Active Suspension System

Lore & Background

The pursuit of perfect stability led engineers to adopt 'Skyhook theory,' an ideal where a vehicle maintains a stable posture as if suspended from an imaginary hook at a constant altitude. Since an actual skyhook is impractical, real systems like Williams' 1992 F1 car used actuator operations based on data from acceleration sensors installed on the body. The system calculated an imaginary line of zero vertical acceleration to control linear springs and dampers. While this theoretically allowed the vehicle to remain completely fixed to that line if damping reached infinite values, the real-world implementation relied on high-pressure hydraulic servos controlled by electronic computing. These systems made rapid adjustments to suspension settings, allowing the car to react instantly to road conditions and driver inputs.

In Their Own Story

In 1992, Williams Grand Prix Engineering unveiled an active suspension devised by Frank Dernie that transformed their Formula 1 cars into dominant machines. The system utilized sensors to detect body movement and vehicle ride level, constantly supplying data to a computer that operated hydraulic servos mounted beside each wheel. As the car accelerated or braked, the servo-regulated suspension generated counter forces almost instantly to prevent dive and squat. During cornering, the chassis stayed remarkably flat, eliminating the roll that typically unsettled drivers. This performance was so superior that the FIA intervened, deciding to ban the technology specifically to decrease the gap between Williams and its competitors, ending an era where electronic precision could overcome mechanical limitations.

Reader's Guide

Active suspension in Formula 1 operates by using actuators to exert independent force on each wheel, raising or lowering the chassis based on real-time data. Sensors monitor acceleration and body movement, feeding this information to an onboard computer which controls hydraulic servos. This allows the system to virtually eliminate body roll and pitch variation during cornering, accelerating, and braking. The technology relies on a 'Skyhook' principle where the goal is to keep the vehicle stable as if suspended from a constant altitude line. While traditional suspension reacts to road irregularities after they occur, active systems use predictive or immediate counter-forces to maintain optimal tire contact and chassis levelness, though this complexity led to its eventual prohibition.

Did You Know?

• The FIA banned active suspension in Formula 1 as part of a broader push to reduce costs and driver aids, not solely to target Williams.
• The claim that Williams' 1992 system made around 1,000 adjustments every second is an unverified figure not confirmed in official F1 technical records.
• Active suspensions use actuators to raise and lower the chassis independently at each wheel, unlike adaptive systems that only vary shock absorber firmness.
• The 'Skyhook theory' imagines a vehicle suspended from an imaginary hook in the sky to maintain constant altitude unaffected by road irregularities.