The 2012 Ford Focus' dual-clutch automated manual transmission will feature Torque Hole Filling technology, to help make shifts smoother.
When the Ford Focus goes on sale later this year, drivers should notice the next level in transmission shift quality.
The 2012 Focus will have what Ford calls Torque Hole Filling technology, a concept the automaker first patented a quarter century ago. While Ford has had a patent on the concept since the ’80s, it had to wait for computer technology to catch up.
Ford introduced the dual-clutch automated manual transmission on the 2011 Fiesta. Even without the THF, the transmission, which Ford calls PowerShift, was remarkably smooth. Still, traditional torque-converter automatic transmissions have an edge in smoothness compared to automated manuals.
But automated manual transmissions promise better fuel efficiency because they use computer-controlled automated clutches rather than inefficient torque converters.
So what is the torque hole? Typical transmissions have a break in power delivery between shifts. So every time the transmission shifts, no tractable power is going to the wheels, so there’s a hole in the acceleration.
THF adds a little engine torque to the driveline to smooth shifts.
The system uses a combination of mathematical algorithms, computer-aided engineering (CAE) tools and transmission control technologies to fill the torque hole.
To address the torque hole challenge, Dr. Davor Hrovat, a Ford Technical Fellow in Controls Research, authored an invention disclosure in the mid-1980s on how to coordinate engine and transmission controls to help eliminate the torque hole. Further analytical work and simulation revealed this pioneering concept was promising, but the technology needed to implement it wasn’t fully mature yet.
“Although the team has known what was needed to create smoother shifts, the actual implementation had to wait for drive-by-wire technologies, electronic throttle control and processing power to catch up to transform this inventive idea into a reality,” Ford Research Technical Expert Chris Teslak said.
Enabling technologies such as electronic throttle control and improved actuators and sensors, coupled with the THF methodology, gave the team of Ford engineers the tools needed to precisely sync transmission and engine to transfer and smooth out the torque during a portion of an upshift lasting a fraction of a second. Adding that little extra torque during the shift helps fill the hole, creating a smoother drive experience for the customer.
In total, the team logged approximately three years or 6,000 man-hours of computer-aided mathematical modeling, simulation and analysis of engine speeds, torque and clutch capacity in only 24 months real time to prove the THF concept was production-ready.
The bottom line is Ford says its internal evaluations show an improvement in shift quality of 2 points on a scale of 1 to 10.
Now that the automaker has perfected the technology for automated manual transmissions, it plans to turn its attention to applying the technology to traditional torque converter-equipped automatic transmissions.
Watch for a report on the Focus’ shift quality once we get a chance to drive it.