啥叫“保持运动轨迹不动”？你要车子不能改变运动方向？

double wishbone 是最能保持车轮和路面垂直的悬挂，甚至在拐弯车身倾斜时

https://www.google.com/search?q=double+wishbone+suspension+diagram&client=firefox-b-1-d&tbm=isch&source=iu&ictx=1&fir=SJlw4xRAhgqrMM%253A%252CeuvbUSxEK7CnTM%252C_&vet=1&usg=AI4_-kSZMz6CORYakCWQzClnJ1Mg_OmjFA&sa=X&ved=2ahUKEwiG8ZKRgLnlAhWBmuAKHSUnDA0Q9QEwCXoECAMQMg#imgrc=6esqtyR5PXLbVM:&vet=1