Horner, C. G. | Search NASA

NASA NTRS1991

Kinematic analysis of generalized adaptive trusses

Adaptive trusses offer the greatest stiffness and strength for a given weight of any articulated structure or mechanism. Because of this, there are many potential extraterrestrial applications of these variable-geometry trusses, including serpentine manipulators, payload isolation, tracking, pointing and docking mechanisms, and gimbals. All of these applications will require the ability to precisely control the kinematic parameters of the mechanism, including position, velocity, and acceleration. This paper explores the fundamental nature of adaptive trusses by examining the basic truss elements or unit cells. A general method for analyzing forward and inverse motion of all the basic truss units is presented, followed by a more efficient formulation for the octahedral unit cell. Finally, general closed-form techniques are presented for finding velocity, acceleration, and all higher derivatives of truss motion.

Tidwell, Paul H.↗

NASA NTRS1990

Adaptive truss structure

This paper discusses the research in adaptive structures conducted at NASA Langley Research Center. The objective in the research program on adaptive truss structures is to develop an integrated approach for the design, test, and evaluation of adaptive trusses. An adaptive structure must include sensors for measuring some of the states of the mechanism, a controller that processes the sensor information and generates command signals, and a device that will cause the struts in the mechanism to change length. Based on the results of the research program, it is concluded that alternative designs for future space applications are offered, and adaptive truss has been demonstrated to be effective for vibration suppression.

Horner, C. G.↗