The intelligent chassis has now entered its 2.0 stage. OEM manufacturers no longer focus solely on the performance of individual components but increasingly emphasize chassis collaboration, namely the deep integration of steering, braking, and suspension systems. Some models are already equipped with full drive-by-wire systems, achieving integrated chassis domain control (CDC) and possessing initial vehicle-to-infrastructure (V2X) collaborative perception capabilities. These systems are gradually being mass-produced and installed on production vehicles. This article explores how steering systems can leverage Steer-by-Wire (SbW) technology to optimize collaboration with other intelligent chassis systems, enhancing safety, comfort, and autonomous driving performance.
Limitations of Traditional Chassis
In traditional vehicles, the steering system controls direction, the braking system handles deceleration and stopping, and the suspension ensures comfort and stability. However, this independent design approach has clear limitations:
- Information Silos: Systems operate independently with limited real-time data sharing.
- Response Delays: Steering response speed may not meet the dynamic control requirements in high-speed driving or emergency maneuvers.
- Autonomous Driving Limitations: L2+ or L3 autonomous driving functions require multi-system chassis collaboration to optimize trajectory and vehicle posture, which traditional chassis cannot fully support.
For instance, during a high-speed evasive maneuver, relying solely on the braking system may cause vehicle instability. If the suspension cannot adjust vehicle posture in real time, both passenger comfort and safety are compromised.
Introduction to Intelligent Chassis
The intelligent chassis represents the evolution of traditional automotive chassis toward electrification, digitization, and intelligence. It is composed of key by-wire systems such as Brake-by-Wire, Steer-by-Wire, and Active Suspension System. By integrating sensors, actuators, and a central domain controller, the intelligent chassis enables seamless coordination among braking, steering, suspension, and power systems, forming a cohesive, software-defined control platform.
Key Systems in an Intelligent Chassis
- Steer-by-Wire (SbW): EPS is mature, with a market adoption rate exceeding 98%. SbW replaces mechanical connections with electronic control to decouple the steering wheel from the wheels. While still in the R&D stage, it serves as a foundation for full intelligent chassis integration.
- Brake-by-Wire (BBW): EHB One-box is the mainstream solution currently used by automakers, while EMB represents a true full drive-by-wire braking system, still under development.
- Active Suspension System: Air springs with CDC-controlled dampers are currently mainstream. In the future, AI algorithms could enable dynamic adaptation and deep integration with steering and braking, achieving full-domain drive-by-wire control.
Chassis Collaboration Technology Solutions
Achieving true intelligent chassis performance requires not only advanced subsystems such as SbW, BBW, and active suspension systems, but also their deep coordination through a unified control platform. This integration transforms independent systems into a full-domain drive-by-wire architecture, delivering superior precision, safety, and adaptability.
- Steer-by-Wire and Brake-by-Wire Collaboration
During automated lane changes or emergency maneuvers, SbW precisely adjusts steering angles while BBW dynamically modulates braking force. This synchronized response optimizes vehicle posture and trajectory tracking, ensuring enhanced dynamic stability control.
- Steer-by-Wire and Active Suspension Coordination
In high-speed cornering or sharp steering scenarios, SbW works with active suspension systems to reduce body roll and optimize damping in real time, providing a balance between vehicle handling, ride comfort, and road feel.
- Chassis Domain Controller (CDC)
The CDC acts as the “brain” of the intelligent chassis, managing steering, braking, and suspension in a unified manner. It enables cross-system data sharing and coordinated control, reduces ECU count, lowers wiring complexity, and supports OTA updates, ultimately improving vehicle reliability and development efficiency.
Value of Chassis Collaboration
Implementing an intelligent chassis system that integrates SbW, BBW, and active suspension systems provides OEMs with multiple advantages in safety, comfort, energy efficiency, and autonomous driving readiness:
- Enhanced Safety and Dynamic Stability: Coordinated SbW, BBW, and active suspension systems improve stability during emergency or high-speed maneuvers, reducing understeer, oversteer, and rollover risks.
- Improved Comfort and Road Feel: Active suspension continuously adapts damping and stiffness, while SbW and BBW provide smooth steering and deceleration, minimizing body roll and vibrations.
- Autonomous Driving Support: Coordinated chassis systems allow precise trajectory following, accurate lane changes, and adaptive responses to unpredictable road conditions, supporting software-defined motion control.
- Energy Efficiency and Cost Optimization: Electronic coordination optimizes energy distribution, reduces energy consumption, and simplifies component architecture, lowering ECU count and wiring complexity.
- Safety Redundancy and Reliability: Each subsystem incorporates electronic backups. When interconnected, they form a multi-layered safety architecture, minimizing single-point failure risks.
By integrating SbW, BBW, and active suspension systems into a cohesive intelligent chassis, OEMs can achieve enhanced safety, superior comfort, optimized energy efficiency, and autonomous driving readiness, laying the foundation for next-generation software-defined vehicles.
Application Scenarios
- Automated Parking: Steering, braking, and suspension collaborate at low speeds for precise, smooth parking, even in tight spaces.
- Highway NOA (Navigation-Assisted Driving): During high-speed lane changes or overtaking, the three systems collaborate to ensure smooth transitions and improved safety.
- EV Range Optimization: Coordinated control of posture and energy recovery extends driving range.
- V2X Scenarios: The intelligent chassis leverages vehicle-to-infrastructure perception to anticipate road conditions, proactively adjusting braking and suspension to improve safety and efficiency.
The Future of Intelligent Chassis Collaboration
As intelligent chassis systems gradually enter mass production, the steering system becomes a critical node in the chassis collaboration network. OEMs must plan ahead, integrating the collaborative capabilities of SbW, BBW, and active suspension systems into chassis design. Scalable steering solutions supporting drive-by-wire and CDC interfaces will be key for suppliers to deliver core value to OEMs.
About XEPS
XEPS specializes in R&D, production, and sales of automotive steering systems, providing advanced steering solutions to global OEMs. In the era of intelligent chassis, XEPS offers safe and scalable Steer-by-Wire solutions, supporting intelligent chassis deployment and mass production, and accelerating the development of software-defined vehicles. Our solutions integrate seamlessly with Brake-by-Wire, active suspension systems, and autonomous driving systems, helping OEMs optimize vehicle dynamics and enhance intelligent driving experiences.
