On January 14, Xiaomi Corporation (1810.HK) founder, chairman, and CEO Lei Jun announced that Xiaomi Auto places significant emphasis on the winter driving experience, stating the company will conduct the YU7 winter handling stability test to provide a clear demonstration of how Xiaomi vehicles maintain control stability on icy and snowy road surfaces.
He also shared a promotional article from Xiaomi Auto providing scientific insights into winter handling safety.
Winter driving presents specific challenges: whether facing the rainy season in the south or heavy snow in the north, vehicles experience longer braking distances on low-traction surfaces, potential skidding during acceleration, and tendencies to understeer or oversteer when cornering. This sensation of losing control is often the most daunting aspect of winter driving.
Achieving greater stability during winter conditions fundamentally relies on three key elements: tire grip on the road surface, the stability of chassis tuning, and the timely intervention of intelligent electronic control systems. Among these, traction is the absolute foundation—even the most advanced electronic controls and chassis require winter tires on snow-covered roads for subsequent technologies to function effectively.
Winter tires feature specialized rubber compounds and tread patterns optimized for cold temperatures and icy conditions, delivering superior grip on both cold asphalt and snow-covered surfaces. For residents in cities with frequent snow cover or where ambient temperatures drop below -7°C, switching to winter tires is strongly recommended to enhance driving safety.
ESP serves as a core safety feature in managing complex winter driving scenarios, acting as an invisible guardian for vehicle stability.
ESP, or the Electronic Stability Program, activates with a flashing yellow indicator on the instrument panel depicting a car with two skid marks when the system intervenes.
When a vehicle experiences skidding, sudden steering maneuvers, oversteer, or understeer, the ESP system utilizes onboard sensors to monitor steering wheel angle, individual wheel speeds, yaw rate, and other data to determine if the vehicle is approaching or entering a skid state.
Upon detecting an imminent skid, the system automatically applies braking force to specific wheels, limits torque output, adjusts vehicle attitude, and assists the driver in correcting the trajectory to return to a safe path.
As the critical component for maintaining body stability, the ESP system integrates multiple functions including ABS, TC, and ESC.
ABS, the Anti-lock Braking System, prevents wheel lock-up during full braking on low-triction surfaces where wheels might transition from rolling to sliding. This not only maintains steering capability and prevents fishtailing but also reduces braking distances.
The core function of ABS involves continuous monitoring of each wheel's slip and acceleration/deceleration status via wheel speed sensors. When incipient lock-up or instability is detected, the system employs high-frequency pulsating braking to modulate brake force individually, maintaining optimal tire-road contact to enhance braking stability, steerability, and shorten stopping distances.
TC, the Traction Control system, addresses wheel spin during acceleration on low-grip surfaces where drive torque exceeds road adhesion limits. This explains why front-wheel-drive vehicles tend to understeer and rear-wheel-drive vehicles oversteer under such conditions.
The traction control system promptly identifies spinning wheels and reduces torque output to quickly curb slippage, ensuring stable acceleration and improved dynamic balance both in straight lines and through curves.
ESC, the Electronic Stability Control system, activates when a vehicle enters a curve at higher speeds on low-triction roads or during emergency obstacle avoidance maneuvers where oversteer or understeer occurs.
The system applies calibrated braking to one or multiple wheels while adjusting powertrain output to help the driver maintain intended steering direction. This reduces the need for frequent corrective steering inputs in challenging conditions, thereby enhancing vehicle controllability.
The ESP system functions like an intelligent driving safety assistant, constantly monitoring vehicle behavior and immediately intervening to correct attitude when skidding is detected.
Beyond basic stability enhancement, Xiaomi Auto has implemented several key optimizations and upgrades to the conventional ESP system.
First, calibration is more refined. The ESP 10.0 system in Xiaomi vehicles, paired with the VDC 2.0 vehicle dynamics control system, allows precise management of intervention timing and intensity, transitioning from abrupt control to seamless assistance for a truly integrated driving experience.
During a single lane-change maneuver, Xiaomi evaluates and calibrates over 50 parameters. The system monitors the entire process from steering initiation to completion, ensuring not just stability maintenance but also linear body control throughout the maneuver, with细腻 power/brake modulation that accurately reflects driver intent for genuinely imperceptible control.
Xiaomi Auto views stability maintenance as the safety baseline, asserting that ESP should not abruptly override driver inputs—which could severely compromise obstacle avoidance capability. Optimal ESP calibration involves linearly correcting driver errors while filtering out road disturbances to accurately restore intended vehicle trajectory, delivering a harmonious human-vehicle connection.
Second, mode differentiation is more granular. Xiaomi Auto offers multiple stability control levels tailored to drivers of varying skill levels.
The most stable setting imposes appropriate limits on driver authority, accommodating imprecise inputs like lag or overshoot from average drivers while maintaining good dynamic agility and linearity.
As settings progress from neutral to flexible, more vehicle control is gradually returned to the driver, allowing greater command over dynamics with increased agility tolerance, while still ensuring stability during high-dynamic maneuvers.
Concurrently, Xiaomi vehicles feature an evolved version of TCS called dTCS, which improves anti-slip response speed by over 10 times.
In traditional internal combustion engine vehicles, TCS systems suffer from extended control loops as algorithms and engine control units (ECUs) operate separately, resulting in lag exceeding 100 milliseconds from wheel slip detection to torque limitation.
Xiaomi Auto employs Bosch's distributed Traction Control System (dTCS), embedding control algorithms within the vehicle control unit (VCU) to slash control cycles to just 2 milliseconds. This represents a more than tenfold response time improvement over conventional vehicles, enabling superior wheel slip suppression.
Additionally, Xiaomi Auto has developed specialized functions for energy recovery scenarios, utilizing controlled front-rear torque distribution and anti-lock kinetic energy recovery to prevent skidding and enhance stability.
The dual-motor all-wheel-drive torque control (eAWD) enables real-time, dynamic torque distribution between front and rear motors (wheels) to improve handling stability and tracking during hard acceleration, cornering, hill climbs, and slippery conditions // Available only on Max trim.
Regenerative Torque Control Logic (RTCL) integrates advanced driver-assistance sensor data with conventional vehicle dynamics, assessing road surface conditions, gradient, and driver braking intent to calculate maximum friction available per axle. It adjusts regeneration intensity while maintaining consistent deceleration to prevent wheel lock-up or instability, supporting future higher regeneration levels.
Electro-hydraulic coordinated braking activates hydraulic braking when battery recovery capacity is limited (e.g., low temperatures or full charge) and provides failsafe hydraulic stopping during motor faults. It automatically triggers ABS functionality on low-grip surfaces.
Finally, to further enhance stability on slippery surfaces, Xiaomi Auto developed a dedicated 'Slippery Mode' for low-traction conditions like ice and snow. This mode reduces acceleration/deceleration-induced drive wheel slip and vehicle instability risks, delivering safer driving experiences applicable to southern rainy seasons and northern snow seasons alike.
When Slippery Mode is engaged, power delivery becomes smoother to minimize rear-wheel slip tendencies. Max trim models additionally adopt a more stable AWD distribution strategy prioritizing front-wheel torque to further prevent slippage. During acceleration, the system preferentially utilizes the front motor to preserve rear tire grip and reduce rear axle slip risk. Braking energy recovery intensity is also optimized for enhanced winter driving security.
To further ensure winter driving safety, Xiaomi Auto has brought the YU7 to Mohe, where temperatures plunge to -30°C, for a series of winter tests including "Ice and Snow Circle Tests," "Ice and Snow High-Speed Double Lane Change Tests," and "15% Split Mu Hill Climb" evaluations, committed to delivering robust safety assurances for users.
Sophisticated intelligent electronic control systems provide crucial safety safeguards for daily driving, effectively enhancing stability in complex road conditions and boosting driver confidence. We strongly advise against deactivating electronic stability systems during normal operation and emphasize disciplined driving habits and safety awareness.
Xiaomi Auto remains steadfastly user-focused, continuously advancing electronic control technology and subjecting vehicles to rigorous testing to fortify safety for every winter journey. The company is dedicated to delivering the reassurance of stable, reliable control—ensuring drivers remain confident and in command throughout the winter season.
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