TAS-Paths

Triple-axis spectrometers (TAS) for neutron inelastic scattering have a complex measuring strategy. As part of the efforts of the Institut Laue-Langevin in the field of autonomous instrument control, we present a safe pathfinding software for TAS spectrometers. Due to angular constraints in the instrument space, as well as from obstacles such as walls, not every (Q, E) coordinate point is accessible for the instrument. A careful mapping of the available positions is usually required before each experiment to avoid any collisions. The algorithm is able to automatically find the optimal path for the instrument, keeping it at the furthest possible distance from obstacles. It does so by calculating the Voronoi bisectors of the instrument's angular configuration space. Of these it creates a mesh of possible paths and finds the shortest path along the bisectors.