Key Takeaways:
- NIO has mapped out a decade of work on its chassis technology, transitioning from reliance on international suppliers to in-house R&D and development of key components and control systems.
- The company has developed a full-stack Intelligent Chassis Controller (ICC) to put control logic and algorithms in its own hands, enabling continuous optimization of product experience.
- NIO has integrated advanced technologies such as fully active hydraulic suspension, steer-by-wire, and rear-wheel steering into its flagship sedan, the ET9.
- The company has worked with domestic suppliers and partners to develop and refine these technologies, and has pursued a "new-technology review" process to address gaps in domestic standards.
- The smart chassis is evolving from a purely mechanical performance carrier into an intelligent platform that fuses perception, decision-making, and execution.
Introduction to NIO’s Chassis Technology
NIO, a Chinese electric vehicle manufacturer, has recently outlined its decade-long journey in developing its chassis technology. From its early days as a new entrant in the carmaking industry, NIO has transitioned from relying on international suppliers to bringing key components and control systems in-house. This shift has enabled the company to optimize its product experience and take part in setting industry standards. NIO’s first volume model, the ES8, featured high-spec hardware at the chassis level, including an all-aluminum structure and air suspension. However, the company encountered challenges in working with top-tier international suppliers, who typically worked on an "off-the-shelf" basis with no room for customization.
From Supplier Reliance to Core In-House R&D
As a new entrant, NIO faced caution from top-tier international suppliers, who were hesitant to work with the company. To address this, NIO set up joint task forces with suppliers’ senior management and spent over two years refining logic and calibration at the software layer. This effort helped to lift the experience to mainstream levels, but the company realized that under traditional supply models, the chassis’ core control logic is a "black box" to OEMs. This limitation hindered NIO’s ability to quickly implement fixes and iterations in response to user feedback. To overcome this, NIO decided to develop a full-stack Intelligent Chassis Controller (ICC) in late 2019 to early 2020, despite facing heavy operational pressure. The goal was to put the system’s "brain" – control logic and algorithms – firmly in its own hands, securing the ability to define and continuously optimize product experience.
Developing the Intelligent Chassis Controller
The development of the ICC went beyond software to the hardware supply chain. Leading international suppliers typically sold hardware bundled with controller algorithms and refused to provide core mechanical parts such as air springs on a standalone basis. NIO turned to supporting domestic suppliers with strong potential but limited series-production experience. The company offered deep support in validation systems, production process set-up, and even early talent hiring – effectively helping build partners’ capabilities. For the domain controller hardware, NIO adopted a "white-box" cooperation model with domestic electronics partners: tightly integrated teams, shared IP, co-development. In 2021, the ET7 equipped with the full-stack ICC went into production, marking the point where NIO could directly adjust parameters and deploy algorithms at the central domain controller layer, enabling the chassis system to receive OTA updates for feature upgrades and experience refinement.
Complex Engineering Rollout and Standard-Building
With chassis domain control in hand, NIO planned a more complex, cutting-edge integration package for its flagship sedan, the ET9. The program aimed to combine fully active hydraulic suspension (FAS), steer-by-wire (SbW), and rear-wheel steering (RWS) – technologies not yet commonplace in the industry. Each is challenging on its own; integrating multiple high-dynamic, high-complexity actuators on one platform and making them work in concert is a systems-engineering hurdle. NIO partnered with ClearMotion, a startup with advanced concepts but limited mass-production experience, to develop the FAS system. The company’s engineering team brought its self-developed control logic and matched components to the partner’s site for months of joint tuning, reworking the hydraulic system’s matching logic to meet China’s specific road challenges.
Advanced Technologies and Safety Philosophy
The SbW implementation reflected a different safety philosophy. On the ET9, NIO adopted an all-electronic solution with no mechanical backup. To ensure absolute reliability, its safety architecture drew on aerospace thinking and built three tiers of redundancy: first, dual-channel backups across sensing, compute, communications, power, and actuation; second, primary and secondary systems sourced from different suppliers with divergent software logic to prevent common-cause failures; and third, a vehicle-level fallback, where coordinated braking and rear-wheel steering keep the car controllable in extreme situations. NIO also developed a chassis compute platform (VMC), acting as the hub for vehicle-level motion coordination, allowing for cross-system optimal decision-making and predictive control. This enables rapid assessment and orchestration of system-wide interventions during transient extremes such as a high-speed blowout to keep the vehicle stable.
Conclusion and Future Directions
NIO’s chassis journey – from supplier dependence to core in-house development and then to tackling high-complexity system integration – mirrors a broader shift in smart EVs: the chassis is evolving from a purely mechanical performance carrier into an intelligent platform that fuses perception, decision-making, and execution. Today, intelligence has entered deep water, and the core of the smart chassis race is shifting from standalone hardware metrics to system-level, fine-grained mastery of vehicle motion control. Striking the right balance among technological foresight, engineering reliability, cost, and user experience will remain a long-running test for the industry. As NIO continues to push the boundaries of chassis technology, its efforts will likely have a significant impact on the future of the automotive industry.