In November, the delivery of the first mass-produced model of the million-level high-end new energy vehicle brand Yangwang U8 luxury version officially began. The new car integrates many black technologies, and the application of a number of technologies not only broadens the technical boundaries of new energy vehicles, but also subverts the public's inherent perception of hard-core off-road. After picking up the car, many car owners immediately showed off the "unique learning" of the U8 luxury version - turned around on the spot, which quickly attracted widespread attention on social media.
In the analysis of in-situ U-turn technology, four-wheel independent drive is the key
The birth of the in-situ U-turn function originated from the easy Sifang technology platform brought by Yangwang through technological breakthroughs in distributed drives. The core of Yi Sifang's technology lies in the four-wheel independent torque vectoring control, which subverts the traditional centralized drive system in one fell swoop. In other words, each wheel of the U8 Deluxe Edition is controlled by a vertical motor, which rotates forward and backward with different torques without interfering with each other. In addition, the power of the motor covers 220kW 240kW and the torque is 320N·m and 420N·m, ensuring sufficient power output between wheels.
At the same time, Yi Sifang also has the ability to deeply integrate the perception of the whole vehicle, and adopts a highly collaborative control architecture of the first computing platform + domain controller, which can accurately control the independent torque output of the four motors in different scenarios and under different working conditions. In this way, by applying a driving torque in the opposite direction to the left and right wheels of the vehicle, the tires will rotate beyond the limit of road adhesion, causing the vehicle to turn around the center of mass in place. In addition, with the blessing of Yi Sifang technology, the in-situ U-turn of the U8 luxury version is not restricted by the road surface such as high attachment or low attachment, and the urban asphalt, cement road, and off-road non-paved road can be silky and unpaved, and at the same time, it has the characteristics of being fast or slow, and the angle can be selected.
Easy Sifang security redundancy, comprehensively subverting the driving form
It is not difficult to see from the realization of the function of turning around in situ that Yi Sifang can be called a revolutionary existence for traditional automobile drive technology, and its ability is far more than that. In order to further present the subversive technical capabilities of Yi Sifang, Yangwang has specially created a concept car of Yi Sifang. This concept car directly cancels the traditional steering gear and braking device, two very key parts of the car, but can also accelerate and decelerate, turn, U-turn normally, the driver when driving the sense of control is no different from other models, the accuracy of steering control is similar to the ordinary steering system, and the maximum braking deceleration when braking can reach 1g.
As a model that truly realizes the three-in-one of drive, braking and steering, the birth of the Yi Sifang concept car essentially reflects the vehicle-level safety redundancy capability built by Yangwang. By establishing a four-wheel independent drive vehicle kinematics and tire mechanics model, the Yi Sifang concept car can accurately calculate the maximum friction between each wheel and the ground, and then with the independent braking adjustment of the four wheels, it can have braking ability without the help of traditional mechanical calipers, and even rely on the characteristics of motor perception and control speed and high precision, so as to achieve no loss of control and no locking in the braking process. The significance of this braking system is that it is expected to be equipped with traditional mechanical braking in the future, and even if the caliper is affected by malfunction or thermal attenuation, the addition of motor braking can add another "safety lock" to form a brake redundancy.
Similarly, the principle of steering redundancy of the Yi Sifang concept car also lies in the independent control of the four wheels. The steering intention of the driver is identified through the steering wheel angle, and the target torque of the four wheels under the steering characteristics is obtained according to the control model of the differential torque of the four motors and the steering characteristics of the vehicle, and then the torque and speed of the motor are accurately controlled, so that the wheel speed difference between the two sides is formed to complete the steering. Without the help of a traditional steering mechanism, the Yi Sifang concept car achieves a minimum turning diameter of 12 meters, and the maximum passing speed can reach 60 km h in the 18m serpentine pile winding test. Similar to brake redundancy, this control system, if installed as a redundant backup on production vehicles, can also allow the vehicle to maintain control of the vehicle in the event of a failure of the conventional steering mechanism, resulting in a higher degree of safety.
Obviously, the birth of Yi Sifang not only brings strong performance, off-road passability, as well as innovative technology applications such as in-situ U-turn function and emergency floating ability. Through the concept car of Yi Sifang, we can clearly see the subversive value of Yi Sifang's safety redundancy technology. The Yi Sifang concept car has created a new direction of integrated control of chassis and power technology in the industry, innovatively defined a new car form, and brought greater imagination to the future automotive drive technology.