However, due to the different turning radius of each wheel when turning, the speed of wheel rotation is also different (inside and outside, front and rear). The four wheels cannot be connected by a rigid transmission system, and a differential must be set between the left and right wheels and between the front and rear drive shafts.
The problem is that the driving force of the four wheels is limited by the wheel with the least friction with the ground, and a differential lock needs to be set. The electronically controlled four-wheel drive technology senses the situation of the four wheels on the road through the sensor, analyzes and judges through the microcomputer, and changes the characteristics of the mucus coupler through the solenoid valve drive, and distributes the driving force between the front and rear drive shafts and the left and right wheels.