14 accepted papers
Grasp planning must consider an object's local geometry (at the finger contacts), for the range of applicable wrenches under friction, and its global geometry, for force closure and grasp quality. Most everyday objects have curved surfaces unamenable to a pure combinatorial approach but treatable wi
Despite decades of steady research progress, the robotic hand is still far behind the human hand in terms of dexterity and versatility. A milestone in this quest for human-level performance will be possessing the skills of manipulating hand tools, for their non-trivial geometries and for the intrica…
For over three decades, finger gaiting has remained largely a subject for theoretical inquiries. Successful execution of a sequence of finger gaits does not simply reduce to planning collision-free paths for the involved fingers. A major issue is how to move the gaiting finger without losing the fin…
The robotic hand is still no match for the human hand on many skills. Manipulation of hand tools, which usually requires sophisticated finger movements and fine controls, not only poses a clear technical challenge but also carries a great potential for enabling the robot to assist humans in a wide r…
Dexterous robotic cutting needs to demonstrate a skill level with smooth and efficient knife movements. The work performed by the knife mainly generates fracture and overcomes the blade-material friction. This paper presents a recursive least-squares method that repeatedly estimates relevant physica…
Slicing is an important skill for a robot to learn as it is more efficient and results in less deformation in comparison with cutting by pressing. Cutting experiments with foods have indicated that the ease of slicing is caused by a decrease in fracture toughness. In this paper, we formally characte…
Despite more than three decades of grasping research, many tools in our everyday life still pose a serious challenge for a robotic hand to grip. The level of dexterity for such a maneuver is surprisingly "high" that its execution may require a combination of closed loop controls and finger gaits. Th…
Cutting skills are important for robots to acquire not only because of a need from kitchen automation, but also because of the technical challenge for robotic manipulation. Modeling of fracture and deformation during a cutting action, often based on the finite element method (FEM), provides the forc…
Effectiveness of cutting is measured by the ability to achieve material fracture with smooth knife movements. The work performed by a knife overcomes the material toughness, acts against the blade-material friction, and generates shape deformation. This paper studies how to control a 2-DOF robotic a…
This paper studies dexterous manipulation in the plane by a two-fingered hand in the plane. The dynamics of each finger, which consists of two links with coupled joints, are derived based on Lagrangian mechanics. As an object is being manipulated, its orientation and the two independent joint angles…
This paper presents a planning algorithm for a 2-DOF robotic arm to bat a flying 2D object to a targeted location. Impact dynamics are combined with trajectory kinematics and manipulator dynamics to compute the evolving set of states (poses and velocities) of the arm able to achieve the task as the…
This paper presents an impulse-based model for n-body collisions with or without friction. In the frictionless case, impulses at all the contacts, initialized via solution of a non-linear system, accumulate over different phases (compression and restitution) tracked through numerical integration. Ex…
This paper describes a strategy to lift up a deformable 2D object resting on a horizontal plane. Inspired by human hand lifting behavior, the strategy plans grasping trajectories of two fingertips using modified Rapidly-exploring Random Trees (RRT). Compared to a straight squeeze, a planned finger m…
This paper investigates the free motion of a sphere with initial velocity and angular velocity on a plane under sliding and rolling friction. The sphere will first slide along a parabolic trajectory (with a constant direction of its contact velocity), and then roll along a straight trajectory. Such…