The 2013 Ford Fusion. Photo courtesy of Ford.

Ford mining mileage, new patents from Auto Start-Stop technology

The best technology does its job effectively and then gets out of the way.

As they strive to engineer better fuel efficiency for millions of drivers, Ford has more than 25 patents pending from their Auto Start-Stop technology, which is a $295 option on the all-new 2013 Ford Fusion.

“We set out to make Auto Start-Stop in the 2013 Fusion as seamless to drivers as possible,” said Birgit Sorgenfrei, Ford’s Auto Start-Stop program manager. “We wanted the system to improve fuel efficiency but otherwise remain transparent, so we developed a number of unique control strategies to smooth out the performance.”

It was one of the early advantages of the hybrid drive system, which would allow a gas engine to shut down when stopped, such as in rush-hour gridlock. Now this technology is migrating to many straight gasoline vehicles after being developed 15 years ago in the very first hybrid vehicles.

Ford’s Auto Start-Stop will now be available on the new Fusion featuring the 1.6-liter EcoBoost four-cylinder engine.

An ever more common feature on the newest vehicles, Auto Start-Stop switches off the engine when the car stops, instantly restarting it when the driver lets off the brake. This description, however, is a simplification of what really happens and just the tip of an engineering iceberg. That’s why Kirk Pebley and the Ford team have filed over 25 patents for innovations beneath the surface of the electronic controller system.

The new Fusion is the first Ford vehicle to offer Auto Start-Stop with a self-shifting gearbox. Automatic transmission requires maintaining hydraulic pressure even when the engine’s off, so Ford added an electric pump to the transmission, an upgraded starter,as well as an absorbed glass mat battery.

Nevertheless, combining Auto Start-Stop technology with an automatic involved more than just adding a pump. To speed launch after a restart, the engineers wanted the transmission in gear with the engine off – instead of shifting to neutral.

“We had to develop some unique control algorithms for the engine and transmission to overcome this obstacle and still ensure an extremely quick, smooth and quiet restart,” said Sorgenfrei.

“As the vehicle slows down, the brains of Auto Start-Stop are already hard at work even before the Fusion comes to a standstill,” said Pebley. “One of many keys to getting a robust engine restart is to make sure the battery has enough power to spin it back up.”

The controlling software also includes a simulation of the electrical system that constantly monitors the added power loads from accessory systems. It factors in the draw from headlights, climate control, audio and window defoggers; calculating how much power is available while the engine is off and how quickly the battery will drain. If the load is too demanding, Auto Start-Stop may be disabled to prevent a tough restart or a flat battery.

Voltage blending is another aspect currently under evaluation by the United States Patent and Trademark Office.


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