Planning with differential constraints for LAGR Paul Vernaza

Problem definition Given an obstacle map, current position, goal position, plan a path to goal satisfying differential constraints Solution must operate in real-time Robot: wheeled, differential drive

Current approach Disadvantage: no consideration of dynamics Combination of A* and elastic band potential Advantage: speed

Investigated approaches Coupled approach: Incrementally build search graph from sampled controls, dynamics simulator Choose expansion points in A*-like manner Decoupled approach: Find collision-free path Track path via controller that satisfies differential constraints Advantages, disadvantages…

Decoupled path planning A* + elastic band: a little awkward Can we directly and efficiently minimize elastic potential? Possibly… Careful choice of obstacle potential “Simulated gradient descent” Alternatively, A* with roadmap

Path tracking with differential constraints Length-optimal vs. time-optimal Vehicle BVP solvers: Reeds-Shepp, Balkcom-Mason, Chitsaz-LaValle Too unrealistic? No acceleration… Other steering methods Learning a controller

Planned deliverables New path planning approach Path tracker with differential constraints Hopefully, trial on real robot