Mining the Numbers
Mining the Numbers
Sailing from the seat of your pants will only get you so far. If you’re looking to go further, check out this new performance-analysis system adapted from the world of Formula 1 racing. "Electronics" from our September 2010 issue.
Most of us gauge our on-the-water performance by keeping tabs on the instruments, eyeballing our competitors, or simply being in tune with the intuitive feeling from the seat of our pants. But imagine if you could explore virtually every nuance of your sailing to the nth degree—sail trim, design, and selection, maneuvers, straight-line speed, rig-tune, and anything else thinkable. At present, grand-prix teams use expensive custom electronic suites to capture, deliver, and dissect data into mind-numbing masses of gigabytes, but a few top teams have also caught onto off-the-shelf performance-analysis tools transplanted straight from the asphalt-laden realm of Formula 1 car racing. These systems, now being used on dinghies to 100-foot, record-breaking trimarans, are giving sailors the tools to ratchet up their performance to a much higher level.
The Pi Research system from Cosworth Electronics (headquartered in England and a major player in the Formula 1 industry) has two core components: a small, lithium-ion-powered data logger and the Pi Toolbox sofware. The logger itself has an integrated accelerometer (like the device in an iPhone) that measures motion on a three-way axis and a GPS. Additional sensors feed data to the logger: for example, a laser sensor (to measure rudder angle), load cells (to gauge rig tension), video camera, and output from onboard instruments.
The business end, however, is the Pi Toolbox sofware, which allows clever (and committed) sailors to explore and analyze the data in as many ways as are imaginable. One navigator that knows this, perhaps too well, is Robert Hopkins, a veteran of the America’s Cup, and early adapter of the Pi system. For the past year, he’s been using it on Hap Fauth’s R/P 69 Bella Mente, and is a true believer in its potential.
“The whole purpose of buying and changing an instrumentation system is to be able to analyze things better,” says Hopkins, who admits to spending an exorbitant amount of time customizing the Toolbox sofware for Bella. “What the Toolbox lets you do is develop a series of views, reports, charts, and graphs. Once you develop them, you can easily reuse them.”
On Bella Mente, the boat’s electronics processor (B&G WTP2) continuously feeds the Pi logger data, as does an onboard camera mounted on the stern. When sailing, Hopkins simply hits the log button and starts recording data. After racing, he transfers the data from the logger to his laptop via a memory stick and views the results in the Toolbox. In a few hours, he’ll have a report out to the team. The video is synced with the data, so, if need be, they can watch a specific maneuver alongside the boat’s vital signs, such as wind angle, boatspeed, acceleration, rudder angle, and pitch.
One of the frustrating things for navigators is analyzing straight-line performance using traditional strip charts. “They end up with a huge log and can’t fnd the part that they want to know more about,” says Hopkins. “If the log includes the period between races where the guys are having a sandwich, or when another boat is camping on you, it doesn’t work.”
Instead, the Pi system allows him to define what he calls “performance mode.” The logger instantly records when the boat is within a specifed number of degrees of its target angle and knots of its target speed.
“When certain conditions are met the data is deemed to be good,” he says. “If I watch a trace around the course I can see when the boat was sailing unimpeded and when it wasn’t.”
Hopkins also developed a way to watch all maneuvers, such as tacks, laid across each other. This allows him to see how many meters were lost in each tack, plotted against variables, such as turn rate in degrees-per-second or speed going into the tack.
And yet another critical application is a far better understanding of the boat’s sail inventory. The same level of data and analysis can be done on each sail, allowing them to more effectively compare the crossovers from one sail to another.
“In the Block Island Race, we were reaching and tried three different sails that we thought we knew well,” he says, “but using the analysis, we found not just which sail was best in each condition but the difference between the best and the second best sail. From that, and being able to put a value on every maneuver, a sail change for example, we realized that those differences are really important to understand when you’re making the decision to change to another sail.”
While Hopkins, and other top end programs—Niklas Zennström’s Rán, the Groupama trimaran, and assorted America’s Cup and Volvo Ocean Race teams—continue to independently develop the system to suit their needs, Cosworth has introduced a model developed for dinghies and keelboats alike.