|The air suspension system. Click to enlarge.
Continental has developed its first air suspension system for an all-electric vehicle. Following a shortened development phase, the first series delivery of the air suspension system started in spring 2012 to a manufacturer of electric vehicles. Continental’s experience of air suspension systems goes back more than 30 years; its chassis technology has been installed in luxury and other high-end vehicles as well as in minivans, pick-ups and vans.
The vehicle is the first purely electric vehicle to be equipped with a Continental air suspension.
An air suspension system automatically adapts damping and spring characteristics, along with the vehicle’s body level, to changing driving conditions and load changes. This reduces rolling and pitching movements and wheel load fluctuations. The efficiency of an air suspension system is based on the interaction between sensors, electronics, and mechanics. Continental supplies electronic air suspension systems including scalable compressors, valve block, control unit, sensors and software.
To meet requirements such as low weight and low energy consumption for the EV application—but without neglecting aspects such as comfort, range and driving pleasure—Continental developed a closed air supply system with a high-performance compressor and solenoid valve block.
The closed air supply system pumps the air at high pressure back and forth in a circuit between the reservoir and the air springs, allowing a virtually unlimited number of rapid, consecutive changes in pressure levels, said Christian Steinmann, Head of Segment Suspension Systems. Changes to the ride height are either made automatically by the control electronics depending on the vehicle’s speed or by the driver at the touch of a button.
The vehicle plus air suspension were designed as a coordinated package; Continental and the manufacturer specified the most important components and application parameters.
Many of the air suspension design’s functions had already been proven in previous projects, making it possible to produce a design concept quickly. Software modules assembled from the baseline—a database containing functionalities which had already been tested and approved—were used for the Chassis Control Unit (CCU).
Only the relevant communication and diagnostic parts were developed project-specifically and then the software functions were applied. The result is an integrated system, lighter than steel springs, which favors low energy consumption, Continental said. The option of lowering vehicle height also leads to lower air resistance, reducing energy consumption still further.