Thanks for @jingleFun  's comments

Either I am completely mistaken and understand nothing, or the matrix always has the size (n+1)x(n+1) when representing the derivative of nth order polynom.

* * update a picture format

* * add hardware system installation guide cn version

* * add 3d_obstacle_perception_cn.md

* * correction typo

* * update a picture format

* * add hardware system installation guide cn version

* * add 3d_obstacle_perception_cn.md

* Update pereption README.md and add FAQ document

* Update document

* Fix error in document

qp_spline_st_speed_optimizer.md

* fix coding style

* fix conflict

* move the detailed perception readme file to docs/specs