planning on Frenet without kinematic constrain

[stdpython]

When planning on Frenet Frame, it seems impossible to add curvature constrain. And when Apollo optimizes the path, it does not add the curvature constrain. Only check whether the trajectory valid after the the trajectory generation. However, it just return an error msg if not valid.

I just want to know that why don't add the kinematic constrain as mentioned above?

PS: Lattice planner works fine with the problem, it generate many trajectories, which pass the kinematic constrain will be chosen.

[LiJiangnanBit]

I think there are constraints on the curvature. In function common::Status PiecewiseJerkPathOptimizer::Process, a vector ddl_bounds is calculated according to the curvature limit of the vehicle. And it is used as a constraint in the optimization process.