Self-Assembly in Mobile and Modular Robots

Abstract

In this chapter, we put TOTA at work in a totally different application area, i.e., self-assembly robotics. In particular, we intend to show how field-based coordination-as supported by TOTA-can be effectively exploited for orchestrating spatial movements in two different robotics scenarios: 1. a swarm of simple mobile computational particles (i.e., minimal robots), that need to coordinate their independent movements in space so as to have the swarm as a whole assume a specific global shape (e.g., recall the pipe-repairing spray application in Subsect. 2.1.1, or the T1000 robot in the Terminator 2 movie); 2. a modular robot, made up of interconnected autonomous computer-based components (i.e., actuators), connected to each other with joints providing a limited degree of freedom in movements. The components need to coordinate the way in which the joints are bent so as to let the modular robot assume specific shapes and flexibly reshape to enforce a specific motion gait (recall Subsect. 4.2.2). The above two scenarios are representative of the fundamental questions at the very basis of this book: (i) how does one engineer robust coordinated behaviors in a system made up of a large number of components that are interconnected in local, irregular, and time-varying ways? (ii) How does one translate prespecified global goals (e.g., global shapes or global motion gait) into the local interactions of vast numbers of parts (e.g., individual particle movements or bending of single joints)? Earlier in this book (Chap. 4) we have already anticipated how biologically inspired mechanisms such as morphogen gradients and hormones (both of which can be assimilated to fields) can be effectively exploited for that purpose. Here, morphogen gradients and hormones will be translated into TOTA tuples to be applied for enabling adaptive self-organization of spatial shapes in swarms of simple particles and of gait control in modular robots.