China Classification Society (CCS) has established a digitalization rules system, to keep up with the development of ship digitalization, and ensure safety.
Ship digitalization rules system
onsidering the application scenarios such as inspection, testing and verification of digital technologies in ships and offshore facilities, the digitalization rules system shall at least contain the following aspects:
- Ship equipment and system digitalization: Propose technical requirements in multiple levels such as basic universality, spatial organization, virtual-real inter-operation and system application, for the physical entity, digital system and virtual space corresponding to ship equipment and system digitalization.
- Testing and verification: Establish applicable technical requirements and rules focusing on test rules, indicators and cases of digital system.
- Safety guarantee: Establish specific technical requirements in various aspects such as physical safety, functional safety, data security, information security, and network security corresponding to safety guarantee during the digitalization procedure of ships and their system.
The digitalization rules system framework should establish relevant technical requirements in four levels:
Level 1: Clearly stipulate the classification range and conditions for the digitalization of ships and offshore facilities, and specify unclassed survey and technical services.
Level 2: Clearly define the requirement for basic elements and data application capabilities of ships and offshore facilities digitalization, which is the most basic requirement of digitalization and also the technical platform on which other rules and guidelines can stand.
Level 3: Formulate technical requirement and inspection requirement for the digitalization of specific ships, offshore facilities and special technologies, put forward detailed technical requirements and indicators to specific objects of ships and offshore facilities, and use them in combination with the Level-2 basic rules.
Level 4: Formulate instructive technical methods, technical requirements and inspection requirements that are required by rules implementation and new service demands, and the categories of those requirements include guarantee requirements, standard data requirements, and data range requirements; prepare inspection guidelines on the digitalization and capability verification indicators, data application capability, and data verification for different equipment and systems.
II. Ship digitalization testing and verification
Effectively evaluating the ship’s digital system to ensure ship safety is an important challenge to the ship survey field, and it needs constant and in-depth research. At present, the combination of qualitative analysis and quantitative evaluation is used in the testing and verification of ship digital system.
First, it is to perform quantitative analysis on the existing digital system from dimensions such as performance, functions and safety, to obtain relatively objective evaluation; the quantitative analysis can improve the correctness and accuracy of digital system.
Then, qualitative analysis can be carried out by investigation, interview, and questionnaire survey to evaluate the ship digital system on the whole. Based on that, testing and verification of the ship digital system can be divided into the following four steps:
- Build an evaluation indicator system: Through analysis on the business expectations and capability needs of the ship-based system, define the system input and output, determine an evaluation indicator system and establish a capability feature library of the ship-based system.
- Generate simulation data samples: Analyze system and equipment characteristics in combination with business scenarios of the ship-based system, deduce verification elements of system design, design verification experiments, and generate experimental data samples by simulation.
- Establish a laboratory capability model: Match the capability model used by the ship-based system with simulation data samples, establish a confidence interval of the capability models, and adopt test samples for testing and verification to meet the evaluation indicator requirements.
- Verify full-scale ship data: Cut or copy in real time a certain quantity of verifiable data from the shipborne system, input it into the capability model established in Step 3; through comparing the model results with the evaluation indicators, determine whether the output of capability model meets the evaluation indicators. Considering the impact of data diversity on the capability model, this step needs to comprehensively calculate the results of comparison between the capability model and evaluation indicators. Only when the confidence degree of model conforms to a certain confidence interval, can it be judged that the capability model meets the business expectations and capability requirements.