ARTIC ULAT ED ROBOTS MOTION PLANNI NG USING FO RAGING ANT STRATEGY

Abstract

A bst ract : Ma ny different approaches to tac kle the pro blem of motion pla nn ing fo r articu late d robots in an env ironment w ith obstacles based on random sampling have been proposed. One popular ap proac h is called single-query bi-directional motion pla nning w ith a lazy co llision checking pro ba bilistic ro adm ap (S BL-P R. 1.) . However , the performa nce of th is met hod is sub -op tima l in terms o f the num ber of configurations ge nerated, length of path, amount of col lisio n chec king and computatio nal time . To improve the performance, those as pec ts must be co ns idered furt her as they are inter-related with eac h other. A novel mo dification o f SBL­ PRM that dec reas es the size of excessive configurations in th e ro ad map, by incrementa lly bu ildi ng a one-t ree st ructu re orig inat ing from the sta rt configu rat ion, is prese nted. This approach, the single-q uery u nidi rectio na l ap proac h with lazy co llision c hec king (S UL-P R.\1), has ex perimental ly sho w n to be equal to the SBL· PR.\'!. How ever, there still e x ists ge nerated configurations th at were exc luded from the success ful path . The generat ion o f these unco nsume d co nfigurations co rres pond ing to the tree structure has poin tless ly utilized th e com putationa l resource s and affected the planni ng time. Hence, a new method o f configurat ion ge nerat ion a long w ith a novel searc hing style is devised. An alte rnat ive sea rch approac h usi ng ant behav iour in a robotics app lication is a pplied. This paper proposes a nove l searc h technique, the F- Ant a lgorithm, in orde r to find a re liabl e path betw een the initi al con figuration and the goal con figuration of the articulated ro bot. This no ve l algorithm, taking two in put con figu ratio ns, e xplo res th e robot's free s pace by build ing up a u nid irect ional searc h be ginn ing at the init ial configuration. The planner sam ples the free co nfigurat ion repeti t ively in the ne igh bourhood within the rad ius of the c urre nt co nfigurat ion, a nd tests th e edge for a collisio n-free pat h between the new sampled configuratio ns, until it is con nected to th e goal configuration. Simu latio n and experimenta l co mpariso ns o f F-Ant and SBL- PR M have bee n con d ucted, sho w ing t he per forma nce differences betw een these two tec hniques.