Atkins has been subcontracted to the project's preferred foundations supplier, joint venture Smulders Sif Steel Foundations, which was appointed in September.
Innogy said it was pleased to be using UK expertise in a local project.
"It's very exciting to know that UK engineering expertise will be at the heart of driving the design of a monopile foundation, which has the potential to be lighter than any currently installed in comparable site conditions, so helping to deliver cost reductions at Triton Knoll," said Innogy's foundations package manager Richard Hughes.
Atkins and Innogy are members of the Pile Soil Analysis (PISA) joint industry project looking at optimising monopile design.
Monopile design standards had used conservative figures, derived from the oil and gas industry.
PISA was launched in 2013 through the Carbon Trust Offshore Wind Accelerator programme, a UK government-supported agency that promotes cheaper offshore wind power.
Oxford University was heading the investigation with support from Imperial College, London, and University College, Dublin. Industry backers included developers Ørsted (formerly Dong Energy), Innogy, Statoil, SSE and Scottish Power Renewables.
The testing programme, located in different soil types in northern France and northeast England, was completed in September 2015, and the data has been under review since.
Innogy said the XL monopiles destined for Triton Knoll could be among the first to benefit from the research.
Andy Thompson, market lead for offshore engineering at Atkins, said: "Bigger turbines create different engineering challenges; given Triton Knoll is the first offshore wind farm to use the V164-9.5MW turbine, we're taking a unique approach to addressing the design questions posed by the project, drawing on all our previous offshore experience, in wind, and oil and gas."
Early findings from the PISA project found monopiles could use up to 35% less steel.
Triton Knoll secured a Contract for Difference (CfD) in September's auction at £74.75/MWh, and is due online in 2022. It will comprise roughly 90 MHI Vestas V164-9.5MW turbines, installed 22km off England's east coast.