An active rollover protection (ARP), is a system that recognizes impending
rollover and selectively applies
brake
A brake is a machine, mechanical device that inhibits motion by absorbing energy from a moving system. It is used for Acceleration, slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of ...
s 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
Electronic stability control (ESC), also referred to as electronic stability program (ESP) or dynamic stability control (DSC), is a computerized technology that improves a car handling, vehicle's stability by detecting and reducing loss of Tract ...
and its three
chassis
A chassis (, ; plural ''chassis'' from French châssis ) is the load-bearing framework of a manufactured object, which structurally supports the object in its construction and function. An example of a chassis is a vehicle frame, the underpart ...
control systems already on the vehicle –
anti-lock braking system
An anti-lock braking system (ABS) is a Automotive safety, safety anti-Skid (automobile), skid Brake, braking system used on aircraft and on land motor vehicle, vehicles, such as cars, motorcycles, trucks, and buses. ABS operates by preventing t ...
,
traction control
A traction control system (TCS), is typically (but not necessarily) a secondary function of the electronic stability control (ESC) on production motor vehicles, designed to prevent loss of traction (i.e., wheelspin) of the driven road wheels. TCS ...
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 barycenter or balance point) is the unique point at any given time where the weighted relative position of the distributed mass sums to zero. For ...
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 Suspension (vehicle), automotive suspension that uses an onboard control system to control the vertical movement of the vehicle's wheels and axles relative to the chassis or vehicle frame, rather than the conventi ...
system in rollover protection. To accomplish this, the onboard computer uses data from the
inertial measurement unit
An inertial measurement unit (IMU) is an electronic device that measures and reports a body's specific force, angular rate, and sometimes the Orientation (geometry), orientation of the body, using a combination of accelerometers, gyroscopes, an ...
(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 analogue of linear force. It is also referred to as the moment of force (also abbreviated to moment). The symbol for torque is typically \boldsymbol\tau, the lowercase Greek letter ''tau''. Wh ...
) 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 an automobile suspension part that helps reduce the body roll of a vehicle during fast cornering or over road irregularities. It links opposite front or rear wheels to a t ...
*
Crosswind stabilization
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Gyroscope
A gyroscope (from Ancient Greek γῦρος ''gŷros'', "round" and σκοπέω ''skopéō'', "to look") is a device used for measuring or maintaining Orientation (geometry), orientation and angular velocity. It is a spinning wheel or disc in ...
*
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
Side Impact Protection System (SIPS) is a passive safety system in an automobile to protect against injury in a side collision, developed by Volvo Cars.
History
SIPS was first introduced in 1991 for the Volvo 700, 900 and 850 series cars of mod ...
*
WHIPS
A whip is a blunt weapon or implement used in a striking motion to create sound or pain. Whips can be used for flagellation against humans or animals to exert control through pain compliance or fear of pain, or be used as an audible cue thro ...
(Whiplash Protection System)
References
External links
Continental Automotive SystemsSafelyThere – Continental Automotive Systems
{{Authority control
Vehicle safety technologies
Vehicle braking technologies