Another killer feature of Hongmeng Intelligent Driving: Analysis of Tuling’s intelligent chassis technology

From the initial smart cockpit and smart assisted driving to today's smart chassis and AI big models, the intelligence of cars has already embarked on a comprehensive and mature path. The same is true in the Hongmeng Intelligent Driving System. Following Huawei's ADS2.0 and Hongmeng operating system, Tuling's smart chassis has also begun to enter people's field of vision, and Zhijie S7 (configuration Wenjie . Tuling's intelligent chassis is more like a systematic integration and application of Huawei's latest technologies. It has a powerful digital base, which can achieve multi-domain collaborative control, intelligent perception and intelligent control.

In terms of mechanical hardware, the Tuling intelligent chassis is equipped with Huawei DriveONE 800V silicon carbide high-voltage power platform, adopts the design of front double wishbone and rear five-link independent suspension, with lateral stabilizer bar, CDC variable damping shock absorber and air suspension. Under the control of the vehicle intelligent control center, the suspension hardness can be intelligently adjusted when the vehicle passes through different road conditions, taking into account both ride comfort and vehicle support.

Let's first look at the power system. Huawei DriveONE's new generation powertrain consists of ultra-high-density asynchronous front drive and ultra-efficient synchronous rear drive. The motor has a maximum efficiency of 98% and a maximum speed of 22,000 rpm. In addition, it combines intelligent auxiliary drive algorithms, intelligent oil cooling 2.0 + mirror-ground gear shafts, self-developed AI optimization platform NVH design, and full-stack high voltage in the power domain, which has good performance in terms of performance, energy consumption, and comfort.

In addition, the virtual kingpin double wishbone is adopted to achieve the effect of less roll, less impact and high stability. The "golden combination" of CDC + air suspension also greatly improves the upper limit of the chassis performance of the car body.

The vehicle intelligent control center is the brain of the Tuling intelligent chassis on the hardware basis. As the center of perception and vehicle intelligent control in the Tuling intelligent chassis, it integrates a series of intelligent algorithms for collaborative vehicle control, including the HUAWEI MFSS Multimodal Fusion Sensing System, the HUAWEI DATS Dynamic Adaptive Torque System, and the HUAWEI xMotion Intelligent Body Collaborative Control System.

Intelligent perception: Multimodal fusion perception system MFSS

After ensuring power and excellent chassis mechanical qualities, the coordinated effect of vehicle intelligent perception and intelligent control system is also needed to fully bring the powerful mechanical qualities of the Tuling intelligent chassis into play.

During the driving process, if the vehicle's movement state and road conditions cannot be accurately perceived, the vehicle will not be able to respond in time when encountering bumps and other situations.

For example, when a car passes over a speed bump, if the longitudinal impact and vertical bumps cannot be accurately identified, reasonable longitudinal torque control and vertical damping control cannot be performed, and the experience of the driver and passengers will not be comfortable enough.

Only with high-precision perception of vehicle motion and road environment can accurate torque anti-slip control, bump relief control, stable cornering control, etc. be performed to ensure the ultimate performance of the vehicle. The HUAWEI MFSS 1.0 multi-modal fusion perception system is the key to achieving vehicle posture and road pre-perception.

Through the combined action of multiple sets of active and passive sensors on the vehicle, iVSE vehicle state perception technology estimates the vehicle state, identifies the road state, determines the road type, and then controls the vehicle according to different vehicle postures and road conditions. RSS road preview technology uses the camera/lidar of the intelligent driving perception system to identify road information in advance, and adjusts the damping characteristics of the shock absorber in advance according to the road information and vehicle state, achieving more ideal suspension decision control and improving the vehicle's driving comfort.

Intelligent control: HUAWEI DATS 3.0 dynamic adaptive torque control system

HUAWEI DATS stands for Dynamic Adaptive Torque System. It uses the motor resolver sensor to sense road changes, greatly shortening the torque adjustment link and reducing the response delay to 4ms. At the same time, the DATS system can dynamically adjust the torque according to road conditions and wheel adhesion, reducing the bumps and impacts and the shaking of the vehicle. It also supports OTA upgrades, allowing users to keep the car fresh and have a more comfortable driving experience.

Compared with fuel vehicles, new energy vehicles have faster power response, and torque adjustment usually cannot keep up with the response speed. In addition, because new energy vehicles have a kinetic energy recovery process, when the wheels are in the air due to road fluctuations, the wheels will have excessive slip due to excess recovery torque, impacting the body posture and exacerbating the "shaking feeling" and "motion sickness". At the same time, due to the coupling between energy recovery and braking systems, when the chassis vehicle stability function intervenes, kinetic energy recovery is required to be reduced or exited, resulting in a "jumping feeling".

HUAWEI DATS3.0 dynamic adaptive torque system is a solution to the above problems, including three sub-technologies: torque vector control (TVC), electronic anti-skid control (eASC) and collaborative drag torque control (CDTC).

Previously, TVC torque vector control technology has been used on the new M7 (configuration |inquiry) four-wheel drive version. This time, the Tuling intelligent chassis equipped with the Zhijie S7 has made two major optimizations for TVC technology: ① The torque is not transferred forward during the cornering stage, and the expected main front axle distribution is not achieved; ② The deviation between the actual yaw rate and the expected yaw rate is small, so the yaw control intervention is not obvious. The new TVC technology adds the conversion logic of the cornering entry and exit and the two expected steering gain maps as an improvement plan, bringing a wider range of torque distribution to meet the cornering vector control performance requirements. With the update and iteration of TVC technology, the "Sport+" mode ("Sport+ mode") has also come into being. Compared with the sports mode of the previous version of TVC technology, the "Sport+ mode" has better performance in high-speed corners, emergency line changes, fixed radius corners and other scenarios.

Intelligent control: HUAWEI xMotion intelligent body collaborative control system

At present, electric vehicles are facing new problems in complex scenarios. For example, in energy recovery scenarios, cars are prone to large impacts, strong forward rushes, large vibrations, and large lateral swings when passing speed bumps, bumpy roads, etc.; in acceleration drive scenarios, cars may also have problems such as weak acceleration, large vibrations, and large lateral swings when passing bridge joints, connecting roads, etc.

The root cause of the problem is that the motor torque response is fast, which makes it easy to slip; and the electric brake torque is large, which makes the tires easy to lock at low adhesion. If the intelligent body cannot be coordinated, it is easy to trigger chassis functions such as TCS or DTC, resulting in switching between functions, causing impact, torque fluctuations and other problems.

HUAWEI xMotion intelligent body collaborative control system can realize multi-dimensional central collaborative control of electric drive, braking, steering, and suspension, and achieve intelligent adjustment and precise control to reduce the bumps and impact during driving and braking. Among them, ADC adaptive vibration control technology can intelligently adjust the damping, enhance the vibration filtering ability, and improve the driving experience; ICB technology can achieve precise pitch control through intelligent dynamic adjustment, anti-nodding and anti-lifting: combined with braking and driving requirements, advance and finely identify damping requirements; multi-scenario high real-time active adjustment of damping force, suppress the body posture pitch, achieve a more comfortable braking experience, and relieve motion sickness.

The arrival of the Tuling smart chassis is of great significance to Hongmeng Intelligent Driving. It makes "intelligence" no longer just stay in the two major areas of smart driving or smart cockpit, but goes deep into the more basic part of a car: the driving and riding experience. In the future, this will also become another important puzzle of "smart cars", or even a threshold.