Armando Fox Seth Hutchinson 0001 Exploiting Visual Constraints in the Synthesis of Uncertainty-Tolerant Motion Plans II: The Nondirectional Backprojection. 311-316 1993 conf/icra/1993 ICRA (1) db/conf/icra/icra1993-1.html#FoxH93a https://doi.org/10.1109/ROBOT.1993.292000