Mixing simulations and real subsystems for subsea robot development. Specification and development of the core simulation engine

The core simulation engine is a distributed hardware and software environment that allows the interoperable use of simulations and real subsystems. Its primary role is to allow incremental, remote integration and testing of complex engineering systems such as underwater vehicles. Further applications include operator training, mission feasibility assessment and post mission replay. The paper discusses key issues in developing such a hardware-in-the-loop-simulation (HILS) involving an environment and physically distributed sub-systems operating in different logical and real-time modes. Time synchronisation, interoperability, simulation/real world calibration, and a subscription communications protocol are discussed. An implementation using PVM for distributed simulation support, dVise for modelling and a DSP-based vehicle communication spine is presented. A spin off approach for improved UUV navigation is also described.