Massively distributed Embedded Systems (MDES) such as Wireless Sensor Networks (WSN) are gaining increasing attention, since they enable a broad range of novel applications starting from monitoring oceans to exploring...
详细信息
Control systems for process plants are complex applications running in several interacting computers with varying degrees of integration. The construction, deployment and maintenance of the software system is a diffic...
详细信息
ISBN:
(纸本)0780379373
Control systems for process plants are complex applications running in several interacting computers with varying degrees of integration. The construction, deployment and maintenance of the software system is a difficult problem and distributedobjectoriented technology offers a good way to deal with it. The open standard CORBA provides flexible middleware capable of integrating complex applications in heterogeneous environments, but was originally designed with large business applications in mind and is not perfectly suited for the construction of control systems. Even with recent advances in the real-time specification for CORBA, it is only suitable for soft real-time applications and does not deal with the tight requirements of closed control loops. This paper describes the HRTC project, an experiment of CORBA-based control systems. This project addresses the analysis of the technology and the implementation of two testbeds, one in process control and another one in robot control. The benefits of such technology are discussed.
The Common object Request Broker Architecture (CORBA) is the most successful representative of an object-based distributedcomputing architecture. Although CORBA simplifies the implementation of complex, distributed s...
详细信息
ISBN:
(纸本)076951068X
The Common object Request Broker Architecture (CORBA) is the most successful representative of an object-based distributedcomputing architecture. Although CORBA simplifies the implementation of complex, distributed systems significantly, the support of techniques for reliable, fault-tolerant, and secure software is very limited in the state-of-the-art CORBA. Extensions, such Lis the CORBAsec specification provide only a limited choice of coarse-grained mechanisms to specify access rights for components. Any, fault-tolerance or security extension for CORBA components needs to trade off data abstraction and encapsulation against implementation specific knowledge about a component's internal behavior, resource usage, interaction and access patterns. These non-functional aspects of a component are crucial for the predictable behavior of security and fault-tolerance mechanisms. However, in contrast to CORBA's interface definition language (IDL), which describes a component's functional interface, there is no general means to describe a component's non-functional properties, such as security settings or fault-tolerance. Within this paper we present our approach towards role-based security for CORBA. Following the idea of aspect-oriented programming, we have developed a description language for security settings. The description language uses the extended Markup Language (XML) as an underlying representation and allows specification of access rights independently from an object's implementation. A role-editor tool allows for configuration of a component's security settings without affecting the component's source code. Security settings are enforced ky our enhanced version of the ORBacus CORBA implementation. We discuss the necessary description and configuration steps for a secure CORBA service. We demonstrate how our previously developed distributed tele-laboratory application can be configured for secure access. One many notice that, although this configuration step re
暂无评论