Enhancing the blackboard concept to produce a flexible, extensible knowledge-based design tool

MINDS (Measurement INterface Design System) is an interactive tool which supports the design of multisensor measurement systems and assists in the creation of a hardware and software structure which represents the knowledge required to build the system. It uses intelligent subsystems to provide specific information gathered from expert and detailed knowledge sources to support the developing design. MINDS-3, the current version of MINDS, is implemented as an enhanced blackboard architecture using Prolog in a Macintosh environment. Rather than describing the operation of the system, the paper takes a retrospective and more abstract view of a system implementation which has resulted in a flexible and dynamic architecture. It describes the requirements of MINDS-3, and how these led to an architecture which reflects the consideration given to the role and composition of the intelligent subsystems, the dynamic invocation and termination of the subsystems, the role of the user, and the positioning of the user interface in an interactive system. The resulting tailored blackboard architecture offers flexibility as its major strength, while making few modifications to the original blackboard concept. Nevertheless, difficulties in implementing the blackboard architecture for a system of this type (a single-tasking system) were experienced. The paper discusses the successes and difficulties of the MINDS-3 system implementation.