Nonlinear DOB-based explicit NMPC for station-keeping of a multi-vectored propeller airship with thrust saturation

2018 ◽  
Vol 122 (1257) ◽  
pp. 1753-1774 ◽  
Author(s):  
Y. Wen ◽  
L. Chen ◽  
Y. Wang ◽  
D. Sun ◽  
D. Duan ◽  
...  
Keyword(s):  
Control Method ◽  
Aerodynamic Force ◽  
Wind Effect ◽  
Station Keeping ◽  
Globally Asymptotically Stable ◽  
Tracking Differentiator ◽  
Propulsion Force ◽  
Predictive Controller ◽  
Dynamics Models ◽  
The Relationship

ABSTRACTA nonlinear station-keeping control method for a multi-vectored propeller airship under unknown wind field with thrust saturation is developed, which is composed of three modules: nonlinear model predictive controller (NMPC), disturbance observer (DOB) and tracking differentiator (TD). The nonlinear kinematics and dynamics models are introduced, and the wind effect is considered by the wind-induced aerodynamic force. Based on both models, an explicit NMPC is designed. Then a nonlinear DOB is introduced to estimate the wind disturbance. A TD, showing the relationship between the maximum propulsion force and the maximum flight acceleration, is proposed to handle the thrusts’ amplitude saturation. Stability analysis shows that the closed-loop system is globally asymptotically stable. Simulations for a multi-vectored propeller airship are conducted to demonstrate the robustness and effectiveness of the proposed method.

Anti-noise model-free adaptive control and its application in the circulating fluidized bed boiler

2020 ◽  
pp. 095965182097937
Author(s):  
Na Dong ◽  
Wenjin Lv ◽  
Shuo Zhu ◽  
Donghui Li
Keyword(s):  
Adaptive Control ◽  
Complete Convergence ◽  
Circulating Fluidized Bed ◽  
Control Method ◽  
Noise Model ◽  
Good Resistance ◽  
Industrial Systems ◽  
Noise Interference ◽  
Model Free ◽  
Tracking Differentiator

Model-free adaptive control has been developed greatly since it was proposed. Up to now, model-free adaptive control theory has become mature and tends to be an effective solution for complex unmodeled industrial systems. In practical industrial processes, most control systems are inevitably accompanied by noise that will result in indelible error and may further cause inaccurate feedback to the output. In order to solve this kind of problem with model-free technique, this article incorporates an improved tracking differentiator into model-free adaptive control. After that, the anti-noise model-free adaptive control method with complete convergence analysis is proposed. Meanwhile, numerical simulation proves that the improved control method can quickly track a given signal with good resistance to noise interference. Finally, the effectiveness and practicability of the proposed algorithm are verified by experiments through the control of drum water level of circulating fluidized.

Multimode Adaptive Control for Tank Gun Control System Based on Tracking Differentiator

2011 ◽  
Vol 383-390 ◽  
pp. 79-85
Author(s):  
Dong Yuan ◽  
Xiao Jun Ma ◽  
Wei Wei
Keyword(s):  
Adaptive Control ◽  
Control System ◽  
High Speed ◽  
Control Method ◽  
Reference Model ◽  
Gun Control ◽  
Math Model ◽  
Tracking Differentiator ◽  
Switch Control ◽  
Model Reference Adaptive

Aiming at the problems such as switch impulsion, insurmountability for influence caused by nonlinearity in one tank gun control system which adopts double PID controller to realize the multimode switch control between high speed and low speed movement, the system math model is built up; And then, Model Reference Adaptive Control (MRAC) method based on nonroutine reference model is brought in and the adaptive gun controller is designed. Consequently, the compensation of nonlinearity and multimode control are implemented. Furthermore, the Tracking Differentiator (TD) is affiliated to the front of controller in order to restrain the impulsion caused by mode switch. Finally, the validity of control method in this paper is verified by simulation.

Synchronous Control Characteristics Analysis of Shield Propulsion Hydraulic System Based on Tracking Differentiator and Self-Adaptive Nonlinear PID

2021 ◽  
Author(s):  
Sen Li ◽  
XiaoHua Cao
Keyword(s):  
Pid Control ◽  
Hydraulic System ◽  
Control Method ◽  
Hydraulic Systems ◽  
Fuzzy Pid Control ◽  
Synchronous Control ◽  
Tracking Differentiator ◽  
Characteristics Analysis ◽  
Servo Tracking ◽  
Self Adaptive

Aiming at the low precision problem of multi-cylinder cooperative propulsion control in different regions of shield propulsion hydraulic systems under conditions of large load changes, this paper proposes a tracking differentiator and self-adaptive nonlinear PID (TD-NPID) control method to improve the synchronous control characteristics of shield propulsion hydraulic systems. First, the working principles of shield propulsion hydraulic systems were analyzed, and a mathematical model and TD-NPID controller were developed. Then, a simulation model was developed in AMESim-MATLAB environment, and the synchronous dynamic performances of fuzzy PID control, conventional PID control, and TD-NPID control were compared and analyzed. The results demonstrated that the shield propulsion hydraulic system with TD-NPID control had better servo tracking ability and steady-state performance than the systems with fuzzy or conventional PID control, which verified the feasibility of the application of TD-NPID control for the synchronous control of shield propulsion hydraulic systems.

scholarly journals Active Disturbance Rejection Station-Keeping Control of Unstable Orbits around Collinear Libration Points

2014 ◽  
Vol 2014 ◽  
pp. 1-14 ◽  
Author(s):  
Min Zhu ◽  
Hamid Reza Karimi ◽  
Hui Zhang ◽  
Qing Gao ◽  
Yong Wang
Keyword(s):  
Disturbance Rejection ◽  
External Disturbance ◽  
State Observer ◽  
Libration Points ◽  
Extended State Observer ◽  
Unstable Periodic Orbits ◽  
Extended State ◽  
Station Keeping ◽  
Tracking Differentiator ◽  
Active Disturbance Rejection

An active disturbance rejection station-keeping control scheme is derived and analyzed for station-keeping missions of spacecraft along a class of unstable periodic orbits near collinear libration points of the Sun-Earth system. It is an error driven, rather than model-based control law, essentially accounting for the independence of model accuracy and linearization. An extended state observer is designed to estimate the states in real time by setting an extended state, that is, the sum of unmodeled dynamic and external disturbance. This total disturbance is compensated by a nonlinear state error feedback controller based on the extended state observer. A nonlinear tracking differentiator is designed to obtain the velocity of the spacecraft since only position signals are available. In addition, the system contradiction between rapid response and overshoot can be effectively solved via arranging the transient process in tracking differentiator. Simulation results illustrate that the proposed method is adequate for station-keeping of unstable Halo orbits in the presence of system uncertainties, initial injection errors, solar radiation pressure, and perturbations of the eccentric nature of the Earth's orbit. It is also shown that the closed-loop control system performance is improved significantly using our method comparing with the general LQR method.

scholarly journals Nonlinear Compound Control for Nonsinusoidal Vibration of the Mold Driven by Servo Motor with Variable Speed

2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Qiang Li ◽  
Yi-ming Fang ◽  
Jian-xiong Li ◽  
Zhuang Ma
Keyword(s):  
Control Method ◽  
Controller Design ◽  
Rotation Speed ◽  
Pi Control ◽  
Variable Speed ◽  
Servo Motor ◽  
Motor Speed ◽  
Vector Method ◽  
Compound Control ◽  
The Relationship

In this paper, a fuzzy PI control method based on nonlinear feedforward compensation is proposed for the nonsinusoidal vibration system of mold driven by servo motor, rotated in single direction with variable speed. During controller design, there are mainly two issues to consider: (i) nonlinear relationship (approximate periodic function) between mold displacement and servo motor speed and (ii) uncertainties caused by backlash due to motor variable speed. So, firstly, the relationship between mold displacement and motor rotation speed is built directly based on the rotation vector method. Then, an observer is designed to estimate the uncertainties and feedforward compensation. Secondly, as the motor rotates in single direction with variable speed, a fuzzy control with bidirectional parameter adjustment is adopted to improve rapidity and stability based on the traditional PI method. Finally, some simulation results show the effectiveness of the proposed control method.

scholarly journals Deformation Control Method of the Antislide Pile under Trapezoidal Load in the Zhangjiawan Landslide

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Hao Wang ◽  
Zhiying Lv ◽  
Hongyu Qin ◽  
Jianwei Yue ◽  
Jianwei Zhang
Keyword(s):  
Driving Force ◽  
Shear Force ◽  
Control Method ◽  
Slip Surface ◽  
Quadratic Function ◽  
Bending Moment ◽  
Site Investigation ◽  
Horizontal Displacement ◽  
Pile Head ◽  
The Relationship

Antislide piles are set in the Zhangjiawan landslide area, where the general features of the bedrock below the slip surface include upper weak and lower hard strata. Based on a site investigation, the horizontal displacement of the antislide pile head is 14.8 cm, which is not conducive to the stability of the landslide. In the study, a displacement calculation method for the pile under trapezoidal load is proposed for a colluvial landslide controlling. Furthermore, factors affecting the deformation and internal forces of the pile were also studied. The results indicated that (1) when the embedded length of an antislide pile increases, the horizontal displacement on the pile and maximum absolute shear force decrease, while the bending moment of the pile exhibits opposite trends; (2) the relationship between maximum shear force and maximum bending moment is linear with increasing driving force of landslide; and (3) increase in the ratio of the driving force between the pile head and slip surface (q0/q1) steadily increases the horizontal displacement of the pile. The relationship between the distribution of the driving force (q0/q1) and the reasonable embedded length of a pile is a quadratic function, which can be used to determine the reasonable embedded length of a pile under the action of rectangular or triangular loads. It is very useful to use the above method to guide the design of antislide piles in similar areas.

Endogenous Growth Model for China's Green IT Based on Green Technology and Green Society

2012 ◽  
Vol 190-191 ◽  
pp. 83-87
Author(s):  
Feng Tao Liu
Keyword(s):  
Endogenous Growth ◽  
Growth Model ◽  
Control Method ◽  
Green Technology ◽  
Social Risk ◽  
Investment Efficiency ◽  
Green It ◽  
Transversality Conditions ◽  
Endogenous Growth Model ◽  
The Relationship

China's green IT development is faced with the unique “IT social risk”. Therefore, the endogenesis of China's green IT development has been challenged. Using the concept of “society greening”, we divide a green IT system into a technology greening sub-system and a society greening sub-system, based on which an endogenous growth model was built. Using an optimal control method to solve the model, we find the long-term equilibrium rate of economic growth, transversality conditions, the relationship between the output flexibilities of the input factors in the two sub-systems, the relationship among the elasticity coefficients of intertemporal substitution in consumption, as well as the optimal conditions for the whole system. The results show that to allow China's green IT to develop, the output elasticity of the society greening sub-system knowledge must be higher than that of the technology greening sub-system. This urgently requires government incentives and other public products to balance the investment efficiency in the two sub-systems.

Nonlinear and Machine-Learning-Based Station-Keeping Control of an Unmanned Surface Vehicle

2020 ◽  
Author(s):  
Armando J. Sinisterra ◽  
Alexandrea Barker ◽  
Siddhartha Verma ◽  
Manhar R. Dhanak
Keyword(s):  
Machine Learning ◽  
Tracking Control ◽  
Situational Awareness ◽  
Control Method ◽  
Sliding Mode ◽  
Control Technique ◽  
Station Keeping ◽  
Trajectory Tracking Control ◽  
Ongoing Work ◽  
Machine Learning Approach

Abstract This study is part of ongoing work on situational awareness and autonomy of a 16’ WAM-V USV. The objective of this work is to determine the potential and merits of application of two different station-keeping controllers for a fixed-pose motion control of the USV. The assessment includes performance and power consumption metrics tested under harsh environmental disturbances to evaluate the robustness of the control methods. The first is a nonlinear trajectory-tracking control method based on the sliding-mode control technique, while the second method uses a machine-learning approach based on Deep Reinforcement Learning. Results from both the approaches are compared for various case studies.

Numerical simulation and experiment investigation on passive-suction-jet control of wind effect of two tandem cable models

2020 ◽  
pp. 136943322097179
Author(s):  
Wen-Li Chen ◽  
Yan-Jiao Guo ◽  
Xiang-Wei Min ◽  
Hui Li
Keyword(s):  
Numerical Simulation ◽  
Control Method ◽  
Suspension Bridge ◽  
Flow Fields ◽  
Flow Patterns ◽  
Wind Effect ◽  
Long Span ◽  
Spacing Ratio ◽  
Vibration Responses ◽  
Jet Control

Two tandem cables are frequently employed as one group of hangers in a long-span suspension bridge; however, if they are close to each other, the mutual interaction between their flow fields is prone to produce large wind/wake-induced vibrations. In the present study, initially, a numerical simulation was conducted to investigate the interaction between two static tandem cable models with different spacing ratios, SR (center-to-center longitudinal spacing divided by the cable diameter, i.e. L/D). Concurrently, the passive-suction-jet control method was employed to eliminate the interaction of these two tandem cables. Aerodynamic coefficients and time-averaged and instantaneous flow fields were used to evaluate the effectiveness of the passive-suction-jet control. Subsequently, the passive-suction-jet control method was employed in a wind tunnel experiment to manipulate the wind-induced vibrations of two elastically mounted cable models. The flow patterns of the controlled tandem cables were subdivided into three basic regimes in the present study. Furthermore, the aerodynamics force suppression mechanism was explained based on the flow patterns. Both the aerodynamic forces and vibration responses of the tandem cable models reduced significantly when SR >  SRc (critical spacing ratio). Particularly for SR = 4.0, the lift fluctuation reduction of both the cable models was remarkable, the fluctuating lifts of the upstream and downstream cable models decreased by 93.3% and 72.1%, respectively, and the vortex-induced vibration responses decreased by 31.4% and 54.0% respectively. Furthermore, the wake-induced vibration responses of the tandem cable models could be completely suppressed when both were controlled using passive-suction-jet pipes.

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