scholarly journals Research on Kinematics and Pouring Law of a Mobile Heavy Load Pouring Robot

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Long Li ◽  
Chengjun Wang ◽  
Hongtao Wu
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Screw Theory ◽  
Great Influence ◽  
Inverse Kinematic ◽  
The Novel ◽  
Heavy Load ◽  
Motion Characteristics ◽  
The Relationship

In order to meet the requirement of continuous pouring in many varieties and small batches in casting production, a mobile heavy load pouring robot is developed based on a new 4-UPU parallel mechanism due to its strong carrying capacity. Firstly, the instantaneous motion characteristics of the novel 4-UPU parallel mechanism with four degrees of freedom (DOF) are analyzed using screw theory. By using the geometric method, both the forward and inverse kinematic solutions of the proposed robot system are given out. Secondly, based on a common pouring ladle, the volume change of pouring liquid in pouring process and the relationship between tilting angular velocity and flow rate are analyzed, and the results show that the shape of the ladle and the design of the pouring mouth have great influence on the tilting model. It is an important basis for the division of the sectional model. Finally, a numerical example is given to verify the effectiveness of the developed tilting model. The mapping relation between the tilting model and the parallel mechanism shows that the pouring flow can be adjusted by controlling the movement of parallel manipulator. The research of this paper provides an important theoretical basis for the position control of mobile heavy load pouring robot and the research of pouring speed control.

A Novel Two Degrees of Freedom Rotational Decoupled Parallel Mechanism

2012 ◽  
Vol 215-216 ◽  
pp. 293-296 ◽  
Author(s):  
Yu Lei Hou ◽  
Da Xing Zeng ◽  
Zhan Ye Zhang ◽  
Chang Mei Wang ◽  
Xin Zhe Hu
Keyword(s):  
Control System ◽  
Dynamic Analysis ◽  
Spatial Orientation ◽  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
The Novel ◽  
Two Degrees Of Freedom ◽  
Application Fields

In the field of spatial orientation, the rotational parallel mechanism is widely used. While the existence of coupling brings about the parallel mechanism some difficulties in kinematics and dynamic analysis, the development of control system, and so on. This condition restricts the application fields and effects of the rotational parallel mechanism. Therefore, this paper proposes a novel 2-DOF (two degrees of freedom) rotational DPM (decoupled parallel mechanism). The feature of the mechanism is described and their movement form is analyzed with screw theory. The proposition of the novel rotational DPM will enrich the configurations of the parallel mechanism, and the contents of this paper should be useful for the further research and application of the rotational parallel mechanism.

Performance Mapping and Motion Simulation of a 4UPS+PU Redundantly Actuated Parallel Manipulator

2010 ◽  
Author(s):  
Zhen Gao ◽  
Dan Zhang
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Position Control ◽  
Parallel Manipulators ◽  
Inverse Kinematic ◽  
Reachable Workspace ◽  
Redundantly Actuated ◽  
Inverse Kinematic Analysis ◽  
Motion Characteristics ◽  
Operational Capacity

In this paper, a new 4UPS+PU redundantly actuated parallel manipulator is proposed. This mechanism possesses three degrees of freedom (DOF), one translation and two rotations. Different from general parallel manipulators, a passive leg is connected to both centers of the base and the moving platform to constrain the unwanted motion. The mobility study and inverse kinematic analysis are conducted. The reachable workspace is generated with boundary-searching based discretization method. The local and global performance indices including stiffness and dexterity and their atlas are investigated in details. Comprehensive simulation of kinematics, dynamics and proportional-integral-derivative (PID) position control are implemented based on Adams to evaluate and testify the high operational capacity and well motion characteristics.

scholarly journals A New Approach of Soft Joint Based on a Cable-Driven Parallel Mechanism for Robotic Applications

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1468
Author(s):  
Luis Nagua ◽  
Carlos Relaño ◽  
Concepción A. Monje ◽  
Carlos Balaguer
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Kinematic Model ◽  
Experimental Tests ◽  
Humanoid Robots ◽  
Inverse Kinematic ◽  
Element Analysis ◽  
New Approach ◽  
Flexible Polymer ◽  
The Mathematical Model

A soft joint has been designed and modeled to perform as a robotic joint with 2 Degrees of Freedom (DOF) (inclination and orientation). The joint actuation is based on a Cable-Driven Parallel Mechanism (CDPM). To study its performance in more detail, a test platform has been developed using components that can be manufactured in a 3D printer using a flexible polymer. The mathematical model of the kinematics of the soft joint is developed, which includes a blocking mechanism and the morphology workspace. The model is validated using Finite Element Analysis (FEA) (CAD software). Experimental tests are performed to validate the inverse kinematic model and to show the potential use of the prototype in robotic platforms such as manipulators and humanoid robots.

scholarly journals A Flexible Transoral Robot Towards COVID-19 Swab Sampling

2021 ◽  
Vol 8 ◽  
Author(s):  
Changsheng Li ◽  
Xiaoyi Gu ◽  
Xiao Xiao ◽  
Chwee Ming Lim ◽  
Xingguang Duan ◽  
...  
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Flexible Manipulator ◽  
The Novel ◽  
Visual Guidance ◽  
Face To Face ◽  
Tongue Depressor ◽  
Operation Procedure ◽  
The Face ◽  
Master Device

There are high risks of infection for surgeons during the face-to-face COVID-19 swab sampling due to the novel coronavirus’s infectivity. To address this issue, we propose a flexible transoral robot with a teleoperated configuration for swab sampling. The robot comprises a flexible manipulator, an endoscope with a monitor, and a master device. A 3-prismatic-universal (3-PU) flexible parallel mechanism with 3 degrees of freedom (DOF) is used to realize the manipulator’s movements. The flexibility of the manipulator improves the safety of testees. Besides, the master device is similar to the manipulator in structure. It is easy to use for operators. Under the guidance of the vision from the endoscope, the surgeon can operate the master device to control the swab’s motion attached to the manipulator for sampling. In this paper, the robotic system, the workspace, and the operation procedure are described in detail. The tongue depressor, which is used to prevent the tongue’s interference during the sampling, is also tested. The accuracy of the manipulator under visual guidance is validated intuitively. Finally, the experiment on a human phantom is conducted to demonstrate the feasibility of the robot preliminarily.

Aerial Contact Manipulation With Soft End-Effector Compliance and Inverse Kinematic Compensation

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xinjun Sheng ◽  
Zhao Ma ◽  
Ningbin Zhang ◽  
Wei Dong
Keyword(s):  
Degrees Of Freedom ◽  
Position Control ◽  
Mechanical Design ◽  
Impact Resistance ◽  
High Strength ◽  
Inverse Kinematic ◽  
End Effector ◽  
Precise Position ◽  
Positioning Errors ◽  
Aerial Platform

Abstract This paper presents the development of a six degrees-of-freedom manipulator with soft end-effector and an inverse kinematic compensator for aerial contact manipulation. Realizing the fact that aerial manipulators can hardly achieve precise position control, a compliant manipulator with soft end-effector is first developed to moderate end-effector positioning errors. The manipulator is designed to be rigid-soft combined. The rigid robotic arm employs the lightweight but high-strength materials. The compliance requirement is achieved by the soft end-effector so that the mechanical design for the joints are largely simplified. These two features are beneficial to lighten the arm and to ensure the accuracy. In the meantime, the pneumatic soft end-effector can further moderate the probable insufficient accuracy by endowing the manipulator with compliance for impact resistance and robustness to positioning errors. With the well-designed manipulator, an inverse kinematic compensator is then proposed to eliminate lumped disturbances from the aerial platform. The compensator can ensure the stabilization of the end-effector by using state estimation from the aerial platform, which is robust and portable as the movement of the platform can be reliably obtained. Both the accuracy and compliance have been well demonstrated after being integrated into a hexarotor platform, and a representative scenario aerial task repairing the wind turbine blade-coating was completed successfully, showing the potential to accomplish complex aerial manipulation tasks.

Helical Kirigami-Enabled Centimeter-Scale Worm Robot With Shape-Memory-Alloy Linear Actuators

2015 ◽  
Vol 7 (2) ◽  
Author(s):  
Ketao Zhang ◽  
Chen Qiu ◽  
Jian S. Dai
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Degrees Of Freedom ◽  
Screw Theory ◽  
Kinematic Model ◽  
Parallel Structure ◽  
Geometrical Parameters ◽  
Parallel Structures ◽  
Complete Procedure ◽  
Motion Characteristics

The wormlike robots are capable of imitating amazing locomotion of slim creatures. This paper presents a novel centimeter-scale worm robot inspired by a kirigami parallel structure with helical motion. The motion characteristics of the kirigami structure are unravelled by analyzing the equivalent kinematic model in terms of screw theory. This reveals that the kirigami parallel structure with three degrees-of-freedom (DOF) motion is capable of implementing both peristalsis and inchworm-type motion. In light of the revealed motion characteristics, a segmented worm robot which is able to imitate contracting motion, bending motion of omega shape and twisting motion in nature is proposed by integrating kirigami parallel structures successively. Following the kinematic and static characteristics of the kirigami structure, actuation models are explored by employing the linear shape-memory-alloy (SMA) coil springs and the complete procedure for determining the geometrical parameters of the SMA coil springs. Actuation phases for the actuation model with two SMA springs are enumerated and with four SMA springs are calculated based on the Burnside's lemma. In this paper, a prototype of the worm robot with three segments is presented together with a paper-made body structure and integrated SMA coil springs. This centimeter-scale prototype of the worm robot is lightweight and can be used in confined environments for detection and inspection. The study presents an interesting approach of integrating SMA actuators in kirigami-enabled parallel structures for the development of compliant and miniaturized robots.

Workspace Analysis and Parameter Optimization of 3-DOF Parallel Mechanism

2013 ◽  
Vol 373-375 ◽  
pp. 2136-2142 ◽  
Author(s):  
Rui Fan ◽  
Huan Liu ◽  
Dan Wang
Keyword(s):  
Parameter Optimization ◽  
Parallel Mechanism ◽  
Structural Parameters ◽  
Kinematic Model ◽  
Inverse Kinematic ◽  
Search Method ◽  
Architecture Design ◽  
Original Volume ◽  
Workspace Analysis ◽  
The Relationship

A spatial 3-DOF translational parallel mechanism is analyzed. Its inverse kinematic model is established. The section view of the workspace of the parallel mechanism is presented via boundary search method under the defined constraints. Considering the workspace volume as the optimization object, the relationship between structural parameters and workspace volume is obtained and the structural parameters to be optimized are determined. Finally, the optimization configuration of the mechanism is obtained. The results show that the volume of the workspace increases 1.55 times as much as the original volume, which lay the foundation for the architecture design.

scholarly journals A Translational Three-Degrees-of-Freedom Parallel Mechanism With Partial Motion Decoupling and Analytic Direct Kinematics

2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Huiping Shen ◽  
Damien Chablat ◽  
Boxiong Zeng ◽  
Ju Li ◽  
Guanglei Wu ◽  
...  
Keyword(s):  
Parallel Mechanism ◽  
Design Theory ◽  
Degrees Of Freedom ◽  
Analytic Solutions ◽  
Inverse Kinematic ◽  
Kinematic Modeling ◽  
Topological Design ◽  
Prismatic Joints ◽  
Topological Characteristics ◽  
Three Degrees Of Freedom

Abstract According to the topological design theory and the method of parallel mechanism (PM) based on position and orientation characteristic (POC) equations, this paper studied a three-degrees-of-freedom (3-DOF) translational PM that has three advantages, i.e., (i) it consists of three fixed actuated prismatic joints, (ii) the PM has analytic solutions to the direct and inverse kinematic problems, and (iii) the PM is of partial motion decoupling property. First, the main topological characteristics, such as the POC, degree-of-freedom, and coupling degree, were calculated for kinematic modeling. Thanks to these properties, the direct and inverse kinematic problems can be readily solved. Further, the conditions of the singular configurations of the PM were analyzed, which corresponds to its partial motion decoupling property.

scholarly journals Design and Analysis of a Novel Tree Climbing Robot Mechanism

2020 ◽  
Author(s):  
Ru-Gui Wang ◽  
Hai-Bo Huang ◽  
Yi Li ◽  
Ji-Wei Yuan
Keyword(s):  
Numerical Simulation ◽  
Physical Model ◽  
Inverse Kinematics ◽  
Parallel Mechanism ◽  
Screw Theory ◽  
Singular Points ◽  
Climbing Robot ◽  
Overall Design ◽  
Forward And Inverse Kinematics ◽  
The Relationship

Abstract In this paper, a novel tree climbing robot mechanism was designed, based on the tree climbing movement and posture of the primates. The overall design and tree climbing gait of the tree climbing robot were analyzed in detail. According to the screw theory, the DOF of the leg of the tree climbing robot is calculated. The forward and inverse kinematics equations of the tree climbing robot were established and solved. The kinematics of the leg parallel mechanism was established, furthermore, the singularity of the leg mechanism was analyzed and three types of singularity were derived. The simplified diagrams and the corresponding model diagrams, at the singular points, were drawn. Finally, the movement is simulated and analyzed. And the changes of the leg joint angular and the foot-end displacement and the relationship between the driving displacement and angles of the tree climbing robot by numerical simulation is obtained at the same time. Prototype physical model of the tree climbing robot was made, which further verified the rationality and feasibility of the tree climbing robot mechanism studied in this paper.

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