Development of Adaptive Construction Structure by Variable Geometry Truss

Recent years have seen an increasing variety of attractive structures and building with movable functions worldwide (Ishii, 1995). Typical examples are bridges that open to allow ships to pass, revolving restaurants on tops of buildings, sliding roofs of baseball and soccer dome stadiums, and artistic monuments. When we focus on the moving behaviour of these structures, they simply move on rails or turn around a hinge, but do not change in structural shape. That is, their behaviours are not flexible, but monotonous according to a decided patern. However, in the near future, it may become possible to devise structures with a lively motion, freedom as well as intelligence. In particular, they will respond to voice commands with instant and adaptive shape change harmonising with their environment. One mechanism that enables more complicated movement is the Variable Geometry Truss, we call VGT in the chapter. The VGT is a very simple truss structure composed of extendable members, fixed members and hinges, as shown in Fig.1. By controlling the lengths of the extendable members, it is possible to create various truss shapes. The VGT was originally developed as a movable actuator for a spread-type universe construction in space, and it was equipped with a small motor to perform various tasks (Natori & Miura, 1994). Thus, it is considered to be a useful structural tool in various fields as a redundant intelligent structure.