DSG is different from the general semi-automatic gearbox system, which uses manual gearbox instead of automatic gearbox. The structure of manual gearbox is more efficient than that of automatic gearbox, and DSG can provide uninterrupted power output besides the flexibility of manual gearbox and the comfort of automatic gearbox, which is completely different from the two automatic clutches. The traditional manual gearbox uses a clutch. When shifting gears, the driver should step on the pedal of the clutch to make the gears of different gears mesh. When shifting gears, the power is interrupted and the output performance is intermittent. Audi developed DSG to solve this problem. DSG can be imagined as combining the functions of two manual gearboxes and being built in a single system. DSG includes two automatic clutches, which are driven by electric control and hydraulic pressure, and can control the work of two sets of clutches at the same time. When the gearbox is running, one set of gears is in the engaged state, and when it is close to shifting, the gear of the next set of gears has been pre-selected, but the clutch is still in the disengaged state; When shifting gears, one clutch is disengaged from the in-use gear, and the other clutch is engaged with the pre-selected gear, so that at least one gear can output power during the whole shifting period, so that the power is not interrupted. In order to cooperate with the above operations, the transmission shaft of DSG is divided into two parts, one is a solid transmission shaft for putting Uneri, and the other is a hollow transmission shaft outside; The solid transmission shaft inside is connected with 1, 3 and 5 and the rear gear, and the hollow transmission shaft outside is connected with 2, 4 and 6 gears. The two clutches are respectively responsible for the meshing action of a drive shaft, so that the engine power is continuously transmitted by one of the drive shafts. As for the control system, the electro-hydraulic control system is located at the top of the gearbox, connected with the DSG 12 independent sensor, and added with the information of the vehicle driving state, so as to promote the work of various valves and other components. The hydraulic pressure of the two clutches is adjusted by special electronic control valves according to different driving conditions. The electronic control system is also responsible for calculating the pre-selected suitable gear and managing other control rods. The oil pressure cooling system will also be monitored by six groups of pressure regulating valves and five groups of on-off valves. In order to control DSG, the driver can use the shift lever or the shift plate on the steering wheel to shift gears manually in sequence. The clutch operation during gear shifting is completely controlled by DSG computer, so the driver does not need to be distracted. Due to the adoption of dual clutch technology, the power gap during gear shifting can be solved, and the acceleration performance is faster than that of manual gearbox. If the driver wants to get more comfortable driving enjoyment, he can push the shift lever into D gear, which can be used as a general automatic gearbox with ease and comfort. In addition to the general D gear, the automatic gear control mode also provides S gear for the driver to choose, which brings higher revolutions and higher speed to the driver. Another function is the gearshift plate on the steering wheel. Whether you use manual mode or even D or S automatic shift mode when driving, the driver only needs to tap the shift wheel on the steering wheel, and DSG will immediately switch to manual mode and perform the shift program for you, without using the shift lever to shift gears in manual mode, which is convenient and fast. Based on its unique design and manual gearbox, DSG can resist the torque as high as 350Nm, and the accurate computer calculation has more accurate shift control than the general manual gearbox, so DSG has become the most fuel-efficient transmission system. Based on the characteristics and operation mode of DSG, DSG system can give drivers the same feeling as driving a racing car. Compared with manual gearbox, it can provide faster acceleration and save fuel. Based on the above characteristics, DSG has brought a new development direction for transmission system technology.