1D2L: One-Arm Drag and Two-Arm Lift for Manipulating Large and Heavy Tabletop Objects

Abstract

Dual-arm robots are widely used to cooperatively manipulate large, heavy objects that exceed single-arm payload limits. However, conventional dual-arm planners typically assume that the object is already positioned within the reachable and graspable workspace of both end-effectors. When the object lies outside this workspace or in an awkward orientation, such planners often fail or require additional hardware (e.g. a mobile base or overhead cranes) to reposition the robot or the object first. To address this limitation, we present 1D2L (One-Arm Drag and Two-Arm Lift), a task-and-motion planning framework for dual-arm tabletop manipulation. The framework extends manipulation capability by first dragging the object with one arm into a “liftable zone” on a horizontal planar surface, and then performing a cooperative two-arm lift. The liftable zone contains pre-computed set of tabletop poses derived from kinematic reachability, grasp feasibility, and dynamic stability requirements for the subsequent dual-arm lift. Beyond lifting, 1D2L provides as a general paradigm for large-object tabletop manipulation, where one-arm dragging for pre-positioning to enable subsequent two-arm tasks. We validate the 1D2L framework experimentally, demonstrating a successful framework that enables robots to handle large or heavy objects that are initially unreachable.