This article presents a novel on-line optimal control for redundant robot manipulators for which inverse kinematics is not required. The controller considers a Cartesian PID control that yields stability of the closed loop, but presents poor performance unless using high gains. A joint space dynamic optimal control based on the gradient flow approach is introduced to improve the performance of ...

We present a neural method that computes the inverse kinematics of any kind of robot manipulators, both redundant and non-redundant. Inverse kinematics solutions are obtained through the inversion of a neural network that has been previously trained to approximate the manipulator forward kinematics. The inversion provides difference vectors in the joint space from difference vectors in the work...

We report two control schemes for a two-link robot arm system using a neuro-controller. We adopted the simultaneous perturbation learning rule for a neuro-controller. Ordinary gradient type of learning rule uses Jacobian of the objective system in a direct control scheme by a neural network. However, the learning rule proposed here requires only two values of an error function. Without Jacobian...

This paper discusses deriving geometric jacobians and identifying and analyzing the kinematic singularities for two 6 DOF arm robots. First we show the direct kinematics and D-H parameters derived for these two arms. The Geometric jacobian is computed for Barrett WAM and Smokie OUR. By analyzing the jacobian matrices we find the configurations at which J is rank deficient and derive the kinemat...

The following presents a standardized approach to the kinematics of a generalized stereo robot head, providing both forward and inverse kinematic solutions as well as a discussion on the head Jacobian. The paper is intended as a comprehensive tutorial and as a standard notation reference for researchers in the field of active vision.

This article presents a novel on-line optimal control for tracking tasks on robot manipulators for which inverse kinematics is not required. The controller is composed by a stabilization Cartesian PID control plus a joint space optimal control, which is in charge of improving tracking performance. The joint space dynamic optimal control is based on the gradient flow approach with the robot dyna...

This paper studies the motion control of a multiple manipulator free-flying space robot chasing a passive object in near proximity. Free-flyer kinematics are developed using a minimum set of bodyfixed barycentric vectors. Using a general and a quasi-coordinate Lagrangian formulation, equations of motion for model-based controllers are derived. Two model-based and one transposed Jacobian control...

ABSTRACT Finding singular configurations (singularities) of manipulators is obviously important, because these configurations are the ones where the instantaneous kinematics becomes indeterminate. In this paper, singularities of a three degree-of-freedom (DOF) fully parallel planar manipulator are analyzed with the aid of two Jacobian matrices which are expressed through instantaneous centers o...

This paper presents a closed-form formulation and geometrical interpretation of the derivatives of the Jacobian matrix of fully parallel robots with respect to the moving platforms’ position/orientation variables. Similar to the Jacobian matrix, these derivatives are proven to be also groups of lines that together with the lines of the instantaneous direct kinematics matrix govern the singulari...

Using a coarse-and-fine actuator combination (dual stage system), a new design of the three degree-of-freedom (DOF) micro parallel positioning platform with high mobility, high accuracy, and a large working space is proposed. To achieve these three DOFs and implement the dual stage system, there are six possible architectures for the coarse and fine actuators, respectively. This paper is organi...