Electronic suspension preferred over conventional suspension in all tested situations

Electronic suspension preferred over conventional suspension in all tested situationsTenneco Inc. recently published results of a survey showing that consumers experience a feeling of increased comfort, control and safety when driving cars equipped with intelligent (electronically-adjusted) suspension systems versus the same cars equipped with conventional suspension systems. They are also willing to pay for electronic systems.

In the survey,* conducted for Tenneco by TNS Infratest, 94% of sports utility vehicle drivers rated the overall driving experience with a semi-active suspension system as very good or excellent, compared with a rating of 73% for passive suspension systems. In the compact car segment, 86% of drivers rated their overall driving experience as very good or excellent compared with 61% for passive systems, while 88% of upper middle class) segment drivers rated semi-active suspension systems as very good or excellent versus 77% for passive systems.

Tenneco’s Monroe Intelligent Suspension technology continuously adjusts shock absorber damping levels to road conditions and vehicle dynamics such as speed, turning, cornering and other driver inputs to achieve an optimal balance between ride comfort and vehicle handling. The system can be switched from standard to sport or comfort mode at any time according to driver preferences without impacting vehicle dynamics.

The most significant improvement with intelligent suspension systems reported across all segments was vehicle comfort with road holding, stability, agility, control and safety all scoring strongly versus conventional systems. In addition, the ability to change the suspension mode at will resulted in a strong increase in scores for flexibility and driving fun versus conventional systems.

“Our test results confirm that intelligent suspension systems deliver benefits that consumers notice and prefer – notably that there is no need to compromise between ride comfort and handling,” said Sandro Paparelli, Vice President & General Manager, Tenneco Ride Performance Europe. “Consumers clearly feel that intelligent systems reconcile these differences to give drivers the pleasure of both, and they value the ability to vary their ride at the touch of a button.”

When evaluating intelligent suspension systems, 39% of compact car segment drivers said it should be standard in vehicles in all segments from compact class and above. In the SUV segment, 38% of drivers said it should be standard from middle-class vehicles and above. In both segments, drivers were willing to pay a higher price for vehicles incorporating intelligent suspension systems.

After driving both vehicles with and without intelligent systems, the purchase intention rate across all segments was 47%.

“By making vehicles capable of adapting to different environments, situations or ride preferences, intelligent suspension systems provide consumers with alternatives. They respond to today’s consumers who value both comfort and performance, and the freedom to choose their driving experience,” Paparelli concluded.

Following the consumer survey, a series of quantitative tests by TÜV SÜD using vehicles equipped with MonroeIntelligent Suspension confirmed better wheel to road contact, which helps avoid sideslip and oversteer, especially during cornering on uneven road surfaces. In more dynamic driving situations, such as lane changes or obstacle avoidance, the reduction in body movement was found to bring greater stability, which helps increase the feeling of comfort and safety.

*The survey included 155 German consumers who took part in comparative vehicle tests.

The technology

Continuously Variable Semi-Active Suspension (CVSA) changes the feel of a vehicle’s ride by continuously adjusting 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. CVSA is available with both internal and external valve technology in order to find the optimal packaging solution for each vehicle.

CVSA2 is Tenneco’s newest generation of lightweight semi-active dampers. Each damper features two independent electro-hydraulic CES valves for the rebound and compression motions to provide an increased tuning range to reach even higher comfort levels. CVSA2 uses electronic (CES)[1] valves developed by Tenneco in conjunction with Öhlins Racing.

Scalable Architectureuses unique actuator constructions to easily scale vehicles equipped with CVSA2 dampers up into more advanced electronic suspensions systems including Tenneco’s CVSA2/KINETIC® hydraulic anti-roll system and ACOCAR™ fully-active suspension system. The actuator constructions share components, production processes, sensors and electronic control units (ECUs) and can be extended with a variety of hydraulic ride height systems including discrete lifting, continuous leveling or hydro-pneumatic applications.

CVSA2/KINETIC® is an interconnected passive, reactive system that provides continuously controlled damping and high roll stiffness with reduced articulation stiffness. The system combines advanced mechanical and hydraulic systems with intelligent electronics, leading to a suspension concept that improves vehicle handling, stability and driver comfort.

Active Suspension Car (ACOCAR™) is a fully-active suspension system that includes actuators with two continuously variable CVSA2 valves and hydraulic pumps that bring energy to the suspension. The system controls roll, pitch and heave, resulting in superior handling, safety and comfort. ACOCAR targets the next generation of conventional, hybrid or electric luxury vehicles with availability for series production from 2015 on.

DRiV™ technology is derived from the CVSA model and features an affordable adjustable damper technology for the B/C vehicle segment. However, unlike CVSA, no dedicated ECU is required, helping reduce the system cost. The system packaging features 3 internal electronic valves working in parallel with the electronics integrated in the damper, providing minimal deadlength.

RC2 Frequency Dependent Damping offers all the advantages of an active suspension system at a conventional system cost. The system splits comfort and handling into two different frequency areas. Thanks to its unique ability to work bi-directionally in both rebound and compression, RC2 offers high damping at low frequencies for increased body control and low damping at high frequencies for improved comfort. Used as an integral part of the hydraulic valving system, RC2 ends the conventional system’s compromise between comfort and road-holding and without electronics.