The ZF sMotion chassis system is based on an enhancement of the CDC damping system.
ZF
ZF's scalable sMotion chassis system is based on the CDC damping system. It should be capable of "almost completely" isolating body movements from the passengers. This is ensured by intelligent actuators at each corner of the vehicle. They actively adapt each wheel's compression and rebound to the driving situation and road conditions. "When it comes to the development of highly automated and autonomous driving, the chassis plays a key role", says Dr. Holger Klein, head of the Car Chassis Technology Division at ZF. "By the time the autopilot takes over the wheel, all passengers want to be completely relaxed and unaware of the vehicle's movement, regardless of what is happening on the road."
The intelligent sMotion dampers not only dampen shocks, but can also noticeably counteract the vehicle's pitching, rolling and vertical movements. The compact unit comprising electric motor, pump and integrated electronics operates as a bidirectional actuator: The actuators can both pull up and push down the piston rod and thus each wheel. For example, they can retract the inner two and extend the outer two wheels in a bend to keep the vehicle nearly horizontal. The ground clearance can be controlled for the entire vehicle or for one axle or side as well.
ZF sMotion intelligent and fully active chassis
A second, separate hydraulic feedback control loop compensates for minor road irregularities such as transverse gaps or gravel. This enhancement of the CDC technology operates with independent compression and rebound stages, permitting active and stepless variation between hard (dynamic) and soft (comfort) characteristics. Networked sensors play a large part in the active chassis. Surround sensors such as cameras recognise the road conditions ahead so that the chassis can adapt to them. Vertical dynamics data is measured directly on the actuator units or via further sensors in the vehicle. The calculated damper data also can be transmitted to a cloud to warn following vehicles about dangerous road damage.