Integration of CORBA services with a dynamic real-time architecture

Abstract

The Common Object Request Broker Architecture (CORBA) is the most successful representative for an object-based distributed computing architecture. Although CORBA simplifies the implementation of complex, distributed systems significantly, support of techniques for reliable, fault-tolerant software, such as onlinereplacement or replication is not within scope of today's CORBA or Real-time CORBA.The Simplex architecture developed at the Software Engineering Institute at Carnegie Mellon University supports the online-replacement of software components within a fault-tolerant, real-time control application. Simplex middleware consist of both a hard real-time publisher/subscriber service and a soft real-time service to support human-in-the-loop supervisor control activities.We have replaced Simplex' soft real-time services with CORBA services while retaining its hard real-time publication and subscription service. This composite approach allows us to take advantage of both the strength of CORBA in distributed computing and Simplex' strength in hard real-time control applications.In this paper, we will discuss the trade-off issues in this composite system approach and present the telelaboratory experiment, which is based on the extended Simplex system.

Mobility-as-a-Service: A Distributed Real-Time Simulation with Carrera Slot-Cars

“…Additionally, the board monitors 4 position sensor ports each of which can be connected to up to 8 position sensors. The race cars on the track contain an LED that produces an edge on a position sensor signal every k · 32μs whith the car id k ∈ [1,8]. An edge on a sensor signal triggers a procedure in the microcontroller that evaluates all sensors connected to the shared port that registered the edge.…”

“…While within the safety envelope, a advanced controller can deliver results in a higher quality than the safety controller, whose sole responsibility is to bring the system back into safe state. Within previous work, the authors have studied the integration of CORBA middleware with real-time control systems following the Simplex approach [8].…”