Increased Efficiency in Planar Near-Field Scanning Using Combined Multi-Robot Motion

Robotic antenna ranges are highly configurable, but traditional pose-selection methods do not utilize the collaborative motion capabilities presented by these positioners. We present methods to reduce planar scan measurement time on robotic antenna ranges with redundant actuation. The inverse kinematics problem is formulated as a general optimization problem to solve for a relative Antenna-Probe transform using all controllable joints of the positioning system. A secondary objective is introduced to minimize velocity-weighted joint excursion, and resultant poses are ordered to minimize motion time using a Travelling Salesman Problem heuristic. This approach is validated using experimental planar measurements collected at the WR62 band using the Large Antenna Positioning System robotic antenna range. Compared to traditional pose-selection, combined motion reduced required scan volume by 49.9 % and motion time by 19.7 % and 20.5 % for standard and TSP pose ordering, respectively. A maximum pattern difference of -38.9 dB was found between the transformed far-field patterns.