Ford Brings Electric Power Steering to More Models
DEARBORN, MI --- Ford Motor Co. said it has opted to bring its Electric Power Steering (EPS), designed to enhance drive quality and control, to a variety of Ford, Lincoln and Mercury products.
One EPS-enabled feature, pull-drift compensation, is a software-based technology that helps drivers offset vehicle pulling or drifting that can occur in steady crosswinds or on uneven roads.
"Pull and drift are major customer annoyances that have been difficult to completely eliminate because of multiple factors that contribute to this phenomenon," said Ali Jammoul, Ford's chief engineer for chassis engineering and steering systems. "Ford's innovative pull-drift technology compensates to provide driving comfort straight down the road, even in steady crosswinds and on banked and uneven roads."
Customer complaints about a "constant pull or drift to one side" or "steering that requires extra uneven effort" historically have been a source of customer dissatisfaction in steering, ride and handling in quality studies. Ford's EPS with drift-pull compensation is projected to improve customer satisfaction in these areas by up to 50 percent.
The 2008 Escape, one of the first vehicles to showcase EPS with pull-drift technology in North America, substantiated this projected improvement, cutting the number of customer complaints associated with steering in half.
EPS uses sensors to constantly measure the wheel torque applied by the driver to maintain the vehicle's path. The feature continually resets to adapt to changing road conditions or the vehicle turning a corner. Ford's pull-drift software technology gives the EPS system the added ability to compensate for slight steering torque changes caused by environmental factors such as road crowning or steady crosswinds.
"If you're on the expressway and the road is crowned to the left or right for better water drainage, for example, you may need to make a slight steering compensation for that crowning," said Brian Kosztowny, a Ford product development engineer in vehicle dynamics. "With pull-drift compensation, the EPS system gradually will dial in torque for easier steering in these conditions without the driver feeling it in his or her fingers or needing to make an extra effort. The electric motor does more, so you don't have to."
Ford's application of this technology only corrects for road and environmental conditions within reason, adding slight torque up to a proprietary set limit so inherent steering issues are not masked. In addition, Ford has fine-tuned the software-based technology so it can be adapted to fit driving characteristics of individual products, whether it's a luxury sedan or a sporty compact SUV.
Ford's Active Park Assist -- which debuts on several 2010 Ford, Lincoln and Mercury vehicles -- is, in fact, enabled by EPS. This technology uses EPS and an ultrasonic-based sensing system to position a vehicle for parallel parking, calculating the optimal vehicle angle and carefully steering the vehicle into a parking spot.
EPS also can be programmed to communicate with a vehicle's camera, opening the door for Ford to introduce lane-assist and accident avoidance systems such as lane departure warning systems.
"EPS gives us more warning options for these advanced systems," adds Darrel Recker, Ford's EPS supervisor. "With EPS, we can consider more tactile versus visual warning mechanisms, such as a vibration in the steering wheel, and we don't have to add a lot of components or additional hardware to make it happen."
EPS has the potential to add steering features for comfort and personalization. Ford currently is examining how to calibrate the system so that customers can select their desired steering effort. Drivers that prefer a sportier ride, for instance, would choose a higher steering effort than someone who prefers a more luxury-car feel.
EPS continues to gain momentum in North America, with Ford acting as a major player in adapting this technology across nearly 90 percent of its lineup by 2012. For 2010, the Ford Fusion, Mercury Milan, Ford Taurus SHO and Lincoln MKT include EPS.
Ford's aggressive migration of EPS represents up to a 5-percent gain in fuel economy for each product application and CO2 emissions savings of approximately 3.5 percent because the system operates on demand. EPS also means less maintenance for customers since it is completely free of the complicated mix of hydraulic pumps, hoses, power steering fluids and drive belts that can require regular service and repair.
"As we use advanced technology such as electric power steering to improve fuel efficiency across our vehicle lineup, we have the opportunity to introduce new innovations such as pull-drift compensation and Active Park Assist," said Ford's Jammoul. "We are applying these technologies not for the sake of technology, but because they meet the needs and wants of our customers."