scholarly journals Consistent Total Traction Torque-Oriented Coordinated Control of Multimotors with Input Saturation for Heavy-Haul Locomotives

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Changfan Zhang ◽  
Qian Zhang ◽  
Jing He ◽  
Jianhua Liu ◽  
Xingxing Yang ◽  
...  
Keyword(s):  
Sliding Mode ◽  
Characteristic Curve ◽  
Input Saturation ◽  
Coordinated Control ◽  
Mode Switching ◽  
Control Input ◽  
Saturation Problem ◽  
Parameter Perturbations ◽  
Heavy Haul ◽  
Traction Characteristic

In the coordinated control of multiple motors for heavy-haul locomotives, the input value for a motor often exceeds its maximum allowable input value, resulting in the saturation problem. A traction total-amount coordinated tracking control (TACTC) strategy is proposed to address the input saturation of heavy-haul locomotives driven by multiple motors. This strategy reduces control input and suppresses input saturation. First, a multimotor traction model with uncertain parameter perturbations and external disturbances was established. Next, a sliding-mode disturbance observer (SMDO) was designed to reduce the sliding-mode switching gain, thereby decreasing the control input. An auxiliary anti-windup (AW) system was used to weaken the effect of input saturation on tracking performance. Then, the observed value and auxiliary state were fed back to the sliding-mode controller to design a TACTC protocol and ensure that the total amount of traction torque follows the desired traction characteristic curve. Finally, the Matlab/Simulink simulation and RT-Lab semiphysical experiment results show that the proposed strategy can effectively suppress the input saturation problem of multimotor coordinated control.

Three-dimensional adaptive fixed-time guidance law against maneuvering targets with impact angle constraints and control input saturation

2021 ◽  
pp. 014233122110598
Author(s):  
Fei Ma ◽  
Yunjie Wu ◽  
Siqi Wang ◽  
Xiaofei Yang ◽  
Yueyang Hua
Keyword(s):  
Sliding Mode ◽  
Input Saturation ◽  
Three Dimensional ◽  
Fixed Time ◽  
Impact Angle ◽  
Guidance System ◽  
Control Input ◽  
Guidance Law ◽  
The Stability ◽  
And Control

This paper presents an adaptive fixed-time guidance law for the three-dimensional interception guidance problem with impact angle constraints and control input saturation against a maneuvering target. First, a coupled guidance model formulated by the relative motion equation is established. On this basis, a fixed-time disturbance observer is employed to estimate the lumped disturbances. With the help of this estimation technique, the adaptive fixed-time sliding mode guidance law is designed to accomplish accurate interception. The stability of the closed-loop guidance system is proven by the Lyapunov method. Simulation results of different scenarios are executed to validate the effectiveness and superiority of the proposed guidance law.

scholarly journals Tracking control via sliding mode for heavy-haul trains with input saturation

2020 ◽  
pp. 002029402095245 ◽  
Author(s):  
Jing He ◽  
Xingxing Yang ◽  
Changfan Zhang ◽  
Jianhua Liu ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Tracking Control ◽  
Control Method ◽  
Sliding Mode ◽  
Input Saturation ◽  
Tracking Accuracy ◽  
Uncertain Disturbances ◽  
Heavy Haul ◽  
New Type ◽  
Heavy Haul Trains ◽  
Compensation Signal

To address the tracking control problem of heavy-haul trains (HHTs) with input saturation during operation, an anti-saturation sliding mode (SMES) control method based on dynamic auxiliary compensator (DAC) is presented. Firstly, an HHT model with nonlinear coupling and uncertain disturbances is built. Secondly, a new type of DAC is introduced to overcome the difficulty of traditional dynamic auxiliary compensator (TDAC) with a large upper bound on the compensation signal. Finally, an anti-saturation SMES control algorithm is designed to reduce the influence of input saturation on the tracking accuracy of each carriage. Simulation results verify the effectiveness of the algorithm in terms of tracking accuracy, anti-interference, and anti-saturation.

Adaptive Robust Tracker Design for Nonlinear Sandwich Systems Subject to Saturation Nonlinearities

Robotica ◽  
2020 ◽  
pp. 1-16 ◽  
Author(s):  
Meysam Azhdari ◽  
Tahereh Binazadeh
Keyword(s):  
Sliding Mode ◽  
Input Saturation ◽  
Reference Signal ◽  
Second Phase ◽  
Control Input ◽  
Tracking Problem ◽  
Saturation Nonlinearity ◽  
Saturation Constraint ◽  
Constraint Model ◽  
Sandwich System

SUMMARY This paper addresses the tracking problem for uncertain nonlinear sandwich systems that consist of two nonlinear subsystems and saturation nonlinearity, which is sandwiched between the subsystems. The considered sandwich system is also subject to a nonsymmetric input saturation constraint. Due to the nonsmooth characteristics of sandwiched saturation nonlinearity and also the input saturation function, the design procedure deals with hard challenges. To overcome these difficulties, a recursive approach is suggested that consists of two phases. For the implementation of the proposed approach, a tracking problem is solved in each phase. In the first phase, the second subsystem with sandwiched saturation nonlinearity is considered and the output tracking problem of the desired time-varying reference signal is solved using backstepping method. The outcome of the first phase is the desired reference signal that should be tracked by the first subsystem in the next phase. In the second phase, the robust control input is designed for the first subsystem by employing adaptive sliding mode technique such that, despite the nonsymmetric input saturation constraint, model uncertainty and external disturbances, the output of the first subsystem follows the desired signal that is obtained in the previous phase. The simulation results for a mechanical sandwich system are illustrated to verify the effectiveness of the proposed control method.

A dual-loop robust controller for DC electro-mechanical servo system

2015 ◽  
Vol 06 (03) ◽  
pp. 1550026
Author(s):  
Tianpeng He ◽  
Shu Li ◽  
Xiaodong Liu
Keyword(s):  
Sliding Mode ◽  
Servo System ◽  
Differential Method ◽  
Control Input ◽  
Tracking Accuracy ◽  
Loop Control ◽  
Control Scheme ◽  
Control Schemes ◽  
Parameter Perturbations ◽  
System Robustness

In order to further improve the tracking performances of the conventional disturbance observer (DOB)-based control schemes, a dual-loop robust control scheme is proposed for DC electro-mechanical servo system. The outer-loop sliding mode controller (SMC) is designed in order to deal with the impacts from the remainder equivalent disturbances, which is due to the inadequate estimation of the inner-loop DOB. Meanwhile, the existence of DOB can reduce the switching gain of SMC law, which can suppress the high-frequency chattering of control input to a certain extent. Moreover, an approximate differential method is employed in order to reliably acquire the differential information in a noisy environment. From the experiment results on a DC motor servo system, it is presented that the proposed dual-loop control scheme can effectively improve the tracking performances with respect to higher tracking accuracy and stronger system robustness against external disturbances and parameter perturbations, compared with the traditional DOB+PD control scheme.

Fault-tolerant control of hypersonic vehicles based on fast fault observer under actuator gain loss fault or stuck fault

2020 ◽  
Vol 124 (1278) ◽  
pp. 1190-1207
Author(s):  
P. Zhu ◽  
J. Jiang ◽  
C. Yu
Keyword(s):  
Simulation Experiment ◽  
Fault Tolerant ◽  
Sliding Mode ◽  
Input Saturation ◽  
Fault Tolerant Control ◽  
Fault Estimation ◽  
Hypersonic Vehicles ◽  
Control Input ◽  
Actuator Faults ◽  
Gain Loss

ABSTRACTThis paper proposes a fault-tolerant control (FTC) method based on fast fault observer (FFO) to solve the problem of actuator gain loss fault and stuck fault for hypersonic vehicles. Firstly, an input-output feedback linearisation model is presented that considers parametric uncertainties, control input saturation, disturbances and actuator faults. Secondly, the above factors are defined as an integrated fault item, and an improved fast fault observer is designed to estimate the integrated fault in real time. Finally, the fault-tolerant controller is constructed based on the sliding mode and fault estimation. In case of unknown faults, the effects of gain loss fault or stuck fault happen on elevators and the engine can be quickly processed, Also, the asymptotically stable tracking of the flight output reference command is completed to achieve fault-tolerant control. The final simulation experiment verifies the effectiveness of the proposed method.

scholarly journals Synchronization of a Non-Equilibrium Four-Dimensional Chaotic System Using a Disturbance-Observer-Based Adaptive Terminal Sliding Mode Control Method

Entropy ◽  
2020 ◽  
Vol 22 (3) ◽  
pp. 271 ◽  
Author(s):  
Shaojie Wang ◽  
Amin Yousefpour ◽  
Abdullahi Yusuf ◽  
Hadi Jahanshahi ◽  
Raúl Alcaraz ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Chaotic System ◽  
Disturbance Observer ◽  
Sliding Mode ◽  
Input Saturation ◽  
Control Input ◽  
Terminal Sliding Mode Control ◽  
Terminal Sliding Mode ◽  
Mode Control ◽  
And Control

In this paper, dynamical behavior and synchronization of a non-equilibrium four-dimensional chaotic system are studied. The system only includes one constant term and has hidden attractors. Some dynamical features of the governing system, such as invariance and symmetry, the existence of attractors and dissipativity, chaotic flow with a plane of equilibria, and offset boosting of the chaotic attractor, are stated and discussed and a new disturbance-observer-based adaptive terminal sliding mode control (ATSMC) method with input saturation is proposed for the control and synchronization of the chaotic system. To deal with unexpected noises, an extended Kalman filter (EKF) is implemented along with the designed controller. Through the concept of Lyapunov stability, the proposed control technique guarantees the finite time convergence of the uncertain system in the presence of disturbances and control input limits. Furthermore, to decrease the chattering phenomena, a genetic algorithm is used to optimize the controller parameters. Finally, numerical simulations are presented to demonstrate the performance of the designed control scheme in the presence of noise, disturbances, and control input saturation.

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