scholarly journals Adaptive Barrier Control for Nonlinear Servomechanisms with Friction Compensation

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Shubo Wang ◽  
Haisheng Yu ◽  
Xuehui Gao ◽  
Na Wang
Keyword(s):  
Control Method ◽  
Design Procedure ◽  
Lyapunov Stability Theory ◽  
Friction Compensation ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Full State ◽  
Loop Control System ◽  
The Stability ◽  
The Given

This paper proposes an adaptive barrier controller for servomechanisms with friction compensation. A modified LuGre model is used to capture friction dynamics of servomechanisms. This model is incorporated into an augmented neural network (NN) to account for the unknown nonlinearities. Moreover, a barrier Lyapunov function (BLF) is utilized to each step in a backstepping design procedure. Then, a novel adaptive control method is well suggested to ensure that the full-state constraints are within the given boundary. The stability of the closed-loop control system is proved using Lyapunov stability theory. Comparative experiments on a turntable servomechanism confirm the effectiveness of the devised control method.

Research on INS-Aided GNSS Carrier Tracking Loop in High Dynamic Circumstance

2013 ◽  
Vol 464 ◽  
pp. 215-221
Author(s):  
Xin Long Wang ◽  
Chuan Jun Li ◽  
Xing Cheng Li
Keyword(s):  
Dynamic Environment ◽  
Coupled System ◽  
Tracking Performance ◽  
Tracking Loop ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Tightly Coupled ◽  
High Dynamic ◽  
The Stability

GNSS receiver will produce a large Doppler shift in high dynamic environment, thus causing lock-lose of the tracking loop. INS-aided GNSS tightly coupled system can improve tracking performance in high dynamic environment by introducing the Doppler information estimated by INS. Through analyzing by the theory of closed loop control system theory and numerical simulation of the INS-aided carrier tracking loop, the results show that INS-aided carrier tracking loop can obviously improve the stability of carrier tracking performance and anti-jamming ability of the satellite navigation receiver in high dynamic circumstance.

The Fuzzy Rule Based the BDFM Torque Control

2012 ◽  
Vol 203 ◽  
pp. 226-230
Author(s):  
Peng Chen ◽  
Jian Yang Zhai ◽  
Zheng Zhu
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Direct Torque Control ◽  
Fuzzy Rule ◽  
Torque Control ◽  
Closed Loop Control ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Doubly Fed

Combining with some fuzzy of the direct torque control and the fuzzy control which is often used in the traditional AC motor control,we put forward a direct torque control theory based on the fuzzy rule. The brushless doubly-fed machine(BDFM) closed-loop control system with the direct torque control based on the fuzzy rule is simulated by using of the Matlab/Simulink software, and the simulation results show that the closed-loop control method is correct and effective.

scholarly journals Research on Discretization PI Control Technology of Single-Phase Grid-Connected Inverter with LCL Filter

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Jianke Li ◽  
Jinquan Wang ◽  
Ye Xu ◽  
Jianting Li ◽  
Jingjing Chen ◽  
...  
Keyword(s):  
Dynamic Performance ◽  
Numerical Algorithms ◽  
Switching Frequency ◽  
Lcl Filter ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Grid Connected Inverter ◽  
The Stability ◽  
The Cost

Compared with L-type filter, LCL-type filter is more suitable for high-power low-switching frequency applications with reducing the inductance, improving dynamic performance. However, the parameter design for the LCL filter is more complex due to the influence of the controller response performance of the converter. If the harmonic current around switching frequency can be fully suppressed, it is possible for inverter to decrease the total inductance as well as the size and the cost. In this paper, the model of the LCL filter is analyzed and numerical algorithms are adopted to analyze the stability of the closed-loop control system and stable regions are deduced with different parameters of LCL filter. Then, the minimum sampling frequencies are deduced with different conditions. Simulation and experimental results are provided to validate the research on the generating mechanism for the unstable region of sampling frequency.

scholarly journals Perturbation Observer-Based Robust Control Using a Multiple Sliding Surfaces for Nonlinear Systems with Influences of Matched and Unmatched Uncertainties

Mathematics ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1371 ◽  
Author(s):  
Ha Le Nhu Ngoc Thanh ◽  
Mai The Vu ◽  
Nguyen Xuan Mung ◽  
Ngoc Phi Nguyen ◽  
Nguyen Thanh Phuong
Keyword(s):  
Robust Control ◽  
Control Method ◽  
Lyapunov Theory ◽  
Loop Control ◽  
Single Input Single Output ◽  
Single Output ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Unmatched Uncertainties ◽  
Matched And Unmatched Uncertainties

This paper presents a lumped perturbation observer-based robust control method using an extended multiple sliding surface for a system with matched and unmatched uncertainties. The fundamental methodology is to apply the multiple surfaces to approximate the unknown lumped perturbations simultaneously influencing on a nonlinear single input–single output (SISO) system. Subsequently, a robust controller, based on the proposed multi-surface and the approximated values, is designed to highly improve the control performance of the system. A general stability of the lumped perturbation observer and closed-loop control system is obtained through the Lyapunov theory. Results of a numerical simulation of an illustrative example demonstrate the soundness of the proposed algorithm.

The Direct Torque Control Research of Permanent Magnet Linear Synchronous Motor

2011 ◽  
Vol 143-144 ◽  
pp. 350-354
Author(s):  
Jun Zhu ◽  
Xu Dong Wang ◽  
Bao Yu Xu ◽  
Hai Chao Feng
Keyword(s):  
Simulation Experiment ◽  
Control Method ◽  
Dynamic Performance ◽  
Direct Torque Control ◽  
Torque Control ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Hysteresis Controller ◽  
Control Research ◽  
Loop Control System

In order to improve the dynamic servo performance of PMLSM, a classical direct torque control (DTC) scheme based on bang-bang control is proposed in the paper. The proposed control method uses the bang-bang hysteresis controller formed a dual-closed loop control system, it contains torque loop and flux loop. The DTC control model was established and the simulation experiment was made. The simulation experiment results show that the DTC can improve the dynamic performance of PMLSM. It can reduce the ripples of speed and torque, so that it can provide more precision and accuracy servo performance.

The role of walking surface in enhancing the stability of the simplest passive dynamic biped

Robotica ◽  
2014 ◽  
Vol 33 (1) ◽  
pp. 195-207 ◽  
Author(s):  
Ali Tehrani Safa ◽  
Mahyar Naraghi
Keyword(s):  
Gait Stability ◽  
Loop Control ◽  
Contact Points ◽  
Closed Loop Control System ◽  
Bipedal Gait ◽  
Loop Control System ◽  
The Stability ◽  
Straight Lines ◽  
Inclined Surface

SUMMARYEmploying passive dynamics of the simplest point-foot walker, we have shown that the walking surface could have a great role in promoting the gait stability. In this regard, the stabilization of the simplest walking model,3 between the range of slopes greater than 0.0151 rad. and less than 0.26 rad., has been achieved. The walker like other passive dynamic walking models has no open or closed-loop control system; so, is only actuated by the gravity field. Moreover, no damper or spring is used. Obviously, according to the model's unstable behavior, it is unable to walk on an even flat ramp between the mentioned intervals.3 Here, instead of restraining the model, we let it explore other smooth surfaces, walking on which, will end in an equally inclined surface. To reach the objective, we employ a parallel series of fixed straight lines (local slopes) passing through contact points of an unstable cycling gait, which is generated by an ordinary ramp. To categorize, we have nicknamed those local slopes that guide the biped to a stable cyclic walking, “Ground Attractors,” and the other, leading it to a fall, “Repulsive Directions.” Our results reveal that for the slope <0.26 rad., a closed interval of ground attractors could be found. Stabilization of those unstable limit cycles by this technique makes obvious the key role of walking surface on bipedal gait. Furthermore, following our previous work,13 the results confirm that the two thoroughly similar walking trajectories can have different stability. All of these results strongly demonstrate that without considering the effects of a walking surface, we cannot establish any explicit relationship between the walker's speed and its stability.

Application of Back-to-Back Circuit in the Intelligent Wheelchair Charging Technology

2014 ◽  
Vol 631-632 ◽  
pp. 654-659
Author(s):  
Li Wang ◽  
Rong Yang ◽  
Xiu Feng Zhang ◽  
Yan Ma
Keyword(s):  
Design Method ◽  
Voltage Source ◽  
Super Capacitor ◽  
Loop Control ◽  
Intelligent Wheelchair ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Pwm Rectifiers ◽  
Bus Voltage ◽  
The Stability

Intelligent wheelchair charging technology put forward a very high request to the stability of the DC bus voltage. This paper describes the three phase principles and topology with Back-to-Back, SVPWM is used to the voltage-source PWM rectifiers, the principle of voltage and current double closed loop control system design the system. According to the principle of super-capacitor store energy for the load and construct their simulation model with SIMULINK. Simulation results demonstrate the feasibility of the above design method.

A Novel Nonlinear and Adaptive Control of Grid Connected Inverters

2016 ◽  
Vol 25 (11) ◽  
pp. 1650132 ◽  
Author(s):  
Murat Karabacak
Keyword(s):  
Control System ◽  
High Performance ◽  
Closed Loop ◽  
External Disturbance ◽  
Lyapunov Stability Theory ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Dc Bus ◽  
Bus Voltage

In this study, a new nonlinear and adaptive state feedback controller is proposed for the control of grid connected inverters (GCIs). All the other parameters apart from direct current (DC) bus capacitor are considered uncertain in the design of proposed controller, without disadvantages of singularity and over-parametrization. Three-phase source currents, DC bus voltage and load current are supposed to be available for feedback in the closed loop control system. In this respect, the whole control loop, consisting of DC bus voltage and [Formula: see text]–[Formula: see text] axis current loops, is closed. It is important to highlight that closed loop DC voltage control cannot be achieved by most of nonlinear controllers proposed in literature. In the sense of Lyapunov stability theory, overall control system has the global asymptotic stability. Experimental results demonstrate that the proposed controller guarantees to asymptotically drive tracking errors to zero despite all parameter and external disturbance uncertainties. Results also verify that the proposed controller shows high performance and feasibility.

scholarly journals Adaptive neural back-stepping control of flexible air-breathing hypersonic vehicles with parametric uncertainties

2018 ◽  
Vol 10 (6) ◽  
pp. 168781401878284
Author(s):  
Xiangwei Bu ◽  
Humin Lei ◽  
Guangjun He ◽  
Yupeng Gao ◽  
Yan Zhao
Keyword(s):  
Neural Network ◽  
Control System ◽  
Lyapunov Stability Theory ◽  
Weight Vector ◽  
Neural Network Approach ◽  
Air Breathing ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Back Stepping Control

Control system is significant for making flight safety. In this study, a novel adaptive neural back-stepping controller is exploited for the longitudinal dynamics of a flexible air-breathing hypersonic vehicle. A combined neural network approach and back-stepping scheme is utilized for developing an output-feedback controller that provides robust tracking of the velocity and altitude commands. For each subsystem, only one neural network is employed to approximate the lumped system uncertainty by updating its weight vector adaptively while the problem of possible control singularity is eliminated. The uniformly ultimately boundedness is guaranteed for the closed-loop control system by means of Lyapunov stability theory. The main contribution is that the design complexity is reduced and less neural networks are required. Finally, simulation results illustrate that the proposed control strategy achieves satisfying tracking performance in spite of flexible effects and system uncertainties.

Aspects of the Energy Consumption of a Digital Hydraulic Power Management System Supplying a Digital and Proportional Valve Controlled Multi Actuator System

2014 ◽  
Author(s):  
Matti Karvonen ◽  
Mikko Heikkilä ◽  
Seppo Tikkanen ◽  
Matti Linjama ◽  
Kalevi Huhtala
Keyword(s):  
Energy Consumption ◽  
Power Management ◽  
Management System ◽  
Control Method ◽  
Inverse Kinematic ◽  
Hydraulic Power ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Power Management System

Hydraulic motion control is traditionally done with servo or proportional valves. A digital hydraulic valve is based on arrays of simple on/off valves. Independent metering control is possible with digital valves since control notches are not linked together. With commonly used commercial proportional valves constant opening ratios are used. In this paper, a small mobile boom is studied. The lift and tilt cylinders can be controlled with proportional or digital valves. Closed loop control system is based on a robust control method of a multi actuator boom and also inverse kinematic equations are required in coordinate drive. The supply system consists of a Digital Hydraulic Power Management System (DHPMS) which is capable of supplying separate supply pressures for both actuator supply lines. Measurements are done, and one vs. two supply pressures and digital vs. proportional valves are compared. Two different test trajectories and two different load masses are used. Analysis focuses on the energy consumption of different test cases and sources of losses are inspected. Results show that energy consumption can be reduced up to 44%.

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