project specification

Superbot

A modular, multifunctional, and easily reconfigurable robot. This robot is a deployable and multifunctional self-reconfigurable robotic system designed for NASA space exploration programs. SuperBot designed for NASA space exploration programs. It's modules have three degrees of freedom, which increases the mobility and flexibility of individual and networked modules. They are designed to be strong, flexible, and capable of performing efficient locomotion, self-reconfiguration, and manipulation tasks. A network of SuperBot modules can perform as both lattice-based and chain-type self-reconfigurable robots. A network of SuperBot modules is capable of sharing power and communicating using high-speed infra-red LEDs.

Specifications

Height84 mm
Width84 mm
Length84 mm
Module length168 mm
Weight500 g
Materialhard aluminum alloy
Controller16 MHZ ATmega 128 microcontroller

Overview

SuperBot designed for NASA space exploration programs. It's modules have three degrees of freedom, which increases the mobility and flexibility of individual and networked modules. They are designed to be strong, flexible, and capable of performing efficient locomotion, self-reconfiguration, and manipulation tasks.

A network of SuperBot modules can perform as both lattice-based and chain-type self-reconfigurable robots. A network of SuperBot modules is capable of sharing power and communicating using high-speed infra-red LEDs.

The on-board multi-threaded software controls modules’ functionalities and coordinates the behaviours of the network of modules in a distributed fashion.  

Design

SuperBot is intended to operate in a harsh and rough environment,  therefor the design has roughed and sealable modules. The modules and connectors cover the internal electronic and mechanical components and protect them from dust, moisture, and physical impact. 

SuperBot performs locomotion, manipulation and self-reconfiguration tasks in the presence of obstacles in an uncontrolled environment.  For that reason,  the robot's modules have enough dexterity to maneuver around obstacles to perform the task at hand and at the same time conserve energy by minimizing the number of required movements.  

The modules have enough torque to move and lift a number of neighboring modules and exert force whenever it is needed. This required maximizing the power of actuators while the size and weight of the modules are kept to a minimum.

A network of SuperBot modules are cognizant of their environment through a series of sensors which allow them to avoid obstacles and navigate in the environment. This includes the ability of sensing and communicating  with other SuperBot modules.

Superbot has distributed control software for effective use of  the robot. The control software is real-time,  fault tolerant and scalable.  In  addition,  it accepts and   executes high-level commands for locomotion, manipulation and self-reconfiguration from a remote host without requiring detailed instructions for individual modules.

Mechanical design

There are six connectors on each Superbot module; one on each side of the end effectors. Any of the six connectors of a module can connect to any connectors of another module in all 90◦ interval orientations. The drive train of each degree offreedom of a modul  consists of a MicroMo® DC electric   motor, a planetary gearbox, and an external gearbox. The DC motor outputs between 5 to 21.18 milli Newton-meter torque.   

Hardware architecture

Each module’s on-board hardware is responsible for controlling the actuators, connectors and sensors, power management, communicating with neighboring modules, autonomous decision-making, and distributed control of high-level behaviours. Each half module (cube) has a controller. The controller of the half module containing the battery and one motor is called  the  ‘master  controller’  and  the controller of the other half is called the ‘slave controller’. Both controllers are connected through power lines and a bi-directional 400 Kb/SI2C bus.  I2C is a two-wire bus and is selected to provide enough bandwidth between half modules and at the same time keep the number of wired among the cubes low.  Each controller is responsible for managing the motors, sensors, communication, power and docking of its corresponding cube. In addition, the master controller is responsible for running the  high-level behavior controller in each module.  

References

Discusses the considerations in designing SuperBot. Describes its hardware architecture and he software architecture. Describes some performance evaluation experiments; concludes and describes the future research directions.

B. Salemi, M. Moll, W. Shen. - IEEE/RSJ International Conference on Intelligent Robots and Systems, January 2007.

Describes a taxonomy of different architectures, as well as application areas of these type of robotics.

B. Salemi, M. Moll, W. Shen, et al. - IEEE Robotics & Automation Magazine, 2007.

Describes the design features of SuperBot modules. Presents the experimental results and a set of different locomotion modes and their characteristics. Introduces a set of potential space applications that utilize the SuperBot features, and concludes the paper with future work.

B. Salemi, M. Moll, W. Shen. - Article, September 2006. [Paywall]