ArvinMeritor's car guys in Europe.

Taking advantage of the continuing trend of outsourcing sections of the vehicle to the full-service suppliers, the Light Vehicle Systems (LVS) business group of ArvinMeritor (www.arvinmeritor.com) has unveiled its suspension module product portfolio for the first time in Europe. It comprises the cross-car cradle module containing 12 major components including the axle, cradle, lower control arm, steering gear and stabilizer bar, the wheel-end module, and the coil-over shock module, all of which are in production. The parts of the portfolio currently in development are the air suspension systems, active roll control systems and the adaptive damping systems. New to the portfolio is the hydraulically coupled, electric power steering system that the company plans to develop and commercialize. Taken together, it is the extension of a strategy that has seen LVS supply three different suspension models for the 2005 Jeep Grand Cherokee in North America.

"We at LVS decided to put our efforts into the undercarriage strategy for ArvinMeritor as it is part of our heritage, it's in our DNA," says Sidney Del Gaudio, vice president and general manager of LVS undercarriage systems for ArvinMeritor. "We developed our suspension module strategy in 2002 resulting in the release of several products since then. However, while we have been strong in North America with our undercarriage business, it has not been the same in Europe, which is why we have decided to develop this strategy in the region. We have consequently set ourselves up in Augsburg, Germany, where ArvinMeritor already has an engineering center and plant, for this purpose."

While LVS has targeted SUVs and pick-up trucks in North America, it is spreading its aim far wider in Europe due to the fact that the light truck market here is far less developed. Consequently, it is now involved in developing the suspension module for an unspecified high-end performance car in Europe. Initially this will be for a limited production run, but Del Gaudio expects that the technology will be used in a way that is scaleable and so become affordable and fitted to a wider range of vehicles. "We already have interest from some customers in Europe," says Cesar Ungaretti, senior director of LVS Undercarriage Systems for ArvinMeritor, "but our plan is to grow and strengthen our light vehicle undercarriage product portfolio, including full integration of all systems impacting chassis performance.

Initially, though, it is meeting or exceeding the customers' functional requirements that are of fundamental importance if LVS's suspension strategy is going to make any advances in Europe. Simon Dean, manager, advanced undercarriage systems, LVS, argues that the challenges set by a European manufacturer of a high-end sports car are no more challenging than those set by a SUV manufacturer in the U.S. It is all about meeting the deliverables set by the customer. "While the expectations of customer A in the U.S., for example, are different to those of customer B in Europe, it doesn't mean that one is harder than the other, it's just that they are different. It's partly subjective but we also take objective measurements as far as isolation, ride quality or noise, vibration, harshness amongst other things."

"We also have a mobile lab," says Everett Hall, manager, vehicle dynamics and testing, suspension modules, LVS, "that we take to our customers so that we can do the development work with them and provide whatever level of service that they want. We'll tune dampers, we'll tune shocks and even sway bar mounts if necessary. We'll get down to the fine details so that we can understand the customer's desires more than just the functional requirements. We want to understand the synergy of the car and how one system affects another. We can do all the tuning mechanically, but we also have the software tools and can correlate our models so that we understand the vehicle and how changing a damper not only might affect the ride of a car, but also the handling characteristics. These are the kind of things we have in our mobile lab. This kind of capability that ArvinMeritor has in the U.S. is what we are in the process of bringing to Europe."

"When working on a project, it's extremely important that we also develop our own specifications," says Dean, "as they may be better than that asked by the customer."

"We not only look at the vehicles of the company we are working with," says Hall, "but also the vehicles that compete with it. It's a car culture, we are car guys and we like driving vehicles," he says with a glint in his eye.

As part of its suspension module product portfolio, LVS is currently developing a series of hydraulically-coupled, electric power steering systems designed to outperform other electric power steering systems.

ArvinMeritor acquired the patents from Techco Corp, a private intellectual property company that invents and licenses controlled-theory automotive steering applications but which has retained as a co-developer. "The development of this patented power steering technology, which has generated significant interest from our customer base, is directly in line with the company's strategy to design and deliver complete undercarriage systems," says Ungaretti. This on-demand power steering system, which is not constrained to packaging on the rack, will provide improved vehicle control, quicker steering response and measurable fuel savings for a full range of vehicles. Consuming only the power it needs when it needs it, the system is capable of adding functionality such as active return, autonomous parking and lane departure warning.

"We did a patent search when we first started getting into this field," says Hall, "looking at all the possibilities with steering systems. What we found was that there were several areas where there is technology available that would give us a kind of protected position. The fundamental heart of the technology is the closed-loop feedback control between the wheels and the steering wheel. The advantages are better feel, more precise control, meeting crosswinds, road crown sensitivity and advance features like auto-park and road following. However, it's not steer-by-wire as there is a direct connection to the road."

"The integrated chassis is the future," says Del Gaudio, "including hydraulically-coupled, electric power steering systems and making everything working together as a system is our ultimate goal with safety as the backdrop as we want to provide the safest vehicles for our customers. This is why we are developing so many advanced systems as we know that is the future and we want to be part of that."

By William Kimberley, Editor

Automotive Engineer, London, [e-mail]