Control of Surface Configuration by Application of Concentrated Loads

Abstract

The literature on active control of mirrors is briefly reviewed. An analysis method is formulated in which the surface quality of free axisymmetric spherical mirrors is controlled by actuators that produce concentrated forces or self-equilibrating moment pairs. Normal displacement fields arising from unit actuator loads are generated with the use of thin shell theory by discretization of the radial coordinate and trigonometric expansion of the circumferential coordinate. It is found that local ripples caused by rather closely spaced self-equilibrating moment actuators are more pronounced than those caused by single force actuators, indicating that the former are not as suitable for surface quality control as the latter.

Control of Surface Configuration of Nonuniformly Heated Shells

“…The results presented here are derived from the theory developed in Ref. 1. The main purpose of this paper is to determine rms residual errors in surfaces which have been warped by nonuniform temperature.…”

“…1. By "active optics" is meant the control of one or more optical surfaces in an optical system to counteract the effects of changes in the environment.…”

Effect of sensor and actuator errors on static shape control for large space structures

“…[7][8][9][10][11]). However, Bushnell [7] characterizes some of these (e.g. [12,13]) as displacement actuators because they are stiff enough to enforce prescribed displacements.…”

Selection of actuator locations for static shape control of large space structures by heuristic integer programing

“…[7][8][9][10][11]). Bushnell [7] characterizessome such actuators (e.g. [12,13]) as displacementactuatorsbecausethey are stiff enough to enforce a prescribeddisplacementat a point.…”

“…Generally,the actuatorsemployed are force actuators (e.g. [7][8][9][10][11]). Bushnell [7] characterizessome such actuators (e.g.…”