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Optimal coordination of robotic systems with redundancy
Title
Optimal coordination of robotic systems with redundancy.
Creator
Varma, K. R. Hareendra., Florida Atlantic University, Huang, Ming Z., College of Engineering and Computer Science, Department of Ocean and Mechanical Engineering
Abstract/Description
The research work described in this dissertation is primarily aimed at developing efficient algorithms for the rate allocation problem in redundant serial chain manipulators. While the problem of redundancy resolution in the context of robot manipulators, had been a well researched one, search for optimality in computational efficiency has caught the attention only recently. Further, the idea of modifying the already developed performance criteria to improve computational efficiency, had...
Show moreThe research work described in this dissertation is primarily aimed at developing efficient algorithms for the rate allocation problem in redundant serial chain manipulators. While the problem of redundancy resolution in the context of robot manipulators, had been a well researched one, search for optimality in computational efficiency has caught the attention only recently. Further, the idea of modifying the already developed performance criteria to improve computational efficiency, had rarely been treated with the importance it deserves. The present work in fact, provides many alternative formulations to the existing performance criteria. As a result of the present investigation, we developed a mathematical tool for the minimum norm solution for underdetermined systems of linear equations, using the orthogonal null space. Closed form equations were provided for cases with two or three degrees of redundancy. Detailed study of computational efficiency showed substantial reduction in the arithmetic operations necessary for such a solution. The above concept was later generalized to utilize the self motion characteristics of redundant manipulators, to provide alternate solutions. The duality concept between the Jacobian and the null space, established in this work, enabled the authors to develop a highly efficient formulation as an alternative to the commonly used pseudoinverse-based solution. In addition, by providing the example of a 7R anthropomorphic arm, the feasibility of obtaining analytical formulation of null space coefficient matrix and the transformed end effector velocity vector for any geometry has been demonstrated. By utilizing the duality between the Jacobian and its null space, different performance criteria commonly used in the redundancy resolution problem have been modified, increasing the computational efficiency. Various simulations performed as part of the present work, utilizing the analytical null space coefficient matrix and the transformed end effector velocity vector for 3R planar case and 7R spatial anthropomorphic arm corroborates the theories. Another practical application has been demonstrated by the example of a Titan 7F arm mounted on a mobile base. The work is consolidated by reiterating the insight obtained to the physical aspects of the redundancy resolution problem and providing a direction for future work. Suggestions are given for extending the work for high d.o.r. systems, with relevant mathematical foundations. Future work in the area of dynamic modelling, is delineated which also includes an example of modified dynamic manipulability measure.
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Date Issued
1992
PURL
http://purl.flvc.org/fcla/dt/12292
Subject Headings
Algorithms, Redundancy (Engineering), Robotics, Robots--Motion
Format
Document (PDF)
Robot singularities under small perturbations in the kinematic parameters
Title
Robot singularities under small perturbations in the kinematic parameters.
Creator
Mohile, Ajey Avinash., Florida Atlantic University, Roth, Zvi S., College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
When small perturbations in the kinematic parameters of a robot are taken into consideration, the model of a robot no longer contains perfect parallelism and perpendicularity that makes the nominal inverse kinematics so simple. In particular, the effect of joint axis misalignments and small perturbations in the kinematic parameters on the robot singularities is of interest. This aspect is particularly important when planning the workspace of a robot that must undergo calibration. To utilize...
Show moreWhen small perturbations in the kinematic parameters of a robot are taken into consideration, the model of a robot no longer contains perfect parallelism and perpendicularity that makes the nominal inverse kinematics so simple. In particular, the effect of joint axis misalignments and small perturbations in the kinematic parameters on the robot singularities is of interest. This aspect is particularly important when planning the workspace of a robot that must undergo calibration. To utilize the work volume most efficiently, one must know exactly what points are permissible as taught points. In other words, reachable workspace must be clearly defined to avoid the robot from entering the singularity zones not only of the nominal robot but also of all future actual robots. Once singularity zones for the actual robot are correctly identified, workspace planning becomes a simple task. In this thesis the relationship between small perturbations in kinematic parameters and singularities of a simple three-revolute articulated arm are studied. It is shown that singularities in such a robot do shift to new locations.
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Date Issued
1989
PURL
http://purl.flvc.org/fcla/dt/14476
Subject Headings
Robots--Dynamics, Robots--Motion
Format
Document (PDF)
Simulation of autonomous knowledge-based navigation in unknown two-dimensional environment with polygonal obstacles
Title
Simulation of autonomous knowledge-based navigation in unknown two-dimensional environment with polygonal obstacles.
Creator
McKendrick, John DeMilly., Florida Atlantic University, Cheng, Linfu, College of Engineering and Computer Science, Department of Computer and Electrical Engineering and Computer Science
Abstract/Description
The problem of finding optimal paths for a robot navigating in an environment where the position of each obstacle is precisely known has received much attention in the literature, however, the majority of applications problems for a robot would require it to navigate in a completely unknown. This paper focuses on an approach to solving the problem of robot navigation in an unknown, unstructured, two-dimensional environment where the positions of the polygonal obstacles were fixed in time. Few...
Show moreThe problem of finding optimal paths for a robot navigating in an environment where the position of each obstacle is precisely known has received much attention in the literature, however, the majority of applications problems for a robot would require it to navigate in a completely unknown. This paper focuses on an approach to solving the problem of robot navigation in an unknown, unstructured, two-dimensional environment where the positions of the polygonal obstacles were fixed in time. Few studies have reported on the utilization of an expert system to govern robot motion. This study relied on a knowledge-based expert system that interacted with lower-level procedures to carry out path finding and exploration functions. The expert-system shell used was OPS5 which ran on top of Lisp.
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Date Issued
1988
PURL
http://purl.flvc.org/fcla/dt/14496
Subject Headings
Robots--Motion, Expert systems (Computer science), Robots--Motion--Computer simulation
Format
Document (PDF)