Systematic Damping
When it comes to driving comfort, dynamics and safety, the sMOTION active damping system has raised the bar. It is an enhanced version of the tried-and-trusted damping systems from ZF, as a more detailed look at the technology shows.
No doubt about it, vehicle damping requirements are high. The main task of the shock absorbers is to quiet down the vehicle body as quickly as possible after driving over bumpy road surfaces. Moreover, the shock absorbers must ensure that the wheels always have contact with the ground. Both tasks have a considerable impact on driving safety and ride comfort. Though hard damping increases both driving safety and dynamics, it also reduces comfort for the passengers. The reverse also applies: Soft damping increases driving comfort, but driving safety and dynamics suffer. What is needed is a balanced damping behavior. To successfully walk this fine line in all vehicle categories, ZF offers different types of shock absorbers.
Premium Add-on for Standard and Semi-Active Shock Absorbers
Today, modern passenger car chassis are almost exclusively equipped with hydraulic shock absorbers in a single or twin-tube design. A compromise always has to be made between a sporty and comfortable shock setup. In terms of design, these shocks consist of a cylinder in which a piston moves up and down, pushing the oil through openings or valves in the process. The resistance as the oil flows through the openings essentially determines the damping properties. Over the last 20 years, in addition to standard shock absorbers with a fixed characteristic curve, ZF has been offering shocks with Continuous Damping Control (CDC) as well as semi-active damping systems. sMOTION – since 2024 in series production – completes this product range as an active system at the top end.
Damping Systems for Any Purpose
ZF damping systems vary in their complexity, thus giving auto manufacturers the freedom to equip the same vehicle platform with one of its systems based on the model, engine type or configuration. The decision on which shock absorber will be installed also depends on whether a person will be driving the vehicle or whether it will be operated autonomously. Even for autonomous vehicles, an active chassis is important because the driver will no longer be permanently looking at the road. In light of this, sMOTION generates a noticeable gain in comfort, safety and driving dynamics.
How the Technology Works
Power perfectly metered
Frequency Sensitive Control (FSC)
The heart of FSC is a frequency-dependent valve module that divides the damping force characteristics in the rebound direction into highand low-frequency damping forces. In the case of low-frequency excitations – high cornering forces which occur during evasive maneuvers on the highway or when cornering on a country road – stabilizing, high damping forces are generated. The car is easier to steer, which increases safety. In case of high-frequency vibrations – small, rapidly occurring road unevenness from sources such as cobblestones, rough asphalt or tar patches – FSC operates on a low damping force level. The passengers remain isolated from the vibrations, which leads to a noticeable increase in comfort.
Optimum damping for every wheel on any road
Continuous Damping Control (CDC)
The semi-active damping system, which has proven itself millions of times over, constantly uses its sensor architecture to collect data on the condition of the road, the vehicle speed and driver actions and transmits it to a central control unit. A solenoid-controlled valve provides each individual wheel with the ideal damping force for the current situation. Because CDC can switch so smoothly and quickly, it can optimally cope with many challenges – and is able to do so in all vehicle segments, from compact cars to luxury sedans. CDC also guarantees a good ride on motorcycles, be it while racing through curvy switchbacks or on an adventure tour.
Smooth as can be
Active Damping Concept sMOTION
Each wheel is fitted with an actuator that can actively pull the wheel upwards or push it downwards. It almost eliminates car body vibrations that might be unpleasant for the driver and passengers. It doesn’t matter whether the vehicle is exposed to immense lateral forces when cornering fast, generating pitching movements when accelerating or braking, or driving over bumps, humps, rough asphalt, gravel or the like: sMOTION effectively smoothes over any unwanted, bothersome movement.
