Continuously controlled Electronic Suspension
CES integrates the latest advances in both hydraulics and electronics into a highly advanced semi-active suspension technology. CES removes most of the compromise between ride and handling found in conventional suspensions. CES can provide sportscar characteristics in cornering and lane changes while giving the ride of a limousine during cruising.
In standard CES applications for passenger cars, cross overs and SUVs the driver can freely and at any time switch between different pre-programmed settings giving the suspension widely different characteristics, typically one comfort setting, one sport setting, and one advanced, adaptive seeting that automatically adjusts to the current driving conditions and the driver’s current driving style (cf. the example dashboard interface above). From these base settings the system automatically controls the damping charachteristics of each of the four shock absorbers in real time, changing settings up to 400 or 500 times per second, given information about the movements of the wheels and car body and many other parameters guaranteeing optimum damping performance in all conditions – all the time!
A typical CES system architecture is shown in the illustration below. The key components are the four shock absorbers featuring Öhlins’ controllable CES valves, position and acceleration sensors monitoring the movements of the wheels and body, and an electronic control unit realizing the control functionality and managing the necessary communication between the shock absorbers, the different sensors and other systems in the vehicle.
At the heart of the system is the CES valve, a hydraulic pressure controller specifically designed to fit the requirements for use in a suspension system. The CES valve combines a small size with a very wide working area and an extremely quick reaction time. Öhlins’ offer a wide range of valve products for shock absorbers of so called uniflow type, plus matching coils, meeting the demands of even the most challenging customers and applications. A selection of these products are shown in the picture below.
Öhlins also offer application and system development services and support our customers with different tasks such as shock absorber design and tuning, system design and sensor selections, and algorithm and software development.
In addition to CES valves designed for external mounting on uniflow shock absorbers we are also developing CES solutions for mounting on the piston rod in monotube and doubletube shock absorbers, actively controlling the oil flow in the shock absorber in both compression and rebound. More information about these developments is available upon request.
The high performance, quick response, and flexibility of Öhlins’ CES technology makes it very suitable also for other applications than passenger vehicles, including semi-active dampers for racing cars and motorcycles, for heavy trucks and buses, and for different types of military vehicles. The CES technology also offers new possibilities to improve the performance of other types of dampers, for instance cab and seat dampers in heavy trucks, excavators, tractors etc. Contact us for a discussion concerning the possibilities with CES!