RBI-RRT*: Efficient Sampling-based Path Planning for High-dimensional State Space

Sampling-based planning algorithms such as RRT have been proved to be efficient in solving path planning problems for robotic systems. Various improvements to the RRT algorithm have been presented to improve the performance of the extension and convergence of the random trees, such as Informed RRT*. However, with the growth of spatial dimensions, the time consumption of randomly sampling the entire state space and incrementally rewiring the random trees raises drastically before a feasible solution is found. In this paper, to enhance the convergence performance of optimal solutions, we present Reconstructed Bi-directional Informed RRT* (RBI-RRT*) path planning algorithm. The algorithm acts as RRT-Connect to rapidly find a feasible solution, which helps compress the sampling space as Informed RRT* does. After the random trees are transformed into RRT* structure by the reconstruction process in RBI-RRT*, the algorithm continues to find the near-optimal path. A series of simulations and real-world robot experiments were conducted to evaluate the algorithm against existing planning algorithms. Compared to Informed RRT* Connect, RBI-RRT* reduced the computation time of achieving a specific cost by 22.1% on average in simulations and 11.2% in the real-world robotic arm experiments. The results show that RBI-RRT* is more efficient in high-dimensional planning problems.