Redundancy resolution and obstacle avoidance for cooperative industrial robots

Abstract

Planning methods for effective manipulation of single or multiple redundant arm systems must take account of DOF, the task, constraints, and joint drifts. Here, a new approach to redundancy resolution and obstacle avoidance for cooperative robot arms is proposed. In this development, a relative Jacobian and a relative dexterity measure for cooperative robot arms are derived. A nonlinear programming method is used to optimize the relative dexterity while satisfying cooperative task requirements, limits on joint angles, and obstacle avoidance. With this approach, it is not necessary to balance the weightings between the cost term to be optimized and the penalty from constraints. Configuration jumps over obstacles are avoided. Further, since globally optimal joint configurations are produced, drifts in joint configurations will be absent from the resulting configurations. This article includes several illustrative examples to demonstrate the effectiveness and usefulness of this approach. Results have indicated the benefits of both the relative dexterity and the sum of individual arm dexterities in planning of cooperative tasks. ©1999 John Wiley & Sons, Inc.

Task-Space Modular Dynamics for Dual-Arms Expressed through a Relative Jacobian

“…In previous expressions of modular relative Jacobian [36][37][38], the wrench transformation matrix was considered to be an identity matrix. Here, we refer to such relative Jacobian as J ′ R .…”

Natural redundancy resolution in dual-arm manipulation using configuration dependent stiffness (CDS) control

“…B), which lead to the generation of corresponding configurations. Inspired by similar observations, the problem of redundancy resolution has been extensively addressed in the field of robotics by establishing task-related artificial potential fields [2], [3], [4], while, only few studies have drawn attention to the acquired human-like natural motion [5], [1], [6]. With the advent of higher demands on dual-arm manipulation, interaction with the environment using impedance control [7] became the focus of many studies in dual-arm systems.…”

“…since Σ G is considered rigidly attached to Σ obj , the components of the stiffness matrix are expressed in Σ obj 2. By taking into account that for a square and invertible matrix X, ∂ X −1 = −X −1 (∂ X)X −1 .…”

Obstacle avoidance for kinematically redundant manipulators using polyhedral approximations

“…By applying various p…y † functions, subtasks such as avoiding obstacles [2][3][4][5][6][7][8][9][10][11][12], joint limits [3] and singularities [1,13], minimizing the magnitudes of individual joint velocities [14,15], reducing the peak torque [1] and increasing the dexterity [16] can be performed. The problem of collision avoidance of redundant manipulators has been widely investigated in the robotics literature.…”

“…In reference [8], M a and H irose proposed an approach for dynamic obstacle avoidance, which is formulated in the acceleration level. The elastic model method, by which each revolute joint of the manipulator is represented as an elastic spring, is investigated by Cao et al [3]. In Liang and Liu's work [7], the minimum distance function is employed to solve the obstacle avoidance problem.…”