Motion planning for cooperating mobile manipulators

1999 ◽  
Vol 16 (10) ◽  
pp. 557-579 ◽  
Author(s):  
Jaydev P. Desai ◽  
Vijay Kumar
Mechatronics ◽  
2021 ◽  
Vol 79 ◽  
pp. 102639
Author(s):  
Hongjun Xing ◽  
Ali Torabi ◽  
Liang Ding ◽  
Haibo Gao ◽  
Weihua Li ◽  
...  

Author(s):  
Bin Du ◽  
Jing Zhao ◽  
Chunyu Song

A mobile manipulator typically consists of a mobile platform and a robotic manipulator mounted on the platform. The base placement of the platform has a great influence on whether the manipulator can perform a given task. In view of the issue, a new approach to optimize the base placement for a specified task is proposed in this paper. Firstly, the workspace of a redundant manipulator is investigated. The manipulation capability of the redundant manipulator is maximized based on the manipulability index through the joint self-motion of the redundant manipulator. Then the maximum manipulation capability in the specified work point is determined. Next, the relative manipulability index (RMI) is defined for analyzing manipulation capability of the manipulator in its workspace, and the global manipulability map (GMM) is presented based on the above measure. Moreover, the optimal base placement related to the given task is obtained, and the motion planning is implemented by an improved rapidly-exploring random tree (RRT) algorithm with the RMI, which can enhance the manipulation capability from the initial point to the target point. Finally, the feasibility of the proposed algorithm is illustrated with numerical simulations and experiments on the mobile manipulator.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Chuande Liu ◽  
Bingtuan Gao ◽  
Chuang Yu ◽  
Adriana Tapus

Purpose Many work conditions require manipulators to open cabinet doors and then gain access to the desired workspace. However, after opening, the unlocked doors can easily close, interrupt a task and potentially break the operating end-effectors. This paper aims to address a manipulator's behavior planning problem for responding to a dynamic workspace released by door opening. Design/methodology/approach A dynamic model of the restricted workspace released by an unlocked door is established. As a whole system to treat, the interactions between the workspace and robot are analyzed by using a partially observable Markov decision process. A self-protective policy decision executed as a belief tree is proposed. To respond to the policy, this study has designed three types of actions: stay on guard in the workspace, using an elbow joint to defense the door and linear escape out of the workspace for self-protection by observing collision risk levels to trigger them. Finally, this study proposes self-protective motion controllers based on risk time optimization to act to the planned actions. Findings The elbow defense could balance robotic safety and work efficiency by interrupting the end-effector's work and using the elbow joint to prevent the door-closing in an active collision way. Compared with the stay and escape action, the advantage of the elbow defense is having a predictable performance to quick callback the interrupted work after the risk was relieved. Originality/value This work provides guidance for the safe operation of a class of robot operations and the upgrade of motion planning.


Robotica ◽  
2015 ◽  
Vol 35 (1) ◽  
pp. 1-25 ◽  
Author(s):  
Bibhya Sharma ◽  
Jito Vanualailai ◽  
Shonal Singh

SUMMARYThe paper considers the problem of motion planning and posture control of multiple n-link doubly nonholonomic mobile manipulators in an obstacle-cluttered and bounded workspace. The workspace is constrained with the existence of an arbitrary number of fixed obstacles (disks, rods and curves), artificial obstacles and moving obstacles. The coordination of multiple n-link doubly nonholonomic mobile manipulators subjected to such constraints becomes therefore a challenging navigational and steering problem that few papers have considered in the past. Our approach to developing the controllers, which are novel decentralized nonlinear acceleration controllers, is based on a Lyapunov control scheme that is not only intuitively understandable but also allows simple but rigorous development of the controllers. Via the scheme, we showed that the avoidance of all types of obstacles was possible, that the manipulators could reach a neighborhood of their goal and that their final orientation approximated the desired orientation. Computer simulations illustrate these results.


2021 ◽  
Author(s):  
Jun Shao ◽  
Hao Xiong ◽  
Jianfeng Liao ◽  
Wei Song ◽  
Zheng Chen ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document