Wheel-side control research: the “last mile” chassis innovation

Wheel-side control dismantles the traditional drive, braking, steering, and suspension control of the chassis from a "centralized" style to "making each wheel independent." By integration level, there are currently four development stages:

The first stage: distributed in-wheel/wheel-side motors are driven separately, and mass production has been achieved (BYD e4 is a typical case);
The second stage: the drive-brake integrated electric wheel integrates the electric motor and brake at the wheel side, with mass production cases available (Schaeffler PowerWheel);
The third stage: there are currently few R&D cases in integration of drive, brake and suspension;
The fourth stage: the drive-brake-suspension-steer integrated corner module features ±90° independent steer-by-wire, with typical cases including Hyundai Mobis e-Corner and Protean 360+.

 1. Distributed drive: wheel-side motors represent the mainstream route

Wheel-side drive and wheel hub drive are two important technical routes for distributed drive. Wheel-side drive arranges the drive motor on the axle or suspension near the wheel, and the motor output is transmitted to the wheel through the reducer and half shaft; wheel hub drive integrates the drive motor and reduction mechanism directly inside the wheel hub, and the motor rotor is directly connected to the wheel, and drives the wheel after being reduced by the planetary gear.
 
In the current market structure, wheel-side motors are absolutely the mainstream. BYD e4, Changan Taihang Distributed Electric Drive, ZEEKR Quad-Motor Distributed Electric Drive, GAC Triple-Motor Four-Wheel Drive, Xiaomi SU7 Ultra Triple-Motor Solution, etc. have been mass-produced, with wheel-side motor architectures. The core advantages lie in that most of the mass is unsprung isolated, delivering better maneuverability and comfort; there is a higher power ceiling, with a single unit capable of outputting over 200-300kW, which meets the power requirements of high-performance vehicles.
 
Taking the Changan Taihang Distributed Electric Drive as an example, the system adopts a "1+2" or "0+2" flexible configuration. The left and right motors of the rear axle are completely independent, controlling the left and right wheels separately. Each wheel can independently output forward, reverse or zero torque. Based on four-wheel independent control, the driving and braking response speed is compressed from the industry average 100ms to 10ms. Superimposed on TVC, scenario functions such as high-speed tire puncture control, pendulum/compass U-turn, wet/ice and snow pavement control can be realized. It is reported that this product was first used on Avatr 12.
 
Although the in-wheel motor frees up more space, it has the disadvantage of significantly increasing the unsprung mass, which directly affects the suspension response speed and driving comfort. At present, only one production vehicle model in China, namely the flash version of Dongfeng eπ 007, is equipped with a hub motor. The product is led by Dongfeng Motor Corporation, with Shanghai Electric Drive Co., Ltd. responsible for manufacturing and integration. In terms of performance parameters, the flash version of Dongfeng eπ 007 has four motors that control the four wheels separately. The maximum power of each motor is 100kW, the combined maximum power is as high as 400kW (approximately 544 horsepower), and the peak torque is up to 620 Nm. Thanks to the shortened physical link, the wheel-side torque response is faster by more than 10 times.
 
2. Drive-brake integration: three technology routes in parallel
 
The core of drive-brake integration is to break the traditional architectural boundary of "separate control over drive and brake" and deeply integrate the mechanical structure and control logic of the originally independent drive system and braking system to achieve functional coordination, structural integration and unified scheduling. At present, there are three mainstream technology routes for drive-brake integration:

Integration of drive and brake at the control level: drive and brake units are mechanically separated but control is centralized. This is the lightest integrated route without changing the hardware architecture. A typical example is HUAWEI DriveONE, which can shorten the braking distance on slippery pavements by nearly 10 meters through drive-brake synchronous-timing control;

Axle-wheel integrated solution: the brake is relocated from the wheel side into the electric drive axle, realizing physical integration of drive and brake. Representative cases include Mercedes-Benz In-Drive, which integrates the motor, transmission and differential into the same module by migrating the traditional braking device from the wheel to the electric drive unit. Different from the "rotating brake disc + fixed brake pad" structure of traditional brakes, In-Drive uses a pair of stationary brake discs fixed on both sides of the drive unit to clamp a rotating double-sided brake pad connected to the drive shaft to enable the braking function.

In-wheel motor wheel-side integrated solution
This solution integrates the powertrain, transmission and braking devices inside the wheel hub as the most integrated route. Typical cases include Protean Pm18-800V, Schaeffler PowerWheel, AUMOVIO Drive-Brake Unit, Asia-Pacific Mechanical & Electronic’s in-wheel motor and Tsingshan Industrial's in-wheel motor and other products. This route is the most technically difficult, but it is also the only way to the corner module.
 
In-wheel motor wheel-side integration case: Tsingshan Industrial & Changan Automobile & Change Technology

In December 2025, Chongqing Tsingshan Industrial teamed up with Changan Automobile and Change Technology to successfully roll off the first "drive-brake integrated" in-wheel motor engineering prototype. The peak torque of the in-wheel motor exceeds 2300N·m, the peak speed reaches 1600rpm, and the peak torque density of the motor alone exceeds 60Nm/kg. By being equipped with a new lightweight brake-by-wire architecture, the weight is reduced by 50% compared to the traditional braking architecture.
 
New energy vehicles equipped with such in-wheel motors can achieve diversified motion functions such as turning around without tire wear, traveling laterally and diagonally. The in-wheel motors can support a 2-ton vehicle to acceleration from 0 to 100 km/h in 3 seconds. It is reported that the product will be industrialized in 2028.
 
3. Corner module: the ultimate form of wheel-side control

A corner module integrates all drive, brake, steering, and suspension functions into a single wheel-side module. It is connected to the body through a standardized interface to reconstruct the chassis architecture. It is the ultimate form of wheel-side control. Vehicles equipped with corner modules can achieve disruptive functions such as in-situ 360° steering, lateral movement, and fulcrum steering (rotating with a single wheel as a fulcrum).
 
Representative cases of corner modules include Protean 360+, Schaeffler iCM, AUMOVIO Corner Module, Mobis e-Corner, Asia Pacific APG Corner Module, Ackerman Matrix Corner Module and other products. Based on four iCMs, Schaeffler has created an urban autonomous driving concept platform - Schaeffler Mover. Because the iCMs on the four corners work independently of each other, the platform is extremely flexible:

360° in?place rotation, with vehicle turning radius less than 5m;
Lateral side?shift parking: the vehicle can directly slide sideways into parking spots without reverse maneuvering.
Since the chassis is completely flat, the body can be replaced like building blocks with an unmanned cabin, unmanned courier vehicle or sweeper vehicle (skateboard chassis platform) as needed.
 
At present, passenger car wheel-side control is still in the first stage - wheel-side drive is mostly installed in mid-to-high-end vehicle models.

In the second stage of wheel-side control, namely drive-brake integration, many vendors have planned related products. For example, Schaeffler has deployed a variety of in-wheel motors and has already applied them to low-speed sweepers; Zhejiang Asia-Pacific Mechanical & Electronic disclosed in April 2026 that its in-wheel motors had undergone small-batch production, with mass production projects under experiments; Protean's Pm18-800V in-wheel motor is planned to be mass produced in 2027, and has received an order from a European OEM.

The final stage of wheel-side control - the corner module is still in the engineering prototype verification stage, but many companies are making layout herein, like OEMs including Hongqi, Chery, and Harmony Intelligent Mobility Alliance (HIMA). As for suppliers, Schaeffler, Protean, AUMOVIO, Mobis, Zhejiang Asia-Pacific Mechanical & Electronic, Zhida Technology, Ackerman Matrix, MATIC Robotic Vehicle Technology, and Tsingshan Industrial are deploying corner modules. Corner modules will be applied to certain scenarios (such as closed scenarios (mines, ports), low-speed operations (buses, distribution, connections), heavy-duty autonomous scenarios (mining trucks, IGVs), etc.) involved with commercial vehicles instead of passenger cars.