Smoothing the Curvature of Trajectory of Ground Robot in 3D Space

Abstract

Purpose or research. Development of an algorithm for smoothing the trajectory of a ground robot over rough terrain, represented as a graph in three-dimensional space. Methods. This article presents the CSA (Curve Smoothing and Averaging) algorithm for smoothing local curves in the Oxy plane that make up a global curve, represented as a path on a connected graph in 3D space. The presented algorithm is based on the previously developed LRLHD-A * approach, which uses information about the vertices of the graph, their neighbors and the edges connecting them to select the area through which the smoothed curve will run. In order to avoid a broken curve at the output of the algorithm, a curve averaging method was developed, the idea of which is to shift the midpoints of local curves along the edges on which they are located. Results. An experimental comparison was made of the curvature of the trajectories obtained using the curve smoothing algorithm with curve averaging (CSA) and without it (CS). The method was carried out on a threedimensional map of the area, presented in the form of a graph with 100082 vertices. For the experiments, a sample of 10 pairs of random vertices was used, between which a path was built using the LRLHD-A * algorithm. The results of the experiments have shown that averaging the curve after smoothing reduces its curvature from 24 to 42%. Conclusion. Trajectories smoothed using the developed CSA algorithm have smoother curve bends at turns, compared to the algorithm taken as a basis. This allows the robots to move more smoothly and, as a consequence, reduce the consumption of the robot's battery.