COAST: Constraints and Streams for Task and Motion Planning

Abstract-- Task and Motion Planning (TAMP) algorithms solve long-horizon robotics tasks by integrating task planning with motion planning; the task planner proposes a sequence of actions towards a goal state and the motion planner verifies whether this action sequence is geometrically feasible for the robot. We aim to equip a robot with the ability to solve complex We propose a probabilistically-complete, plan-first TAMP long-horizon tasks that require a combination of symbolic algorithm that is significantly faster than PDDLStream and geometric reasoning. This speedup occurs by using a direct stream is an approach for solving such tasks. TAMP methods often planning algorithm to create stream objects after task use task planning to produce a sequence of symbolic planning rather than before to avoid the computational cost actions, i.e. a task plan, in addition to using sampling-based of task planning with many unnecessary stream objects. We motion planning to ensure the task plan is geometrically validate our method on three TAMP domains (Figure 1), each feasible.