Speeding Up Learning in Real-Time Search through Parallel Computing

Abstract

Real-time search algorithms solve the problem of path planning, regardless the size and complexity of the maps, and the massive presence of entities in the same environment. In such methods, the learning step aims to avoid local minima and improve the results for future searches, ensuring the convergence to the optimal path when the same planning task is solved repeatedly. However, performing search in a limited area due to real-time constraints makes the run to convergence a lengthy process. In this work, we present a parallelization strategy that aims to reduce the time to convergence, maintaining the real-time properties of the search. The parallelization technique consists on using auxiliary searches without the real-time restrictions present in the main search. In addition, the same learning is shared by all searches. The empirical evaluation shows that even with the additional cost required to coordinate the auxiliary searches, the reduction in time to convergence is significant, showing gains from searches occurring in environments with fewer local minima to larger searches on complex maps, where performance improvement is even better.