Being a captive supplier to an OEM has its advantages, believes Hyundai Mobis. Unlike other automotive suppliers that focus on select systems and make specific parts, it believes it is uniquely capable of developing key vehicle systems, tapping its broad capabilities in steering, braking, connectivity, and electrification as the primary supplier to its parent company’s Hyundai, Kia, and Genesis vehicle brands.

Its development plans include various future technologies, notably a foldable steering system and e-corner module, to address market needs for self-driving cars and future mobility including purpose-built vehicles (PBVs) for mobility services.

“Hyundai Mobis goes beyond simply reinterpreting existing technologies and instead develops parts technologies that apply to future cars in totally new ways,” said Jang-don Choi, Managing Director, Chassis/Safety Business Unit, Hyundai Mobis.

The company announced in late October that it has developed technology that enables the folding and storing of a steering wheel in preparation for future mobility vehicles with greater vehicle autonomy and allowing for more space in the driver’s seat to bring about design innovation. The system features a steering wheel that can move forward and backward by up to 25 cm (9.8 in).

To develop this system, it designed new core parts, including a steering column and a “reaction force control device,” and applied a sliding rail mechanism to secure system durability and reliability goals. The technology, for which the company is currently filing patents globally, took about two years to develop and has not yet been commercialized.

The system enables greater design flexibility for steering wheel folding, retraction, and storage in the dashboard. The company says that this means that the innovative driver’s environments shown in future concept cars at motor shows are now coming closer to road reality.

The new system is designed to go with the company’s previously developed steer-by-wire (SBW) system that relies on electrical signals rather than mechanical connections to deliver the steering force generated from the steering wheel to the road wheels. In addition, it provides better steering performance in challenging driving conditions, for instance by minimizing steering wheel vibration from rumble strips and speed bumps, for greater driver comfort and vehicle stability. Design for redundancy of core parts such as sensors and ECUs ensures that the vehicle is capable of maintaining normal steering in an emergency.

 

Inside look: by-wire steering

The development of by-wire systems, especially for steering and braking, has challenged the automotive industry for the past few decades. Seung Hwa Kim, Head of Steering System Development, at Hyundai Mobis, provided exclusive insight to Futurride on how Hyundai Mobis is overcoming the challenges.

He says that one of the biggest advantages of adopting SBW is that it increases the use of space in autonomous driving situations. To achieve greater versatility in the use of space, he adds that the steering wheel must be either foldable or at least able to be stowed away.

“In an effort to realize that foldability, we need to turn to SBW because this cannot be done with the current, existing systems, as they are all mechanically connected,” he elaborated. “As such, we are expecting to see an organic transition of the steering system into one that is foldable by the time we can manufacture our own SBW system.”

In a conventional electric power steering (EPS) system, the parts from the steering wheel to road wheels are connected mechanically. This allows a driver to still steer the vehicle, but with greater effort, when steering assistance fails if errors occur in key modules such as the ECU, sensors, motor-related electric parts, or if there are signal or software problems.

In contrast, a pure SBW system is operated via electric signals and without mechanical connections from the steering wheel to the road wheels. However, this means that a car potentially could not be steered in the event of a failure due to ECUs, sensors, or motors—which is a critical safety issue.

“To realize the mass production of an SBW system, it is an absolute must that it can never be broken and that it needs to be able to perform normal steering functions,” said Kim. “However, since there is no such thing as a 0% defective manufacturing process with the current level of quality, we are dualizing the electric/electronic parts of ECU, sensors, and motor units to compensate for this issue. The electronic parts—sensors, ECU, and motors—will have a dual design with two independent control systems that communicate with each other and then take over if a problem occurs to assist the driver’s steering.”

Hyundai Mobis is looking to patent certain aspects of the SWB system, which consists of the SFA (Steering Force or Feedback Actuator) and RWA (Road Wheel Actuator). The SFA creates steering torque when a driver manipulates the steering wheel, and the RWA receives the driver’s steering intention as well as signals from the vehicle to steer the tires.

The patent applied for involves the SFA system’s logic that provides drivers a similar steering sensation compared to that of existing EPS systems. Another for the RWA system is about the control logic involved with using the received information to precisely steer the tires. For the SFA, since it’s a rotating unit, the steering limits have to be defined, so Hyundai Mobis has also applied a patent for a structure that controls the rotation of the steering wheel mechanically along with a software-controlled rotation stopper.

One of the biggest remaining challenges is to solidify trust in the system’s safety, but Kim is optimistic about the dualization approach that Hyundai Mobis is implementing.

“However, there are problems that can arise from such a complex connection when integrating with other systems, or the system may not be able to operate normally due to unexpected conditions or situations,” he said. “In the end, a rigorous qualification approach is required to address any potential problems that may be induced by external causes outside of the system (i.e. connections with other systems, natural environment, incidents, etc.) as well as the reliability of the system itself. For me, I think that finding an appropriate way to verify these issues is one of the most critical tasks at hand.”

To find the best possible solution, company engineers are currently using a virtual qualification process as part of its continued analysis and data collection, through verification of software/hardware integrity, and durability testing on a real road similar to the actual user environment.

 

E-corner and systems integration

Hyundai Mobis is focusing much of its R&D capabilities on developing redundant technology for key parts and for driver safety in the era of autonomous driving. After the creation of a redundant steering system in 2018, the company continued down the by-wire path by developing redundant brake devices in 2019. One key focus is preparing vehicles for system errors or other incidents during autonomous driving in the absence of human engagement.

The company is hoping to combine its expertise in production and R&D of key automobile parts related to steering, brakes, and suspension connections between systems and components, which it says are becoming more important in the time of “MECA” (Mobility, Electrification, Connectivity, Autonomous).

To accomplish this, Hyundai Mobis is investing significantly to strengthen its competitiveness in software. At its Transformation Strategy Presentation in March, the company announced its vision to become a global OEM partner as a provider of an integrated hardware/software solution through an open-innovation collaboration with major global companies.

At the road-wheel end of the system, Hyundai Mobis has developed what it regards as a core technology for future urban mobility. An example of its systems capabilities, and integration with the folding steering wheel concept, is the company’s e-corner module, which combines steering, braking, suspension, and drive systems into a road wheel.

Hyundai Mobis first unveiled the e-corner module concept at the 2018 CES in Las Vegas but has now redefined the concept for more practical automobile use by further developing the control ECU and completing functional testing. Once it is done with reliability verification and a feasibility study for mass production, the company will begin taking mass production orders from global carmakers for its application.

The biggest advantage of the e-corner module is that it does not require any mechanical connection between parts, allowing for better use of space within a vehicle. Not only does it make it easier to change a vehicle’s wheelbase but it also ensures much more design flexibility. This is especially true for the design of vehicle doors, for orientation and opening direction, and for vehicle size—for essential flexibility in making purpose-built vehicles that are designed to provide mobility services.

Notably, the e-corner allows for 90-degree (vs. the traditional 30-degree) road wheel articulation when needed, for example when parking. It also enables crab (sideways) driving and “zero-turning” without moving forward or backward. The system increases the agility of a vehicle running on the narrow streets of urban driving environments, which the company says is essential for making purpose-built mobility service vehicles a reality.

Hyundai Mobis plans to develop a skateboard module by 2023 through the integrated control of four e-corner modules and then combining it with the automatic driving control technology to ultimately provide a PVB mobility solution in the year 2025.