Chris Needes, a chassis segment developer at Saint-Gobain, gives his view of the latest advances in automotive steering systems and what changes an autonomous future may hold in store
What is your personal background and at which position are you at in the company?
I’m currently chassis segment developer at Saint-Gobain, producer of Norglide bearings and Rencol tolerance rings. I’ve worked for the Rencol brand since 1999, specializing in application engineering of steering systems, including upper column applications such as anti-theft, collapsible steering columns, and electric power steering applications. My expertise is in process benchmarking, project management, application development, materials and material forming processes. Having completed a degree in materials engineering at university, I started my career in 1987 at British Steel, working on automotive gear steels.
What is the latest steering systems innovation that Saint-Gobain has developed?
Several years ago, we started looking at innovation for steering systems and one of the things we realized very quickly was that while we understood component-level performance, we had not been able to fully understand the link between individual component performance and the overall steering system performance.
Consequently, we have invested in testing capabilities. We’ve built an anechoic chamber (pictured below), and developed an approach for testing rack noises at a system level so we can change individual components and look at the changes in noise and vibration performance inside that steering rack. Using a system testing rig, we can test the performance of the overall system with regards to torque and linear motion: we are able to apply a torque and look at the effect of linear motion to see if you get an equal effect. We are then able to really understand the complete system and we can then retrofit our components and look at the improvements in the entire steering column. We are able to identify weaknesses in components and focus our innovations in these areas.
We have the ability to test the noise and vibration of a complete steering system and to measure torque, frictional performance and linear movement inside the steering system, to understand how it behaves. Once you get the overall performance regarding torque and linear actuation, suddenly you can test everything up front. This benefits automotive manufacturers, allowing them to offer consumers increased steering wheel responsiveness and an enjoyable driving experience.
What are your current challenges when it comes to developing new steering parts?
Our biggest challenge has been understanding what all this brings to the overall system. For the last five or six years, we’ve had individual component test rigs – for example a linear friction tester in Germany – so we could look at an individual component and understand how it behaves as a single component. Often what happens is our components get used in a system and they’re tested by the automotive manufacturers, but we don’t see any output. All we hear is that it works fine, and the car producers want to go ahead with it.
We want to know what that system performance is now. That has been our biggest challenge. That’s why we have expanded our testing capabilities and are now working directly with system suppliers and automotive manufacturers on creating noise-free, responsive steering systems that will take driving experience to the next level.
Steering systems have changed a lot since the dawn of the automobile. What does the future have in store?
First of all, I want to challenge that statement – I don’t believe steering systems have changed that much. They have been very similar for 40 to 50 years. It has been a steel shaft connected via a pinion gear to a steel rack-shaft, and everything has been made of metal. Going forward, I think there will be a lot more lighter weight components, composites and plastics being used in steering systems.
Also, we’re looking towards trying to get an equal and opposite reaction. You want consistency. Historically, we’ve gone from a manual steering gear to a powered steering gear using a hydraulic pump, which gives you this feel of assist. If we are going to get to autonomous driving, however, we’re going to have to get consistency in the steering feel. If you go down different roads – cobbled stones versus a motorway for example – inconsistencies come about, which makes autonomous driving hard.
Going forward, the industry is going to try and find ways of making the whole system more consistent, lighter and more responsive. Instead of steel columns or aluminum columns, we might see a composite column in the future. Today, there’s more emphasis on bearings being more responsive, so if you put a micro amount of torque into a steering wheel you see a linear response to the steering. This is exactly what automotive manufacturers are looking at. If you move a steering wheel by two degrees, do you get an equal and opposite response from the road wheels? They want to see that. In the past, maybe you would move the steering wheel by three or four degrees and it wouldn’t change anything. That indicates a poor steering response.
The steering rack not only allows the driver to feel the state of the road beneath the car but also helps them to respond accordingly, creating the sense of control and enjoyment – a crucial factor in consumers’ perception of quality. The increased responsiveness also reduces stress and fatigue levels during the journey. These consumer trends are becoming more and more important and that’s where I see the future of steering system improvement.
Will there be significant changes to steering systems with the push towards autonomous driving?
There will still be what you would call a mechanical linkage – you’ve got a steering column linked to a steering rack. Ultimately, they want to go to true steer-by-wire but to do that requires a lot of changes and a lot of safety systems to be upgraded. You’ve got to optimize responsiveness, and you’ve got to prove that it can work across all systems. Autonomous driving is going to be good, but there are many things to solve first and a lot of it is responsiveness. At the moment, if you go down a cobbled stone road you feel it in the steering wheel. If you go down a smooth motorway, you feel it in the steering wheel.
With autonomous driving, who’s going to judge that? You’ve got to have a system in there to evaluate all these effects, and make a steering adjustment. We’ve got to get the computers to understand that and analyse the response they are getting back off the wheels.
What type of testing do you do for your customers in terms of steering?
We have always done individual component testing, so we’ve looked at friction, we’ve looked at levels of vibration, in regards to feedback from friction testing; we have looked at things like torque testing in the past; but everything has been worked on component by component – we never looked at the entire system. What we want to do now is understand the whole system and how it behaves. We want to be able to look at steering system torque, where you are looking at very small inputs, looking for an equal and opposite response in the rack. We need to be able to measure the linear movement of the steering rack in relation to the steering angle and the steering torque. And we need to be able to do all of this in an anechoic chamber and look at how that movement is generating noise and how we can design bearings that can limit or dampen that noise generation.
Doing this makes us much more relevant to the automotive manufacturers. This allows them to take that knowledge forward and say, ‘okay, how do we rewrite our performance specifications for a system so we get the best performance in future for individual components?’ The objective is always to get the best performance for the least cost. We’ve got to make car producers understand that the performance they have today doesn’t have to be the performance they can have tomorrow, and we can make step-changes. They can rewrite the specifications and really drive the market forward.
What trends in the industry have made this necessary?
One of the key trends remains weight and emissions reduction. I would, however, argue that adding weight to cars in the past has hidden noises; you dampen noises with weight. The industry is now trying to reduce weight to get the emissions down. When you get rid of weight, you get more vibration. With engines in cars now getting quieter, you are hearing things more easily. It’s the emissions trend that is really taking the weight out of cars and causing you to hear and feel things more.
I’ve had three generations of company car and every time I get a new one, the emissions get better. The first company car felt fantastic in terms of steering feel, but over time they’ve taken weight out of the car, and they’ve changed the type of steering system with each generation, and I honestly feel the performance of the steering system has decreased over that time.
That trend of reducing weight is going to continue: they want quieter cars and they want to reduce emissions. We’ve got to change system performance by changing components, which enables them, even though they are taking weight out, to still have the performance they had originally.
The big trend really is the emissions, the second trend is the quieter cars, and overall there’s more technology in the car nowadays. There are a lot more voice commands, a lot more self-parking. We talk about autonomous driving, and today you can press a button on a car and it will try and park itself. That’s the first step forward in autonomous driving. It’s a slow manoever though with a lot of radar and sensors. They are proving slow-speed manoeuvring to show that autonomous driving can work. The future is obviously high-speed autonomous motorway driving, but that needs a lot more confidence in systems to be developed.
About Chris Needes
Needes joined Saint-Gobain in 2008 as product manager in the automotive sector, after having worked for Rencol Tolerance Rings since 2000 as technical project manager and product manager in automotive. He began his career in 1987 working as an automotive product technologist for British Steel. He has a degree in materials engineering and is an expert in process benchmarking, project management, application development, costing, materials and material-forming processes. In his current position as chassis segment developer, Needes’ role includes business planning, developing global strategies, developing new applications, marketing materials and training materials.