Researchers, developers and system integrators require more openness in control systems in order to design, develop and rapidly integrate functionalities to fulfill new application requirements. Even if several robot control vendors provide their products with customized development tools, low cost and not proprietary solutions should be preferred to face the rapid market changes and to reduce control life… cycle costs. In fact, most important success factors are the use of off-the-shelf hardware and open source and/or free software, as well as a design focused on reconfigurability and portability of the control software is crucial. In this paper a control architecture which complies with the above mentioned requirements is presented. Specifically a modular control portable on different platforms has been designed, implemented and then validated on two different platforms both based on real-time operating systems (RTOS). The porting activity between the two platforms and specifically between QNX 4.25 and RTAI Linux has been done using features compliant to the POSIX standard. As specific target, the proposed architecture has been exploited to control two robots with different kinematics architectures. The first one is a 4 d.o.f parallel robot prototyped at ITIA-CNR while the second one is an industrial 7-d.o.f robot manufactured by Mitsubishi which is based on a serial kinematic chain. The obtained results for the second application case are presented more in detail. Such a robot has an open architecture dedicated to Research & Development that allows the direct control of servo PLC controller through an upper level PC controller. To guarantee the real-time communication, the servo and upper level controller are linked by a dedicated fiber optic network based on Arcnet interface at 100 Mb/s. Procedures have been developed to move the robot in a safe and robust way.

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