Vibracoustic addressing emerging AV challenges

DARMSTADT, Germany—Vibracoustic GmbH has developed a range of noise, vibration and harshness solutions, specifically to address the emerging challenges of autonomous driving.

According to Vibracoustic, NVH likely will be a critical factor to acceptance and mass adoption of self-driving vehicles, as drivers and passengers will have a heightened perception of NVH issues in driverless cars.

"Once the driver becomes a passenger without the need to control the vehicle or focus on the road, their perception of noise, vibration and harshness are significantly enhanced," said Dr. Joerg Boecking, Vibracoustic's chief technology officer.

Vibracoustic has, therefore, developed solutions to address the two main causes of NVH issues: excitations from the road surface and from the vehicle's drivetrain and auxiliaries. For these internal excitations, Vibracoustic has a range of advanced mounts and bushings that mitigate vibrations transmitted through the axles and body to the seats and steering system.

By minimizing the effect of these inputs and isolating vibrations from the passengers, comfort is increased significantly, Vibracoustic noted.

Vibracoustic's product portfolio includes conventional rubber bushings to complex, hydraulic, switchable or even active mounting solutions, the company added.

For excitations coming from the road, Vibracoustic is offering switchable air springs, which are suitable for the transition to autonomous vehicles.

The digitally controlled units continuously monitor loads to keep the vehicle level. They can provide different degrees of stiffness, allowing quick transition between a firm chassis for a confident and safe driving behavior, and a more comfortable setup for long motorway trips. The technology is ideally suited to the transition from semi-autonomous to fully autonomous light vehicles, "enabling the best of both worlds," Vibracoustic said.

As the driver switches their attention away from actively driving the vehicle, the air springs adjust from a driver-focused setting to one that is more relaxed and comfortable, providing an improved passenger experience.

Motion sickness

Another complex issue facing vehicle manufacturers is motion sickness. Studies show that motion sickness is caused by a sustained conflict between vestibular and visual sensory inputs. It may be further intensified by the inability to anticipate the direction of motion, especially when the subject has a lack of control over the motion.

Studies from other forms of transport, such as rail or aviation, cannot be extrapolated to autonomous vehicles as it is a substantially different form of motion. Therefore, watching a film or reading a book during a car journey can quickly cause or compound a sense of nausea . It is highly likely that passengers of autonomous vehicles will want to enjoy a variety of screen-based entertainment, including films and video games, on their journeys.

Vibracoustic already has developed seat dampers that are able to minimize the vibration of screens positioned on the rear of vehicle seats. The tuned mass dampers are adapted to the given package space inside the seat and eliminate perceivable vibration. Using silicone rubber and a custom fit, they provide a cost-effective solution that is 100 percent recyclable.

"Vibracoustic is dedicated to anticipating and solving the NVH challenges of tomorrow," Boecking said. "Whether it's as a partner early in the development cycle or supplying class leading NVH products, we are well positioned to help our automotive customers through this significant transition. …While it may still be some time until we witness the widespread adoption of autonomous vehicles, our engineers are already working with vehicle manufacturers to solve the NVH challenges of tomorrow."