The Orocos Control Box project

Providing a FOSS solution to the controls community…

Objectives

The Orocos Control Box (OCB) project works towards an “easy to use” entry-level software system for controls engineers, including: realtime execution of control diagrams on realtime Linux-ready controls hardware; online plotting of signals; online configuration of control parameters; loading signals from file; storing measurement results to file; coordination of deployment of the system over desktop/laptop and dedicated control box; etc.

“Easy to use” means that OCB will provide a set of workflows that mainstream controls people expect to be available, and will make sure that these workflows are supported by a customized Graphical User Interface. For example:

• Making a controller in Simulink, 20Sim, Scilab,…, and execute the generated code in an Orocos component.
• Connecting to a control box running an Orocos application, and get the GUI that represents the actions that can be done with that application.
• Changing control parameters online, and immediately see their effects in the realtime plotted output signals of the control system.
• (Your workflow use case to be inserted here…)

The concrete short term objectives (i.e., to be finished before the end of 2011) are as follows: the EtherCat-based e/Box control systems (see picture below) should get (i) a graphical user interface (GUI) to launch, configure, log, plot, and coordinate Orocos control applications, and (ii) a set of control function implementations in C++ (as part of the upcoming Systems & Control Library in Orocos; this library will be designed to be stand-alone, hence not dependent on RTT).

Picture of two e/Boxes connected together. (The connection is not visible, since it is done at the back of the boxes.) Each eBox has two analog in/outs, two encoder/PWM connectors, and eight digital in/out pins.

Related projects

• EtherLab: a partially closed source by Ingenieurgemeinschaft IgH,.

Realtime software

• Orocos/RTT, the Orocos Realtime ToolKit.
• SOEM, the Simple Open EtherCAT master.

Graphical User Interface

Possible candidates:

• Kst (GPL)
• dygraphs JavaScript Visualization Library (MIT).
• Qt Creator (LGPL).
• QtPdWidgets Library (LGPL v3)

Control functionality and tools

Possible candidates:

• the soon-to-be-created Systems & Control Library of the Orocos project.
• Scilab/Xcos: has control design toolboxes, and code generation for realtime Linux.
• Scicos/Xenomai: idem.
• Python Control Systems Library (python-control).

Documentation

• Control theory.
• PID controller.
• Lead-lag compensator.
• Butterworth filter.
• Alpha beta filter.
• State Space control.
• Nonlinear control.
• Model predictive control.

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