scholarly journals Simulation of a Mobile Manipulator on Webots

2018 ◽  
Vol 14 (02) ◽  
pp. 90 ◽  
Author(s):  
Oscar F. Avilés S. ◽  
Oscar G. Rubiano M ◽  
Mauricio F. Mauledoux M ◽  
Angie J. Valencia C ◽  
Robinson Jiménez M
Keyword(s):  
Virtual Environment ◽  
Degrees Of Freedom ◽  
Simulation Software ◽  
Mobile Platform ◽  
Mobile Manipulator ◽  
Mobile Platforms ◽  
Robotic Arms ◽  
Robotic Simulation ◽  
Working Space ◽  
Manipulator Arm

A mobile manipulator is a mobile platform with a mounted serial manipulator. A Mobile Manipulator is a system subject to its kinematic restrictions and the degrees of freedom of the manipulator arm mounted on it. These systems combine the advantages of mobile platforms and robotic arms, and reduce their disadvantages. For example, a mobile manipulator has larger working space when it has a mobile platform, as it offers more functionality during operation. For the previously mentioned in this work will be shown the implementation in the robotic simulation software Webots, a mobile manipulator that allows to determine its operation in a virtual environment

scholarly journals Electronic Architecture for a Mobile Manipulator

2018 ◽  
Vol 14 (02) ◽  
pp. 133
Author(s):  
Oscar Aviles ◽  
Mauricio Felipe Mauledoux Monroy ◽  
Oscar Rubiano
Keyword(s):  
Mobile Robot ◽  
Degrees Of Freedom ◽  
Robot Manipulator ◽  
Robotic System ◽  
Mobile Platform ◽  
Mobile Manipulator ◽  
Human Being ◽  
Manipulator Arm ◽  
Electronic Design

A mobile manipulator is a robotic system consisting of a mobile platform on which a manipulator arm is mounted, allowing the robotic system to perform locomotion and manipulation tasks simultaneously. A mobile manipulator has several advantages over a robot manipulator which is fixed, the main advantage is a larger workspace. The robots manipulators are oriented to work collaboratively with the human being in tasks that simultaneously require mobility and ability to interact with the environment through the manipulation of objects. This article will present the electronic design for a mobile robot manipulator with five degrees of freedom and a 6-wheel traction with four of these directional.

scholarly journals Real Time System Design for a Mobile Manipulator

2018 ◽  
Vol 14 (12) ◽  
pp. 126
Author(s):  
Oscar Fernando Aviles Sánchez ◽  
Mauricio Felipe Mauledoux Monroy ◽  
Oscar Gerardo Ribiano ◽  
Angie Julieth Valencia
Keyword(s):  
Real Time ◽  
Degrees Of Freedom ◽  
Mobile Manipulator ◽  
Robotic Platform ◽  
Time System ◽  
Real Time System ◽  
Working Space ◽  
Cartesian Plane ◽  
Manipulator Arm ◽  
Manipulator Robot

A mobile manipulator is defined as a mechanism composed by a serial manipulator located just above robotic platform. Besides, is a system with kinematic restrictions determined by an independent movement of the wheels and the degrees of freedom of the manipulator arm. The combination of the previous systems increases the advantages in terms of maneuverability, efficiency, range, between others. Another advantage of manipulator robot is the larger working space when it moves over a mobile platform allowing to reach different position on XY cartesian plane. Therefore, the design of a real-time system for a mobile manipulator will be shown in this paper.

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.

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.

Maximum load determination of nonholonomic mobile manipulator using hierarchical optimal control

Robotica ◽  
2011 ◽  
Vol 30 (1) ◽  
pp. 53-65 ◽  
Author(s):  
M. H. Korayem ◽  
V. Azimirad ◽  
H. Vatanjou ◽  
A. H. Korayem
Keyword(s):  
Optimal Control ◽  
Degrees Of Freedom ◽  
Large Scale ◽  
Maximum Load ◽  
Mobile Manipulator ◽  
Interaction Terms ◽  
Different Types ◽  
Interaction Variables ◽  
Maximum Allowable Dynamic Load

SUMMARYThis paper presents a new method using hierarchical optimal control for path planning and calculating maximum allowable dynamic load (MADL) of wheeled mobile manipulator (WMM). This method is useful for high degrees of freedom WMMs. First, the overall system is decoupled to a set of subsystems, and then, hierarchical optimal control is applied on them. The presented algorithm is a two-level hierarchical algorithm. In the first level, interaction terms between subsystems are fixed, and in the second level, the optimization problem for subsystems is solved. The results of second level are used for calculating new estimations of interaction variables in the first level. For calculating MADL, the load on the end effector is increased until actuators get into saturation. Given a large-scale robot, we show how the presenting in distributed hierarchy in optimal control helps to find MADL fast. Also, it enables us to treat with complicated cost functions that are generated by obstacle avoidance terms. The effectiveness of this approach on simulation case studies for different types of WMMs as well as an experiment for a mobile manipulator called Scout is shown.

Instant Center Based Kinematic Formulation for Planar Wheeled Platforms

2010 ◽  
Vol 2 (3) ◽  
Author(s):  
Amit Kulkarni ◽  
Delbert Tesar
Keyword(s):  
Rigid Body ◽  
Input Parameter ◽  
Radial Distance ◽  
Planar Motion ◽  
Mobile Platform ◽  
General Point ◽  
Kinematic Modeling ◽  
Mobile Platforms ◽  
General Order ◽  
Operational Criteria

For a general J wheeled mobile platform capable of up to three-degrees-of-freedom planar motion, there are up to two J independent input parameters yet the output of the platform is completely represented by three independent variables. This leads to an input parameter resolution problem based on operational criteria, which are in development just as they have been developed for n input manipulator systems. To resolve these inputs into a meaningful decision structure means that all motions at the wheel attachment points must have clear physical meaning. To this effect, we propose a methodology for kinematic modeling of multiwheeled mobile platforms using instant centers to efficiently describe the motion of all system points up to the nth order using a generalized algebraic formulation. This is achieved by using a series of instant centers (velocity, acceleration, jerk, and jerk derivative), where each point in the system has a motion property with its magnitude proportional to the radial distance of the point from the associated instant center and at a constant angle relative to that radius. The method of instant center provides a straightforward and physically intuitive way to synthesize a general order planar motion of mobile platforms. It is shown that a general order motion property of any point on a rigid body follows two properties, namely, directionality and proportionality, with respect to the corresponding instant center. The formulation presents a concise expression for a general order motion property of a general point on the rigid body with the magnitude and direction separated and identified. The results are summarized for up to the fifth order motion in the summary table. Based on the initial formulation, we propose the development of operational criteria using higher order properties to efficiently synthesize the motion of a J wheeled mobile platform.

Quasi-human biped walking

Robotica ◽  
2005 ◽  
Vol 24 (2) ◽  
pp. 257-268 ◽  
Author(s):  
Hun-ok Lim ◽  
Sang-ho Hyon ◽  
Samuel A. Setiawan ◽  
Atsuo Takanishi
Keyword(s):  
Motion Control ◽  
Continuous Time ◽  
Degrees Of Freedom ◽  
Biped Robot ◽  
Humanoid Robots ◽  
Compensation Method ◽  
Biped Walking ◽  
Working Space ◽  
Physical Construction

Our goal is to develop biped humanoid robots capable of working stably in a human living and working space, with a focus on their physical construction and motion control. At the first stage, we have developed a human-like biped robot, WABIAN (WAseda BIped humANoid), which has a thirty-five mechanical degrees of freedom. Its height is 1.66 [m] and its weight 107.4 [kg]. In this paper, a moment compensation method is described for stability, which is based on the motion of its head, legs and arms. Also, a follow walking method is proposed which is based on a pattern switching technique. By a combination of both methods, the biped robot is able to perform dynamic stamping, walking forward and backward in a continuous time while someone is pushing or pulling its hand in such a way. Using WABIAN, human-fellow walking experiments are conducted, and the effectiveness of the methods are verified.

scholarly journals Planning Fail-Safe Trajectories for Space Robotic Arms

2021 ◽  
Vol 8 ◽  
Author(s):  
Oliver Porges ◽  
Daniel Leidner ◽  
Máximo A. Roa
Keyword(s):  
Degrees Of Freedom ◽  
Fault Tolerant ◽  
Robotic Manipulators ◽  
Task Completion ◽  
Joint Failure ◽  
Space Applications ◽  
Robotic Arms ◽  
Hazardous Environments ◽  
Potential Risks ◽  
Fail Safe

A frequent concern for robot manipulators deployed in dangerous and hazardous environments for humans is the reliability of task executions in the event of a joint failure. A redundant robotic manipulator can be used to mitigate the risk and guarantee a post-failure task completion, which is critical for instance for space applications. This paper describes methods to analyze potential risks due to a joint failure, and introduces tools for fault-tolerant task design and path planning for robotic manipulators. The presented methods are based on off-line precomputed workspace models. The methods are general enough to cope with robots with any type of joint (revolute or prismatic) and any number of degrees of freedom, and might include arbitrarily shaped obstacles in the process, without resorting to simplified models. Application examples illustrate the potential of the approach.

Balancing Control of a Mobile Manipulator with Two Wheels by an Acceleration-Based Disturbance Observer

2018 ◽  
Vol 15 (03) ◽  
pp. 1850005 ◽  
Author(s):  
Yeong-Geol Bae ◽  
Seul Jung
Keyword(s):  
Disturbance Observer ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Experimental Studies ◽  
Service Robot ◽  
Mobile Manipulator ◽  
Control Performance ◽  
Six Degrees Of Freedom ◽  
Inertia Model ◽  
Balancing Control

This paper presents the balancing control performance of a mobile manipulator built in the laboratory as a service robot called Korean robot worker (KOBOKER). The robot is designed and implemented with two wheels as a mobile base and two arms with six degrees-of-freedom each. Kinematics and dynamics of the robot are analyzed. For the balancing control performance, two wheels are controlled independently by the time-delayed control method based on the inertia model of the robot. The acceleration information obtained directly from the sensor is used for the modified disturbance observer structure called an acceleration-based disturbance observer (AbDOB). Experimental studies of the balancing control of the robot are conducted to compare the control performances by both a PID control method and an AbDOB.

Comparison of under-actuated and fully-actuated serial robotic arms: a case study

2021 ◽  
pp. 1-13
Author(s):  
Matteo Bottin ◽  
Giulio Rosati
Keyword(s):  
Degrees Of Freedom ◽  
Simple Point ◽  
Controllable System ◽  
Robotic Arms ◽  
Passive Joint ◽  
Final Configuration ◽  
Vibration Behavior ◽  
Rotational Joint ◽  
Point To Point

Abstract Under-actuated robots are very interesting in terms of cost and weight since they can result in a state-controllable system with a number of actuators lower than the number of joints. In this paper, a comparison between an under-actuated planar 3 degrees of freedom (DOF) robot and a comparable fully-actuated 2 degrees of freedom robot is presented, mainly focusing on the performances in terms of trajectories, actuator torques, and vibrations. The under-actuated system is composed of 2 active rotational joints followed by a passive rotational joint equipped with a torsional spring. The fully-actuated robot is inertial equivalent to the under-actuated manipulator: the last link is equal to the sum of the last two links of the under-actuated system. Due to the conditions on the inertia distribution and spring placement, in a simple point-to-point movement the last passive joint starts and ends in a zero-value configuration, so the 3 DOF robot is equivalent, in terms of initial and final configuration, to the 2 DOF fully-actuated robot, thus they can be compared. Results show how while the fully actuated robot is better in terms of reliable trajectory and actuator torques, the under-actuated robot wins in flexibility and vibration behavior.

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