Separation of Concerns in Component-based Robotics

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Separation of Concerns in

Component-based Robotics

Davide Brugali

Università degli Studi di Bergamo, Italy

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Politecnico di Milano, 7-06-2010

Robot Control Architectures

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• Typical functions implemented in software

– Acquiring and interpreting input from sensors

– Controlling the motion of all moving parts

– Representing the robot’s and environment’s state

– Managing all kinds of resources (power, CPU, memory, devices)

– Planning future activities

– Reacting to unpredictable events

• Typical control paradigms

– Sense  Plan  Act

– Behavior-based control

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Robot Software Architectures

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• Typical aspects of software architectures

– decomposition of the robot control system into a collection of software components

– encapsulation of functionality and control activities into components

– definition of data flow and control flow among components

• Typical software quality factors – Reusability

– Portability

– Interoperability – Maintainability

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Control vs Software Architecture

W. Li, H. I. Christensen, A. Orebäck, D. Chen,

“An Architecture for Indoor Navigation”, ICRA 2004

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Control vs Software Architecture

M. Kim, S. Kim, S. Park, M. Choi, M. Kim and H. Gomaa

“Service Robot Software Development with the COMET/UML Method”, IEEE Robotics and Automation Magazine, March 2009

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Control vs Software Architecture

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Control vs Software Architecture

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Control vs Software Architecture

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Control vs Software Architecture

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Control vs Software Architecture

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Control vs Software Architecture

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Control vs Software Architecture

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 The same sensor component is not reusable in two different

robotic systems

 Where is the problem?

 Not in the control architecture

 Both architectures indicate that the sensors supply data

to the control modules

 Not in the software architecture

 The interaction pattern (push / pull) depends on specific

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Separation of concerns

• The implementation of the sensor components mixes two

different aspects:

– The component functionality

– The interaction mechanism

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Separation of concerns

different aspects:

– The component functionality is stable  should be reusable

– The interaction mechanism

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Separation of concerns

different aspects:

– The component functionality is stable  should be reusable

– The interaction mechanism is variable  should be flexible

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Separation of Concerns

18 Component Functional Specification Provided Interface Required Interface Contract 1..* 1..* 1..* Component Implementation * 1 * Object 1 * Class 1 * instance Component Extra-Functional Specification Computation Configuration 1..* 1..* Container * 1 * 1 * Resource Service Port System Specification Communication Coordination 1..* 1..* * 1 * System

Connector Connections E2E QoS

1 *

• IEEE RAM Tutorial on Component Based Robotic Engineering

• Part I : December 2009

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Component Interface & Implementation

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Component Interface & Implementation

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

Refactoring aims at restructuring a set of existing software

libraries without affecting their external behavior in order to

harmonize their architecture, data structures, and APIs.

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Refactoring Mobile Manipulation libraries

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CONFIGURATION C-SPACE

PATH INTERFACES FOR COLLISION DETECTION

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Component Interface & Implementation

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Computation

23 Sequential Components Navigator Service Components Path Planner Collision Checker Configuration Space Cartesian Space Map Updater Resource

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Configuration

24 Sequential Components Navigator Service Components

Path Planner Configuration Space Cartesian Space Map Updater Collision Checker Collision Checker Collision Checker Collision Checker Resource

Manager Container Component Scheduler QoS

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Communication

25 Distributed Middleware Container Path Planner Container Potential Field Navigator Event Manager Obstacle Avoider Event Manager

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Communication

26 Distributed Middleware Container Path Planner Container Motor Driver Navigator Stub Locomotor Scheleton

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Communication

27 Distributed Middleware Container Path Planner Container Motor Driver Navigator Stub Locomotor Scheleton

Assembly

_Assembly

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Coordination

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Coordination

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BRICS Research Camps on

Mobile Manipulation

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Invite best Ph.D. students AND PostDocs from all

over the world

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We will provide

− travel grants (1250 EUR for European students, 2000 EUR for international students)

− the latest and coolest pieces of robot hardware in mobile manipulation

− a DVD with best practice software for mobile manipulation

− a fast Internet access

− typical mobile manipulation tasks

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We expect in return

− a competitive solution to the given tasks either using the provided or self-developed algorithms for mobile manipulation demonstrated in two competitions on the last day of the research camp

− critical feedback and revisions of the provided hardware and software

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