The document discusses Orocos, an open source real-time control software. It provides a component model for developing reusable software components for robot and machine control. The component model defines how components communicate through configuration, data exchange, and cooperation. An example application shows how components are connected to define the control behavior through state machines and different interaction patterns.

1. Flanders’
MECHATRONICS
Technology Centre
www.fmtc.be
Orocos
Open Robot Control Software
Peter Soetens
Flanders’ Mechatronics Technology Centre
Leuven
5 July 2006
V Jornades de Programari Lliure
Barcelona
FMTC Celestijnenlaan 300 D B-3001 Leuven Belgium
Tel: +32-16-32.25.90 Fax: +32-16-32.27.46 Email: info@fmtc.be FMTC 2006

2. Outline
1 Introduction
2 Approach
3 Results

3. Section Outline
1 Introduction
Examples
Challenges
Orocos’ Solution
Orocos History
2 Approach
The Component Model
3 Results
Interaction Categories
Example Application

4. Orocos in one-liners
Open Robot Control Software
⇒ Open Source ’robot’ control and interfacing
Real-time Software Toolkits in C++
⇒ Developer’s tool
Tool for developing components for control
⇒ Real-time, thread-safe, interactive
Offers common component implementations
⇒ Optional
Freely available on:
http://www.orocos.org

5. Outline
1 Introduction
Examples
Challenges
Orocos’ Solution
Orocos History
2 Approach
The Component Model
3 Results
Interaction Categories
Example Application

6. Interaction and Behaviour
Force control influences behaviour.

7. Interaction and Behaviour
Continuous control: tracking a light source.

8. Interaction and Behaviour
Continuous and discrete control: Placing a car window

9. Introduction
In these examples, Orocos was used to
do the real-time communications
define the real-time behaviour of machines in response to
communication
calculate real-time kinematics
access the hardware devices
create components which do all this.

10. Introduction
In these examples, Orocos was used to
do the real-time communications
define the real-time behaviour of machines in response to
communication
calculate real-time kinematics
access the hardware devices
create components which do all this.

11. Introduction
In these examples, Orocos was used to
do the real-time communications
define the real-time behaviour of machines in response to
communication
calculate real-time kinematics
access the hardware devices
create components which do all this.

12. Introduction
In these examples, Orocos was used to
do the real-time communications
define the real-time behaviour of machines in response to
communication
calculate real-time kinematics
access the hardware devices
create components which do all this.

13. Introduction
In these examples, Orocos was used to
do the real-time communications
define the real-time behaviour of machines in response to
communication
calculate real-time kinematics
access the hardware devices
create components which do all this.

14. Outline
1 Introduction
Examples
Challenges
Orocos’ Solution
Orocos History
2 Approach
The Component Model
3 Results
Interaction Categories
Example Application

15. What is Real-Time?
react always on time to a given event

16. Why Real-Time Software?
Consider solving. . .
Robot or machine interaction with the environment
Without guarantees.
What use is SLAM if your mobile platform bumps into
obstacles ?
What use is a camera if your manipulator crushes your
object ?
What use is controller tuning in MATLAB if the controller
fails in practice ?
⇒ They all need real-time control software !

17. Rapid Software Development
Consider solving. . .
More hardware ⇒ Much more software
With monolithic software.
New devices, same
problems to solve
More software and
features
Device connectivity and
networking

18. Safe Software Development
Consider solving. . .
More threads ⇒ Much more trouble
With bare threads and locks
as tools.
Deadlocks, thread races,
data corruption
Synchronisation
between threads ?
Communication between
threads ?

19. Flexible Software Development
Consider solving. . .
More layers ⇒ Less control
With closed toolkits.
’Solutions’ restrict the
solution
Software interaction ?
Dead vendor products ?

20. Outline
1 Introduction
Examples
Challenges
Orocos’ Solution
Orocos History
2 Approach
The Component Model
3 Results
Interaction Categories
Example Application

21. Rapid Software Development
Orocos provides . . .
Middleware for Machine Control
⇒ Software Component deployment and interconnection

22. Safe Software Development
Orocos provides . . .
Tools for Communication ⇒ Thread-safe and Real-Time

23. Flexible Software Development
Orocos is . . .
Free Software ⇒ Open Infrastructure with ∞ lifetime

24. Outline
1 Introduction
Examples
Challenges
Orocos’ Solution
Orocos History
2 Approach
The Component Model
3 Results
Interaction Categories
Example Application

25. History
2001: Started as a ‘small’ research project
Founded by Prof H. Bruynickx, KU Leuven
2001-2005: Developed during the PhD of Peter Soetens
Sponsored by the EU IST “Orocos”, “Ocean” and “Open
Machine Controller” projects and FMTC.
2005-. . . : Maintained by the FMTC.
‘Modular Machines Group’

26. Section Outline
1 Introduction
Examples
Challenges
Orocos’ Solution
Orocos History
2 Approach
The Component Model
3 Results
Interaction Categories
Example Application

27. Outline
1 Introduction
Examples
Challenges
Orocos’ Solution
Orocos History
2 Approach
The Component Model
3 Results
Interaction Categories
Example Application

28. A Software Component Model for
Control
Approach
Create a software component for each ‘task’ within the
machine

29. Component Definition
Communication
Defined by the
component interface
Middleware
Mediates component
communication and
distribution
Behaviour
Defined by real-time
state machines

30. Component Definition
Communication
Defined by the
component interface
Middleware
Mediates component
communication and
distribution
Behaviour
Defined by real-time
state machines

31. Component Definition
Communication
Defined by the
component interface
Middleware
Mediates component
communication and
distribution
Behaviour
Defined by real-time
state machines

32. Definitions
What is a Software Component ?
Definition
A modular and replaceable part of a system that encapsulates
implementation . . . and exposes a set of interfaces.
What is a Component Model?
Definition
A framework for describing components . . . with the purpose for
creating software from re-usable software components.

33. Definitions
What is a Software Component ?
Definition
A modular and replaceable part of a system that encapsulates
implementation . . . and exposes a set of interfaces.
What is a Component Model?
Definition
A framework for describing components . . . with the purpose for
creating software from re-usable software components.

34. What is a Component Model?
Component Model
Toolkit to describe
Real-Time components
Components
Re-usable part of an
application
Applications
‘Templates’ select and
connect Components

35. What is a Component Model?
Component Model
Toolkit to describe
Real-Time components
Components
Re-usable part of an
application
Applications
‘Templates’ select and
connect Components

36. What is a Component Model?
Component Model
Toolkit to describe
Real-Time components
Components
Re-usable part of an
application
Applications
‘Templates’ select and
connect Components

37. Section Outline
1 Introduction
Examples
Challenges
Orocos’ Solution
Orocos History
2 Approach
The Component Model
3 Results
Interaction Categories
Example Application

38. Outline
1 Introduction
Examples
Challenges
Orocos’ Solution
Orocos History
2 Approach
The Component Model
3 Results
Interaction Categories
Example Application

39. Component Interaction Patterns
In which ways can components communicate?
Configuration of parameters
Exchange data
Cooperate to achieve a task

40. Component Interaction Patterns

41. Component Interface

42. Component Interface

43. Component Implementation

44. State Machine Example

45. Outline
1 Introduction
Examples
Challenges
Orocos’ Solution
Orocos History
2 Approach
The Component Model
3 Results
Interaction Categories
Example Application

46. Example Application
How are these communication primitives used ?

47. Example Application

48. Application Template

49. Component Interface

50. Communication: Configuration
Configuration Flow : Properties

51. Communication: Data
Data Flow : Ports and Connectors

52. Communication: Data
Data Flow : Ports and Connectors

53. Communication: Execution
Execution Flow

54. Communication: Execution
Execution Flow: Methods

55. Communication: Execution
Execution Flow: Commands

56. Communication: Execution
Execution Flow: Events

57. Communication: Complete Picture

58. Behaviour — State Chart

59. Example Application Summary
The following steps lead to a control application design:
identification of the ‘control tasks’ → components
defining each component’s interface
setting up components connections
defining component or application behaviours

60. Outline
1 Introduction
Examples
Challenges
Orocos’ Solution
Orocos History
2 Approach
The Component Model
3 Results
Interaction Categories
Example Application

61. The Future of Orocos
Today:
Feature freeze, focus on usability:
Components, API, Real-Time Tookit...
Brand new Kinematics-Dynamics Library (KDL):
Online this summer.
Bayesian Filtering Library (BFL)
http://people.mech.kuleuven.be/~kgadeyne/
bfl.html
September 2006:
Orocos 1.0 Release and new web-site
Afterwards;
Focus on components and kinematics

62. Conclusion
Orocos offers
a software toolkit for building real-time components
rich online browsable component interface
user defined real-time state machines
Further Reference:
http://www.orocos.org

63. Recap: Data Flow Communication

64. Measurement results
Measure communication times with
ideal ‘instant’ communication
traditional ‘lock-based’ communication
‘lock-free’ communication for all communication primitives

65. Measurement results
Measure communication times with
ideal ‘instant’ communication
traditional ‘lock-based’ communication
‘lock-free’ communication for all communication primitives

66. Measurement results
Measure communication times with
ideal ‘instant’ communication
traditional ‘lock-based’ communication
‘lock-free’ communication for all communication primitives

67. Measurement results
Measure communication times with
ideal ‘instant’ communication
traditional ‘lock-based’ communication
‘lock-free’ communication for all communication primitives

68. Measurement results
Measure communication times with
ideal ‘instant’ communication
traditional ‘lock-based’ communication
‘lock-free’ communication for all communication primitives

69. Ideal ‘Instant’ Communication
Measured execution latencies: high and low priority.

70. Ideal ‘Instant’ Communication
Measured execution latencies: lower priority.

71. Validation : Data Flow
0.1
1
10
100
1000
10000
100000
1e-06 1e-05 1e-04 0.001 0.01 0.1
Occurences
Latency time ( s ). Bucket size: 5 us
0.5ms/0.1ms
0.1
1
10
100
1000
10000
100000
1e-06 1e-05 1e-04 0.001 0.01 0.1
Occurences
Latency time ( s ). Bucket size: 5 us
0.5ms/0.1ms
Measured communication latencies: high priority locked and
lock-free.

72. Validation : Data Flow
0.1
1
10
100
1000
10000
100000
1e-06 1e-05 1e-04 0.001 0.01 0.1
Occurences
Latency time ( s ). Bucket size: 5 us
1ms/0.2ms
0.1
1
10
100
1000
10000
100000
1e+06
1e-06 1e-05 1e-04 0.001 0.01 0.1
Occurences
Latency time ( s ). Bucket size: 5 us
1ms/0.2ms
Measured communication latencies: medium priority locked
and lock-free.

73. Validation : Data Flow
0.1
1
10
100
1000
10000
100000
1e-06 1e-05 1e-04 0.001 0.01 0.1
Occurences
Latency time ( s ). Bucket size: 5 us
2ms/0.3ms
0.1
1
10
100
1000
10000
100000
1e-06 1e-05 1e-04 0.001 0.01 0.1
Occurences
Latency time ( s ). Bucket size: 5 us
2ms/0.3ms
Measured communication latencies: low priority locked and
lock-free.

74. Conclusion
Orocos offers
a software toolkit for building real-time components
rich online browsable component interface
user defined real-time state machines
Further Reference:
http://www.orocos.org