Continuous damping control
Continuous Damping Control (CDC)
The MAN Nutzfahrzeuge Group develops intelligent systems which protect driver, passengers, vehicle and road and also guarantee a very high level of safety.
One of these is electronic control of the shock absorbers called Continuous Damping Control (CDC) in trucks or Comfort Drive Suspension (CDS) in buses from NEOPLAN and MAN. Both systems are based on the new generation of air-suspension systems ECAS2 (Electronically Controlled Air Suspension) and modified dampers.
Intelligent damping in all situations
Continuous Damping Control (CDC) calculates all forces required from the shock absorbers as a function of the vehicle load and the nature of the road. It does this for braking and accelerating, on bends or on gradients.
A control unit, the system's brain, electro magnetically regulates a proportional value which determines the flow rate of the oil in the damper. If, for example, the valve is under a higher voltage, the opening in the damper is made smaller. The oil flows more slowly and the damping is "harder". The system calculates and regulates the damping force every 25 milliseconds and thus constantly reads the entire driving situation.
Height and pressure sensors in the vehicle supply the data for the calculations. The CAN bus also supplies the damper control system with information: road speed, retardation or acceleration signals, lateral acceleration and wheel speed are all included in the precise calculations. In just fractions of a second the CDC adjusts a basic damping applying in normal conditions to the new circumstances.
Normal damping can be varied in two stages, which the driver can conveniently select at a rocker switch. In a truck, for example, the centre of gravity can be optimised to achieve high-load stabilisation or roll stabilisation. In a coach the system meets the special demands for comfort or adjusts itself to the load. This dynamic stabilisation has further advantages: CDC reduces the tyre wear and protects the roads.
High safety means more favourable insurance
CDC tends to shorten the braking distance, the steering reacts in a more direct manner and the vehicle is comfortable and easy to operate. Even in serious situations it helps the driver to remain fully in control. A truck with CDC ensures a high level of safety.
Some insurance companies are so convinced of the benefits of this system that they want to offer cheaper policies. In trucks in particular, where loads and centres of gravity vary so much, stabilisation of vehicle roll is a real benefit for stability, cornering and safety. The load and the vehicle are protected, the service life of the components is considerably increased and the risk of accident significantly reduced.
