scholarly journals Robust Control for the Suspension Cable System of the Unmanned Helicopter with Sensor Fault under Complex Environment

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Rong Mei
Keyword(s):  
Control Method ◽  
Sliding Mode ◽  
System Stability ◽  
Unmanned Helicopter ◽  
Sensor Fault ◽  
Complex Environment ◽  
Cable System ◽  
Control Scheme ◽  
Suspension Cable ◽  
Nonlinear Line

Aiming at the suspension cable system of an unmanned helicopter with sensor fault under complex environment, this paper studies the robust antiswing tolerant control scheme. To suppress the swing of the hanging load when the unmanned helicopter is in the forward flight state, a nonlinear line motion model is firstly established. Considering the sensor fault of the unmanned helicopter, a sensor fault estimator is developed. By using the fault estimator output, the robust antiswing tolerant controller is proposed using the backstepping technique and sliding mode control method. Under the designed robust antiswing tolerant controller, the desired tracking control performance can be obtained and the swing angle of the load is guaranteed small under the sensor fault. Furthermore, the closed-loop system stability is analyzed by using the Lyapunov technique. Simulation studies are given to show the efficiency of the designed robust antiswing control strategy.

scholarly journals Dynamic Sliding Mode Control Based on Fractional Calculus Subject to Uncertain Delay Based Chaotic Pneumatic Robot

2020 ◽  
Vol 10 (3) ◽  
pp. 413-420 ◽  
Author(s):  
Sara Gholipour ◽  
Heydar Toosian Shandiz ◽  
Mobin Alizadeh ◽  
Sara Minagar ◽  
Javad Kazemitabar
Keyword(s):  
Fractional Calculus ◽  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Robot Manipulator ◽  
Lyapunov Stability Theory ◽  
Mode Control ◽  
Control Scheme ◽  
Dynamic Sliding Mode Control ◽  
Dynamic Sliding Mode

Background & Objective: This paper considers the chattering problem of sliding mode control in the presence of delay in robot manipulator causing chaos in such electromechanical systems. Fractional calculus was used in order to produce a novel sliding mode to eliminate chatter. To realize the control of a class of chaotic systems in master-slave configuration, a novel fractional dynamic sliding mode control scheme is presented and examined on the delay based chaotic robot. Also, the stability of the closed-loop system is guaranteed by Lyapunov stability theory. Methods: A control scheme is proposed for reducing the chattering problem in finite time tracking and robust in presence of system matched disturbances. Results: Moreover, delayed robot motions are sorted out for qualitative and quantitative study. Finally, numerical simulations illustrate feasibility of the proposed control method. Conclusion: The control scheme is viable.

scholarly journals Using Adaptive Second Order Sliding Mode to Improve Power Control of a Counter-Rotating Wind Turbine under Grid Disturbances

2020 ◽  
Vol 22 (6) ◽  
pp. 427-434
Author(s):  
Adil Yahdou ◽  
Abdelkadir Belhadj Djilali ◽  
Zinelaabidine Boudjema ◽  
Fayçal Mehedi
Keyword(s):  
Power Control ◽  
Wind Turbine ◽  
Control Method ◽  
Sliding Mode ◽  
Second Order ◽  
Control Scheme ◽  
Doubly Fed ◽  
Twisting Algorithm ◽  
Unbalanced Network ◽  
Second Order Sliding Mode

This work presents a new control strategy for counter-rotating wind turbine (CRWT) driven doubly-fed induction generator (DFIG) under grid disturbances, such as unbalanced network voltage scenarios. The proposed strategy based on the power control used dynamic gains second order sliding mode control (SOSMC). The power control of a DFIG by SOSMC widely based on the super-twisting (ST) algorithm with invariable parameters and sign functions. The proposed control method consists in using dynamic-parameters ST algorithm that ensures a better result than a conventional strategy. The proposed control scheme used 2 sliding surfaces such as reactive and active powers to control them. Also, the sign functions are replaced by saturation (sat) functions in order to minimize the chattering problems. Simulation results depicted in this research article have confirmed the good usefulness and effectiveness of the proposed adaptive super-twisting algorithm of the CRWT system during grid disturbances.

scholarly journals Fuzzy Sliding Mode Control Method for AUV Buoyancy Regulation System

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Wende Zhao ◽  
Decheng Wang ◽  
Zhenzhong Chu ◽  
Mingjun Zhang
Keyword(s):  
Sliding Mode Control ◽  
Autonomous Underwater Vehicle ◽  
Control Method ◽  
Sliding Mode ◽  
Regulation System ◽  
Fuzzy Sliding Mode Control ◽  
Mode Control ◽  
Control Scheme ◽  
Fuzzy Sliding Mode ◽  
Control Accuracy

This paper investigates the control problem of the buoyancy regulation system for autonomous underwater vehicle (AUV). There are some problems to be considered in the oil-water conversion-based buoyancy regulation system, including the external seawater pressure, the pressure fluctuations, and the slow switching speed of the ball valve. The control accuracy of the buoyancy regulation under the traditional PID controller cannot meet the requirements of the project. In this paper, a fuzzy sliding mode control scheme is developed for the buoyancy regulation system to solve the abovementioned problems. At first, a mathematical model of the buoyancy regulation system is established, and the stability of the system is analyzed. Then, the sliding mode control algorithm is combined with the fuzzy system to improve the control accuracy. Finally, the pool-experiment results on a prototype show that the developed control scheme can meet the requirements of the control accuracy for the buoyancy regulation system.

scholarly journals Fallback options for airgap sensor fault of an electromagnetic suspension system

2013 ◽  
Vol 3 (2) ◽  
Author(s):  
Konstantinos Michail ◽  
Argyrios Zolotas ◽  
Roger Goodall
Keyword(s):  
Genetic Algorithms ◽  
Control Method ◽  
Realistic Model ◽  
Sensor Fault ◽  
Reliable Operation ◽  
Control Loops ◽  
Electromagnetic Suspension ◽  
Control Scheme ◽  
Analytical Redundancy ◽  
Classical Control

AbstractThe paper presents a method to recover the performance of an electromagnetic suspension under faulty airgap sensor. The proposed control scheme is a combination of classical control loops, a Kalman Estimator and analytical redundancy (for the airgap signal). In this way redundant airgap sensors are not essential for reliable operation of this system. When the airgap sensor fails the required signal is recovered using a combination of a Kalman estimator and analytical redundancy. The performance of the suspension is optimised using genetic algorithms and some preliminary robustness issues to load and operating airgap variations are discussed. Simulations on a realistic model of such type of suspension illustrate the efficacy of the proposed sensor tolerant control method.

scholarly journals Fault Diagnosis and Fault-Tolerant Control Scheme for Quadcopter UAVs with a Total Loss of Actuator

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1139 ◽  
Author(s):  
Ngoc Nguyen ◽  
Sung Hong
Keyword(s):  
Fault Diagnosis ◽  
Active Fault ◽  
Control Method ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Fault Tolerant Control ◽  
Total Loss ◽  
Actuator Faults ◽  
Control Scheme ◽  
Robust Adaptive

Fault-tolerant control has drawn attention in recent years owning to its reliability and safe flight during missions. In this article, an active fault-tolerant control method is proposed to control a quadcopter in the presence of actuator faults and disturbances. Firstly, the dynamics of the quadcopter are presented. Secondly, a robust adaptive sliding mode Thau observer is presented to estimate the time-varying magnitudes of actuator faults. Thirdly, a fault-tolerant control scheme based on sliding mode control and reconfiguration technique is designed to maintain the quadcopter at the desired position despite the presence of faults. Unlike previous studies, the proposed method aims to integrate the fault diagnosis and a fault-tolerant control scheme into a single unit with total loss of actuator. Simulation results illustrate the efficiency of the suggested algorithm.

scholarly journals An adaptive seamless assist-as-needed control scheme for lower extremity rehabilitation robots

2020 ◽  
pp. 095965182097072
Author(s):  
Xiaodong Zhang ◽  
Gui Yin ◽  
Hanzhe Li ◽  
Runlin Dong ◽  
Huosheng Hu
Keyword(s):  
Lower Extremity ◽  
Control Method ◽  
Sliding Mode ◽  
Rehabilitation Robot ◽  
Robotic Assistance ◽  
Forgetting Factor ◽  
Rehabilitation Robots ◽  
Normal Gait ◽  
Participation Level ◽  
Control Scheme

Most control methods deployed in lower extremity rehabilitation robots cannot automatically adjust to different gait cycle stages and different rehabilitation training modes for different impairment subjects. This article presents a continuous seamless assist-as-needed control method based on sliding mode adaptive control. A forgetting factor is introduced, and a small trajectory deviation from reference normal gait trajectory is used to learn the rehabilitation level of a human subject in real time. The assistance torque needed to complete the reference normal gait trajectory is learned through radial basis function neural networks, so that the rehabilitation robot can adaptively provide the assistance torque according to subject’s needs. The performance and efficiency of this adaptive seamless assist-as-needed control scheme are tested and validated by 12 volunteers on a rehabilitation robot prototype. The results show that the proposed control scheme could adaptively reduce the robotic assistance according to subject’s rehabilitation level, and the robotic assistance torque depends on the forgetting factor and the active participation level of subjects.

Sliding Mode Control of Magnetic Bearing System Based on Variable Rate Reaching Law

2011 ◽  
Vol 460-461 ◽  
pp. 827-830 ◽  
Author(s):  
Jing Feng Mao ◽  
Ai Hua Wu ◽  
Guo Qing Wu ◽  
Xu Dong Zhang
Keyword(s):  
Sliding Mode Control ◽  
Control Method ◽  
Sliding Mode ◽  
Magnetic Bearing ◽  
System Stability ◽  
Control Law ◽  
Variable Rate ◽  
Reaching Law ◽  
Mode Control ◽  
Bearing System

In order to eliminate the chattering phenomena caused by conventional sliding mode control (SMC) method in magnetic bearing system control, this paper proposes a variable rate reaching law approach based sliding mode controller to achieve higher system stability and robustness. In this control law, system states’ normal numbers are brought in to automatic adjust the gain of the switching control part of SMC. The controller output amplitude of chattering can be progressively damped, and the system will converge to zero asymptotically. The system stability is proved by Laypunov theory, and the prerequisite of control law parameters design is deduced out. Simulation results show that the proposed SMC control method has effectiveness in dynamic suspension position tracking performance and obtaining system robustness.

Duffing Chaotic System Stability Control Based on Sliding Mode Control

2012 ◽  
Vol 605-607 ◽  
pp. 1639-1642
Author(s):  
Ding Ma
Keyword(s):  
Chaotic System ◽  
Control Method ◽  
Sliding Mode ◽  
Variable Structure ◽  
Stability Control ◽  
System Stability ◽  
Terminal Sliding Mode ◽  
Sliding Mode Variable Structure ◽  
The Stability ◽  
And Control

Considering the Duffing chaotic system, the problem of stability control based on the terminal sliding mode variable structure is studied. A new terminal sliding mode surface and control law are designed. On this basis, the stability of closed-loop system is analyzed. Simulation results show the effectiveness of the control method.

A new effective nonlinear strategy for lateral stability increment of an articulated vehicle rigid cargo

2021 ◽  
pp. 095440702110090
Author(s):  
Mohammad Amin Saeedi
Keyword(s):  
Dynamic Model ◽  
Feedback Linearization ◽  
Control Method ◽  
Sliding Mode ◽  
Center Of Mass ◽  
Front Axle ◽  
System Stability ◽  
State Variables ◽  
Lateral Velocity ◽  
Articulated Vehicle

In this paper, the effects of the most important parameters on directional dynamics of a tractor-semitrailer vehicle are examined. Initially, a three DOF dynamic model of a tractor-semitrailer vehicle is proposed. Then, the developed model is validated by means of TruckSim software during a standard maneuver. In order to analyze the system stability, the Lyapunov method has been used and the stability conditions have been extracted based on Routh criterion. The most important parameters are selected based on the articulation angle gain. Among the studied parameters, the semitrailer mass, the distance of the tractor unit center of mass and its front axle, and the tires cornering stiffness exhibited more effective behavior on the vehicle’s stability. The simulation results show that as the tractor center of mass moves toward its rear axle, the probability of the jackknifing increases. Moreover, an increment in the semitrailer mass leads to a turn of the semitrailer with respect to the tractor. Also, the understeer specification of the vehicle strengthens due to the tire cornering stiffness increment. Moreover, in order to increase the maneuverability of the articulated vehicle a new active steering controller is proposed using two different control methods. The controller is developed using the simplified dynamic model and the basis of feedback linearization method using dynamic sliding mode control method. In this system, the yaw rate and the lateral velocity of the tractor unit as well as articulation angle are studied as state variables which are targeted to track their desired references. Then, the vehicle dynamic performance is investigated during standard maneuvers. A more investigation shows that the track of the desired values of the vehicle state variables leads to eliminate off-tracking path.

scholarly journals A Theoretical Concept of Decoupled Current Control Scheme for Grid-Connected Inverter with L-C-L Filter

2021 ◽  
Vol 11 (14) ◽  
pp. 6256
Author(s):  
Mohamad Amin Ghasemi ◽  
Seyed Fariborz Zarei ◽  
Saeed Peyghami ◽  
Frede Blaabjerg
Keyword(s):  
Control Method ◽  
Controller Design ◽  
Current Control ◽  
System Stability ◽  
State Equations ◽  
Lcl Filter ◽  
Control Scheme ◽  
Grid Connected Inverter ◽  
The Stability ◽  
Grid Side

This paper proposes a nonlinear decoupled current control scheme for a grid-connected inverter with LCL filter. Decoupling the active and reactive current control channels is one of the main demands in the control of inverters. For inverters with an L filter, the decoupling can be achieved by a proper feed-forward of grid voltages. However, the coupling of channels is a complex issue for converters with LCL filters. The resonance mode of the LCL filter may cause instability, which adds more complexity to the analysis. In this paper, state equations of the system are provided, which highlight the coupling between active and reactive currents injected into the grid. Accordingly, a non-linear control scheme is proposed which effectively decouples the channels and dampens the resonant modes of the LCL filter. The stability of the proposed control method is verified by the Lyapunov criterion. Independency of the system stability to the grid-impedance is another feature of the proposed approach. Moreover, only grid-side currents are needed for implementation of the proposed scheme, avoiding the need for additional current sensors for the output capacitor and grid-side inductor. For accurate modelling of the inverter, the computation and PWM sampling delays are included in the controller design. Finally, various case studies are provided that verify the performance of the proposed approach and the stability of the system.

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