Engineering topics

Desforges, D. T.

Publications and source records attributed to Desforges, D. T..

3 records

NASA NTRS1979

Spacecraft damping considerations in structural design

The role of damping in the prediction of spacecraft structural responses and loads, and in the structural design of spacecrafts is discussed. The methods used to incorporate damping in the structural analysis are summarized and some experiences and procedures relating to damping in recent spacecraft design are discussed. Methods for modal testing and the experimental determination of damping, the use of discrete dampers, and the estimation of payload response are studied. A collection of damping data for recent spacecraft and related hardware is provided in the appendix.

Wada, B. K.↗

NASA NTRS1979

Robotic manipulator control systems with invariant dynamic characteristics

The paper deals with robotic manipulator control systems with dynamic characteristics. It is shown that using model reference adaptive control techniques makes it possible to develop control algorithms which will maintain uniformly high performance over a wide range of system motions and payloads.

Dubowsky, D.↗

NASA NTRS1979

The application of model-referenced adaptive control to robotic manipulators

The achievement of quality dynamic performance in manipulator systems is difficult using conventional control methods because of both the inherent geometric nonlinearities of these systems and the dependence of the system dynamics on the characteristics of manipulated objects. A model-referenced adaptive control law is developed for maintaining uniformly good performance over a wide range of motions and payloads. The effectiveness of the approach is demonstrated in several simulations and the system stability as a function of input is investigated. Also developed is a 'learning signal' approach designed to minimize initial transients arising from abrupt changes in the inertial payload.

Dubowsky, S.↗