Showing papers in "Journal of Dynamic Systems Measurement and Control-transactions of The Asme in 1971"
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TL;DR: In this article, the authors investigate the effect of vehicle-guided-way DYNAMIC interactions between a single vehicle and a GUIDEWAY on a one-dimensional high-speed ground-transportation system.
Abstract: MODAL ANALYSIS TECHNIQUES ARE USED TO STUDY THE DYNAMIC INTERACTIONS BETWEEN A ONE-DIMENSIONAL HIGH SPEED GROUND TRANSPORT VEHICLE MODEL AND A GUIDEWAY CONSISTING OF MULTIPLE INDEPENDENT SPANS RESTING FREELY ON RIGID DISCRETE SUPPORTS THE STUDY INCLUDES AN EVALUATION OF THE EFFECTS OF VARIATIONS IN THE FUNDAMENTAL VEHICLE AND GUIDEWAY PARAMETERS ON SPAN MAXIMUM DYNAMIC DEFLECTIONS AND VEHICLE HEAVE ACCELERATIONS RESULTS INDICATE THAT VEHICLE-GUIDEWAY DYNAMIC INTERACTIONS STRONGLY INFLUENCE BOTH VEHICLE SUSPENSION AND GUIDEWAY SPAN DESIGN FOR THE RANGE OF PARAMETERS OF INTEREST IN HIGH SPEED SYSTEMS (200-300MPH), GUIDEWAY SPAN DYNAMIC TO STATE DEFLECTION AND STRESS RATIOS, OR IMPACT FACTORS, MAY APPROACH VALUES OF 20 FOR A SINGLE VEHICLE PASSAGE, AND VEHICLE HEAVE ACCELERATIONS MAY EXCEED THE LEVELS OF 005G DESIRED FOR GOOD RIDE QUALITY UNLESS VERY STRONG CONSTRAINTS ARE PLACED UPON VEHICLE SUSPENSION REQUIREMENTS AND GUIDEWAY STIFFNESS, WEIGHT, AND SPAN LENGTH SPECIFICATIONS /AUTHOR/
29 citations
TL;DR: In this paper, a method for estimating parameters in distributed systems which can be analyzed by the method of characteristics is presented, both the very real problems of noisy measurements and limited available measurement transducers are discussed in some depth.
Abstract: : A method is presented for estimating parameters in distributed systems which can be analyzed by the method of characteristics. Both the very real problems of noisy measurements and limited available measurement transducers are discussed in some depth. Convergent algorithms are developed using a Robbins-Munro stochastic approximation scheme. The extension of these methods to the identification of functions, multidimensional systems and diffusion terms is considered. (Author)
TL;DR: A model is derived to predict human reflex motion that contains a set of seven neuromuscular parameters which are evaluated on the basis of results obtained from experiments performed on the human forearm.
Abstract: In a companion paper to the present, a model is derived to predict human reflex motion. This model contains a set of seven neuromuscular parameters which are evaluated in the present paper on the basis of results obtained from experiments performed on the human forearm. In these experiments, forearm position is studied following an abrupt change in load and the parameters are evaluated using an identification scheme which minimizes an error function containing forearm position. The relative importance of the various parameters is discussed as well as the relation between the proposed model and previous models in this field.
TL;DR: In this article, the authors modeled trains of high speed air cushion vehicles traversing simple spans as uniform pressure segments traveling at arbitrary speeds over identical Bernoulli-Euler beams and found that the dynamic deflection factors (maximum ratios of dynamic to static deflection at midspan) approach 2.0 at speeds between 300 and 600 mph, and occur as the end of the train approaches, midspan.
Abstract: Trains of high speed air cushion vehicles traversing simple spans are modeled as uniform pressure segments traveling at arbitrary speeds over identical Bernoulli-Euler beams. Series solutions are found for the transient span and vehicle responses where the trains overlap several spans at a time. Elastic foundation, span tension, and span damping effects are included. Conclusions reached after studying some realistic numerical examples for constant-speed trains on elevated spans are: (a) for trains which are longer than one span length, the dynamic deflection factors (maximum ratios of dynamic to static deflection at midspan) approach 2.0 at speeds between 300 and 600 mph, and occur as the end of the train approaches, midspan; (b) these dynamic deflections may be reduced by the addition of damping, by a reduction of span length, by the addition of span tension, and by an increase in span stiffness; (c) the high vertical accelerations of the vehicles, which may approach 2 g’s at speeds of 300 mph, show the need for advanced suspension systems to insure passenger safety and comfort.
TL;DR: In this article, it is shown that sensitivity functions are discontinuous at the discontinuous points and relations between elements of sensitivity functions at these points are linear for a given nominal solution of the system.
Abstract: : The well known method of obtaining sensitivity functions is usually restricted by the condition of continuity imposed on the functions of the coordinates in system equations. For the case of discontinuous functions, more elaborate procedures are required to give a good linear approximation. It is shown that sensitivity functions are discontinuous at the discontinuous points. Also, relations between elements of sensitivity functions at these points are shown to be linear for a given nominal solution of the system. The switching time of the desired Bang-Bang control can be estimated if variations in initial conditions are known. The changes in terminal states and cost function due to deviations in initial conditions can be determined, to first order, by the use of sensitivity functions. Bounds on the deviations in initial conditions can be found by a worst case approach so that the desired terminal conditions are satisfied within given tolerances. The fundamental importance of these techniques in a number of areas of application, for instance, guidance and control of aerospace vehicles, is well known. (Author)