CDC

The task

Over recent decades, electronic systems have substantially enhanced the operation of vehicle mechanical functions - and the field of damping technology is no exception. Development work on the next generation of vehicles is focusing to an ever greater degree on active and semi-active damping and suspension systems. With its electronically controlled damping systems, ZF is setting new standards in driving safety, comfort, and dynamics.

One of the strenghts at ZF is that it supplies not only components but also entire systems including both hardware and software. ZF Sachs is also a leading module supplier of active chassis systems such as roll stabilization, spring mount adjustment, and pneumatic suspension. Many of the major vehicle manufacturers rely on the systems expertise of ZF Sachs for their high-end products.

Today's mid-sized and high-end vehicles feature a number of active electronically controlled systems that have thus far operated largely independently of each other. In order to further resolve the compromise between driving safety, comfort, and dynamics, the automotive industry is increasingly seeking to integrate individual systems. ZF is superbly prepared for this development and will play an active role in shaping it.

Function & Benefit

The technology

CDC is an electronic damping system that noticeably increases driving safety, comfort, and dynamics by adjusting damping forces optimally for each individual wheel. A control unit calculates the requisite damping forces within milliseconds, and adjusts the dampers just as quickly. Vehicle sensors monitor values such as body, wheel, and lateral acceleration, and use them to generate the ideal damping forces for each individual wheel on a continuous basis.

1. ECU
2. CDC damper
3. Body acceleration sensor
4. Wheel acceleration sensor
5. CDC valve

CDC® - Skyhook control strategy

Damping forces for each wheel are individually controlled for the directional movements of wheel and body. Thus they always provide the best possible compensation for vehicle body movement relative to a stationary center position. The skyhook principle keeps the vehicle body as stable as possible, independent of driving and road conditions. The control strategy seeks to calm vehicle body movement, as if the moving vehicle were connected to a hook fixed on the sky. As a result, the body moves along like a sedan chair parallel to the sky.

Benefits

• Greater safety thanks to optimized wheel damping
• Enhanced driving comfort and dynamics
• Reduced roll, pitch, and vertical motion
• Shorter braking distances thanks to better road contact
• Continuous adjustment in real time
• Faster steering response
• Better control and handling during lane changes
• Available with external or internal valve