Optimal Base Placement and Motion Planning for Mobile Manipulators

2012 ◽  
Author(s):  
Bin Du ◽  
Jing Zhao ◽  
Chunyu Song
Keyword(s):  
Motion Planning ◽  
Great Influence ◽  
Initial Point ◽  
Mobile Manipulator ◽  
Target Point ◽  
Mobile Manipulators ◽  
Redundant Manipulator ◽  
Self Motion ◽  
The Given ◽  
Manipulation Capability

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.

scholarly journals A new method on motion planning for mobile robots using jump point search and Bezier curves

2021 ◽  
Vol 18 (4) ◽  
pp. 172988142110192
Author(s):  
Ben Zhang ◽  
Denglin Zhu
Keyword(s):  
Motion Planning ◽  
Initial Point ◽  
Target Point ◽  
Jump Point ◽  
Bezier Curves ◽  
Bézier Curves ◽  
Front End ◽  
Planning Algorithm ◽  
Point Search ◽  
Path Planning Algorithm

Innovative applications in rapidly evolving domains such as robotic navigation and autonomous (driverless) vehicles rely on motion planning systems that meet the shortest path and obstacle avoidance requirements. This article proposes a novel path planning algorithm based on jump point search and Bezier curves. The proposed algorithm consists of two main steps. In the front end, the improved heuristic function based on distance and direction is used to reduce the cost, and the redundant turning points are trimmed. In the back end, a novel trajectory generation method based on Bezier curves and a straight line is proposed. Our experimental results indicate that the proposed algorithm provides a complete motion planning solution from the front end to the back end, which can realize an optimal trajectory from the initial point to the target point used for robot navigation.

Coordinated Motion Planning of Legged Mobile Manipulator for Tracking the Given End-Effector’s Trajectory

2019 ◽  
Author(s):  
Kondalarao Bhavanibhatla ◽  
Sulthan Suresh-Fazeela ◽  
Dilip Kumar Pratihar
Keyword(s):  
Motion Planning ◽  
Degrees Of Freedom ◽  
Robotic System ◽  
Simulation Software ◽  
Body Motion ◽  
Whole Body ◽  
Mobile Manipulator ◽  
Coordinated Motion ◽  
Multibody Dynamic ◽  
The Given

Abstract In this paper, a novel algorithm is presented to achieve the coordinated motion planning of a Legged Mobile Manipulator (LMM) for tracking the given end-effector’s trajectory. LMM robotic system can be obtained by mounting a manipulator on the top of a multi-legged platform for achieving the capabilities of both manipulation and mobility. To exploit the advantages of these capabilities, the manipulator should be able to accomplish the task, while the hexapod platform moves simultaneously. In the presented approach, the whole-body motion planning is achieved in two steps. In the first step, the robotic system is assumed to be a mobile manipulator, in which the manipulator has two additional translational degrees of freedom at the base. The redundancy of this robotic system is solved by treating it as an optimization problem. Then, in the second step, the omnidirectional motion of the legged platform is achieved with a combination of straight forward and crab motions. The proposed algorithm is tested through a numerical simulation in MATLAB and then, validated on a virtual model of the robot using multibody dynamic simulation software, MSC ADAMS. Multiple trajectories of the end-effector have been tested and the results show that the proposed algorithm accomplishes the given task successfully by providing a singularity-free whole-body motion.

Dynamical Sliding Mode Control of Mobile Manipulators

2009 ◽  
Vol 626-627 ◽  
pp. 453-458
Author(s):  
Hong Mei ◽  
Yong Wang
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
Convergence Speed ◽  
Mobile Manipulator ◽  
Control Law ◽  
Mobile Manipulators ◽  
Mode Control ◽  
Chattering Effect ◽  
The Given ◽  
Actual Control

A solution to the problem of the elimination of the chattering effect and the improving of the convergence speed for sliding mode control is presented in this paper.A new dynamical sliding mode controller is developed which takes the first derivative of the control signal instead of the actual control as control and results in smoothed control inputs to the given system.A new nonlinear sliding mode surface is devised which can improve the convergence speed in the sliding phase.Exponential reaching law is taken to determine the control law which can improve the convergence speed in the reaching phase.A mobile manipulator with two arms is taken as an example to track a given trajectory with the proposed controller. It is found that the new developed method has a high convergence speed and the chattering is also reduced greatly.

Mission Design of Mobile Manipulators in Cluttered Environments for Service Applications

2020 ◽  
pp. 1358-1376
Author(s):  
Elias K. Xidias ◽  
Philip N. Azariadis ◽  
Nikos A. Aspragathos
Keyword(s):  
Inverse Image ◽  
Mission Design ◽  
Mobile Manipulator ◽  
Indoor Environments ◽  
Mobile Manipulators ◽  
Higher Dimension ◽  
End Effector ◽  
Cluttered Environments ◽  
Cost Simulation ◽  
The Given

The purpose of this paper is to present a mission design approach for a service mobile manipulator which is moving and manipulating objects in partly known indoor environments. The mobile manipulator is requested to pick up and place objects on predefined places (stations). The proposed approach is based on the Bump-Surface concept to represent robot's environment through a single mathematical entity. The solution of the mission design problem is searched on a higher dimension Bump-Surface in such a way that its inverse image into the actual robot environment satisfies the given objectives and constraints. The problem's objectives consist of determining the best feasible paths for both the mobile platform and for the manipulator's end-effector so that all the stations are served at the lowest possible cost. Simulation examples are presented to show the effectiveness of the presented approach.

Avoidance Ability of Redundant Mobile Manipulators During Hand Trajectory Tracking

2007 ◽  
Vol 11 (2) ◽  
pp. 135-141
Author(s):  
Mamoru Minami ◽  
◽  
Hiroshi Tanaka ◽  
Yasushi Mae ◽  
Keyword(s):  
Mobile Robot ◽  
Obstacle Avoidance ◽  
Trajectory Tracking ◽  
Shape Index ◽  
Mobile Manipulator ◽  
Redundant Manipulators ◽  
Mobile Manipulators ◽  
Redundant Manipulator ◽  
Configuration Control ◽  
Control Study

We propose a criterion of obstacle avoidance for a mobile manipulator, consisting of a redundant manipulator and a mobile robot. In the configuration control study of redundant manipulators, the avoidance manipulability ellipsoid and the avoidance manipulability shape index have been suggested as an index to symbolize avoidance ability of the manipulator’s shape when the hand tracks a desired trajectory. In following proposed criteria of obstacle avoidance ability, we extend concepts for mobile manipulators to discuss the avoidance ability of intermediate links for mobile operations. We start by analytically formulating, the avoidance manipulability ellipsoid and the avoidance manipulability shape index of a mobile manipulator. We then evaluate the avoidance manipulability shape index representing shape changeability for the entire manipulator’s configuration using a mobile manipulator with a three-link arm as an example.

Mission Design of Mobile Manipulators in Cluttered Environments for Service Applications

2016 ◽  
Vol 4 (1) ◽  
pp. 1-18
Author(s):  
Elias K. Xidias ◽  
Philip N. Azariadis ◽  
Nikos A. Aspragathos
Keyword(s):  
Inverse Image ◽  
Mission Design ◽  
Mobile Manipulator ◽  
Indoor Environments ◽  
Mobile Manipulators ◽  
Mathematical Entity ◽  
End Effector ◽  
Cluttered Environments ◽  
Cost Simulation ◽  
The Given

The purpose of this paper is to present a mission design approach for a service mobile manipulator which is moving and manipulating objects in partly known indoor environments. The mobile manipulator is requested to pick up and place objects on predefined places (stations). The proposed approach is based on the Bump-Surface concept to represent robot's environment through a single mathematical entity. The solution of the mission design problem is searched on a higher dimension Bump-Surface in such a way that its inverse image into the actual robot environment satisfies the given objectives and constraints. The problem's objectives consist of determining the best feasible paths for both the mobile platform and for the manipulator's end-effector so that all the stations are served at the lowest possible cost. Simulation examples are presented to show the effectiveness of the presented approach.

Dual arm-angle parameterisation and its applications for analytical inverse kinematics of redundant manipulators

Robotica ◽  
2015 ◽  
Vol 34 (12) ◽  
pp. 2669-2688 ◽  
Author(s):  
Wenfu Xu ◽  
Lei Yan ◽  
Zonggao Mu ◽  
Zhiying Wang
Keyword(s):  
Inverse Kinematics ◽  
Reference Plane ◽  
Redundant Manipulators ◽  
Redundant Manipulator ◽  
Singularity Problem ◽  
Human Arm ◽  
Angle Method ◽  
Self Motion ◽  
Dual Arm ◽  
Configuration Control

SUMMARYAn S-R-S (Spherical-Revolute-Spherical) redundant manipulator is similar to a human arm and is often used to perform dexterous tasks. To solve the inverse kinematics analytically, the arm-angle was usually used to parameterise the self-motion. However, the previous studies have had shortcomings; some methods cannot avoid algorithm singularity and some are unsuitable for configuration control because they use a temporary reference plane. In this paper, we propose a method of analytical inverse kinematics resolution based on dual arm-angle parameterisation. By making use of two orthogonal vectors to define two absolute reference planes, we obtain two arm angles that satisfy a specific condition. The algorithm singularity problem is avoided because there is always at least one arm angle to represent the redundancy. The dual arm angle method overcomes the shortcomings of traditional methods and retains the advantages of the arm angle. Another contribution of this paper is the derivation of the absolute reference attitude matrix, which is the key to the resolution of analytical inverse kinematics but has not been previously addressed. The simulation results for typical cases that include the algorithm singularity condition verified our method.

Cooperation and Null-Space Control of Networked Omni-Directional Mobile Manipulators

2020 ◽  
Author(s):  
Michael John Chua ◽  
Yen-Chen Liu
Keyword(s):  
Degrees Of Freedom ◽  
Null Space ◽  
Kinematic Model ◽  
Mobile Manipulator ◽  
Main Task ◽  
Mobile Manipulators ◽  
Robot Arm ◽  
Task Space ◽  
End Effector ◽  
Mobile Base

Abstract This paper presents cooperation and null-space control for networked mobile manipulators with high degrees of freedom (DOFs). First, kinematic model and Euler-Lagrange dynamic model of the mobile manipulator, which has an articulated robot arm mounted on a mobile base with omni-directional wheels, have been presented. Then, the dynamic decoupling has been considered so that the task-space and the null-space can be controlled separately to accomplish different missions. The motion of the end-effector is controlled in the task-space, and the force control is implemented to make sure the cooperation of the mobile manipulators, as well as the transportation tasks. Also, the null-space control for the manipulator has been combined into the decoupling control. For the mobile base, it is controlled in the null-space to track the velocity of the end-effector, avoid other agents, avoid the obstacles, and move in a defined range based on the length of the manipulator without affecting the main task. Numerical simulations have been addressed to demonstrate the proposed methods.

scholarly journals Path planning for automatic guided vehicle with multiple target points in dynamic environment

2018 ◽  
Vol 159 ◽  
pp. 02029 ◽  
Author(s):  
Chang Kyu Kim ◽  
Huy Hung Nguyen ◽  
Dae Hwan Kim ◽  
Hak Kyeong Kim ◽  
Sang Bong Kim
Keyword(s):  
Path Planning ◽  
Shortest Paths ◽  
Initial Point ◽  
Target Point ◽  
Laser Sensor ◽  
Multiple Target ◽  
Hamilton Path ◽  
Automatic Guided Vehicle ◽  
Planning Algorithm ◽  
Path Planning Algorithm

In path planning field, Automatic guided vehicle (AGV) has to move from an initial point towards a target point with capability to avoid obstacles. There are A*, D* and D* lite path planning algorithms in the path planning algorithm. This paper proposes a modified D* lite path planning algorithm using the most efficient D* lite among these algorithms. The modified D* lite path planning algorithm is to improve these D* lite path planning algorithm’s weaknesses such as traversing across obstacles sharp corners, or traversing between two obstacles. To do this task, the followings are done. First, a work space is divided into square cells. Second, cost of each edge connecting current node to neighbor nodes is calculated. Third, the shortest paths from the initial point to all multiple target points are computed and the shortest paths from any target point to remaining target points including the goal point are computed by using Hamilton path. Fourth, a cost-minimal path is re-calculated as soon as the laser sensor detects an obstacle and make an updated list of target points. Finally, the validity of the proposed modified D* lite path planning algorithm is verified through simulation and experimental results.

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