scholarly journals Improving Interactions between a Power-Assist Robot System and Its Human User in Horizontal Transfer of Objects Using a Novel Adaptive Control Method

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
S. M. Mizanoor Rahman ◽  
Ryojun Ikeura
Keyword(s):  
Adaptive Control ◽  
Horizontal Transfer ◽  
Control Method ◽  
Weight Perception ◽  
The Novel ◽  
Robot System ◽  
Control Scheme ◽  
Dynamics And Control ◽  
Motion Features ◽  
And Control

Power assist systems are usually used for rehabilitation, healthcare, and so forth.This paper puts emphasis on the use of power assist systems for object transfer and thus brings a novelty in the power-assist applications. However, the interactions between the systems and the human users are usually not satisfactory because human features are not included in the control design. In this paper, we present the development of a 1-DOF power assist system for horizontal transfer of objects. We included human features such as weight perception in the system dynamics and control. We then simulated the system using MATLAB/Simulink for transferring objects with it and (i) determined the optimum maneuverability conditions for object transfer, (ii) determined psychophysical relationships between actual and perceived weights, and (iii) analyzed load forces and motion features. We then used the findings to design a novel adaptive control scheme to improve the interactions between the user and the system. We implemented the novel control (simulated the system again using the novel control), the subjects evaluated the system, and the results showed that the novel control reduced the excessive load forces and accelerations and thus improved the human-system interactions in terms of maneuverability, safety, and so forth. Finally, we proposed to use the findings to develop power assist systems for manipulating heavy objects in industries that may improve interactions between the systems and the users.

Dynamics and Control of a Helicopter Carrying a Payload Using a Cable-Suspended Robot

2005 ◽  
Author(s):  
So-Ryeok Oh ◽  
Ji-Chul Ryu ◽  
Sunil K. Agrawal
Keyword(s):  
Control Method ◽  
Dual System ◽  
Robust Controller ◽  
Robot System ◽  
Control Approach ◽  
Cable Robot ◽  
Dynamics And Control ◽  
Position And Orientation ◽  
And Control ◽  
Scale Control

This paper presents a study of the dynamics and control of a helicopter carrying a payload through a cable-suspended robot. The helicopter can perform gross motion, while the cable suspended robot underneath the helicopter can modulate a platform in position and orientation. Due to the under-actuated nature of the helicopter, the operation of this dual system consisting of the helicopter and the cable robot is challenging. We propose here a two time scale control method, which makes it possible to control the helicopter and the cable robot independently. In addition, this method provides an effective estimation on the bound of the motion of the helicopter. Therefore, even in the case where the helicopter motion is unknown, the cable robot can be stabilized by implementing a robust controller. Simulation results of the dual system show that the proposed control approach is effective for such a helicopter-robot system.

Dynamics and Control of a Helicopter Carrying a Payload Using a Cable-Suspended Robot

2005 ◽  
Vol 128 (5) ◽  
pp. 1113-1121 ◽  
Author(s):  
So-Ryeok Oh ◽  
Ji-Chul Ryu ◽  
Sunil K. Agrawal
Keyword(s):  
Control Method ◽  
Dual System ◽  
Robust Controller ◽  
Robot System ◽  
Control Approach ◽  
Cable Robot ◽  
Dynamics And Control ◽  
Position And Orientation ◽  
And Control ◽  
Scale Control

In this paper we present a study of the dynamics and control of a helicopter carrying a payload through a cable-suspended robot. The helicopter can perform gross motion, while the cable suspended robot underneath the helicopter can modulate a platform in position and orientation. Due to the underactuated nature of the helicopter, the operation of this dual system consisting of the helicopter and the cable robot is challenging. We propose here a two time scale control method, which makes it possible to control the helicopter and the cable robot independently. In addition, this method provides an effective estimation on the bound of the motion of the helicopter. Therefore, even in the case where the helicopter motion is unknown, the cable robot can be stabilized by implementing a robust controller. Simulation results of the dual system show that the proposed control approach is effective for such a helicopter-robot system.

scholarly journals Disturbance compensation-based output feedback adaptive control for shape memory alloy actuator system

2021 ◽  
Vol 18 (1) ◽  
pp. 172988142199399
Author(s):  
Xiaoguang Li ◽  
Bi Zhang ◽  
Daohui Zhang ◽  
Xingang Zhao ◽  
Jianda Han
Keyword(s):  
Adaptive Control ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Control Method ◽  
Control Law ◽  
Reference Trajectory ◽  
Disturbance Compensation ◽  
Comparison Results ◽  
Control Scheme ◽  
Actuator System

Shape memory alloy (SMA) has been utilized as the material of smart actuators due to the miniaturization and lightweight. However, the nonlinearity and hysteresis of SMA material seriously affect the precise control. In this article, a novel disturbance compensation-based adaptive control scheme is developed to improve the control performance of SMA actuator system. Firstly, the nominal model is constructed based on the physical process. Next, an estimator is developed to online update not only the unmeasured system states but also the total disturbance. Then, the novel adaptive controller, which is composed of the nominal control law and the compensation control law, is designed. Finally, the proposed scheme is evaluated in the SMA experimental setup. The comparison results have demonstrated that the proposed control method can track reference trajectory accurately, reject load variations and stochastic disturbances timely, and exhibit satisfactory robust stability. The proposed control scheme is system independent and has some potential in other types of SMA-actuated systems.

Design of a Multi-Arm Robot for Mandible Reconstruction Surgery

2014 ◽  
Vol 654 ◽  
pp. 187-190 ◽  
Author(s):  
Hong Hua Zhao ◽  
Jian Ying Tian ◽  
Dong Song Li ◽  
Chang Sheng Ai
Keyword(s):  
Mechanical Design ◽  
The Novel ◽  
Robot System ◽  
Mandible Reconstruction ◽  
3D Navigation ◽  
Reconstruction Surgery ◽  
And Control ◽  
Robotic Surgical System ◽  
Surgical System ◽  
Poor Stability

Clinical treatment for mandible defects is Mandible Reconstruction Surgery (MRS) including bone grafts, distraction osteogenesis and bone tissue engineering, however, MRS is operated by doctors without 3D navigation at present which leads to lots of disadvantages such as bad operational control, low positioning accuracy and poor stability. Therefore, a robotic surgical system was designed to assist surgeons on manipulating. For this study, the robot system was given in brief, then mechanical design and control system of the novel three-arm robot.And experiment results in this study show that the robot works stably and accurately. The development of this medical robot system contributes to the promotion and popularization of the MRS in clinics.

Estimation of Critical Damping in Robot Joints and Identification of the Joint for Design With Most Effective Damping Enhancement

1994 ◽  
Author(s):  
Ahmad A. Smaili ◽  
Muhammad Sannah
Keyword(s):  
Natural Frequency ◽  
System Stability ◽  
Flexible Robot ◽  
Robot System ◽  
Joint Compliance ◽  
Dynamics And Control ◽  
Joint Identification ◽  
The One ◽  
And Control ◽  
Critical Damping

Abstract A major hindrance to dynamics and control of flexible robot manipulators is the deficiency of its inherent damping. Damping enhancement, therefore, should result in lower vibration amplitudes, shorter settling times, and improvement of system stability. Since the bulk of robot vibrations is attributed to joint compliance, it is a prudent strategy to design joints with sufficient inherent damping. In this article, a method is proposed to estimate critical damping at each joint and identify the joint that should be targeted for design with sufficient built-in damping. The target joint identification process requires that a n-joint robot system is divided into n-subsystems. Subsystem i includes the compliance of joint i and the inertia of the succeeding links, joint mechanisms, and payload. An equivalent single degree of freedom torsional model is devised and the natural frequency and critical damping is evaluated for each subsystem. The estimated critical damping at the joints are used to determine the elastodynamic response of the entire robot system from a model that includes joint compliance, shear deformation, rotary inertia, and geometric stiffness. The response revealed the following conclusion: The joint of the manipulator that would result in lower amplitudes of vibrations and shorter settling times when designed with sufficient built-in damping is the one that renders a subsystem whose natural frequency is the lowest of all subsystems comprising the robot.

Nonlinear dynamics and control of crank–slider mechanism with link flexibility and joint clearance

2015 ◽  
Vol 230 (5) ◽  
pp. 737-755 ◽  
Author(s):  
Sadeq Yaqubi ◽  
Morteza Dardel ◽  
Hamidreza Mohammadi Daniali
Keyword(s):  
Point Contact ◽  
Joint Clearance ◽  
Connecting Rod ◽  
Continuous Contact ◽  
Saturation Limit ◽  
Dynamical Behaviors ◽  
Control Scheme ◽  
Dynamics And Control ◽  
Link Flexibility ◽  
And Control

Dynamical behaviors and control of planar crank–slider mechanism considering the effects of joint clearance and link flexibility are studied. A control scheme for maintaining continuous contact is proposed. It was observed that using one actuator for control scheme might cause the actuator to reach its saturation limit, a problem that was bypassed by installing an additional actuator on connecting rod. In one actuator case, only continuous contact can be obtained, while with the aid of two actuators, point contact can be achieved. Great improvements in the performance of mechanism and reduction of vibrations are observed in the case of using an additional actuator.

scholarly journals Adaptive PD Control Based on RBF Neural Network for a Wire-Driven Parallel Robot and Prototype Experiments

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Yuqi Wang ◽  
Qi Lin ◽  
Xiaoguang Wang ◽  
Fangui Zhou
Keyword(s):  
Neural Network ◽  
Adaptive Control ◽  
Control Method ◽  
Rbf Neural Network ◽  
Approximation Error ◽  
Wind Tunnel Test ◽  
Parallel Robot ◽  
Network Control ◽  
Pd Control ◽  
Control Scheme

An adaptive PD control scheme is proposed for the support system of a wire-driven parallel robot (WDPR) used in a wind tunnel test. The control scheme combines a PD control and an adaptive control based on a radial basis function (RBF) neural network. The PD control is used to track the trajectory of the end effector of the WDPR. The experimental environment, the external disturbances, and other factors result in uncertainties of some parameters for the WDPR; therefore, the RBF neural network control method is used to approximate the parameters. An adaptive control algorithm is developed to reduce the approximation error and improve the robustness and control precision of the WDPR. It is demonstrated that the closed-loop system is stable based on the Lyapunov stability theory. The simulation results show that the proposed control scheme results in a good performance of the WDPR. The experimental results of the prototype experiments show that the WDPR operates on the desired trajectory; the proposed control method is correct and effective, and the experimental error is small and meets the requirements.

Dynamics and control of a 6-DOF space robot with flexible panels

2016 ◽  
Vol 231 (6) ◽  
pp. 1022-1034 ◽  
Author(s):  
Yu Zhang-Wei ◽  
Liu Xiao-Feng ◽  
Li Hai-Quan ◽  
Cai Guo-Ping
Keyword(s):  
Dynamic Model ◽  
Control Method ◽  
Torque Control ◽  
Space Robot ◽  
Velocity Variation ◽  
Variation Principle ◽  
Dynamics Modeling ◽  
Dynamics And Control ◽  
Flexible Panels ◽  
And Control

With the development of space exploration, researches on space robot will cause more attentions. However, most existing researches about dynamics and control of space robot concern planar problem, and the effect of flexible panel on dynamics of the system is not considered. In this article, dynamics modeling and active control of a 6-DOF space robot with flexible panels are investigated. Dynamic model of the system is established based on the Jourdain's velocity variation principle and the single direction recursive construction method. The computed torque control method is used to design point-to-point active controller of the space robot. The validity of the dynamic model is verified through the comparison with ADAMS software; the effects of panel flexibility on the system performance and the active controller design are studied in detail. Simulation results indicate that the proposed model is effective to describe the dynamics of space robot; panel flexibility has large influence on the dynamic behavior of space robot; the designed controller can effectively make the robot reach a specified position and the elastic vibration of the panels may be suppressed simultaneously.

scholarly journals A Distributed Autonomous Control Method for TCUL Transformers Using a Fuzzy Adaptive Control Scheme

1999 ◽  
Vol 119 (12) ◽  
pp. 1455-1461 ◽  
Author(s):  
Naoto Yorino ◽  
Takanori Shuto ◽  
Masaomi Nishimoto ◽  
Hiroshi Sasaki ◽  
Hiroaki Sugihara ◽  
...  
Keyword(s):  
Adaptive Control ◽  
Control Method ◽  
Autonomous Control ◽  
Fuzzy Adaptive Control ◽  
Control Scheme ◽  
Adaptive Control Scheme ◽  
Fuzzy Adaptive

Theoretical and Experimental Investigation of Elevator Cable Dynamics and Control

2005 ◽  
Vol 128 (1) ◽  
pp. 66-78 ◽  
Author(s):  
W. D. Zhu ◽  
Y. Chen
Keyword(s):  
Control Method ◽  
Upward Movement ◽  
High Rise ◽  
Cable Dynamics ◽  
Theoretical Predictions ◽  
Dynamics And Control ◽  
And Control ◽  
Elevator Cable ◽  
Parameter Estimation Techniques ◽  
Good Agreement

The vibratory energy of a moving cable in an elevator increases in general during upward movement. A control method is presented to dissipate the energy associated with the lateral vibration of the cable. A novel experimental method is developed to validate the theoretical predictions for the uncontrolled and controlled lateral responses of a moving cable in a high-rise elevator. This includes the design and fabrication of a scaled elevator, experimental setup, and development of measurement and parameter estimation techniques. Experimental results show good agreement with the theoretical predictions.

Sign in / Sign up

Export Citation Format

Share Document