We know that the body and tires of the car are connected together by the suspension, and the suspension system vibrates due to the impact of the elastic elements, so that if the body shakes up and down when passing through uneven roads, it will remain for a long time, causing extreme discomfort for the driver and passengers. Therefore, in order to improve the driving smoothness of the car, shock absorbers are installed in parallel with the elastic elements in the suspension, and the shock absorbers can absorb the vibrations generated by the elastic elements, so that the car can return to stability in a short time after bumps.