Tenneco Inc. (NYSE:TEN) today introduced its “Scalable Architecture” concept for advanced electronic suspension technologies. This uses intelligent actuator constructions to easily scale semi-active suspension systems up to advanced and fully-active applications.
Tenneco’s Scalable Architecture concept leverages the power of Tenneco’s latest generation of Continuously Variable Semi-Active Suspension systems (CVSA2) which continuously adjust shock absorber damping levels to road conditions and vehicle dynamics like speed, turning, cornering and driver inputs. The system provides optimum driving safety and improves ride smoothness and NVH (noise, vibration and harshness), achieving the optimal balance between ride comfort and handling. Each CVSA2 damper features two internal, independent electro-hydraulic (CES)1 valves developed by Tenneco in conjunction with Öhlins Racing which provide an increased tuning range in rebound and compression motions to reach even higher comfort levels than first generation CVSA dampers featuring external valves.
The CVSA2 system is triggered by a powerful Electronic Control Unit (ECU) designed to exploit the full potential of the electro-hydraulic valving system by processing input data sent by a group of sensors placed at key locations on the vehicle. Further input signals are provided from the in-car network (CAN).
The CVSA2 system uses control software that processes the sensor information regarding steering wheel angle, vehicle speed, brake pressure and other chassis control information and sends signals that independently adjust the damping level of each shock absorber. CVSA2 dampers allow a large separation between maximum and minimum damping levels and adjust instantaneously to ensure the optimum in ride comfort and firm, safe vehicle control.
Using Tenneco’s unique Scalable Architecture concept, platforms already equipped with CVSA2 can be easily upgraded with Kinetic H2CES or ACOCAR as an option. The actuator constructions share components, production processes, sensors and ECUs.
Kinetic™ H2 CES is an interconnected passive, reactive system that provides continuously controlled damping and high roll stiffness with reduced articulation stiffness. Vertical tire loads are optimized, resulting in significantly improved on-road traction and performance. The continuously controlled damping works with the “skyhook” principle for body control with additional algorithms for wheel hop, steering, braking and acceleration control.
In the new-generation Kinetic™H2 CES system, the front anti-roll bar, rear anti-roll bar and four shock absorbers have been replaced by four double-acting hydraulic cylinders each with two integrated CES damper valves in each corner, four roll accumulators, local comfort valves, an automatic pressure maintenance unit (APMU) and interconnecting hydraulic lines. The two CES damper valves restrict the flow between the cylinder and accumulators to electronically control roll, bounce and pitch modes, allowing decoupling of transient ride and handling performance. Combined with intelligent control algorithms, these allow independent control of body and wheel motions.
Using the Scalable Architecture concept, Kinetic™H2 CES can easily be implemented as an option on platforms already equipped with the CVSA2. The anti-roll bars are replaced by hydraulic connections between the corners and the system can be extended with a variety of hydraulic ride height systems including discrete lifting, continuous leveling or hydropneumatic, to fully leverage the APMU.
ACOCAR™ is the next generation of advanced and innovative Tenneco suspension systems – a fully active system which provides ultimate comfort for the driver combined with excellent handling.
Hydraulic pumps have been added to the shock absorbers. These bring energy to the suspension, resulting in better control of damping and spring forces. Additionally, oil is constantly circulated through the shock absorbers whose damping valves can each be closed independently to make the car body move up when it would otherwise be moving down and vice versa. In this way the system works to keep the car body flat at all times while controlling wheel movements to improve tire to road contact. The addition of a pump at each corner means the system does not depend on the movement of the wheels to generate damping force. The result is that the ACOCAR™ system controls roll, pitch and heave, therefore providing superior handling, safety and comfort.
Using the Scalable Architecture concept, ACOCAR™ can easily be implemented as an option on platforms already equipped with CVSA2 by replacing the anti-roll bars by electro-hydraulic power packs on each corner. As with Kinetic™H2 CES, the system can be extended with a variety of hydraulic ride height systems including discrete lifting, continuous leveling or hydropneumatic, to fully leverage the APMU.
