Digital chassis research: Local OEMs accelerate chassis digitization and AI  

1. What is the “digital chassis”?

Previously, we mostly talked about concepts such as traditional chassis, chassis-by-wire, and intelligent chassis. How is the digital chassis different from them?
 
According to the definition of "intelligent chassis" in the "Electric Vehicle Intelligent Chassis Technology Roadmap" compiled by Brake-By-Wire and Intelligent Chassis Control Working Group of China-SAE: the intelligent chassis is a system that provides a carrier platform for autonomous driving system, cockpit system, and power system, and has the ability to perceive, predict and control the interaction between wheels and the ground, manage its own operating status, and specifically realize vehicle's intelligent driving tasks, as shown in the figure below. In the intelligent chassis, key components are brake-by-wire, steer-by-wire and intelligent suspension systems.
 
Evolved based on the intelligent chassis, functions of digital chassis include wire-controlled actuation system, chassis coordinated control, perceptible, OTA, advanced chassis, AI chassis, etc.
Wire-controlled actuation system: The digital chassis needs to realize wire control of driving, braking, steering, suspension and other actuation systems, which is the basis for vehicles to realize digital coordinated control of the chassis.
Chassis coordinated control: Under the concept of digital chassis, chassis components are no longer independent of each other, but are coordinated by the control system to achieve 3-direction 6-freedom-degree coordination of vehicle body posture.
Perceptible: The digital chassis integrates with the vehicle's perception systems, such as LiDAR and cameras, to construct a model of the road conditions ahead. This allows the system to make decisions and respond in advance, ensuring the optimal body posture.
OTA: The digital chassis supports Over-The-Air (OTA) technology, enabling the vehicle to receive remote updates after leaving the factory, continuously optimizing and improving chassis performance.
Advanced Chassis Functions: The digital chassis supports advanced functions such as crab walking, jumping in place, lateral movement, and spinning in place.
AI chassis: In early 2024, NIO launched AI chassis technology, which integrates multiple vehicle-side sensors and cloud data. It can confirm, verify, fine-tune, and adjust the vehicle's response to road bumps based on multiple (four or more) drives over the same road section, pre-matching various chassis parameter combinations in advance.

 2. Independent brands are the main force driving the development of digital chassis

From 2024 to early 2025, a number of brands have successively released digital chassis-related technologies, including IM's Lingxi Digital Chassis, Geely's AI Digital Chassis, BYD Yangwang U7 Full Digital Chassis, Chery Yuntai Intelligent Chassis 2.0, Huawei Tuling Longxing Platform, etc.
 
Geely's AI Digital Chassis

In 2024, Geely Auto debuted its AI Digital Chassis at the Beijing Auto Show. By January 2025, at the CES exhibition, Geely Auto introduced its "Full-domain AI Technology System for Intelligent Vehicles." Under this technological framework, Geely has developed a series of AI achievements, including the AI Digital Chassis, Flyme Auto intelligent cockpit, intelligent driving systems, and end-to-end voice foundation model.

The AI Digital Chassis implements an AI algorithm control system, combining high-performance local domain control with Xingrui Intelligent Computing Platform. Through wire-controlled decoupling and multi-domain fusion technology, it achieves coordination between the body domain, power domain, and intelligent driving domain. It also monitors the vehicle's overall status in real-time. When the vehicle shows signs of instability, such as skidding or side slipping, the AI Digital Chassis instantly intervenes through feedforward control. By utilizing X/Y/Z 3-direction integrated posture coordination control, it precisely adjusts the vehicle's posture.

In addition to AI algorithm control, Geely's AI Digital Chassis also boasts several highlights in hardware configuration:

① Dual-Chamber Closed Air Spring + Linear Motor + CDC (Continuous Damping Control)

Dual-Chamber Closed Air Spring: Beyond adjusting spring stiffness and body rigidity, these air springs can also derive additional functions. Utilizing the air pump within the springs, they can supply oxygen to the cabin and inflate external equipment. Geely has leveraged this feature to expand into two derivative functions: automatically replenishing cabin oxygen and inflating external equipment such as tents.
Linear Motor + CDC Damper: CDC dampers assist the linear motors in their operation.

This system supports adjustable suspension height and stiffness, allowing for independent control of all four wheels. The suspension mileage can reach up to ±65mm, with an adjustment speed of up to 0.5m/s.
 
② Four-Wheel Hub Motors 

The four-wheel hub motor solution integrates two motors on the same axle to independently drive two wheels. Each motor has a peak power of 150–230 kW, a peak torque at the wheel of 2300–2600 Nm, and a maximum speed of 18,000 rpm. It is compatible with both 400V and 800V voltage platforms, with an integrated weight of only 115 kg. 
With the four-wheel hub motor drive, functions such as in-place turning, single-wheel blowout control, and assisted braking can theoretically be achieved.
 
③ Steer-by-Wire + Rear-Wheel Steering

The AI Digital Chassis adopts a steer-by-wire system and rear-wheel steering, achieving complete decoupling between the steering wheel and the steering system. This allows for flexible adjustment of the steering ratio based on different road conditions and driving needs.
Geely's rear-wheel steering is currently limited to 10° (with a maximum support of 15°), effectively reducing the vehicle's turning radius.
 
④ EMB

The EMB system works in coordination with the four-wheel hub motors to achieve precise and independent control of traction and braking forces on all four wheels. This shortens braking distances and effectively reduces slippage on low-grip surfaces.

With the above configurations, Geely's AI Digital Chassis can achieve a range of advanced functions, including: Unmanned high-speed drifting; Four-wheel steering; Active side collision defense; Active height adjustment for wading; Active welcome mode (actively lowering the suspension and unfolding the steering wheel from a folded position), Agile exit from parking spaces (automatically adjusting steering ratios, etc.); Dancing mode (actively adjusting suspension height, etc.); Tank turn (enabling automatic parking to judge parking space and decide whether to activate the function). Additionally, the chassis response time is as fast as 4ms, enabling "automatic vehicle control for hazard avoidance" in extreme situations.

Huawei Tuling Longxing Platform

On February 20, 2025, Huawei unveiled its intelligent digital chassis platform—Huawei Tulin Longxing Platform—at the HIMA MAEXTRO Technology Launch Event. Huawei defines it as an "innovative full-domain fusion architecture, the industry's first independent intelligent digital chassis platform." It supports integrated control of six systems: body control, powertrain control, suspension, steering, braking, and thermal management. In terms of hardware, it is equipped with distributed electric drive, brake-by-wire, multi-wheel steering, and active suspension systems.

In terms of vehicle performance, the MAEXTRO S800, equipped with Tulin Longxing Platform, demonstrates exceptional capabilities:  maintains stability on icy and snowy roads without deviation or tail swing, and climbs snowy slopes without losing speed or traction; ensures stable control even when a single tire blows out at a speed of 120 km/h; With a crab-walking angle of 16°, it easily handles extreme scenarios such as narrow roads and tight parking spaces; achieves a minimum turning radius of 5.05 meters within its class (compared to the MAEXTRO S800's wheelbase of 3.37 meters and vehicle length of 5.48 meters).

3. From the supplier side, there are only a handful of manufacturers that have the ability to supply chassis XYZ 3-direction products + coordinated control.

For suppliers, it is currently quite difficult to combine the supply capabilities of XYZ 3-direction products and chassis coordinated control capabilities. According to ResearchInChina's review of more than 60 manufacturers in the chassis field, the only foreign manufacturer that currently has XYZ + coordinated control (has mass-produced or has plans to mass-produce steer-by-wire, brake-by-wire, suspension-by-wire and chassis coordinated control) is ZF.

Chinese manufacturers have also demonstrated commendable capabilities in the supply of digital chassis components. For instance, Beijing West Industries' EMB products have secured designated projects and are expected to be mass-produced in 2026. Bethel Automotive, LeeKr Technology, Tongyu Automotive, Global Technology, Trugotech, etc. have all achieved mass production of hydraulic brake-by-wire One-box products. Baolong Automotive, Zhongding Group, and Kh Automotive Technologies have achieved large-scale mass production of air suspensions.

In July 2024, Beijing West Industries disclosed that its EMB product has secured strategic collaborations with Kaiyi Auto and U POWER, with mass production slated for 2026. Beijing West Industries EMB adopts a fully redundant hardware solution, supporting high-level autonomous driving at L4 and above. Its key features include:
Integration of functions such as ABS, ESC, TCS, and ACC, with wheel lock-up time as short as 75 milliseconds.
True wire-controlled system without the need for servo mechanisms or ESC modules, completely eliminating brake fluid lines.
The system utilizes plug-and-play electronic structural interfaces, eliminating the need for filling or draining brake fluid, and simplifying the assembly process.
The Beijing West Industries EMB system achieves instant caliper release after braking, enabling zero drag and effectively reducing energy consumption.