This paper addresses the problem of designing guidance, control and navigation systems for autonomous underwater vehicles (AUVs). Its contribution is twofold: i) it introduces a new methodology for the integrated desi...
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This paper addresses the problem of designing guidance, control and navigation systems for autonomous underwater vehicles (AUVs). Its contribution is twofold: i) it introduces a new methodology for the integrated design of guidance and control, and ii) it describes a novel approach to the analysis and design of multi-rate complementary filters for navigation. The methodologies proposed lead to an efficient procedure for the design of controllers for AUVs, to accurately track reference trajectories defined in an inertial reference frame. The paper illustrates the application of that procedure to the design of a tracking controller for the MARIUS AUV. The design phase is summarized, and the performance of the resulting controller is assessed in simulations, using dynamic models of the vehicle and its sensor suite.
This study appraised the utility of SAT scores in combination with grades in high school courses and the number and quality of these courses in predicting college grades in various fields of study, with the object of ...
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This study appraised the utility of SAT scores in combination with grades in high school courses and the number and quality of these courses in predicting college grades in various fields of study, with the object of providing students with predictions of their academic performance for guidance purposes. The possible impact of this feedback on the flow of students into these fields was also assessed. Data for an entering class at a large state university were used. The SAT and collateral variables were able to predict college grades in different academic areas by taking account of marked variations in grade distributions among fields. These predictions could be potentially useful in guidance. Students' predicted grades in the fields and their intended majors were unrelated, and many students had their highest predicted grades in the humanities, though few intended to major in this field. Hence this feedback would probably stimulate students to take courses or major in the humanities.
The Secretary of Defense has designated facilities demolition as an important element of the Department of Defenses (DOD) strategy to improve facilities management and reduce maintenance costs. The military services h...
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The Secretary of Defense has designated facilities demolition as an important element of the Department of Defenses (DOD) strategy to improve facilities management and reduce maintenance costs. The military services have programs in place to identify unneeded facilities on active bases that the services intend to dispose of through demolition.
In order to assist the people in the transportation industry in accurately understanding and interpreting the transportation regulations, a prototype expert guidance system called REGS has been developed for Part 382 ...
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In order to assist the people in the transportation industry in accurately understanding and interpreting the transportation regulations, a prototype expert guidance system called REGS has been developed for Part 382 of the Federal Motor Carrier Safety Regulations. This PC-based system models the regulatory guidance methodology employed by statutory interpretation experts in the industry. The working environment of this system is very user-friendly. When a query is put forth requesting interpretation, the system is initiated and the user is presented with a set of choices. These choices are designed to cater to the needs of the user for providing appropriate and adequate guidance. If the user chooses to run the REGS module, the system puts forth a series of questions to arrive at the conclusions. While the user responds to these questions, the system evaluates the responses, internally reviews the relevant regulations and past interpretations and stops to provide a conclusion. The system can also handle "how", "why" and "what-if' type of questions by giving explicit explanations. While the system searches through its regulations knowledge base, the user is provided an option to look at the regulatory text, select the relevant sections and print them if it is required to answer the request for interpretation. This type of "all at one place" guidance helps the user to understand the intent latent in the regulations. It also helps the user in assembling a boilerplate response based on which an interpretation for the request can be prepared. The system is useful to enforcement officials, motor carrier company officials, drivers and government regulators, who all need to be intimately familiar with Part 382 of the FMCSRs. Since the architecture of REGS is transportable to any set of regulations, similar systems could easily be developed for any other set of transportation regulations.
Additional guidance has been published on the third edition of the Civil Engineering Standard Method of Measurement. John Banyard, chairman of ICE's standing CESSM review committee, explains.
Additional guidance has been published on the third edition of the Civil Engineering Standard Method of Measurement. John Banyard, chairman of ICE's standing CESSM review committee, explains.
This paper describes a solution to the problem of 3-D trajectory tracking for Autonomous Underwater Vehicles (AUVs). The trajectories considered consist of segments of trimming helices, which are parameterized by the ...
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This paper describes a solution to the problem of 3-D trajectory tracking for Autonomous Underwater Vehicles (AUVs). The trajectories considered consist of segments of trimming helices, which are parameterized by the vehicle's linear speed, yaw rate and flight path angle. Motivated by recent developments in robotics, the linear position of an AUV is given in terms of its location with respect to the closest point on a desired trajectory, together with the length of an imaginary curve traced along that trajectory. Tracking of a trimming trajectory by the vehicle at a fixed speed is then converted into the problem of driving a generalized error vector - that implicitly includes the distance to the trajectory - to zero. By showing that the linearization of the generalized error dynamics about trimming trajectories is time-invariant, the problem of trajectory tracking is posed and solved in the framework of gain scheduled control theory. This leads to a new method for the integrated design of guidance and control systems for AUVs.
Optimal guidance of a dynamic process requires a fast algorithm for the computation of optimal trajectories. The method described in this paper modifies the conventional “direct approach” with control parametrizatio...
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Optimal guidance of a dynamic process requires a fast algorithm for the computation of optimal trajectories. The method described in this paper modifies the conventional “direct approach” with control parametrization. A special integration formula, which uses the Jacobian of the system, facilitates the computation of gradients. A special stepsize control monitors the integration error. The simulation of an aircraft, which is to intercept a moving target in minimum time, demonstrates the real-time capability.
In order to assist the people in the transportation industry in accurately understanding andinterpreting the transportation regulations, a prototype expert guidance system called REGShas been developed for Part 382 of...
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In order to assist the people in the transportation industry in accurately understanding and
interpreting the transportation regulations, a prototype expert guidance system called REGS
has been developed for Part 382 of the Federal Motor Carrier Safety Regulations. This PC-based
system models the regulatory guidance methodology employed by statutory
interpretation experts in the industry.
The working environment of this system is very user-friendly. When a query is put forth
requesting interpretation, the system is initiated and the user is presented with a set of
choices. These choices are designed to cater to the needs of the user for providing appropriate
and adequate guidance. If the user chooses to run the REGS module, the system puts forth
a series of questions to arrive at the conclusions. While the user responds to these questions,
the system evaluates the responses, internally reviews the relevant regulations and past
interpretations and stops to provide a conclusion. The system can also handle "how", "why"
and "what-if’ type of questions by giving explicit explanations. While the system searches
through its regulations knowledge base, the user is provided an option to look at the
regulatory text, select the relevant sections and print them if it is required to answer the
request for interpretation. This type of "all at one place" guidance helps the user to
understand the intent latent in the regulations. It also helps the user in assembling a boilerplate
response based on which an interpretation for the request can be prepared.
The system is useful to enforcement officials, motor carrier company officials, drivers and
government regulators, who all need to be intimately familiar with Part 382 of the FMCSRs.
Since the architecture of REGS is transportable to any set of regulations, similar systems
could easily be developed for any other set of transportation regulations.
Glass surfaces were patterned with cell-adhesive regions of laminin adhesive peptides YIGSR, RGD, and IKVAV, and cell-repulsive regions of poly(ethylene glycol) (PEG). The patterns were created by sputter-coating tita...
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To fully automate some in-field agricultural tasks, an autonomous vehicle has to be guided along a crop held. In this work, we describe how a vision system extracts the guidance information for vehicle navigation in a...
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To fully automate some in-field agricultural tasks, an autonomous vehicle has to be guided along a crop held. In this work, we describe how a vision system extracts the guidance information for vehicle navigation in a crop row. The method is based on extraction of the scene structure from perspective information that a set of coplanar parallel lines, representing the crop rows, generate in the image. To solve some drawbacks caused by these natural environments, a method to extract the row lines is described, and an approach to calculate the vanishing point proposed. A technique to recover missing information is also introduced. The method has been applied to long sequences of images taken by a moving vehicle in crop row scenes.
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