DETROIT--While the switch to electric power steering will boost fuel economy, it also opens the door to driver-friendly features for Ford vehicles--specifically, parallel-parking assist and a torque-assist feature that reduces driver effort on crowned road surfaces.
By 2012, 90 percent of Ford's vehicles, including light-duty trucks, will be equipped with standard electric power steering, replacing hydraulic steering.
"It improves fuel economy by 3 to 5 percent--which, depending on the size of the vehicle and the engine, equates to somewhere between 0.4 and a full 1 mpg," said Ali Jammoul, chief engineer of North American chassis.
Ford is purchasing electric power steering systems from Delphi and TRW Automotive. Valeo provides the parking-assist module.
The parking system determines whether a parking space is large enough for the vehicle, using sensors at the front corners of the car. If the space is big enough, the driver activates the parking feature, places the car in reverse, takes his hands off the steering wheel and, by using the accelerator and brake, moves the car into the parking space. The system steers itself into the space.
Park-assist becomes possible because electric power steering has two elements hydraulic systems don't: a motor that can move the steering gear without human input and an electronic control module that tells the motor how much to turn the wheels.
"The system does the hard part for you, and I can pay attention to what is around me," said Erick Lavoie, design engineer for advanced chassis control algorithms, North America product development. A demonstration was conducted Thursday, March 12, at Ford's test track in Dearborn, Mich.
The parking-assist option will be available on the 2010 Lincoln MKS sedan and Lincoln MKT, Ford Escape, Ford Flex, and Mercury Mariner crossovers. The company gave no indication of what the system will cost.
The torque sensor, which Ford calls Pull-Drift Compensation, is standard with electric power steering. The sensor is activated when a driver needs to turn the steering wheel slightly to keep on a straight path when the pavement is uneven or winds are gusty.
(Source: Automotive News)