An active rollover protection (ARP), is a system that recognizes impending
rollover and selectively applies
brakes to resist.
[http://www-nrd.nhtsa.dot.gov/pdf/esv/esv19/05-0471-O.pdf Bosch Rollover Mitigation Functions]
ARP builds on
electronic stability control and its three
chassis control systems already on the vehicle –
anti-lock braking system,
traction control and
yaw control. ARP adds another function: detection of an impending rollover. Excessive lateral force, generated by excessive speed in a turn, may result in a rollover. ARP automatically responds whenever it detects a potential rollover. ARP rapidly applies the brakes with a high burst of pressure to the appropriate wheels and sometimes decreases the engine torque
to interrupt the rollover before it occurs.
Rollovers can also occur when the vehicle is knocked into a stationary object such as a curb. In these so-called "trip events",
[Hrovat, Davorin D., Hongtei E. Tseng, and Michael G. Fodor. "Roll over stability control for an automotive vehicle having an active suspension". Ford Global Technologies, assignee. Patent 7140619. 2006.] a vehicle hit from the side but kept from moving laterally by a curb would produce a
moment about the
center of gravity
In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force ma ...
sufficient to produce a rollover. To counteract this, rollover stability systems have begun to incorporate an
active suspension An active suspension is a type of automotive suspension on a vehicle. It uses an onboard system to control the vertical movement of the vehicle's wheels relative to the chassis or vehicle body rather than the passive suspension provided by large sp ...
system in rollover protection. To accomplish this, the onboard computer uses data from the
inertial measurement unit (IMU) to determine when a vehicle is in a rollover condition independent of
yaw rate and vehicle speed. When the computer determines that the vehicle is at risk of rollover, it calculates the direction of roll and activates the active suspension system. The force produced in the suspension creates a moment (
torque
In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...
) opposite to that created by the lateral force, and keeps the vehicle safe.
Other uses
The phrase is also used for active roll over bars for convertible cars, such as the Volkswagen Beetle, which can detect potential roll-over situations and automatically raises rollover bars hidden in the rear head restraints in a fraction of a second.
See also
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Anti-roll bar
An anti-roll bar (roll bar, anti-sway bar, sway bar, stabilizer bar) is a part of many automobile suspensions that helps reduce the body roll of a vehicle during fast cornering or over road irregularities. It connects opposite (left/right) whee ...
*
Crosswind stabilization
Crosswind stabilization (CWS) is a relatively new advanced driver-assistance system in cars and trucks that was first featured in a 2009 Mercedes-Benz S-Class. CWS assists drivers in controlling a vehicle during strong wind conditions such as dr ...
*
Gyroscope
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Roll cage
A roll cage is a specially engineered and constructed frame built in (or sometimes around, in which case it is known as an exo cage) the passenger compartment of a vehicle to protect its occupants from being injured or killed in an accident, pa ...
*
Roll over protection structure
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Side Impact Protection System
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WHIPS
A whip is a tool or weapon designed to strike humans or other animals to exert control through pain compliance or fear of pain. They can also be used without inflicting pain, for audiovisual cues, such as in equestrianism. They are generally ...
(Whiplash Protection System)
References
External links
Continental Automotive SystemsSafelyThere – Continental Automotive Systems
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Vehicle safety technologies
Vehicle braking technologies