We propose a hierarchical scheme for rapid learning of context dependent "skills" that is based on the recently introduced "Parameterized SelfOrganizing Map" ("PSOM"). The underlying idea is to first invest some learning effort to specialize the system into a rapid learner for a more restricted range of contexts. The specialization is carried out by a prior "investment learning stage", during w...

In this paper we present an algorithm to compute set-point (i.e. a position to be reached by the robot) automatically from conic features virtually placed by an operator onto the object. We then use a visual servoing algorithm to guide the gripper to its final position. We have tested this algorithm in trying to open a valve with a 6 degree of freedom robot arm, using only visual information an...

This paper proposes a three-dimensional force field (3D-F) method for efficient motion planning and collision avoidance of a 6DOF manipulator in complex and dynamic environments while keeping the planned end-effector’s path and speed unchanged. The 3D-F is defined as ellipsoid shapes covering selected links of a manipulator. When the manipulator moves and its ellipsoid force field approaches to...

The increasing demand for robotic applications in dynamic unstructured environments is motivating the need for dextrous end-effectors which can cope with the wide variety of tasks and objects encountered in these environments. The human hand is a very complex grasping tool that can handle objects of different sizes and shapes. Many research activities have been carried out to develop artificial...

In this paper, we propose a novel design of end-effectors that is specialized in caging manipulation. Caging manipulation has several advantages comparing with traditional grasping manipulation. For example, caging can allow small gap/margin between end-effectors and a target object, making the manipulator relieved from constant contact and precise control. Therefore, caging manipulator can avo...

Algorithmic data fusion for multi-sensory system becomes extremely challenging, particularly where the elemental sensory units do vary in type, size and characteristics. Although traditional theories on sensory data fusion fit quite satisfactorily in searching a pre-defined object with a tentative dimension and depth perception, they fail to do justice in cases where profile of the object do va...

Mobile manipulator systems, comprised of a mobile platform with one or more manipulators, are of great interest in a number of applications. This paper presents a planning and control methodology for such systems allowing them to follow simultaneously desired end-effector and platform trajectories without violating the nonholonomic constraints. Based on a reduction of system dynamics, a model-b...

An important issue in designing manipulators for dynamic performance is the determination of the acceleration properties of (some reference-point on) the end-effector of the manipulator. Given the dynamical equations of the planar two degree-of-freedom manipulator and a set of constraints on the actuator torques and on the rates-ofchanges of the joint variables, we systematically develop (a) th...

Hand-eye calibration, which consists in identifying the rigidbody transformation between a camera mounted on the robot end-effector and the end-effector itself, is a fundamental problem in robot vision. Mathematically, this problem can be formulated as: solve for X in AX = XB. In this paper, we provide a rigorous derivation of the covariance of the solution X , when A and B are randomly perturb...

We develop non-smooth motion controllers that enable a manipulator to perform surface tasks that do not involve force/torque interactions, while maintaining bounded joint rates. The robot’s end-effector is first stabilized to a point close to the surface, and then it tracks a trajectory on the surface, while avoiding certain prescribed regions. We show that the resulting closed loop system is u...