A framework for the analysis and control of manipulator systems with respect to the dynamic behavior of their end-effectors is developed. First, issues related to the description of end-effector tasks that involve constrained motion and active force control are discussed. The fundamentals of the operational space formulation are then presented, and the unified approach for motion and force cont...

Free-flying space manipulator systems, in which robotic manipulators are mounted on a free-flying spacecraft, are envisioned for assembling, maintenance, repair, and contingency operations in space. Nevertheless, even for fixed-base systems, control of mechanical manipulators is a challenging task. This is due to strong nonlinearities in the equations of motion, and consequently different algor...

In this paper a general formulation for finding the maximum allowable dynamic load (MADL) of flexible link mobile manipulators is presented. The main constraints used for the algorithm presented are the actuator torque capacity and the limited error bound for the end-effector during motion on the given trajectory. The precision constraint is taken into account with two boundary lines in plane w...

A second-generation automated deburring cell is currently under development at the National Institute of Standards and Technology. This cell will be capable of automatically generating, from part geometry and machining information, a series of robot paths for deburring aerospace parts made from superalloys. In order to compensate for the inaccuracy of robots when following computed coordinates,...

Measures of dynamic manipulability summarize a manipulator’s capacity to generate accelerations for arbitrary tasks, and such measures are useful tools for the design and control of generalpurpose robots. Existing measures, however, downplay the effects of velocity or else ignore them altogether. In this paper we derive the relationship between joint velocity and end-effector acceleration, and ...

This paper is an investigation of completely mechanical quick changeable joints for multipurpose explosive ordnance disposal (EOD) robots. With the assistance of a quick changeable joint, an ordinary EOD robot becomes a multipurpose robot with an end effector which can be switched during the task. This exchangeable end effector permits the robot to perform more complex duties. Making the joint ...

This paper presents a motion planning method for mobile manipulators for which the base locomotion is less precise than the manipulator control. In such a case, it is advisable to move the base to discrete poses from which the manipulator can be deployed to cover a prescribed trajectory. The proposed method finds base poses that not only cover the trajectory but also meet constraints on a measu...

We use the recently introduced factorization of motion polynomials for constructing overconstrained spatial linkages with a straight line trajectory. Unlike previous examples, the end-effector motion is not translational and the link graph is a cycle. In particular, we obtain a number of linkages with four revolute and two prismatic joints and a remarkable linkage with seven revolute joints one...

The method for parallel mechanism type synthesis is introduced based on the kinematic characteristics flow process from the joints to the end-effector of parallel mechanism. Some new kinds of redundant input parallel mechanisms are brought forward by this method. By adopting double-inputs interface module, a kind of parallel earthquake simulator is presented and manufactured. The according cont...

A scheme for learning to grasp objects using visual information is presented. A system is considered that coordinates a parallel-jaw gripper (hand) and a camera (eye). Given an object, and considering its geometry, the system chooses grasping points, and performs the grasp. The system learns while performing grasping trials. For each grasp we store location parameters that code the locations of...