The ATRON Self-reconfigurable Robot

The ATRON Self-reconfigurable Robotchallenges and future directions

The ATRON Self-reconfigurable Robotchallenges and future directions

Kasper Støy

AdapTronics GroupThe Maersk Institute for Production Technology

University of Southern Denmark

www.hydra-robot.dk

Kasper StøyAdapTronics Group

The Maersk Institute for Production TechnologyUniversity of Southern Denmark

www.hydra-robot.dk

ATRON

Terrestrial Self-Reconfiguration

Henrik H. Lund, Esben H. Ostergaard

Richard Beck, Lars Dalsgaard, Morten W. Jorgensen

Associated:

Kristian Kassow, Leonid Paramonov, Kasper Støy,

David Christensen, David Brandt, Danny Kyrping

Maersk Institute, University of Southern Denmark, Denmark

Self-reconfigurable robotsSelf-reconfigurable robots

ATRON ConceptATRON Concept

Key insight: 3D self-reconfiguration can be achieved even-though each module only has one rotational degree of freedom

Key insight: 3D self-reconfiguration can be achieved even-though each module only has one rotational degree of freedom

Mechanics : Prototype 0Mechanics : Prototype 0

Concept:

Using arms for alignment and screw to connect

Produced in 3D printer

Concept:

Using arms for alignment and screw to connect

Produced in 3D printer

Mechanics : Prototype 1AMechanics : Prototype 1A

Connector Concept Two arms

parallel to equator

Test of connector Too weak

Connector Concept Two arms

parallel to equator

Test of connector Too weak

Mechanics : Prototype 1BMechanics : Prototype 1B

Connector Concept Trippel Hooks Dual bars

Test of connector Prototype broke

Connector Concept Trippel Hooks Dual bars

Test of connector Prototype broke

Mechanics : Final PrototypeMechanics : Final Prototype

Improved main bearing

Improved connector-mechanism

Improved main bearing

Improved connector-mechanism

ElectronicsElectronics Two hemispheres

Two sets of main processors

Connector actuation Hemispheres

connected by slipring One power management

processor Sensors

Two hemispheres Two sets of main

processors Connector actuation Hemispheres

connected by slipring One power management

processor Sensors

Electronics : Power SupplyElectronics : Power Supply

Manages recharging Shares power Selects best power source Monitors the organism

power supply Regulates power 600 batteries sponsored by

Danionics

Manages recharging Shares power Selects best power source Monitors the organism

power supply Regulates power 600 batteries sponsored by

Danionics

Current MechanicsCurrent Mechanics

Final Module DesignFinal Module Design

IROS2004 - Demonstration videos

IROS2004 - Demonstration videos

Misalignment correction Double rotation Power sharing

Misalignment correction Double rotation Power sharing

Concept DemonstationsConcept Demonstations

David Christensen Meta module demo (ATRON Demo 1)

Jakob Stampe Mikkelsen Walker

David Christensen Meta module demo (ATRON Demo 1)

Jakob Stampe Mikkelsen Walker

Explored control conceptsExplored control concepts

Local control Local rules (Esben H. Østergaard) Gradients and scaffolds (Kasper Støy) Meta modules (David Christensen)

Centralized control Planning (David Brandt)

Local control Local rules (Esben H. Østergaard) Gradients and scaffolds (Kasper Støy) Meta modules (David Christensen)

Centralized control Planning (David Brandt)

Gradients and scaffoldGradients and scaffold

QuickTime™ and a decompressor

are needed to see this picture.

Local RulesLocal Rules

Esben ØstergaardEsben Østergaard

QuickTime™ and aYUV420 codec decompressor


Meta modulesMeta modules

David ChristensenDavid Christensen

QuickTime™ and a decompressor


ConclusionConclusion

Control achievements Control is difficult, but experience gained

ATRON Achievements Innovative connector design Innovative lattice structure resulting in

Simplified modules Easier control…

Control achievements Control is difficult, but experience gained

ATRON Achievements Innovative connector design Innovative lattice structure resulting in

Simplified modules Easier control…

IntermezzoIntermezzo

Queen of Denmark admires ATRON module together with the Japanese emperor

The Cruel Reality of Self-

Reconfigurable Robots





Vision of self-reconfigurable robots

Vision of self-reconfigurable robots

Robust Versatile Cheap

Robust Versatile Cheap

The Reality of Self-Reconfigurable Robots


Fragile Useless Expensive

Fragile Useless Expensive

Robust vs FragileRobust vs Fragile

Robustness comes from redundancy If a module fails it can be ejected and other

modules can take over Graceful degradation of performance

Robustness comes from redundancy If a module fails it can be ejected and other

modules can take over Graceful degradation of performance


are needed to see this picture. USC’s ISI

Robust vs FragileRobust vs Fragile

Difficult to detect if a module has failed Due to motion constraints it is difficult to eject the failed

module Due to weakness of modules it may not be possible to eject

the failed module at all

Difficult to detect if a module has failed Due to motion constraints it is difficult to eject the failed

module Due to weakness of modules it may not be possible to eject

the failed module at all

Versatile vs UselessVersatile vs Useless

A self-reconfigurable robot can change into any shape needed for the task

A self-reconfigurable robot can change into any shape needed for the task







Versatile vs uselessVersatile vs useless

In practice motion constraints make it difficult to change shape








David Brandt

Start

Goal


Too weak to interact with the world The ATRON and the MTRAN robots can only

lift in the order of a few modules

Too weak to interact with the world The ATRON and the MTRAN robots can only

lift in the order of a few modules

Cheap vs ExpensiveCheap vs Expensive

ATRON $2000 MTRAN $3500 ….

ATRON $2000 MTRAN $3500 ….



Fragile! Useless! Expensive!

Fragile! Useless! Expensive!

Challenges of self-reconfigurable robots


How do we Make robot strength greater than O(1)? Reduce motion constraints to facilitate easy

self-reconfiguration? Reduce the consequences of module failure? Reduce module complexity (cost)?

…while maintaining our successful results

How do we Make robot strength greater than O(1)? Reduce motion constraints to facilitate easy



Make robot strength greater than O(1)?

Make robot strength greater than O(1)?

Use module weight to gain leverage (seesaw)

Crystalline/Telecube parallel chains

….

Use module weight to gain leverage (seesaw)

Crystalline/Telecube parallel chains

….

Reduce module complexity (cost)?

ATRON is a step forward, but further - no idea…

Reduce module complexity (cost)?

ATRON is a step forward, but further - no idea…

Reduce the consequences of module failure?•No idea

Reduce motion constraints to facilitate easy self-reconfiguration?

Reduce motion constraints to facilitate easy self-reconfiguration?

Metamodules Scaffold Telecube

Metamodules Scaffold Telecube

Hypothesis Hypothesis

The challenges cannot only be addressed at the level of control

The challenges have to be addressed by new innovative hardware design

The challenges cannot only be addressed at the level of control

The challenges have to be addressed by new innovative hardware design



How do we design the module to Make robot strength greater than O(1)? Reduce motion constraints to facilitate easy



How do we design the module to Make robot strength greater than O(1)? Reduce motion constraints to facilitate easy



Deformable Modular RobotsDeformable Modular Robots

All modules are permanently connected in a lattice

Modules can only contract or expand

(limited but flexible

crystalline module)

All modules are permanently connected in a lattice

Modules can only contract or expand

(limited but flexible

crystalline module)

Concept DemonstrationConcept Demonstration

Physical implementation Deformatron Hexatron

Simulation

Physical implementation Deformatron Hexatron

Simulation

Deformable Modular RobotsDeformable Modular Robots

Make robot strength greater than O(1)? Through parallelisms

Reduce motion constraints to facilitate easy self-reconfiguration? Done

Reduce the consequences of module failure? Done

Reduce module complexity (cost)? No connectors

…while maintaining our successful results Shape change within limits No self-replicating robot

Make robot strength greater than O(1)? Through parallelisms

Reduce motion constraints to facilitate easy self-reconfiguration? Done

Reduce the consequences of module failure? Done

Reduce module complexity (cost)? No connectors

…while maintaining our successful results Shape change within limits No self-replicating robot

ConclusionConclusion

Self-reconfigurable robots are facing serious challenges Increase strength, reduce motion constraints,

increase fault tolerance, reduce complexity (price)

Radical new hardware designs needed Deformable modular robots may be able to

sidestep the hardest problems, but at a cost

Self-reconfigurable robots are facing serious challenges Increase strength, reduce motion constraints,

increase fault tolerance, reduce complexity (price)

Radical new hardware designs needed Deformable modular robots may be able to

sidestep the hardest problems, but at a cost