The Orocos Component Builder’s Manual

Contents

• The Orocos Component Builder’s Manual

  • How to Read this Manual

    • Component Interfaces

    • Component Implementation

    • Orocos Toolchain Overview

  • Setting up the Component Interface

  • Orocos RTT Scripting Reference

  • Distributing Orocos Components with CORBA

  • Real-time Inter-Process Data Flow using MQueue

  • Core Primitives Reference

  • OS Abstraction Reference

  • Hardware Device Interfaces

How to Read this Manual

This manual is for Software developers who wish to write their own software components using the Orocos Toolchain. The HTML version of this manual links to the API documentation of all classes.

Component Interfaces

The most important Chapters to get started building a component are presented first. Orocos components are implemented using the ‘TaskContext’ class and the following Chapter explains step by step how to define the interface of your component, such that you can interact with your component from a user interface or other component.

Component Implementation

For implementing algorithms within your component, various C++ function hooks are present in wich you can place custom C++ code. As your component’s functionality grows, you can extend its scripting interface and call your algorithms from a script.

The Orocos Scripting Chapter details how to write programs and state machines. “Advanced Users” may benefit from this Chapter as well since the scripting language allows to ‘program’ components without recompiling the source.

If you’re familiar with the Lua programming language, you can also implement components and statemachines in real-time Lua scripts, check out the Lua Cookbook website.

Orocos Toolchain Overview

The Toolchain allows setup, distribution and the building of real-time software components. It is sometimes refered to as ‘middleware’ because it sits between the application and the Operating System. It takes care of the real-time communication and execution of software components.

Fig. 1 Orocos Toolchain as Middleware

The Toolchain provides a limited set of components for application development. The Orocos Component Library (OCL) is a collection of infrastructure components for building applications.

The Toolchain contains components for component deployment and distribution, real-time status logging and data reporting. It also contains tools for creating component packages, extremely simple build instructions and code generators for plain C++ structs and ROS messages.

Setting up the Component Interface

• The Orocos TaskContext Manual
  • Introduction
  • Hello World !
  • Creating a Basic Component
  • Connecting Services
  • Providing and Requiring Services
  • Using Tasks
  • Deploying Components
  • Advanced Techniques

Orocos RTT Scripting Reference

• The Orocos Scripting Reference Manual
  • Introduction
  • General Scripting Concepts
  • Orocos Program Scripts
  • Starting and Stopping Programs from scripts
  • Orocos State Descriptions : The Real-Time State Machine
  • Program and State Example

Distributing Orocos Components with CORBA

• Distributing Orocos Components with CORBA
  • The CORBA Transport
  • Setup CORBA Naming (Required!)
  • Connecting CORBA components
  • In-depth information
  • Code Examples
  • Timing and time-outs
  • Orocos Corba Interfaces
  • The Naming Service

Real-time Inter-Process Data Flow using MQueue

• Distributing Communication with Real-Time Message Queues
  • Overview
  • Transporting user types.
  • Connecting ports using the MQueue transport

Core Primitives Reference

• The Orocos Core Primitives Manual
  • Introduction
  • Activities
  • Signals
  • Time Measurement and Conversion
  • Attributes
  • Properties
  • Extra Stuff
  • Logging

OS Abstraction Reference

• Orocos Operating System Abstraction
  • Introduction
  • The Operating System Interface
  • OS directory Structure
  • Using Threads and Real-time Execution of Your Program

Hardware Device Interfaces

• Orocos Hardware Device Interface
  • The Orocos Device Interface (DI)
  • The Device Interface Classes
  • Porting Device Drivers to Device Interfaces
  • Interface Name Serving