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Engineering topics

Fisher, P. H., Jr.

Publications and source records attributed to Fisher, P. H., Jr..

Transfer function tests of the Joy longwall shearer

A series of operational tests was performed on the Joy longwall shearer located at the Bureau of Mines in Bructon, Pennsylvania. The purpose of these tests was to determine the transfer function and operational characteristics of the system. These characteristics will be used to generate a simulation model of the longwall shearer used in the development of the closed-loop vertical control system.

Fisher, P. H., Jr.↗

Optimum propellant usage for reaction jet systems of space vehicles

The on-off type control for reaction jet systems is proven to be the optimal fuel scheme. However, due to the nonlinear characteristics of this type control, no direct method of solution is known for this optimal process being applied to the attitude control of space vehicles. This paper will discuss the optimization of fuel usage for an attitude control of space vehicles. A computation technique is developed for the calculation of optimal control law. The method of calculus of variations is applied to the estimation of the changes of performance index as well as terminal constraints. Thus an algorithm is obtained by the steepest descent method. A numerical example is given in the paper.

Liu, T. C.↗