Grand Blanc’s CNXMotion has unveiled its Brake-to-Steer technology, which is designed to provide driver safety through an additional layer of directional control for highly automated and autonomous vehicles.
In highly automated vehicle applications, steering systems feature multiple protections to ensure the steering safety net is always on. The BtS technology adds another layer by using the electronic brake system to safely steer the vehicle while simultaneously controlling its speed.
In a fully autonomous vehicle with no steering wheel, BtS will negotiate a commanded path until the vehicle can safely pull over.
“Perhaps the most critical challenge in highly automated and autonomous driving is ensuring the robustness of system redundancies to keep drivers, passengers, and road users safe,” says Alan Davis, general manager of CNXMotion. “CNXMotion’s Brake-to-Steer technology offers another steering safety layer for a wide range of automated driving conditions.”
The technology uses a vehicle’s existing braking and steering systems. The BtS function resides in the motion control system, which acts as an intermediary between the vehicle’s path planner (automated driving system) and actuators (steering, brakes, and powertrain) to determine the best path forward.
Integrated with a performance manager, the vehicle’s intended path is compared to the system’s ability to steer the vehicle via BtS while constantly negotiating the safest route ahead.
In the event that BtS needs to engage, it reacts in one of three ways:
- Continues on the intended path before ultimately moving to the first or second option,
- Performs a minimum risk maneuver, such as slowing and braking to steer the vehicle to the side of the road, or
- Stops in the lane.
Originally developed for steering redundancy in Level 4+ autonomy, the feature can be adapted to assist a driver in multiple scenarios for lower levels, such as lane keep and obstacle avoidance, while a driver is still present, following the intentions provided from the driver’s steering input.
CNXMotion was established in 2017 as a joint venture between Continental, which is based in Germany and has its U.S. headquarters in Auburn Hills, and Nexteer Automotive in Auburn Hills to innovate motion control solutions for advanced applications and accelerate research and development for the parent companies. It employs about 30 people.
“As we progress toward higher levels of automation in vehicles, secondary and tertiary redundancy becomes crucial in executing successful minimum risk maneuvers,” says Hiren Desai, head of strategy, autonomous mobility, and safety for Continental North America. “This helps keep vehicle occupants and road users safe. Cross-domain functionalities such as Brake-to-Steer are enabled by, and housed on, existing hardware, like Continental’s MKCx brake-by-wire systems, eliminating the need for additional, costly components.”
“While steering traditionally manages the lateral control of a vehicle, Brake-to-Steer enables braking to contribute to lateral control as well,” says Robin Milavec, senior vice president, executive board director, chief technology officer, and chief strategy officer at Nexteer. “When combined with advanced steering systems like Nexteer’s High Availability Electric Power Steering or Steer-by-Wire, Brake-to-Steer gives an additional layer of redundancy – further enhancing the safety net.”
Nexteer and Continental each hold 50 percent ownership. Continental was founded in 1871 and develops pioneering technologies and services for sustainable and connected mobility. It employs more than 233,000 people in 59 countries and markets.
Nexteer is a global steering and driveline business delivering electronic and hydraulic power steering systems, steering columns, driveline systems, advanced driver assistance systems, and automated driving enabling technologies for OEMs. It has facilities in North and South America, Europe, Asia, and Africa.