When the new 2011 Explorer goes on sale later this year, Ford plans to highlight the new unibody ‘ute’s safety and fuel efficiency. The Explorer will be exclusively powered by four- and six-cylinder EcoBoost engines, which are expected to increase efficiency by 20-25 percent, while delivering the power consumers crave. Expect more drivetrain details to be forthcoming, but before then, Ford invited us out to its Dearborn proving grounds to see what it has in store on the safety front.
Ford confirmed last fall that the Explorer would be the first vehicle to get its new inflatable rear seat-belts, but the latest – and arguably more interesting – feature on the Explorer is dubbed “Curve Control.” The system is a software enhancement built on top of the existing roll stability control (RSC) and electronic stability control (ESC) systems, and we had a chance to experience it first hand. Make the jump to find out more.
Gallery: 2011 Ford Explorer curve control demonstration
[Source: Ford]
According to Ford, over 50,000 accidents a year happen in the United States as a result of people trying to drive through curves (think highway interchanges) too quickly. This is especially problematic for SUVs, crossovers and pickups, which have a higher center of gravity and are more prone to trip-over curbs and shoulders when they run wide. The engineer’s answer to this problem is Curve Control, which goes above and beyond existing ESC to more actively slow down the vehicle when these conditions are detected.
Before we get into the nitty-gritty of Curve Control, let’s do a quick review of ESC. Electronic Stability Control is based on the hydraulic brake control technology originally developed for ABS and later, traction control. The hydraulic control unit has the ability to individually manage the pressure to each brake and, in the case of traction control, build pressure to the brakes on the driven wheels independent of the driver. For most ESC systems, the ability to apply brake pressure is expanded to all four wheels.
In order to manage the vehicle dynamics, ESC also includes a set of inertial sensors, including lateral and longitudinal accelerometers and a yaw rate sensor. Yaw is the rotation around the vertical axis of the vehicle when it’s turning or worse, spinning. These sensors help the system know what the vehicle is doing. Throttle, brake and steering angle sensors are used to determine what the driver is asking the vehicle to do.
The electronic controls include models of the vehicle’s dynamic behavior which are compared against the actual behavior and driver commands. The sensors are used to estimate factors like side slip at the wheels, front slip angles and overall body slip angle (slip angle is the difference between the direction that the wheels are pointed and the actual trajectory of the vehicle). A set of software control functions determine when the vehicle is not tracking where the driver wants, and the system uses a combination of individual brake applications and management of the engine torque to get the vehicle back on track.
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