Like a bird in flight
Automotive-sector | Bumps, joints, potholes: these things can be a nightmare for car drivers and passengers. thyssenkrupp Bilstein aims to put an end to all the frustration. The automotive expert is developing electronic shock absorber systems with intelligent data processing capabilities that can detect and deploy its suspension just when it is needed, making every car ride as safe and comfortable as possible. These sorts of shock absorbers, which recognize the road surface, are also crucial for the future of autonomous driving.
Cars jerk, bounce, jump and rock. “Vertical dynamism” is what experts call these forces and motions, which occupants of the vehicle experience in the form of vibrations. These vertical forces mostly consist of suspension and dampening forces that ensure the body is supported relative to the chassis and the vehicle’s movements are under control relative to the road. The springs absorb the impact from the roads and convert it into vibrations. The shock absorbers then counterbalance these vibrations for a smooth and safe ride. Without them, the car’s wheels would quickly loose traction on bumpy roads.
Vibration absorbers, not shock absorbers
Shock absorbers — the correct description should actually be vibration absorbers —counteract centrifugal, braking and acceleration forces. The traditional shock absorber responds to impulses coming from the road. But what if it could act in advance? If it saw approaching bumps and was able to deploy its dampening force at exactly the right moment? If it knew how fast and at which angle the vehicle would take a curve, and could react immediately? This is where Andreas Rohde comes in. He heads the Innovation and Technology division at thyssenkrupp Bilstein, where he and his team are researching how to more precisely transfer the dampening effect to the wheels and how to most efficiently filter the vast amount of data a moving vehicle provides every second so that its control system can send the right commands to the shock absorbers at the right time.
A shock absorber that thinks for itself
So-called semi-active shock absorbers are the latest technological advancement in this field. They incorporate highly developed software to utilize data collected by sensors on the vehicle in a matter of milliseconds. The high-end system developed by thyssenkrupp Bilstein is called DampTronic sky. Attached to each of the system’s four shock absorbers are two valves that can infinitely adjust the dampening effect via regulation of the compression and decompression, respectively. This way, optimal dampening can be achieved for each individual wheel. “Say, for example, that you drive over a speed bump with your front wheels. This information, along with the speed of the car and the height and width of the bump, is gathered and processed”, Rohde explains. Then, with the help of these valves, the rear wheels can react precisely: first in the compression stage, then in the rebound. “We know just how each individual shock absorber must be set for any situation in order to achieve optimum performance”, he adds. The tricky part is processing the driving and vehicle data. “We’re constantly at work trying to improve the algorithms we use to filter out the data relevant to the vehicle’s dampening from the vast pool of information gathered.” And with the advent of vehicle cameras, vehicle-to-vehicle communication and satellite data transfer, this flood of information is only set to increase.
Thinking about tomorrow today
Rohde tells us that this is all still a long way off, just like autonomous—or driverless—driving, which many vehicle manufacturers are currently working on. And make no mistake about it: thyssenkrupp Bilstein intends to be prepared when the time comes. Driverless cars will require even better shock absorber systems than those currently in use. Car bodies will have to be as resilient as ever against possible vibrations, not least in order to prevent motion sickness, but also to improve safety. Ideally, the vehicle’s occupants will glide straight over bumps, take curves, brake and accelerate without feeling a thing. “We’re trying to find out which forces and acceleration rates impact the human body and interact with other sensory perceptions to cause motion sickness”, says Andreas Rohde. “We will use this information to improve and adapt our dynamic stability control.” Perhaps one day, driving will be as smooth as train travel.