for the children. The forms of the distributions of factor indices over the degree of mental deterioration were similar to the distributions over the age groups for the children. Motor activity was reduced among more deteriorated patients. When explaining the childlike strategies in the exploratory behavior of the demented patients, it was hypothesized that, due to deficient memory, the patients had to manipulate the objects to find their qualities. This exploratory behavior was more or less advanced and flexible depending on the degree of mental deterioration. However, possible negative effects of high anxiety and high social inhibition were also touched upon.

Experiment in Quantitative Geologic Modeling

An experiment in three-dimensional quantitative description and computer manipulation of geologic and oil-occurrence information illustrates the versatility with which these data can be utilized. A geologic unit--for example, a sedimentary basin--is divided into discrete cells. Descriptive attributes such as lithology or oil reserves are assigned to each of the cells. A computer program selectively samples the data set for units with specified characteristics and handles the resulting subset by adding, counting, cross-tabulating, or general FORTRAN manipulation. Output may be in the form of printed maps and cross sections, quantitative description of geologic conditions, and tabulated relations between oil occurrence and various geologic parameters. Data organized in this manner can be utilized efficiently and flexibly for exploration and management purposes.

A Computer-Based Learning System for Remote Manipulator Control

A concept of adaptive aiding for performance improvement in remote handling is described. The concept incorporates an autonomous control subsystem (ACS) that is able to supplement the operator's control function. The behavior of the ACS is established through a process of learning by observing the operator's control function in relation to the environment and manipulator output. The computer-based system establishes a decision-making policy which is based on conditional probability. Initially, the output device is totally controlled by the operator, while the computer system acts as a passive observer. As the operation continues, the computer system gradually assumes the role of active controller, reducing the operator's function to that of an action initiator and inhibitor. A pilot experiment indicates the feasibility of the concept; with a relatively short training period, the ACS was able to assume the bulk of the decision-making load and guide a three-dimensional manipulator satisfactorily through a series of manipulative tasks.

Response to stimulus complexity in the Rat

An experiment is reported that is relevant to the Dember-Earl (1957) theory of stimulus complexity. Two mazes were constructed. One had four compartments in which the patterns painted on the walls were varied in complexity, and in the other, the number of baffles was varied as a three-dimensional manipulation of stimulus complexity. Thirty-two naive, male, hooded rats were divided into two equal groups, one group for each maze. Animals were placed individually in one of the mazes for 30 min. per day for 5 days. Higher complexity interaction index scores were achieved in the baffle pattern maze than in the wall pattern maze. There was some increase in the complexity of the preferred compartment over days. The results raise questions concerning the theoretical and experimental treatment of the stimulus complexity variable. The behavior of the animals appears to require a two-process explanation including an initial ‘information gaining’ exploratory phase. There appears to be need for a more general theory in addition to that proposed by Dember and Earl.