Design Robust Artificial Intelligence Model-base Variable Structure Controller with Application to Dynamic Uncertainties OCTAM VI Continuum Robot

Omid Mahmoudi,Farzin Piltan,Omid Reza Sadrnia,Mahdi Jafari,Mehdi Eram 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.1

Design a robust artificial intelligent nonlinear controller for second order nonlinear uncertain dynamical systems is one of the most important challenging works. This paper focuses on the design of a robust chattering free mathematical model-base artificial intelligence (fuzzy inference system) variable structure controller (MFVSC) for highly nonlinear dynamic continuum robot manipulator, in presence of uncertainties. In order to provide high performance nonlinear methodology, variable structure controller is selected. Pure variable structure controller can be used to control of partly known nonlinear dynamic parameters of continuum robot manipulator. In order to reduce/eliminate the chattering, this research is used the artificial intelligence (fuzzy logic) theory. The results demonstrate that the model base fuzzy variable structure controller with switching function is a model-based controllers which works well in certain and partly uncertain system. Lyapunov stability is proved in mathematical model-based fuzzy variable structure controller with switching (sign) function. This controller has acceptable performance in presence of uncertainty (e.g., overshoot=1%, rise time=0.9 second, steady state error = 1.6e-8 and RMS error=4.8e-8).

가반하중 변동에 대응하는 중력보상장치 개발

황적규,조창현,이영호,최문택,송재복,김문상 제어로봇시스템학회 2011 제어로봇시스템학회 국내학술대회 논문집 Vol.2011 No.5

This paper proposes a 1 DOF gravity compensator which can counterbalance variable loads completely. A gravity compensator is usually used to perform static balancing of the manipulator’s own masses in most cases. Considering manipulation tasks (e.g., picking up an object), however, the magnitude and distribution of the total masses vary by the mass of an object, which deteriorates the performance of a static balancer. To obtain the complete static balancing for all situations, a control scheme is derived for a 1 DOF gravity compensator in this paper. The control scheme is only activated, when the distribution of masses varies. A power analysis is performed for practical implementation. Various simulations verify that a 1 DOF gravity compensator with the proposed control scheme is applicable to the variable payloads.

Sliding Mode Control for a Robot Manipulator with Passive Joints

Kim, Won,Shin, Jin-Ho,Lee, Ju-Jang Institute of Control 2002 Transaction on control, automation and systems eng Vol.4 No.1

In this paper, we propose a sliding mode controller for a robot manipulator with passive joints. A robot manipulator with passive joints which are not equipped with any actuators is a kind of underactuated system. Underactuated systems have some advantages compared to fully-actuated ones. For example, they weigh less and consume less energy because they have smaller number of components than fully-actuated ones. However the control of an underactuated manipulator is much more difficult than that of fully- actuated robot manipulator. In this paper a complex dynamic model of a manipulator with passive joints is manipulated for sliding mode control. Sliding mode controllers are designed for this complex system and the stability of the controllers is proved mathematically. Finally a simulation for this control system is executed for evaluating the effectiveness of the designed sliding mode controller.

Sliding Mode Control for a Robot Manipulator with Passive Joints

WonKim,신진호,이주장 제어·로봇·시스템학회 2002 International Journal of Control, Automation, and Vol.4 No.1

In this paper, we propose a sliding mode controller for a robot manipulator with passive joints. A robot manipulatorwith passive joints which are not equipped with any actuators is a kind of underactuated system. Underactuated systems have someadvantages compared to fully-actuated ones. For example, they weigh less and consume less energy because they have smaller numberof components than fully-actuated ones. However the control of an underactuated manipulator is much more difcult than that of fully-actuated robot manipulator. In this paper a complex dynamic model of a manipulator with passive joints is manipulated for sliding modecontrol. Sliding mode controllers are designed for this complex system and the stability of the controllers is proved mathematically.Finally a simulation for this control system is executed for evaluating the effectiveness of the designed sliding mode controller.

개입 인과 이론에 따른 원인 효과 해명에 대한 평가와 인과 상호작용 효과에 관한 반 사실적 조절 변수로 원인 효과를 추정하기

김준성 한국과학철학회 2020 과학철학 Vol.23 No.2

In this paper, I first critically examine the debate on the intervention theory of causation and another intervention theory of causation that articulates the first theory. Secondly, I show that causal structure is explicated and estimated in terms of counterfactual moderator variables for causal interaction. The paper consists of four parts. First, I examine Strevens’(2007, 2008) criticism of Woodward’s(2005) intervention theory of causation. In particular, I examine the problem that causal significance of a variable for another variable is different, depending on what variables we are considering. I also examine the problem with the intervention theory of causation due to monotonicty. Second, I introduce Statham’s(2018) analysis of and his criticism of Woodward’s theory(2005, 2008, 2009) and critically examine Statham’s intervention theory of causation that is intended to articulate Woodward’s theory. In particular, I criticize Statham’s distinction between background variables and system variables. Third, I argue that Woodward’s theory and Statham’s theory both do not fully explicate multiple causal significance of a variable for another variable that matters in the world of causal network. Finally, assuming confounding variables, I explicate and estimate multiple causal significance of a variable for another variable in terms of counterfactual moderator variables for causal interaction. 이 글에서 필자는 우선, 인과에 대한 개입(조종) 이론에 대한 논쟁을 검토하고, 그 이론의 대안을 비판적으로 평가한다. 다음으로, 인과 상호작용을 반 사실적 조절 변수로 전제하여 인과 구조를 유의미하게 해명하고 추정할 수 있는 방법을 제시한다. 이 글의 구조는 다음과 같다. 첫째, 우드워드(Woodward 2005)의 개입(조종) 인과 이론에 대한 스트레븐스(Strevens 2007, 2008)의 비판과 이에 대한 우드워드(Woodward 2008, 2009)의 응답을 검토하고, 이들 논쟁의 의미에 주목한다. 특별히 변수 상대성에 따른 원인 효과의 다양성 문제와 원인 효과의 단조성 문제를 검토한다. 둘째, 우드워드의 이론에 대한 스태텀(Statham 2018)의 분석과 비판 그리고 대안을 검토하고 평가한다. 특별히 스태텀이 제시한 배경 조건 변수와 시스템 변수의 구분에 대해 비판적으로 검토하고 평가한다. 셋째, 우드워드의 이론과 스태텀의 이론 모두가, 결과 변수에 대한 원인 변수의 상반된 다양한 원인 효과를 해명하는 데에 한계가 있음을 논의한다. 넷째, 인과 상호작용을 반 사실적 조절 변수로 고려하여, 그 방식이 앞선 이론들의 문제에 대하여 어떻게 답이 될 수 있으며, 한 변수의 또 다른 변수의 원인 효과를 교란하는 변수를 전제하고도 인과 구조를 추정하는 방법을 제시한다.

Neuro-adaptive sliding-mode tracking control of robot manipulators

Topalov, Andon V.,Kaynak, Okyay,Aydin, Gokhan John Wiley Sons, Ltd. 2007 International journal of adaptive control and sign Vol.21 No.8

<P>In this work, a new dynamical on-line learning algorithm for robust model-free neuro-adaptive control of a class of nonlinear systems with uncertain dynamics is proposed and experimentally tested in order to evaluate its performance and practical feasibility in industrial settings. The control application studied is the trajectory tracking control task for the first three joints of an open architecture articulated robot manipulator. The control scheme makes use of variable structure systems theory and the feedback-error-learning concept. An inner sliding motion is established in terms of the neurocontroller parameters, aiming to lead the error in its control signal towards zero. The outer sliding motion bears on the system under control, the state tracking error vector of which is simultaneously driven towards the origin of the phase space. The existing relation between the two sliding motions is shown. Experimental results illustrate that the proposed neural-network-based controller possesses a remarkable learning capability to control complex dynamical systems, virtually without requiring a priori knowledge of the plant dynamics and laborious start-up procedures. Copyright © 2007 John Wiley & Sons, Ltd.</P>

A Study on Sliding Mode Tracking Control for a Robotic Manipulator

Won Ho Kim,Ha Quang Thinh Ngo,Jin Ho Shin 한국정보기술학회 2007 한국정보기술학회논문지 Vol.5 No.4

This paper proposes a novel sliding mode tracking control scheme for a robotic manipulator. Generally, sliding mode control which has more advantages than the others, is used to track the error and control the torque applied to each joint of manipulators. However, it exhibits chattering imposed by the discontinuity of the control action. By using the proposed controller, a proportional-integral combination of the sliding function in the boundary layer, it holds all good properties of sliding mode system while avoiding unnecessary discontinuity of the control. Thus, chattering is alleviated without deterioration of system robustness. The results of simulation for a two-link robot are presented to show the feasible and systematic control scheme. Numerical simulation compared with the other control scheme is also performed for the same robot.

신경회로망을 이용한 매니플레이터의 슬라이딩모드 제어

양호석(Ho Seog Yang),이건복(Gun Bok Lee) 한국생산제조학회 2006 한국생산제조학회지 Vol.15 No.5

This Paper presents a new control scheme that combines a sliding mode control and a neural network. In the proposed sliding mode control, a continuous control is employed removing the switching phenomena and the equivalent control within the boundary layer is estimated through on-line learning of the neural network. The performances of the proposed control are compared with off-line neural network and on-line neural sliding mode control by computer simulation. The simulation results show that the proposed control reduces high frequency chattering and tracking error in example of the two link manipulator.

모델링 오차를 갖는 유연 링크 로봇 최적 제어

한기봉,이시복 한국소음진동공학회 1996 소음 진동 Vol.6 No.6

Linear LQG controller has been investigated to control flexible link manipulators. The performance and complexity of these depend largely on the model upon which the controller is designed. In this study, the flexible modes of the link manipulator are considered to have uncertain parameters, which can be represented by random variable and these parameters are reflected on the weighting of performance. In this method, the exact modelling for the flexible modes is not necessary. The order of the resulting controller is much lower than the one based on a full model. Through numerical study, it is shown that the performance and the stability-robustness of the proposed controller reaches reasonably the one based on the full model.

Variable Impedance Control of Cable Actuated Continuum Manipulators

Guangping He,Yanan Fan,Tingting Su,Lei Zhao,Quanliang Zhao 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.7

Continuum manipulators are a class of special compliant robots that have important potential applications in the field of human-machine interactive operations, or work in cluttered and constrained environments. In these application scenarios, the most popular operation tasks are those with coupling force-position constraints. To simultaneously stabilize the desired operation force and the position of the manipulator, variable impedance control issues of the cable driven continuum manipulators are investigated in this paper. On the basis of constructing a novelLyapunov function, a variable impedance control law is presented and the stability of the closed-loop system has also been analyzed. Then the operation space variable impedance control for a single segment cable driven continuum manipulator is realized by the aid of a pseudo-rigid-body model. Some numerical simulations also demonstrate the stability of the variable impedance control system.