Browsing by Author "Kluwer Academic Publishers, publisher"

Now showing 1 - 7 of 7

Open Access
Calculation of repeatable control strategies for kinematically redundant manipulators
(Colorado State University. Libraries, 1995) Maciejewski, Anthony A., author; Roberts, Rodney G., author; Kluwer Academic Publishers, publisher
A kinematically redundant manipulator is a robotic system that has more than the minimum number of degrees of freedom that are required for a specified task. Due to this additional freedom, control strategies may yield solutions which are not repeatable in the sense that the manipulator may not return to its initial joint configuration for closed end-effector paths. This paper compares two methods for choosing repeatable control strategies which minimize their distance from a nonrepeatable inverse with desirable properties. The first method minimizes the integral norm of the difference of the desired inverse and a repeatable inverse while the second method minimizes the distance of the null vectors associated with the desired and the repeatable inverses. It is then shown how the two techniques can be combined in order to obtain the advantages of both methods. As an illustrative example the pseudoinverse is approximated in a region of the joint space for a seven-degree-of-freedom manipulator.
Open Access
Extended Gergonne syllogisms
(Colorado State University. Libraries, 1997) Johnson, Fred (Frederick A.), author; Kluwer Academic Publishers, publisher
Syllogisms with or without negative terms are studied by using Gergonne's ideas. Soundness, completeness, and decidability results are given.
Open Access
Planning of collision-free paths for a reconfigurable dual manipulator equipped mobile robot
(Colorado State University. Libraries, 1996) Chien, Stanley Y. P., author; Maciejewski, Anthony A., author; Sheu, Philip C.-Y., author; Xue, Qing, author; Kluwer Academic Publishers, publisher
In this paper, we study the problem of finding a collision-free path for a mobile robot which possesses manipulators. The task of the robot is to carry a polygonal object from a starting point to a destination point in a possibly culttered environment. In most of the existing research on robot path planning, a mobile robot is approximated by a fixed shape, i.e., a circle or a polygon. In our task planner, the robot is allowed to change configurations for avoiding collision. This path planner operates using two algorithms: the collision-free feasible configuration finding algorithm and the collision-free path finding algorithm. The collision-free feasible configuration finding algorithm finds all collision-free feasible configurations for the robot when the position of the carried object is given. The collision-free path finding algorithm generates some candidate paths first and then uses a graph search method to find a collision-free path from all the collision-free feasible configurations along the candidate paths. The proposed algorithms can deal with a cluttered environment and is guaranteed to find a solution if one exists.
Open Access
Robotic workspaces after a free-swinging failure
(Colorado State University. Libraries, 1997) Maciejewski, Anthony A., author; English, James D., author; Kluwer Academic Publishers, publisher
A robotic manipulator can fail in many different ways, and its capabilities after a failure are a major concern, especially for manipulators used in hazardous and remote environments, where the cost of repair or replacement is high. This article presents a study of the workspaces of robotic arms after a free-swinging failure, defined as a hardware or software failure that prevents the application of actuator torque on a joint. Two analytical methods are discussed. The first is for planar arms only and is based on a positional inverse-kinematic algorithm that uses polynomial roots, guaranteeing that all solutions, and therefore the postfailure workspace, can be found. The second method has no such guarantee, but is applicable to general spatial manipulators. It is based on a differential technique for tracing the postfailure workspace boundary.
Open Access
Syllogisms with fractional quantifiers
(Colorado State University. Libraries, 1994) Johnson, Fred (Frederick A.), author; Kluwer Academic Publishers, publisher
Aristotle's syllogistic is extended to include denumerably many quantifiers such as more than 2/3' and exactly 2/3'. Syntactic and semantic decision procedures determine the validity, or invalidity, of syllogisms with any finite number of premises. One of the syntactic procedures uses a natural deduction account of deducibility, which is sound and complete. The semantics for the system is non-classical since sentences may be assigned a value other than true or false. Results about symmetric systems are given. And reasons are given for claiming that syllogistic validity is relevant validity.
Open Access
The land ethic at the turn of the millennium
(Colorado State University. Libraries, 2000) Rolston, Holmes, 1932-2025, author; Kluwer Academic Publishers, publisher
Aldo Leopold's land ethic has proved more complex and subtle than he envisioned. Nevertheless Leopold launched what, facing a new millennium, has proved urgent on the global agenda: an environmental ethics concerned in theory and practice about appropriate respect for values carried by the natural world and human responsibilities for the sustaining of these values. A blending of anthropocentric and biocentric values continues to be vital. These duties toward nature involve analysis of ecosystem integrity and evolutionary dynamism at both scientific and philosophical levels; any responsible environmental policy must be based on plausible accounts of ecosystems and a sustainable biosphere. Humans and this planet have entwined destinies. We now envision an Earth ethic beyond the land ethic.
Open Access
What is a gene? From molecules to metaphysics
(Colorado State University. Libraries, 2006) Rolston, Holmes, 1932-2025, author; Kluwer Academic Publishers, publisher
Mendelian genes have become molecular genes, with increasing puzzlement about locating them, due to increasing complexity in genomic webworks. Genome science finds modular and conserved units of inheritance, identified as homologous genes. Such genes are cybernetic, transmitting information over generations; this too requires multi-leveled analysis, from DNA transcription to development and reproduction of the whole organism. Genes are conserved; genes are also dynamic and creative in evolutionary speciation - most remarkably producing humans capable of wondering about what genes are.