scholarly journals Realisation of model reference compliance control of a humanoid robot arm via integral sliding mode control

2016 ◽  
Vol 7 (1) ◽  
pp. 1-8 ◽  
Author(s):  
S. G. Khan ◽  
J. Jalani
Keyword(s):  
Feedback Linearization ◽  
Reference Model ◽  
Sliding Mode ◽  
Physical Interaction ◽  
Robot Arm ◽  
Compliance Control ◽  
Model Reference ◽  
Integral Sliding Mode ◽  
Control Scheme ◽  
Compliant Control

Abstract. Human safety becomes critical when robot enters the human environment. Compliant control can be used to address some safety issues in human-robot physical interaction. This paper proposes an integral sliding mode controller (ISMC) based compliance control scheme for the Bristol Robotics Laboratory's humanoid BERT II robot arm. Apart from introducing a model reference compliance controller, the ISMC scheme is aimed to deal with the robot arm dynamic model's inaccuracies and un-modelled nonlinearities. The control scheme consists of a feedback linearization (FL) and an ISMC part. In addition, a posture controller has been incorporated to employ the redundant DOF and generate human like motion. The desired level of compliance can be tuned by selecting the stiffness and damping parameters in the sliding mode variable (compliance reference model). The results show that the compliant control is feasible at different levels for BERT II in simulation and experiment. The positioning control has been satisfactorily achieved and nonlinearities and un-modelled dynamics have been successfully overcome.

Optimal Model Reference Control Scheme Design for Nonlinear Strict-Feedback Systems

2020 ◽  
Vol 38 (9A) ◽  
pp. 1342-1351
Author(s):  
Musadaq A. Hadi ◽  
Hazem I. Ali
Keyword(s):  
Reference Model ◽  
Feedback System ◽  
Optimization Method ◽  
Feedback Systems ◽  
Model Reference ◽  
Scheme Design ◽  
Model Reference Control ◽  
Control Scheme ◽  
Lyapunov Stability Analysis ◽  
Strict Feedback

In this paper, a new design of the model reference control scheme is proposed in a class of nonlinear strict-feedback system. First, the system is analyzed using Lyapunov stability analysis. Next, a model reference is used to improve system performance. Then, the Integral Square Error (ISE) is considered as a cost function to drive the error between the reference model and the system to zero. After that, a powerful metaheuristic optimization method is used to optimize the parameters of the proposed controller. Finally, the results show that the proposed controller can effectively compensate for the strictly-feedback nonlinear system with more desirable performance.

scholarly journals Compliant control for wearable exoskeleton robot based on human inverse kinematics

2018 ◽  
Vol 15 (6) ◽  
pp. 172988141881213 ◽  
Author(s):  
Brahim Brahmi ◽  
Maarouf Saad ◽  
Abdelkrim Brahmi ◽  
Cristobal Ochoa Luna ◽  
Mohammad Habibur Rahman
Keyword(s):  
Inverse Kinematics ◽  
Sliding Mode ◽  
New Technology ◽  
Time Delay Estimation ◽  
Compliance Control ◽  
Exoskeleton Robot ◽  
Main Challenge ◽  
Compliant Control ◽  
Wearable Exoskeleton ◽  
Set Up

Rehabilitation robots are a new technology dedicated to the physiotherapy and assistance motion and has aroused great interest in the scientific community. These kinds of robots have shown a high potential in limiting the patient’s disability, increasing its functional movements and helping him/her in daily living activities. This technology is still an emerging area and suffers from many challenges like compliance control and human–robot collaboration. The main challenge addressed in this research is to ensure that the exoskeleton robot provides an appropriate compliance control that allows it to interact perfectly with humans. This article investigates a new compliant control based on a second-order sliding mode with adaptive-gain incorporating time delay estimation. The control uses human inverse kinematics to complete active rehabilitation protocols for an exoskeleton robot with unknown dynamics and unforeseen disturbances. The stability analysis is formulated and demonstrated based on Lyapunov function. An experimental physiotherapy session with three healthy subjects was set up to test the effectiveness of the proposed control, using virtual reality environment.

High-Sideslip Model Reference Adaptive Flight Control for Aileron Locked Aircraft

2014 ◽  
Vol 651-653 ◽  
pp. 751-756
Author(s):  
Peng Fei Cheng ◽  
Cheng Fu Wu ◽  
Yue Guo
Keyword(s):  
Flight Control ◽  
Control Method ◽  
Reference Model ◽  
Sideslip Angle ◽  
Model Reference ◽  
Control Scheme ◽  
Adaptive Flight Control ◽  
Random Initialization ◽  
Model Reference Adaptive ◽  
The Given

This paper develops a high-sideslip flight control scheme based on model reference adaptive control (MRAC) to stabilize aircraft under aileron deadlock of one side. Firstly, the cascaded flight control scheme for high-sideslip straight flight is presented and how the control signals transfer is also analyzed. After that, the control structure and laws of MRAC for attitude inner-loop connected with sideslip command are designed. Finally, the control scheme is verified under a nonlinear aircraft model in conditions of no fault and one side aileron deadlock respectively. The simulation results show that when one side aileron deadlock occurs in accompany with the plant’s aerodynamic data perturbation and random initialization of controller parameters, this control method could utilize operation points of no-fault aircraft to force the faulty aircraft following the given reference model responses and finally tracking given sideslip angle command without static error robustly.

scholarly journals Observer-based leader-following formation control of uncertain multiple agents by integral sliding mode

2017 ◽  
Vol 65 (1) ◽  
pp. 35-44 ◽  
Author(s):  
D.W. Qian ◽  
S.W. Tong ◽  
C.D. Li
Keyword(s):  
Formation Control ◽  
Sliding Mode ◽  
Multiple Agents ◽  
Nonlinear Disturbance Observer ◽  
Integral Sliding Mode ◽  
Agent Platform ◽  
Control Scheme ◽  
Mild Assumption ◽  
Leader Following ◽  
Multi Agent

Abstract This paper investigates the formation control problem of multiple agents. The formation control is founded on leader-following approaches. The method of integral sliding mode control is adopted to achieve formation maneuvers of the agents based on the concept of graph theory. Since the agents are subject to uncertainties, the uncertainties also challenge the formation-control design. Under a mild assumption that the uncertainties have an unknown bound, the technique of nonlinear disturbance observer is utilized to tackle the issue. According to a given communication topology, formation stability conditions are investigated by the observer-based integral sliding mode formation control. From the perspective of Lyapunov, not only is the formation stability guaranteed, but the desired formation of the agents is also realized. Finally, some simulation results are presented to show the feasibility and validity of the proposed control scheme through a multi-agent platform.

scholarly journals Nonlinear Integral Sliding Mode Control for a Second Order Nonlinear System

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Xie Zheng ◽  
Xie Jian ◽  
Du Wenzheng ◽  
Cheng Hongjie
Keyword(s):  
Sliding Mode Control ◽  
Sliding Mode ◽  
External Disturbance ◽  
Lyapunov Stability Theory ◽  
Second Order ◽  
Integral Sliding Mode Control ◽  
Integral Sliding Mode ◽  
Mode Control ◽  
Control Scheme ◽  
Sliding Manifold

A nonlinear integral sliding-mode control (NISMC) scheme is proposed for second order nonlinear systems. The new control scheme is characterized by a nonlinear integral sliding manifold which inherits the desired properties of the integral sliding manifold, such as robustness to system external disturbance. In particular, compared with four kinds of sliding mode control (SMC), the proposed control scheme is able to provide better transient performances. Furthermore, the proposed scheme ensures the zero steady-state error in the presence of a constant disturbance or an asymptotically constant disturbance is proved by Lyapunov stability theory and LaSalle invariance principle. Finally, both the theoretical analysis and simulation examples demonstrate the validity of the proposed scheme.

scholarly journals Design and Analysis of an Integral Sliding Mode Fault-Tolerant Control Scheme

2012 ◽  
Vol 57 (7) ◽  
pp. 1783-1789 ◽  
Author(s):  
Mirza Tariq Hamayun ◽  
Christopher Edwards ◽  
Halim Alwi
Keyword(s):  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Integral Sliding Mode ◽  
Control Scheme

scholarly journals Combination of Two Nonlinear Techniques Applied to a 3-DOF Helicopter

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
P. Ahmadi ◽  
M. Golestani ◽  
S. Nasrollahi ◽  
A. R. Vali
Keyword(s):  
Convergence Rate ◽  
Feedback Linearization ◽  
Sliding Mode ◽  
Control Law ◽  
Sliding Mode Controller ◽  
Control Methods ◽  
Control Effort ◽  
Control Techniques ◽  
Control Scheme ◽  
Feedback Linearization Control

A combination of two nonlinear control techniques, fractional order sliding mode and feedback linearization control methods, is applied to 3-DOF helicopter model. Increasing of the convergence rate is obtained by using proposed controller without increasing control effort. Because the proposed control law is robust against disturbance, so we only use the upper bound information of disturbance and estimation or measurement of the disturbance is not required. The performance of the proposed control scheme is compared with integer order sliding mode controller and results are justified by the simulation.

The Model Reference Adaptive Control of the DC Electric Drive System

2014 ◽  
Vol 875-877 ◽  
pp. 2030-2035 ◽  
Author(s):  
Marian Gaiceanu ◽  
Cristian Eni ◽  
Mihaita Coman ◽  
Romeo Paduraru
Keyword(s):  
Adaptive Control ◽  
Reference Model ◽  
Sliding Mode ◽  
Tracking Error ◽  
Model Reference Adaptive Control ◽  
Drive System ◽  
Mode Switching ◽  
Sigmoid Function ◽  
Model Reference ◽  
Model Reference Adaptive

Due to the parametric and structural uncertainty of the DC drive system, an adaptive control method is necessary. Therefore, an original model reference adaptive control (MRAC) for DC drives is proposed in this paper. MRAC ensures on-line adjustment of the control parameters with DC machine parameter variation. The proposed adaptive control structure provides regulating advantages: asymptotic cancellation of the tracking error, fast and smooth evolution towards the origin of the phase plan due to a sliding mode switching k-sigmoid function. The reference model can be a real strictly positive function (the tracking error is also the identification error) as its order is relatively higher than one degree. For this reason, the synthesis of the adaptive control will use a different type of error called augmented or enhanced error. The DC machine with separate excitation is fed at a constant flux. This adaptive control law assures robustness to external perturbations and to unmodelled dynamics.

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