Sir Ben Ainslie explains how the AC75\u2019s control systems work in the latest episode of our America\u2019s Cup podcastData from the AC75\u2019s complex systems will have a built-in time delay to prevent \u2018autopilot\u2019 sailing by
\nthe crew. Photo: Harry KH \/ Ineos Team UKThe systems that control the aero- and hydrofoils of the new AC75 are covered by some of the most complex parts of the America\u2019s Cup Class. The section on control systems takes up 12 pages of the 67-page rule.
\nThere has been a major philosophical change from the 35th America\u2019s Cup, when all the power to adjust the wing, sails and hydrofoils had to come from the crew. In the coming America\u2019s Cup, the AC75 rule requires the sailors to power the control of the soft wing mainsail and the headsail, along with legal rig adjustments like the runners, but allows electric batteries to power the hydrofoils.
\n\u201cWe\u2019re given a minimum number of batteries,\u201d explained Ben Ainslie. \u201cWe\u2019re allowed more but that\u2019ll add weight and because it\u2019s so tough to build these boats within the maximum weight rule, we really don\u2019t want to do that. So once again, it comes down to having super-fit sailors and efficient control systems so that we can really push the boat to its limits.\u201d
\nBut designing and building efficient control systems is a huge challenge. There are many competing requirements to be balanced in every element of the control systems and deck layout. \u201cThis is something that\u2019s a really interesting focus for all of the teams as we\u2019re coming into the design of the second boat, the race boat, and trying to work out just what the requirements of the crew are for this style of racing,\u201d said Ainslie.
\nReturn to grinding
\nWhat we won\u2019t see is any more cyclors: the rule has been designed to keep them out, and force the use of traditional grinding pedestals. \u201cI think it\u2019d be hard to find a way around that, but it doesn\u2019t mean that there isn\u2019t a lot of interesting work being done to work out how best to optimise the power of the sailors.\u201d
\nThis work will reach into many areas, and some of them will be obvious, like the position of the grinding pedestals. It\u2019s not just about power and efficiency, the position of the crew changes righting moment and the hull centre of gravity and impacts the potential top speed.
\nOthers will be more subtle, hidden in the hydraulic engineering and plumbing deep inside the boat. And between these two extremes will be what\u2019s now called the HMI \u2013 the human machine interface.
\nBack in the good old days this used to be the steering wheel and the sheets. The AC75 still has a wheel, but that may only be because the rule mandates it. The rest of the HMI is more likely to be a box of electronics with more than a passing resemblance to a games console. These will be on deck, but the teams will be doing their very best to stop the opposition and the fans seeing them.
\n\u201cLast time the rules tried to prevent the control of the boat by an autopilot,\u201d explained Ainslie. \u201cHowever, the rule only forbade direct control, and so that effectively left a loophole that allowed an autopilot to display its output.
\nAnd by that I mean what the autopilot thinks the foil should be doing to optimise performance, and the sailors [were] then able to control the foil to mimic that output by following a dot on the screen.
\n\u201cThis time around the Kiwis have reinforced the original intention to stop the boats being sailed by autopilots by delaying the instrument data that appears on the displays. It goes through what we call a media box. So there\u2019s a short time delay there. So even if you were to run an autopilot and show its output for the crew to follow, it would be a second or so behind the action, and that\u2019s a long time in a foiling boat.\u201d
\nThe enforced delay in the data appearing on the crew\u2019s displays, or Crew Information System (CIS) as it\u2019s called in the rule, is combined with a lot of other detailed rules designed to prevent the CIS from knowing anything about the boat state. It\u2019s all intended to prevent teams from running an effective autopilot.
\nArticle continues below\u2026<\/p>\n
\t\t\t\t\t\tRoad to the America\u2019s Cup podcast episode 1: Imagining the AC75<\/p>\n
\t\t\t\t\t\t\tThere is no doubt that the AC75 is a remarkable boat; a monohull designed to fly, engineered to reach speeds\u2026<\/p>\n
\t\t\t\t\t\tRoad to the America\u2019s Cup podcast episode 2: How the AC75 will fly<\/p>\n
\t\t\t\t\t\t\tAmerica\u2019s Cup teams first flew in San Francisco in 2013. The use of hydrofoils to lift the AC72 catamarans out\u2026<\/p>\n
Even slicker
\nThe outcome is that crews will need even slicker ways to control the systems that control the boat. That\u2019s why everyone will be so protective of what\u2019s on those games console-like screens.
\n\u201cWe do rely on guidance. We\u2019ve talked about autopilots that are not allowed under the rules, but there are certain prompts which help the key people in those trimming roles and steering roles to maintain the boat\u2019s optimised position or trim.
\n\u201cThen it\u2019s around your natural instinct as a sailor. It\u2019s the choreography of the whole team that will keep this boat sailing fast and racing well. It really comes back to a full team effort.\u201d
\nAbout the author
\nBen Ainslie is the most successful Olympic sailor of all time, and Team Principal of the British America\u2019s Cup challenger. INEOS Team UK will be challenging for the 36th America\u2019s Cup in New Zealand in 2021. Each month he talks to Mark Chisnell about the innovations and technology behind the new AC75 foiling monohulls.
\nThe post Road to the America\u2019s Cup podcast episode 4: AC75 control systems explained appeared first on Yachting World.<\/p>\n","protected":false},"excerpt":{"rendered":"
Sir Ben Ainslie explains how the AC75\u2019s control systems work in the latest episode of our America\u2019s Cup podcastData from the AC75\u2019s complex systems will have a built-in time delay to prevent \u2018autopilot\u2019 sailing by the crew. Photo: Harry KH … <\/p>\n