Air of intelligence

Air spring technology is common on trucks and trailers, and has obvious advantages for off-road cars and commercial vehicles that do a lot of towing. It is also fitted on some luxury cars.

But even though the technology has been around for a while in these markets, it is not until recently that it has become a possibility for vehicles such as high-performance sports cars, ambulances, disabled transport, motor caravans and those carrying delicate loads.

Tyre giant Firestone has provided the missing link by using ride height sensors and an electronic control unit, called Intelliride, to allow the air springs to adjust to different loads, road conditions — or simply driver requirements.

Air springs produce spring force by compressing a trapped volume of air, contained by a sleeve-like reinforced rubber bladder held between two end-plates. The ride-height of the vehicle can be changed by controlling the air pressure inside the spring with an onboard compressor. Also, by profiling one of the aluminium end-plates into a conical shape, the volume of the air inside the spring can be changed, altering the spring rate or the resistance the spring produces when it is compressed.