Coordinated Control of a 12-TET Robot

The tetrahedral robot architecture produces robots with variable length "struts" that connect "nodes". Each node is connected to at least 4 struts resulting in the relative position of each node being determined by at least 4 distances. This is clearly an over constrained situation. This paper considers the control engineering implications of the additional constraint(s) and suggests one solution. That is, consider three struts as "master struts," the rest as "slave struts," and implement, for each strut a decentralized adaptive controller. The input to the master struts can be nearly arbitrary, whereas the input to the slave struts must be coordinated with that of the master struts. The adaptive control algorithm allows for small errors between the desired positions of the slave struts relative to the master struts and the actual relative positions.