MODULAR SELF -RECONFIGURABLE MULTI-FUNCTIONAL ROBOTIC SYSTEM

INTRODUCTION Robots made of multiple units Possibility of (self) reconfiguration Autonomously change their shape and size When task and environment are not fully known they can out-perform fixed shape robots Versatile, fault tolerant, efficient Building and controlling very difficult Some similarity with multi-cellular biological systems

CATERPILLAR ROBOT TO 4 LEG WALKER

CLASSIFICATION OF MODULAR SELF- RECONFIGURING ROBOTIC SYSTEM Based on Geometric arrangement Lattice architectures Chain/tree architecture Based on the way by which units are reconfigured Deterministic reconfiguration Stochastic reconfiguration

LATTICE BASED DESIGNS

CHAIN BASED DESIGNS

LATTICE OR CHAIN ? Lattice based designs – Reconfiguration is easy – Motion generation is hard – Requires many connectors & actuators Chain based designs – Reconfiguration is hard – Motion generation is easy – Insufficient stiffness

6 SELF-RECONFIGURABLE MODULES

SINGLE MODULE WITH CONNECTORS

DESIGN CONSIDERATIONS Modules and connectors must cover their internal electronic and mechanical components Modules must have enough dexterity Modules must have enough torque Modules must have a series of sensors Power should be efficiently used and managed The control software needed to be real-time, fault tolerant and scalable

DESIGN CONSIDERATIONS OF CONNECTORS Connectors must be genderless Two docked connectors could be oriented relative to each other in 90° intervals Connectors must support communication and power sharing Either side of the two docked connectors must be able to unlock Connectors must sense and guide docking process

MECHANICAL DESIGN In the form of linked cubes Cube dimension 84×84×84 mm Hard aluminum alloy used Weigh about 500 grams

HARDWARE CONTROL ARCHETECTURE 400k b/s1 2c bus

MASTER CONTROLLER ARCHITECTURE 1 Mb/s SPI bus

SLAVE CONTROLLER ARCHITECTURE

Communication Interface On a Dock Face

Power Sharing Circuit Schematic

SOFTWARE ARCHETECTURE Low level software Behavioral level software Remote client software

CONFIGURATIONS AND POTENTIAL FUNCTIONS

ARTIST RENDITION OF A SPACE APPLICATION OF MODULAR ROBOTICS

ADVANTAGES VERSATILE: Modular reconfigurable robots with many modules have the ability to form a large variety of shapes with large numbers of degrees of freedom (DOF). LESS EXPENSIVE: As the numbers of repeated modules increases, the economies of scale come into play and the per-module cost goes down. RELIABLE: Another result of being modular and reconfigurable is the ability of the system to repair itself.

APPLICATIONS NASA program – Space station repair – Mars exploration – Moon station (self replication) Exploration – Search and rescue – Undersea mining – Planetary mining

CONCLUSION Self reconfiguring robotic systems are potentially more robust and more adaptive than conventional systems. The reconfiguration ability allows a robot or a group of robots to disassemble and reassemble machines to form new morphologies that are better suitable for new tasks, such as changing from a legged robot to a snake robot and then to a rolling robot. Self reconfiguring robotic systems can potentially lower overall robot cost by making a range of complex machines out of a single (or relatively few) types of mass-produced modules.

REFRENCE Behnam Salemi, Mark Moll and Wei-Min Shen:”Superbot:A deployable, Multi-Functional, Modular Self Reconfigurable Robotics System.” Mark Yim, Paul White, Jimmy Sastra:”Modular Self Reconfigurable Robots.” Eiichi Yoshida, Satoshi Murata,Akiya Kamimura:”A Self Reconfigurable Modular Robot :Reconfiguration Planning and Experiments.”