Spring Effects on Workspace and Stiffness of a Symmetrical Cable-Driven Hybrid Joint

This paper aims to investigate how to determine the basic parameters of the helical compression spring which supports a symmetrical cable-driven hybrid joint (CDHJ) towards the elbow joint of wheelchair-mounted robotic manipulator. The joint design of wheelchair-mounted robotic manipulator needs to consider lightweight but robust, workspace requirements, and variable stiffness elements, so we propose a CDHJ which becomes a variable stiffness joint due the spring under bending and compression provides nonlinear stiffness characteristics. Intuitively, different springs will make the workspace and stiffness of CDHJ different, so we focus on studying the spring effects on workspace and stiffness of CDHJ for its preliminary design. The key to workspace and stiffness analysis of CDHJ is the cable tension, the key to calculate the cable tension is the lateral bending and compression spring model. The spring model is based on Castigliano’s theorem to obtain the relationship between spring force and displacement. The simulation results verify the correctness of the proposed spring model, and show that the spring, with properly chosen parameters, can increase the workspace of CDHJ whose stiffness also can be adjusted to meet the specified design requirements. Then, the modelling method can be extended to other cable-driven mechanism with a flexible compression spring.

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Analysis on variable stiffness of a cable-driven parallel–series hybrid joint toward wheelchair-mounted robotic manipulator

Advances in Mechanical Engineering ◽

10.1177/1687814019846289 ◽

2019 ◽

Vol 11 (4) ◽

pp. 168781401984628 ◽

Cited By ~ 3

Author(s):

Shan Zhang ◽

Dongxing Cao ◽

Bin Hou ◽

Shuai Li ◽

Hong Min ◽

...

Keyword(s):

Variable Stiffness ◽

Robotic Manipulator ◽

Hybrid Joint ◽

Parallel Series

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Variable Stiffness Analysis on a Pneumatic Soft Manipulator

Journal of Mechanical Engineering ◽

10.3901/jme.2020.09.036 ◽

2020 ◽

Vol 56 (9) ◽

pp. 36 ◽

Cited By ~ 1

Author(s):

YAO Ligang ◽

LI Jingyi ◽

DONG Hui

Keyword(s):

Variable Stiffness ◽

Stiffness Analysis ◽

Soft Manipulator

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Stiffness Analysis of a Variable Stiffness Joint Using a Leaf Spring

Intelligent Robotics and Applications - Lecture Notes in Computer Science ◽

10.1007/978-3-319-65292-4_20 ◽

2017 ◽

pp. 225-237 ◽

Cited By ~ 1

Author(s):

Lijin Fang ◽

Yan Wang

Keyword(s):

Variable Stiffness ◽

Leaf Spring ◽

Stiffness Analysis

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Nonlinear Stiffness Analysis of Spring-Loaded Inverted Slider Crank Mechanisms With a Unified Model

Journal of Mechanisms and Robotics ◽

10.1115/1.4045649 ◽

2020 ◽

Vol 12 (3) ◽

Author(s):

Zhongyi Li ◽

Shaoping Bai ◽

Weihai Chen ◽

Jianbin Zhang

Keyword(s):

Variable Stiffness ◽

Comprehensive Analysis ◽

Unified Model ◽

Nonlinear Stiffness ◽

Stiffness Analysis ◽

Constant Torque ◽

Stiffness Model ◽

Overall Performance ◽

Crank Mechanism

Abstract A mechanism with lumped-compliance can be constructed by mounting springs at joints of an inverted slider crank mechanism. Different mounting schemes bring change in the stiffness performance. In this paper, a unified stiffness model is developed for a comprehensive analysis of the stiffness performance for mechanisms constructed with different spring mounting schemes. With the model, stiffness behaviors of spring-loaded inverted slider crank mechanisms are analyzed. Influences of each individual spring on the overall performance are characterized. The unified stiffness model allows designing mechanisms for a desired stiffness performance, such as constant-torque mechanism and variable stiffness mechanism, both being illustrated with a design example and experiments.

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Conceptual mechanical design of antagonistic variable stiffness joint based on equivalent quadratic torsion spring

Science Progress ◽

10.1177/0036850420941295 ◽

2020 ◽

Vol 103 (3) ◽

pp. 003685042094129

Author(s):

Jishu Guo

Keyword(s):

Degrees Of Freedom ◽

Modular Design ◽

Angular Displacement ◽

Variable Stiffness ◽

Human Robot Interaction ◽

Design Calculation ◽

Robot Arm ◽

Compact Structure ◽

Torsion Spring ◽

Stiffness Characteristics

The variable stiffness joint is a kind of flexible actuator with variable stiffness characteristics suitable for physical human–robot interaction applications. In the existing variable stiffness joints, the antagonistic variable stiffness joint has the advantages of simple implementation of variable stiffness mechanism and easy modular design of the nonlinear elastic element. The variable stiffness characteristics of antagonistic variable stiffness joints are realized by the antagonistic actuation of two nonlinear springs. A novel design scheme of the equivalent nonlinear torsion spring with compact structure, large angular displacement range, and desired stiffness characteristics is presented in this article. The design calculation for the equivalent quadratic torsion spring is given as an example, and the actuation characteristics of the antagonistic variable stiffness joint based on the equivalent quadratic torsion spring are illustrated. Based on the design idea of constructing the antagonistic variable stiffness joint with compact structure and high compliance, as well as the different design requirements of the joints at different positions of the multi–degrees of freedom robot arm, nine types of mechanical schemes of antagonistic variable stiffness joint with the open design concept are proposed in this article. Finally, the conceptual joint configuration schemes of the robot arm based on the antagonistic variable stiffness joint show the application scheme of the designed antagonistic variable stiffness joint in the multi–degrees of freedom robot.

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A stiffness analysis for a hybrid parallel-serial manipulator

Robotica ◽

10.1017/s0263574704000323 ◽

2004 ◽

Vol 22 (5) ◽

pp. 567-576 ◽

Cited By ~ 34

Author(s):

Giuseppe Carbone ◽

Marco Ceccarelli

Keyword(s):

Numerical Investigation ◽

Performance Index ◽

Stiffness Matrix ◽

Mechanical Design ◽

General Procedure ◽

Design Parameters ◽

Serial Manipulators ◽

Stiffness Analysis ◽

Hybrid Manipulator ◽

Stiffness Characteristics

In this paper a hybrid parallel-serial manipulator, named as CaHyMan (Cassino Hybrid Manipulator), is analyzed in term of stiffness characteristics as a specific example of a general procedure for analyzing stiffness of parallel-serial manipulators. A formulation is presented to deduce the stiffness matrix as a function of the most important stiffness and design parameters of the mechanical design. A formulation is proposed for a stiffness performance index by using the obtained stiffness matrix. A numerical investigation has been carried out on the effects of design parameters and fundamental results are discussed in the paper.

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Variable stiffness characteristics of embeddable multi-stable composites

Composites Science and Technology ◽

10.1016/j.compscitech.2014.03.017 ◽

2014 ◽

Vol 97 ◽

pp. 12-18 ◽

Cited By ~ 42

Author(s):

Andres F. Arrieta ◽

Izabela K. Kuder ◽

Tobias Waeber ◽

Paolo Ermanni

Keyword(s):

Variable Stiffness ◽

Stiffness Characteristics

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Stiffness Analysis of 3-RPR Planar Parallel Mechanism to the Stiffness Control

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.16-19.786 ◽

2009 ◽

Vol 16-19 ◽

pp. 786-790 ◽

Cited By ~ 1

Author(s):

Shu Jun Li ◽

Clément Gosselin

Keyword(s):

Stiffness Matrix ◽

Parallel Mechanism ◽

Stiffness Analysis ◽

Numerical Examples ◽

Stiffness Control ◽

Conservative Congruence Transformation ◽

Stiffness Characteristics ◽

External Forces ◽

Congruence Transformation

The analytical stiffness equations of the 3-RPR planar parallel mechanism are derived in this paper based on the Conservative Congruence Transformation (CCT) stiffness matrix proposed in [1-3]. Stiffness maps of the 3-RPR mechanism are plotted in order to show the behaviour of the stiffness with and without external forces. The stiffness characteristics of the mechanism are analyzed and discussed in details. Numerical examples show that the stiffness in x and in y are well balanced, while the stiffness in tends to be lower.

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Screw theory-based stiffness analysis for a fluidic-driven soft robotic manipulator

10.1109/icra48506.2021.9561657 ◽

2021 ◽

Author(s):

Jialei Shi ◽

Julio C. Frantz ◽

Azadeh Shariati ◽

Ali Shiva ◽

Jian S Dai ◽

...

Keyword(s):

Screw Theory ◽

Robotic Manipulator ◽

Stiffness Analysis

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The Dynamic Strength Calculation on the Reel Fulcrum of Crane Based on ADAMS and FEA

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.599-601.551 ◽

2014 ◽

Vol 599-601 ◽

pp. 551-554 ◽

Cited By ~ 1

Author(s):

Feng Qi Wu

Keyword(s):

System Dynamics ◽

Dynamic Strength ◽

Variable Stiffness ◽

Virtual Prototype ◽

Wire Rope ◽

Dynamics Model ◽

Coupling Force ◽

Simulation Results ◽

The Wire ◽

Stiffness Characteristics

Based on the multi-body system dynamics in the ADAMS environment, a virtual prototype of the reel fulcrum of crane was developed. In this model, the whole system was disassembled lifting mechanism system with flexible body dynamics model of the wire rope. The virtual running environment was established according to the actual crane operation cases, which is designed the hanging & lifting working process. It is the key step to build the reel fulcrum dynamics model for performance analysis of system dynamics, which is the basis for the optimize design of the reel fulcrum of crane. Theoretical model analysis usually does not consider the coupling force status of the reel fulcrum of crane. It is a steady-state analysis to the reel fulcrum of crane models. These models have played an important role in the assessment of the reel fulcrum of crane performance and the system parameters, but do not reveal the interaction of the reel fulcrum of crane and the wire rope, which fail to be a comprehensive understanding practical system dynamics characteristic. Virtual prototype simulation results will be applied to prototype design and evaluation, and save a lot of manpower and material resources. At the same time,the method has an advantage for dynamics analysis to simulating some dangerous movement conditions, which is hard to be replayed or simulated at the test actual working condition site. In particular, some cases cannot be recurrence in the accident handling process. The simulation results show that the response value. Variable stiffness characteristics of wire rope of hoisting mechanism are implemented successfully through discrete multiple rigid body being applied to the wire rope in this paper. The establishment of the Reel fulcrum dynamic model is based on ADAMS, which realizes the reel fulcrum of crane system coupling modeling. These results show that the model reflects the actual dynamics of the reel fulcrum of crane, and also presents that some of the theoretical analysis results cannot be usually confirmed.

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