Bidirectional motion planning approaches decrease planning time, on average,
compared to their unidirectional counterparts. In single-query feasible motion
planning, using bidirectional search to find a continuous motion plan requires
an edge connection between the forward and reverse search trees. Such a
tree-tree connection requires solving a two-point Boundary Value Problem (BVP).
However, a two-point BVP solution can be difficult or impossible to calculate
for many systems. We present a novel bidirectional search strategy that does
not require solving the two-point BVP. Instead of connecting the forward and
reverse trees directly, the reverse tree's cost information is used as a
guiding heuristic for the forward search. This enables the forward search to
quickly converge to a feasible solution without solving the two-point BVP. We
propose two new algorithms (GBRRT and GABRRT) that use this strategy and run
multiple software simulations using multiple dynamical systems and real-world
hardware experiments to show that our algorithms perform on-par or better than
existing state-of-the-art methods in quickly finding an initial feasible
solution.Comment: Journal version (Video: https://youtu.be/Rumg66UHfyQ