In response to market demand for Hardware-in-the Loop (HIL) testing, DNV is to offer a certification service for this new type of testing which may well become the industry standard.
Jon Rysst, head of DNV’s maritime technology and production centre says: “DNV is confident that such testing in the industry is a major step towards a better maritime test regime, and is consistent with DNV's increased focus on complex machinery systems.”
Increased complexity
Modern maritime machinery plants are constructed by integration of several computerised control systems and sub-systems. These systems are often delivered by many different suppliers. This has resulted in increased complexity of the machinery system. This has not been followed up with necessary development of quality assurance and the test regime.
“The result is a situation where the test methods have been lagging behind the technology progress. This situation has raised a need for improved comprehensive testing of complex machinery systems,” Rysst says.
In 2003 and 2004, Marine Cybernetics with support from industrial partners, developed and successfully demonstrated test simulation technology for maritime control systems. The demonstration tested a dynamic positioning system. This development has been based on HIL simulation technology, which has been successfully used in the automotive, avionics, space and offshore industries.
Test certification
“The HIL tests require deep technological knowledge of the target control systems. In addition, a large number of detailed HIL tests are available. This means that there is a need for a standard set of HIL requirements and interpretation of the actual test results by a third-party certification body. The stakeholders in the maritime industry have therefore challenged DNV to develop a certification regime for this new type of testing,” Rysst explains.
In response, DNV is developing a draft standard for HIL testing. The first part of this standard gives requirements to the HIL test supplier organisation and quality assurance procedures to be applied by the test supplier. Based on these requirements, DNV can certify the test supplier.
The second part of the standard gives requirements to certification of HIL testing for a specified shipboard system. The main requirements are related to the scope of the test plan, the test setup, HIL surveyors witnessing the tests, interpretation of the test results and requirements for possible re-testing. HIL testing may be performed for newbuildings during Factory Acceptance Tests (FAT), commissioning, sea-trials, as well as for ships in operation.
Industry standard
The main benefits of HIL are that the process simulates the vessel environment, enables comprehensive testing and radically expands test possibilities, the number of potential failure modes which can be tested. In addition, the process reduces the time needed for expensive sea-trial testing and allows for the training of operators.
“As a leading class society, DNV is confident that HIL is the best test method currently available and represents a significant step forward,” says Rysst and concludes “Indeed, the process may well become the industry standard, and compared to today's maritime test standards, enable a significantly improved testing regime. HIL also has the capacity to make systems safer. For these reasons, DNV is committed to HIL testing.”
