scholarly journals On the elastodynamics of a five-axis lightweight anthropomorphic robotic arm

2021 ◽  
Author(s):  
Guanglei Wu
Keyword(s):  
Sensitivity Analysis ◽  
Joint Stiffness ◽  
Robotic Arm ◽  
Response Analysis ◽  
Modeling And Analysis ◽  
Robotic Arms ◽  
Linear Elastic ◽  
Small Influence ◽  
Elastodynamic Modeling ◽  
Five Axis

This paper presents elastodynamic modeling and analysis for a five-axis lightweight robotic arm. Natural frequencies are derived and visualized within the dexterous workspace to show the overall performances and compare them to the frequencies when the robotics is with payload. The comparison shows that the payload has a relatively small influence to the first- and second-order frequencies. Sensitivity analysis is conducted, and the system's frequency is more sensitive to the second joint stiffness than the others. Moreover, observations from the displacement response analysis reveal that the robotics produces linear elastic displacements of the same level between the loaded and unloaded working modes but larger rotational deflections under the loaded working condition. The main contribution of this work lies in that a systematic approach of elastodynamic analysis for serial robotic manipulators is formulated, where the arm gravity and external load are taken into account to investigate the dynamic behaviors of the robotic arms, i.e., frequencies, sensitivity analysis, and displacement responses, under the loaded mode.

Posture Control Considering Joint Stiffness of a Robotic Arm Driven by Rubberless Artificial Muscle

2016 ◽  
Vol 10 (4) ◽  
pp. 503-510 ◽  
Author(s):  
Naoki Saito ◽  
◽  
Toshiyuki Satoh ◽  
Keyword(s):  
Joint Angle ◽  
Joint Stiffness ◽  
Mathematical Expression ◽  
Artificial Muscle ◽  
Good Control ◽  
Robotic Arm ◽  
Rubber Tube ◽  
Robotic Arms ◽  
Control Scheme ◽  
The Relationship

This paper describes a joint angle control considering the passive joint stiffness of robotic arms driven by rubberless artificial muscle (RLAM), which is a pneumatic actuator. The contraction mechanism of RLAM is the same as that of the McKibben artificial muscle. Unlike the McKibben artificial muscle, RLAM is constructed using an airbag made of a nonelastic material instead of a rubber tube.The objective of this study is to realize a soft contact movement of robotic arms by applying the passive compliance characteristics of RLAMs. In this study, we derive a mathematical expression for the relationship between the output of an RLAM and the joint stiffness of a robotic arm. In addition, we suggest a control scheme for each RLAM. We confirm the validity of these suggestions experimentally. From the result, we observe a good control performance of the joint angle. A robotic arm moves smoothly according to the force added from outside by setting the passive stiffness of the arm.

Sensitivity Analysis of Geometric Errors for Five-Axis CNC Machine Tool Based on Multi-Body System Theory

2012 ◽  
Vol 271-272 ◽  
pp. 493-497
Author(s):  
Wei Qing Wang ◽  
Huan Qin Wu
Keyword(s):  
System Theory ◽  
Sensitivity Analysis ◽  
Machine Tool ◽  
Geometric Error ◽  
Machining Accuracy ◽  
Geometric Errors ◽  
Body System ◽  
Cnc Machine ◽  
Multi Body ◽  
Five Axis

Abstract: In order to determine that the effect of geometric error to the machining accuracy is an important premise for the error compensation, a sensitivity analysis method of geometric error is presented based on multi-body system theory in this paper. An accuracy model of five-axis machine tool is established based on multi-body system theory, and with 37 geometric errors obtained through experimental verification, key error sources affecting the machining accuracy are finally identified by sensitivity analysis. The analysis result shows that the presented method can identify the important geometric errors having large influence on volumetric error of machine tool and is of help to improve the accuracy of machine tool economically.

Error Sensitivity Analysis for Machine Tool Based on Three-Dimensional Vector Chain

2013 ◽  
Vol 457-458 ◽  
pp. 1562-1565
Author(s):  
Qiang Huang ◽  
Chan Jun Gao
Keyword(s):  
Sensitivity Analysis ◽  
Machine Tool ◽  
Three Dimensional ◽  
Error Modeling ◽  
Dimensional Vector ◽  
Modeling And Analysis ◽  
Vector Operation ◽  
Error Sensitivity ◽  
Space Error ◽  
Error Sensitivity Analysis

Error modeling and analysis can provide some important direction to the machining precision control. According to the characteristics of topology structure on machine tool, a space error model of machine tool and detailed modeling method are presented in this paper, which are based on three-dimensional vector chain. Taking a lathe as an example, the application method of this model in error sensitivity analysis is introduced. By this model, the relationship between the relative error of workpiece-tool and each source error can be solved by ordinary vector operation, and the analysis efficiency should be enhanced greatly.

scholarly journals Gesture Control of Robotic Arm

2017 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Dharshan Y. ◽  
Vivek S. ◽  
Saranya S. ◽  
Aarthi V.R. ◽  
Madhumathi T.
Keyword(s):  
Batch Process ◽  
Robotic Arm ◽  
Robotic Arms ◽  
Key Technology ◽  
Cleaning Robot ◽  
Gesture Control ◽  
Major Chemical

<div><p><em>Robots have become a key technology in various fields. Robotic arms are mostly remote controlled by buttons or panels and sometimes in batch process they are autonomous. The usage of panel boards or control sticks includes a lot of hardwiring and subject to malfunction.  It also induces some stress on the operators. Hence major chemical industries like cosmetic manufacturing, paint manufacturing and Biosynthesis laboratory etc., which deals with hazardous environment due to the chemicals and other bio substances, involve humans for the processing. The aim is to reduce the bulk of wiring in the robotic arms and reduce the effort and number of operators in controlling the robotic arm operations. To implement gestures into the process this would be a major breakthrough. This can also be used as pick &amp; place robot, a cleaning robot in chemical industries where a human does not need to directly involved in the process of cleaning the chemicals and also for coating underground tanks.</em></p></div>

Trajectory Optimization and Simulation of Aerospace Robotic Arm

2013 ◽  
Vol 655-657 ◽  
pp. 1057-1060
Author(s):  
Li Jun Zong ◽  
Guang Kuo Wang ◽  
Xin Li ◽  
Lei Wang ◽  
Xiao Min Zhang ◽  
...  
Keyword(s):  
Trajectory Optimization ◽  
Inverse Kinematics ◽  
Aerospace Engineering ◽  
Robotic Arm ◽  
Robotic Arms ◽  
Kinematics Model ◽  
Six Dof ◽  
Optimization And Simulation ◽  
Vehicle Activity

Aerospace robotic arms have important applications in aerospace engineering (capture satellite, develop the technology of extra-vehicle activity (EVA), etc.) This paper first introduces the development and background of the Aerospace Robotic Arm. In later sections, a kinematics model of a Six-DOF manipulator is built based on DenavitHartenberg(D-H) method, then, the paper discusses an inverse kinematics solving method of the manipulator. At last, we show the simulation by integrating the use of SolidWorks, Matlab, and a number of their modules.

Fuzzy model predictive control for 2-DOF robotic arms

2018 ◽  
Vol 38 (5) ◽  
pp. 568-575 ◽  
Author(s):  
Weilin Yang ◽  
Wentao Zhang ◽  
Dezhi Xu ◽  
Wenxu Yan
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
Fuzzy Model ◽  
Robotic Arm ◽  
Real Time System ◽  
Content Type ◽  
Loop Control ◽  
Robotic Arms ◽  
Intrinsic Nonlinearity ◽  
Robotic Arm Control

Purpose Robotic arm control is challenging due to the intrinsic nonlinearity. Proportional-integral-derivative (PID) controllers prevail in many robotic arm applications. However, it is usually nontrivial to tune the parameters in a PID controller. This paper aims to propose a model-based control strategy of robotic arms. Design/methodology/approach A Takagi–Sugeno (T-S) fuzzy model, which is capable of approximating nonlinear systems, is used to describe the dynamics of a robotic arm. Model predictive control (MPC) based on the T-S fuzzy model is considered, which optimizes system performance with respect to a user-defined cost function. Findings The control gains are optimized online according to the real-time system state. Furthermore, the proposed method takes into account the input constraints. Simulations demonstrate the effectiveness of the fuzzy MPC approach. It is shown that asymptotic stability is achieved for the closed-loop control system. Originality/value The T-S fuzzy model is discussed in the modeling of robotic arm dynamics. Fuzzy MPC is used for robotic arm control, which can optimize the transient performance with respect to a user-defined criteria.

scholarly journals Modeling and Analysis of Amplitude-Frequency Characteristics of Torsional Vibration for Automotive Powertrain

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Jinli Xu ◽  
Jiwei Zhu ◽  
Feifan Xia
Keyword(s):  
Torsional Vibration ◽  
Transmission Error ◽  
Frequency Characteristics ◽  
Response Analysis ◽  
Lumped Mass ◽  
Modeling And Analysis ◽  
Gear Mesh ◽  
Runge Kutta Method ◽  
Lumped Mass Method ◽  
Automotive Powertrain

In the present paper, the amplitude-frequency characteristics of torsional vibration are discussed theoretically and experimentally for automotive powertrain. A bending-torsional-lateral-rocking coupled dynamic model with time-dependent mesh stiffness, backlash, transmission error etc. is proposed by the lumped-mass method to analysis the amplitude-frequency characteristic of torsional vibration for practical purposes, and equations of motive are derived. The Runge–Kutta method is employed to conduct a sweep frequency response analysis numerically. Furthermore, a torsional experiment is performed and validates the feasibility of the theoretical model. As a result, some torsional characteristics of automotive powertrain are obtained. The first three-order nature torsional frequencies are predicted. Torsional behaviors only affect the vibration characteristics of a complete vehicle at low-speed condition and will be reinforced expectedly while increasing torque fluctuation. Gear mesh excitations have little effects on torsional responses for such components located before mesh point but a lot for ones behind it. In particular, it is noted that the torsional system has a stiffness-softening characteristic with respect to torque fluctuation.

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