This paper presents a unique scheme for reconstructing tethered satellite skiprope motion by ground processing satellite magnetometer measurements. The measurements are modified based on ground knowledge of the Earth&...
详细信息
This paper presents a unique scheme for reconstructing tethered satellite skiprope motion by ground processing satellite magnetometer measurements. The measurements are modified based on ground knowledge of the Earth's magnetic field and passed through bandpass filters tuned to the skiprope frequency. Skiprope motion is then deduced from the steady-state outputs of the filters. Simulation results are presented which verify the scheme and show it to be robust. The concept is not just limited to tethered satellites. Indeed, it can be applied whenever there is a need to reconstruct the coning motion of a body about a known axis, given measurements of a known vector in body-fixed axes.
作者：
POLITES, MEControl Systems Division
Structures and Dynamics Laboratory Marshall Space Flight Center National Aeronautics and Space Administration AL 35812 U.S.A
A new state reconstructor for deterministic digital controlsystems is presented which is ideal in the following sense: if the plant parameters are known exactly, the output of the new state reconstructor will exactly...
详细信息
A new state reconstructor for deterministic digital controlsystems is presented which is ideal in the following sense: if the plant parameters are known exactly, the output of the new state reconstructor will exactly equal the true state of the plant, not just approximate it. Furthermore, this ideal state reconstructor adds no additional states or eigenvalues to the system, nor does it affect the plant equation for the system in any way; it affects only the measurement equation. While there are countless ways of choosing the ideal state reconstructor parameters, two distinct methods are described here. An example is presented which illustrates the procedures for completely designing the ideal state reconstructor using both methods.
This paper derives three discrete state variable representations for a continuous-time plant driven by a zero-order hold with a combination of instantaneous measurements and measurements prefiltered by a multi-input/m...
详细信息
This paper derives three discrete state variable representations for a continuous-time plant driven by a zero-order hold with a combination of instantaneous measurements and measurements prefiltered by a multi-input/multi-output moving average (MA) process. These representations allow the control system engineer to model plants of this type accurately in a form which permits him to use standard techniques to design digital feedback controllers for them. An example is presented which illustrates how to obtain the coefficient matrices in each representation. Guidelines are presented for choosing the best representation to use for any given plant of this type.
A ship design methodology is presented for developing hull forms that attain improved performance in both seakeeping and resistance. Contrary to traditional practice, the methodology starts with developing a seakeepin...
A ship design methodology is presented for developing hull forms that attain improved performance in both seakeeping and resistance. Contrary to traditional practice, the methodology starts with developing a seakeeping-optimized hull form without making concessions to other performance considerations, such as resistance. The seakeeping-optimized hull is then modified to improve other performance characteristics without degrading the seakeeping. Presented is a point-design example produced by this methodology. Merits of the methodology and the point design are assessed on the basis of theoretical calculations and model experiments. This methodology is an integral part of the Hull Form Design System (HFDS) being developed for computer-supported naval ship design. The modularized character of HFDS and its application to hull form development are discussed.
暂无评论