The contribution of this paper is articulated around a new software design approach of autonomous control systems for connected vehicle platoons. Our control system is distributed and real-time based on object-oriented component-based method of design that brakes with the industrial traditions subject to cyclic OS-free approaches. We illustrate our design by relevant case studies of the longitudinal speed control widely studied in industrial and academic research around automotive platooning. Our software is mainly implemented using the Ada standard of programming (in particular the annexes D and E of real-time and distributed systems). The distribution in our software is managed by the versatile middleware PolyORB. The control scenarios and communication aspects covered by the case studies are animated by wheeled robot prototypes commanded by single-board ARM Cortex computers under real-time Linux kernels.