We analyze the behavior of redundant robots when the joint motion is generated by inverting task velocity commands through a kinematic control scheme. Depending on the chosen inversion scheme, the robot motion is subject to differential constraints that may or may not be integrable. Accordingly, we give a classification in terms of holonomic, partially nonholonomic, and completely nonholonomic ...

Accurate and robust object state estimation enables successful object manipulation. Visual sensing is widely used to estimate object poses. However, in a cluttered scene or in a tight workspace, the robot’s end-effector often occludes the object from the visual sensor. The robot then loses visual feedback and must fall back on open-loop execution. In this paper, we integrate both tactile and vi...

Dynamic Singularities are shown for free-floating space manipulator systems where the spacecraft moves in response to manipulator motions without compensation from its attitude control system. At a dynamic singularity the manipulator is unable to move its end-effector in some inertial direction; thus dynamic singularities must be considered in the design, planning, and control of free-floating ...

In this paper we combine a survey of the most important topological properties of kinematic maps that appear in robotics, with the exposition of some basic results regarding the topological complexity of a map. In particular, we discuss mechanical devices that consist of rigid parts connected by joints and show how the geometry of the joints determines the forward kinematic map that relates the...

This paper describes a new structure of a six-DOF parallel robot. First, a known planar three-DOF double-triangular structure is modified by replacing the stationary triangle with a circle. It increases the work envelope considerably especially when rotational motions are required. The ability for unlimited rotational motion allows extending the structure into six-DOF by using two sets of stati...

Achieving the dexterity of the human hand is still a far fetched idea for the robotic and prosthetic hands available today. Nevertheless, there have been attempts to come up with simpler models for constrained tasks to achieve similar results as a human hand for the particular task, if not the same general working complexity as the human hand. We perform a comparison between a simple two-finger...

This paper discusses the design of capturing system with an extremely high response. The key for achieving a quick response is the Arm/Gripper Coupling Mechanism (AGCM), where the potential energy initially accumulated in the arm is transferred to the kinetic energy of the arm and, continuously, to the kinetic energy for closing the gripper at the capturing point without any time lag. The exper...

Generally, the robot manipulators are classified into serial type open loop chains and parallel type closed loop chains. Since decades, robot manipulators were designed and operated using the open loop serial chains. In general, Robots used in industries are all general purpose manipulators, consisting of multiple rigid links and are connected in series by means of joints such as revolute, pris...

In this paper, we address the problem of generating trajectories of some image features in order to control efficiently a robotic system using an image-based control strategy. First, physically valid C2 image trajectories which correspond to quasi-optimal 3D camera trajectory are performed. Both self-occlusion avoidance and visibility constraints are taken into account at the task planning leve...

We present a fast algorithm for solving the problem of the verification of a trajectory for a 6-DOF parallel manipulator with respect to its workspace: i.e., given two different postures for the end-effector, is the straight line joining these two postures in the parameters space fully inside the workspace ? This algorithm is based on the analysis of the algebraic inequalities describing the co...