147 research outputs found
Placing dynamic sensors and actuators on flexible space structures
Input/Output Cost Analysis involves decompositions of the quadratic cost function into contributions from each stochastic input and each weighted output. In the past, these suboptimal cost decomposition methods of sensor and actuator selection (SAS) have been used to locate perfect (infinite bandwidth) sensor and actuators on large scale systems. This paper extends these ideas to the more practical case of imperfect actuators and sensors with dynamics of their own. NASA's SCOLE examples demonstrate that sensor and actuator dynamics affect the optimal selection and placement of sensors and actuators
Experimental investigation of the softening-stiffening response of tensegrity prisms under compressive loading
The present paper is concerned with the formulation of new assembly methods
of bi-material tensegrity prisms, and the experimental characterization of the
compressive response of such structures. The presented assembly techniques are
easy to implement, including a string-first approach in the case of ordinary
tensegrity prisms, and a base-first approach in the case of systems equipped
with rigid bases. The experimental section shows that the compressive response
of tensegrity prisms switches from stiffening to softening under large
displacements, in dependence on the current values of suitable geometric and
prestress variables. Future research lines regarding the mechanical modeling of
tensegrity prisms and their use as building blocks of nonlinear periodic
lattices and acoustic metamaterials are discussed
- …