Motion Feasibility Framework for Remotely Operated Vehicles Based on Dynamic Positioning Capability

Knowing whether a remotely operated vehicle (ROV) is able to operate at certain foreknown environmental conditions is a question relevant to different actors during the vehicle's life cycle: during design stages, buying an ROV, planning operations, and performing an operation. This work addresses a framework to assess motion feasibility in ROVs by using the concept of ROV-dynamic positioning capability (ROV-DPCap). Within the proposed framework, the ROV-DPCap number is defined to measure motion capability, and ROV-DPCap plots are used to illustrate results, for quasi-static standard (L2) and site-specific (L2s) conditions, and dynamic standard (L3) and site-specific (L3s) conditions. Data are computed by steady-state or time-domain simulations from the ROV model, depending on the desired analysis. To illustrate the use of the framework, numerical examples for L2 and L2s motion feasibility analyses for NTNU's ROV Minerva are provided. Motion feasibility can be used to know whether an ROV is appropriately designed for a specific operation and choose the appropriate one for a certain need, for instance, when designing the DP system components or planning an operation from the environmental data and ROV-specific information. As expected, predictions can be improved when more detailed information about the ROV appears; the same framework can be used to provide more detailed answers to motion feasibility-related questions. The results are likely to be straightforwardly understood by people whose work/training is ROV related and can interpret the graphic results for different operation scenarios.