Active suspension
From Wikipedia, the free encyclopedia
Active suspension allows control of the vehicle body motions and therefore virtually eliminates body roll in many driving situations including cornering, accelerating, and braking.
This technology allows car manufacturers to achieve a higher degree of both ride quality and car handling. The Citroen Xantia 'Activa' for example was able to reach more than 1 g lateral acceleration. This technology keeps the tires perpendicular to the road in corners, allowing for much higher levels of grip and control.
Not possible before the advent of modern computing technology, an on-board computer detects body movement from sensors located throughout the vehicle, and controls the action of the active suspension with the use of hydraulic servomechanisms. The hydraulic pressure to the servos is supplied by a high pressure radial piston hydraulic pump. Sensors continually monitor body movement and vehicle level and supply the computer with new data constantly.
As the computer receives and processes data, it operates the hydraulic servos, mounted beside each wheel. Almost instantantly, the servo regulated suspension generates counter forces to body lean, dive, and squat during various driving maneuvers.
In practice, the system has always incorporated the desirable self-levelling suspension and height adjustable suspension features, with the latter now tied to vehicle speed for improved aerodynamic performance, as the vehicle lowers itself at high speed.
The drawback of this design (at least today) is high cost, thus it is only available on premium luxury cars.
Colin Chapman at Lotus Cars developed the original concept of computer management of hydraulic suspension, as a means to improve cornering in race cars. Lotus never developed a road going variant.
[edit] Production Vehicles with Active Suspension
- 1989 Citroen XM
- 1991 Toyota Soarer 'Active'
- 1994 Citroen Xantia Activa variant
- 1999 Mercedes-Benz CL-Class
