An Underactuated Robotic Arm Based on Differential Gears for Capturing Moving Targets: Analysis and Design

2016 ◽  
Vol 8 (4) ◽  
Author(s):  
Qingchuan Wang ◽  
Qiquan Quan ◽  
Zongquan Deng ◽  
Xuyan Hou
Keyword(s):  
Planetary Gear ◽  
Peak Torque ◽  
Robotic Arm ◽  
Moving Targets ◽  
Structural Configuration ◽  
Analysis And Design ◽  
Work Space ◽  
Grasp Stability ◽  
Driving Torque ◽  
Distal Joint

This paper presents the design of an underactuated robotic arm for capturing moving targets with an impact-absorbing capability. The arm consists of three joints (a base joint (BJ), a medial joint (MJ), and a distal joint (DJ)) that are driven by two actuators. A one-input dual-output planetary gear (PG) system, in which neither the ring gear nor the planetary carrier is fixed, is employed to distribute the driving torque between the MJ and DJ. As is well known, an underactuated arm may exhibit unstable grasping performance such that the arm loses contact with the target in certain grasping postures. Therefore, a method is presented for analyzing the equilibrium contact force and the relative movement trend between the target and the arm to determine the work space in which stable grasping is possible. The structural configuration parameters, such as the length ratios among the three beams and the reduction ratio of the PG system, were optimized to maximize the grasp stability work space. Subsequently, a prototype was designed and fabricated based on these optimized parameters. Experiments indicate that this arm design can effectively reduce the peak torque on the joints when grasping a moving target.

scholarly journals Optimal Design of a Bio-Inspired Anthropocentric Shoulder Rehabilitator

2006 ◽  
Vol 3 (3) ◽  
pp. 199-208 ◽  
Author(s):  
S. K. Mustafa ◽  
G. Yang ◽  
S. H. Yeo ◽  
W. Lin
Keyword(s):  
Performance Evaluation ◽  
Shoulder Joint ◽  
Stroke Rehabilitation ◽  
Design Methodology ◽  
Anatomical Structure ◽  
Robotic Arm ◽  
Analysis And Design ◽  
Non Invasive ◽  
Performance Requirements ◽  
Human Arm

This paper presents the design of a bio-inspired anthropocentric 7-DOF wearable robotic arm for the purpose of stroke rehabilitation. The proposed arm rehabilitator synergistically utilizes the human arm structure with non-invasive kinematically under-deterministic cable-driven mechanisms to form a completely deterministic structure. It offers the advantages of being lightweight and having high dexterity. Adopting an anthropocentric design concept also allows it to conform to the human anatomical structure. The focus of this paper is on the analysis and design of the 3-DOF-shoulder module, called the shoulder rehabilitator. The design methodology is divided into three main steps: (1) performance evaluation of the cable-driven shoulder rehabilitator, (2) performance requirements of the shoulder joint based on its physiological characteristics and (3) design optimization of the shoulder rehabilitator based on shoulder joint physiological limitations. The aim is to determine a suitable configuration for the development of a shoulder rehabilitator prototype.

Analysis of Modal Transition and Coincidence Degree Variation Instabilities of Wind Turbine Planetary Gear System

2019 ◽  
Vol 33 (04) ◽  
pp. 1959012
Author(s):  
ChunGuang Wang
Keyword(s):  
Wind Turbine ◽  
Coincidence Degree ◽  
Planetary Gear ◽  
Coupling Factor ◽  
Gear System ◽  
Parameter Instability ◽  
Analysis And Design ◽  
Meshing Stiffness ◽  
System A ◽  
Planetary Gear System

To accurately analyze the dynamic characteristics of the wind turbine planetary gear system, a dynamic model is established. The sensitivity of natural frequency to meshing stiffness is calculated by modal analysis method, the coupling factor is used to judge the occurrence of transition, the parameter instability caused by the meshing stiffness change is analyzed by the multi-scale method. The results the change rule on eigenvalue sensitivity, mode transition criterion and coincidence degree variation instabilities are obtained, the obtained rules can be used for dynamic analysis and design optimization.

Dynamic Modeling of a New Version of Cylindrical Planetary Gear Used for a Robotic Arm

2014 ◽  
Vol 511-512 ◽  
pp. 683-686
Author(s):  
Lucia Pascale ◽  
Paul Ciprian Patic
Keyword(s):  
Mechanical Properties ◽  
Dynamic Response ◽  
Dynamic Modeling ◽  
Equations Of Motion ◽  
Planetary Gear ◽  
Robotic Arm ◽  
Matlab Simulink ◽  
New Variant ◽  
Planetary Mechanism

This paper presents the dynamic modeling of a new variant of helical planetary gear proposed by the authors, generated by the Vaucanson`s planetary mechanism. This model can be apply successfully helping a robotic arm in motion. It is considered that the gear made connects between a motor and a pump, whose mechanical properties are known. Using Matlab-Simulink is setting the equations of motion and dynamic response, both in premise neglect friction and the premise of considering friction.

Optimization of manipulator dynamics in non extreme design case

Robotica ◽  
1990 ◽  
Vol 8 (2) ◽  
pp. 131-136
Author(s):  
Xiong Youlun ◽  
Ding Han
Keyword(s):  
Optimization Procedure ◽  
Minimax Problem ◽  
Optimization Method ◽  
Exchange Algorithm ◽  
Work Space ◽  
Manipulator Dynamics ◽  
Comprehensive Performance ◽  
Design Case ◽  
Driving Torque ◽  
Large Work

SummaryThis paper is concerned with the dynamic merit of robot manipulators and method for the optimization of manipulator dynamics in the case of an extremely bad design, which can be put into three categories: 1. Acceleration performance: minimize 2. Velocity performance: minimize 3. Comprehensive performance: minimize , and are the dynamics indices of API, VPI and CD PI under various conditions respectively.The exchange algorithm is presented and a procedure is developed to solve this kind of Minimax problem. An example is discussed to illustrate the application of the optimization method. The large uniform magnitude of a joint relative driving torque provided by this dynamics optimization procedure will be made into a large work space and large torques.

Analysis and design exploration of single stage compound stepped planetary gear transmissions

2018 ◽  
Vol 7 (1/2/3) ◽  
pp. 1
Author(s):  
Christos Spitas ◽  
Amin Amani ◽  
Efstratios Tsolakis ◽  
Vasilios Spitas
Keyword(s):  
Planetary Gear ◽  
Single Stage ◽  
Design Exploration ◽  
Analysis And Design

Robotic arm dynamics modelling and robust control based on model recognition method

2021 ◽  
pp. 1-11
Author(s):  
Yi Ge ◽  
Jing Zhang
Keyword(s):  
Robust Control ◽  
Degrees Of Freedom ◽  
Weight Ratio ◽  
Planetary Gear ◽  
Parallel Robot ◽  
Robotic Arm ◽  
Joint Motion ◽  
Position Information ◽  
Dynamics Modelling ◽  
Mechanical Decoupling

This paper analyzes the dynamics modelling and robust control of the robotic arm by using a model-based defines method. Firstly, the motion coupling relationship between the front and rear joints of the robotic arm is analyzed, and two kinds of motion decoupling modules based on planetary gear and pulley system are proposed, and the decoupling principle of the motion decoupling module is analyzed to realize the mechanical decoupling of the joint motion of the robotic arm. After that, a comprehensive test bench of two-degree-of-freedom robotic arm joint motion is constructed, and the factors influencing the decoupling effect of the mechanical decoupling module are analyzed through experiments to verify the effectiveness of the motion decoupling module. At the same time, the analysis also shows that: with the increase of the number of robotic arm joints, the number and volume of required decoupling modules increase, and the application of decoupling modules will significantly increase the volume, weight, and torque loss of the robotic arm, thus leading to the robotic arm’s large load to weight ratio which is not an advantage, therefore, mechanical decoupling is not suitable for robotic arms with more than 3 degrees of freedom. The design of a fuzzy incremental controller based on the model dialectic method is proposed for application in parallel robot control; it has universal approximation characteristics and can self-organize the velocity and position information of the parallel robot legs, and dynamically adjust the output of the controller by the designed affiliation function and control rules.

scholarly journals A Versitile Method to Design a Three Fingered Robotic Arm using Cad and Matlab Technique

2019 ◽  
Vol 8 (4) ◽  
pp. 308-310
Keyword(s):  
Kinematic Analysis ◽  
Degrees Of Freedom ◽  
Robotic Arm ◽  
Cad Model ◽  
Kinematic Redundancy ◽  
Work Space ◽  
Revolute Joints ◽  
Human Arm

The main objective of the paper is to design a versatile Robotic Arm that has the capability to mimic the motion of a snake such that work space of the robotic arm is maximized. Design is made to achieve maximum mobility of the Robotic Arm such that it can pick up things and placed in very complex scenarios. The design is able to give degrees of freedom to the robot so that it becomes more versatile. It has a kinematic redundancy, like that of a human arm that enables us to place objects in various orientations. This Robotic arm is equipped with a three fingered gripper that provides for efficient grasping. The paper also provides design details of three fingered gripper that is suitable to hold cylindrical objects such as bolts, cable connectors etc. Autodesk Fusion 360 has been used to make cad model of arm and grippers. The 3D arm and gripper are assembled with revolute joints. The robot is tested for its mobility by performing Kinematic Analysis.

Analysis and design exploration of single stage compound stepped planetary gear transmissions

2018 ◽  
Vol 7 (1/2/3) ◽  
pp. 1
Author(s):  
Christos Spitas ◽  
Amin Amani ◽  
Efstratios Tsolakis ◽  
Vasilios Spitas
Keyword(s):  
Planetary Gear ◽  
Single Stage ◽  
Design Exploration ◽  
Analysis And Design
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