Collision-free kinematics for hyper-redundant manipulators in dynamic scenes using optimal velocity obstacles

Liangliang Zhao,Jingdong Zhao,Hong Liu,Yongjun Sun,Zainan Jiang

doi:10.1177/1729881421996148

Liangliang Zhao, Jingdong Zhao + Show 3 more

Open Access

https://doi.org/10.1177/1729881421996148

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Abstract

Hyper-redundant manipulators have been widely used in the complex and cluttered environment for achieving various kinds of tasks. In this article, we present two contributions. First, we provide a novel algorithm of relating forward and backward reaching inverse kinematic algorithm to velocity obstacles. Our optimization-based algorithm simultaneously handles the task space constraints, the joint limit constraints, and the collision-free constraints for hyper-redundant manipulators based on the generalized framework. Second, we present an extension of our inverse kinematic algorithm to collision avoidance for the hyper-redundant manipulators, where the workspaces may have different types of obstacles. We highlight the performance of our algorithm on hyper-redundant manipulators with various degrees of freedom. The results show that our algorithm has made full use of dexterity of hyper-redundant manipulators in complex environments, enhancing the performance and increasing the flexibility.

Highlights

Hyper-redundant manipulators consist of more degrees of freedom (DOF) than those of traditional manipulators
There are many studies on collision-avoidance problem for motion planning of robots in dynamic workspaces.[24,25,26,27]. The limitations of these studies though are that most of the approaches assume the robots to simple circle models and only take two-dimensional (2D) workspace into account, which limits their applicability to hyper-redundant manipulators. We address those shortcomings by introducing a new collision-free inverse kinematic algorithm for a hyper-redundant manipulator, which operates in a dynamic environment with static and/or dynamic obstacles
We present a novel method toward solving the inverse kinematic problem of hyper-redundant manipulators in complex working environments

Summary

Introduction

Hyper-redundant manipulators consist of more degrees of freedom (DOF) than those of traditional manipulators. The high computational cost of the Jy computation makes the Jacobian inverse methods unsuitable for the manipulators with a large number of DOF.[9,10] This limit leads to the development of shape trajectory control approaches, which use differential geometry to formulate the closed-form modal inverse kinematic solutions and adjust the manipulator configurations to avoid the obstacles.[11,12,13,14,15] Those approaches to solve the inverse kinematic problem are only for limited kinematic models, which constrain the performance (dexterity in cluttered environments) of the hyper-redundant manipulators and restrict their potential applicability. For shape trajectory control approach, Chirikjian and Burdick[11,12] introduce a novel method to solve the inverse kinematic problem of hyper-redundant manipulators based on a “backbone curve.”. Other recent optimization methods studied are based on curve-constrained collision-free trajectory control,[35] vector field inequalities,[36] and Newton’s method.[37]

Materials and methods

Findings

Conclusions