scholarly journals Dynamical Adaptive Integral Sliding Backstepping Control of Nonlinear Nontriangular Uncertain Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Mahmood Pervaiz ◽  
Qudrat Khan ◽  
Aamer Iqbal Bhatti ◽  
Shahzad Ahmed Malik

We present a control strategy for nonlinear nontriangular uncertain systems. The proposed control method is a synergy between the dynamic adaptive backstepping (DAB) and integral sliding mode (ISM) and is referred to as DAB-ISMC. Our main objective is to find a recursive procedure to transform a nontriangular system into an implementable form that enables designing a control law which almost eliminates the reaching-phase. The proposed method further facilitates minimization of chattering which is believed to be a shortcoming of the sliding mode control. In this methodology, the ISM, as an integrated subsystem of DAB, is introduced at the final stage of backstepping. This strategy works very well to obtain a system that is robust against model imperfections, matching and unmatching uncertainties. The DAB-ISMC method is applied on a continuous stirred tank reactor (CSTR) and simulation results obtained on Matlab are found to be very promising.

Author(s):  
Linjie Xin ◽  
◽  
Qinglin Wang ◽  
Yuan Li ◽  
Jinhua She ◽  
...  

This study investigates the terminal sliding mode (TSM) control for a class of first-order uncertain systems with dead-zone and saturation. First, a new adaptive TSM control law was proposed for the single-input and single-output (SISO) systems by employing an integral fast TSM. It achieves rejection for both system uncertainty and input nonlinearity. The global reaching condition of the sliding mode is guaranteed by the Lyapunov stability theory. The new control law possesses faster convergence than the linear sliding mode method, and the singularity problem of TSM is avoided. Then, the control law was extended for tracking control of a dynamic model of spacecraft which was a multi-input and multi-output (MIMO) system. Finally, the simulation results confirmed the effectiveness of the proposed control method.


2000 ◽  
Vol 122 (4) ◽  
pp. 746-752 ◽  
Author(s):  
J. C. Scarratt ◽  
A. Zinober ◽  
R. E. Mills ◽  
Miguel Rios-Bolı´var ◽  
A. Ferrara ◽  
...  

In this paper combined algorithms for the control of nontriangular nonlinear systems with unmatched uncertainties will be presented. The controllers consist of a combination of Dynamical Adaptive Backstepping (DAB) and Sliding Mode Control (SMC) of first and second order. In order to solve a tracking problem, the DAB algorithm (a generalization of the backstepping technique) makes use of virtual functions as well as tuning functions to construct a transformed system for which a regulation problem has to be solved. The new state is extended by an n−ρth order subsystem in canonical form where n is the order of the original system and ρ is the relative degree. The role of the sliding mode control is to replace the last step of the design of the control law to obtain more robustness toward disturbances and unmodeled dynamics. The main advantages of the second-order sliding mode algorithm are the prevention of chattering, higher accuracy, and a significant simplification of the control law. A comparative study of these first and second order sliding controllers will be presented. [S002-0434(00)02604]


2014 ◽  
Vol 1028 ◽  
pp. 186-190
Author(s):  
Hong Cheng Zhou ◽  
Zhi Peng Jiang

The servo control methods of 6-DOF motion configuration are researched. Based on analysis for characteristic of the motion configuration, the control strategy and control law used on the motion control system are presented. The controller in velocity tracking loop and location loop are respectively designed by frequency correcting method and normal control method which belongs to classical control theory. Sliding mode variable structure control method is presented for location control law designing, against the super low velocity creep caused by friction disturbance, so that the problem of location control loop low velocity creeping is solved, and a simulating experimentation demonstrate the effectiveness of the proposed approach.


2021 ◽  
Vol 12 (2) ◽  
pp. 1073-1081
Author(s):  
Zhiguo Lu ◽  
Guoshuai Liu ◽  
Haibin Zhao ◽  
Ruchao Wang ◽  
Chong Liu

Abstract. The bionic-gibbon robot is a popular bionic robot. The bionic-gibbon robot can imitate a gibbon in completing brachiation motion between branches. With nonlinear and underactuated properties, the robot has important research value. This paper designs a type of bionic-gibbon robot with three links and two grippers. To simplify the controller, a plane control model is proposed, and its dynamic model is established. The control strategy in this paper divides the brachiation motion into several processes: adjust posture, open the gripper, the swing process and close the gripper. Based on sliding-mode control (SMC), the control method for the swing process is designed. The target position of the brachiation motion is set as the origin of the sliding-mode surface. In a finite time, the robot will reach the target position along the approach rate we adopt. In this way, the robot can complete the desired brachiation motion only by setting the position parameters of the target bar. We perform some simulations in ROS-Gazebo. The simulation results show that the bionic-gibbon robot can complete continuous brachiation motion on irregularly distributed bars. The sliding-mode control and the three-link structure significantly improve the robustness and swing efficiency of the bionic-gibbon robot.


2020 ◽  
Vol 12 (18) ◽  
pp. 7429
Author(s):  
Weiming Zhang ◽  
Tinglong Pan ◽  
Dinghui Wu ◽  
Dezhi Xu

With the aim of solving the power fluctuation and bus voltage instability problems caused by external environment variations in the photovoltaic grid-connected system, a prescribed performance-based adaptive backstepping controller is proposed for the system to regulate the bus voltage and the inverter current. First, the mathematical model of the grid-connected inverter is established, in which the uncertain system parameters are estimated via a designed projection-based adaptive law. Then, the command-filtered backstepping sliding mode control method is applied to the system for power regulation. In order to achieve favorable tracking performance, the prescribed performance technique is introduced in the voltage regulation strategy by constraining the compensated voltage tracking error within a certain range from a novel point of view. Finally, the simulation is carried out considering the variations of environmental situations, and the obtained results demonstrate the sound performance of the prescribed performance-based control strategy with respect to the photovoltaic grid-connected system.


Author(s):  
Guang Xia ◽  
Yan Xia ◽  
Xiwen Tang ◽  
Linfeng Zhao ◽  
Baoqun Sun

Fluctuations in operation resistance during the operating process lead to reduced efficiency in tractor production. To address this problem, the project team independently developed and designed a new type of hydraulic mechanical continuously variable transmission (HMCVT). Based on introducing the mechanical structure and transmission principle of the HMCVT system, the priority of slip rate control and vehicle speed control is determined by classifying the slip rate. In the process of vehicle speed control, the driving mode of HMCVT system suitable for the current resistance state is determined by classifying the operation resistance. The speed change rule under HMT and HST modes is formulated with the goal of the highest production efficiency, and the displacement ratio adjustment surfaces under HMT and HST modes are determined. A sliding mode control algorithm based on feedforward compensation is proposed to address the problem that the oil pressure fluctuation has influences on the adjustment accuracy of hydraulic pump displacement. The simulation results of Simulink show that this algorithm can not only accurately follow the expected signal changes, but has better tracking stability than traditional PID control algorithm. The HMCVT system and speed control strategy models were built, and simulation results show that the speed control strategy can restrict the slip rate of driving wheels within the allowable range when load or road conditions change. When the tractor speed is lower than the lower limit of the high-efficiency speed range, the speed change law formulated in this paper can improve the tractor speed faster than the traditional rule, and effectively ensure the production efficiency. The research results are of great significance for improving tractor’s adaptability to complex and changeable working environment and promoting agricultural production efficiency.


Author(s):  
Abdelkrim Brahmi ◽  
Maarouf Saad ◽  
Brahim Brahmi ◽  
Ibrahim El Bojairami ◽  
Guy Gauthier ◽  
...  

In the research put forth, a robust adaptive control method for a nonholonomic mobile manipulator robot, with unknown inertia parameters and disturbances, was proposed. First, the description of the robot’s dynamics model was developed. Thereafter, a novel adaptive sliding mode control was designed, to which all parameters describing involved uncertainties and disturbances were estimated by the adaptive update technique. The proposed control ensures a relatively good system tracking, with all errors converging to zero. Unlike conventional sliding mode controls, the suggested is able to achieve superb performance, without resulting in any chattering problems, along with an extremely fast system trajectories convergence time to equilibrium. The aforementioned characteristics were attainable upon using an innovative reaching law based on potential functions. Furthermore, the Lyapunov approach was used to design the control law and to conduct a global stability analysis. Finally, experimental results and comparative study collected via a 05-DoF mobile manipulator robot, to track a given trajectory, showing the superior efficiency of the proposed control law.


2009 ◽  
Vol 22 (2) ◽  
pp. 183-195
Author(s):  
Ján Vittek ◽  
Vladimir Vavrús ◽  
Jozef Buday ◽  
Jozef Kuchta

The paper presents design and verification of Forced Dynamics Control of an actuator with linear permanent magnet synchronous motor. This control method is a relatively new one and offers an accurate realization of a dynamic speed response, which can be selected for given application by the user. In addition to this, the angle between stator current vector and moving part flux vector is maintained mutually perpendicular as it is under conventional vector control. To achieve prescribed speed response derived control law requires estimation of an external force, which is obtained from the set of observers. The first observer works in pseudo-sliding mode and observes speed of moving part while the second one has filtering effect for elimination of the previous one chattering. The overall control system is verified by simulations and experimentally. Preliminary experiments confirmed that the moving part speed response follows the prescribed one fairly closely.


2021 ◽  
Vol 233 ◽  
pp. 01051
Author(s):  
Tianze Miao ◽  
Xiaona Liu ◽  
Siyuan Liu ◽  
Lihua Wang

The bi-directional DC / DC converter in DC microgrid is a typical nonlinear system which has large voltage disturbance during lead accumulator charging and discharging. In order to solve the problem of voltage disturbance, the linearization of the converter is realized by exact feedback linearization, and the sliding mode controller is designed by using exponential approximation law. The simulation results show that the method has fast response speed, strong anti-interference ability and good steady-state characteristics.


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