A Robust Digital-Analog Control Strategy for Ensuring Rapid Response and Zero Tracking Error

1982 ◽  
Vol 15 (1) ◽  
pp. 215-222
Author(s):  
R. Doraiswami ◽  
C.A. Livramento
Keyword(s):  
Control Strategy ◽  
Tracking Error ◽  
Rapid Response ◽  
Analog Control

Adaptive sliding tracking control for nonlinear uncertain robotic systems with unknown actuator nonlinearities

Robotica ◽  
2021 ◽  
pp. 1-20
Author(s):  
Shubo Liu ◽  
Guoquan Liu ◽  
Shengbiao Wu
Keyword(s):  
Control Problem ◽  
Prior Knowledge ◽  
Control Strategy ◽  
Tracking Control ◽  
Disturbance Observer ◽  
Tracking Error ◽  
Small Neighborhood ◽  
Robotic Systems ◽  
Actuator Nonlinearities ◽  
Simulation Results

Abstract This study is concerned with the tracking control problem for nonlinear uncertain robotic systems in the presence of unknown actuator nonlinearities. A novel adaptive sliding controller is designed based on a robust disturbance observer without any prior knowledge of actuator nonlinearities and system dynamics. The proposed control strategy can guarantee that the tracking error eventually converges to an arbitrarily small neighborhood of zero. Simulation results are included to demonstrate the effectiveness and superiority of the proposed strategy.

scholarly journals Zero Average Dynamic Controller for Speed Control of DC Motor

2021 ◽  
Vol 11 (12) ◽  
pp. 5608
Author(s):  
Fredy E. Hoyos ◽  
John E. Candelo-Becerra ◽  
Alejandro Rincón
Keyword(s):  
Direct Current ◽  
Control Strategy ◽  
Power Supply ◽  
Tracking Error ◽  
Reference Signal ◽  
Dc Motor ◽  
Buck Converter ◽  
Speed Tracking ◽  
Direct Current Motor ◽  
Simulation Results

This paper presents the use of the buck converter with Zero Average Dynamics to control the speed of a permanent magnet direct current motor. For this objective, we consider a fourth-order nonlinear model that describes the system’s dynamics and tests different scenarios to determine how the direct current motor responds. The results show a robust speed tracking performance of the direct current motor under the reference signal and controller parameter changes and disturbances in the load torque. A non-saturated duty cycle with fixed commutation frequency is obtained in the power supply of the DC motor, and a low steady-state value of the speed tracking error is achieved in both experimental and simulation results. In summary, the effectiveness of the Zero Average Dynamics control strategy for high order systems was experimentally proved.

scholarly journals Iterative Learning Control of a Nonlinear Aeroelastic System despite Gust Load

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Xing-zhi Xu ◽  
Ya-kui Gao ◽  
Wei-guo Zhang
Keyword(s):  
Control Strategy ◽  
Iterative Learning Control ◽  
Tracking Error ◽  
Learning Control ◽  
Iterative Learning ◽  
Control Surface ◽  
Stream Velocity ◽  
Control Input ◽  
Parameter Uncertainties ◽  
Composite Energy

The development of a control strategy appropriate for the suppression of aeroelastic vibration of a two-dimensional nonlinear wing section based on iterative learning control (ILC) theory is described. Structural stiffness in pitch degree of freedom is represented by nonlinear polynomials. The uncontrolled aeroelastic model exhibits limit cycle oscillations beyond a critical value of the free-stream velocity. Using a single trailing-edge control surface as the control input, a ILC law under alignment condition is developed to ensure convergence of state tracking error. A novel Barrier Lyapunov Function (BLF) is incorporated in the proposed Barrier Composite Energy Function (BCEF) approach. Numerical simulation results clearly demonstrate the effectiveness of the control strategy toward suppressing aeroelastic vibration in the presence of parameter uncertainties and triangular, sinusoidal, and graded gust loads.

Satellite formation keeping using differential lift and drag under J2 perturbation

2017 ◽  
Vol 89 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Xiaowei Shao ◽  
Mingxuan Song ◽  
Jihe Wang ◽  
Dexin Zhang ◽  
Junli Chen
Keyword(s):  
Control Strategy ◽  
Tracking Error ◽  
Flat Plates ◽  
Satellite Formation ◽  
Content Type ◽  
Small Satellites ◽  
J2 Perturbation ◽  
Simulation Results ◽  
Lift And Drag ◽  
Formation Keeping

Purpose The purpose of this paper is to present a method to achieve small satellite formation keeping operations by using the differential lift and drag to control the drift caused by J2 perturbation in circular or near-circular low earth orbits (LEOs). Design/methodology/approach Each spacecraft is equipped with five large flat plates, which can be controlled to generate differential accelerations. The aerodynamic lift and drag acting on a flat plate is calculated by the kinetic theory. To maintain the formation within tracking error bounds in the presence of J2 perturbation, a nonlinear Lyapunov-based feedback control law is designed. Findings Simulation results demonstrate that the proposed method is efficient for the satellite formation keeping and better accuracy advantage in comparison with classical approaches via the fixed maximum differential aerodynamic acceleration. Research limitations/implications Because the aerodynamic force will reduce drastically as the orbital altitude increases, the formation keeping control strategy for small satellites presented in this paper should be limited to the scenarios when satellites are in LEO. Practical implications The formation keeping control method in this paper can be applied to solve satellite formation keeping problem for small satellites in LEO. Originality/value This paper proposes a Lyapunov control strategy for satellite formation keeping considering both lift and drag forces, and simulation results show better performance with high accuracy under J2 perturbation.

scholarly journals Parallel Structure of Feedback Linearization and Sliding Mode Controllers to Track the Desired Velocity Profile in High-Speed Trains

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Iman Ferestade ◽  
Habibollah Molatefi ◽  
Bijan Moaveni
Keyword(s):  
Analytical Solution ◽  
Velocity Profile ◽  
Control Strategy ◽  
Feedback Linearization ◽  
High Speed ◽  
Sliding Mode ◽  
Tracking Error ◽  
Parallel Structure ◽  
Railway Vehicles ◽  
Sliding Mode Controllers

High-speed railway vehicles operate much faster than traditional railway vehicles. After a four-axle high-speed railcar is modeled, an analytical solution is employed in this paper to solve dynamic equations. According to this analytical solution, the coupling of four-axle high-speed railcar equations depends strictly on the adhesion coefficient. A novel parallel control strategy is then formulated to prevent wheels from slipping and track the desired velocity profile. The proposed control strategy includes feedback linearization and sliding mode controllers to achieve the desired performance. Finally, the simulation results indicated the effectiveness of the proposed control system in the high-speed railcar such that the tracking error is less than 12%.

scholarly journals Research on UDE control based on load torque compensation of PMSM

2021 ◽  
Vol 2137 (1) ◽  
pp. 012024
Author(s):  
Hongliang Yan ◽  
Weizhi Zhai ◽  
Yan Geng
Keyword(s):  
Control Strategy ◽  
Permanent Magnet Synchronous Motor ◽  
Tracking Error ◽  
Frequency Component ◽  
High Frequency Component ◽  
Load Torque ◽  
Reduced Order ◽  
System A ◽  
Reduced Order Observer ◽  
Disturbance Estimator

Abstract In order to solve the problem that the traditional uncertainty and disturbance estimator (UDE) control needs to increase the filter order to keep good performance when facing rapid disturbance changes, thus lead to cost increase in implementing the system, a speed control strategy of permanent magnet synchronous motor (PMSM) driver based on reduced order observer compensation is proposed. The designed control strategy is robust to the system with internal parameter variation and external torque disturbance. Through the compensation of load torque, the pressure of UDE controller is relieved, and then the tracking error of high-frequency component in load torque is eliminated, and the control performance of the system is improved more effectively. This paper proves the superiority of the new compound controller through comparison of simulation. results

Performance comparison of electric-vehicle drivetrain architectures from a vehicle dynamics perspective

2019 ◽  
Vol 234 (4) ◽  
pp. 915-935
Author(s):  
Kerem Bayar
Keyword(s):  
Electric Vehicle ◽  
Control Strategy ◽  
Vehicle Dynamics ◽  
Tracking Control ◽  
Tracking Error ◽  
Vehicle Stability ◽  
Electric Motors ◽  
Sideslip Angle ◽  
Stopping Distance ◽  
Braking System

Recent electric vehicle studies in literature utilize electric motors within an anti-lock braking system, traction-control system, and/or vehicle-stability controller scheme. Electric motors are used as hub motors, on-board motors, or axle motors prior to the differential. This has led to the need for comparing these different drivetrain architectures with each other from a vehicle dynamics standpoint. With this background in place, using MATLAB simulations, these three drivetrain architectures are compared with each other in this study. In anti-lock braking system and vehicle-stability controller simulations, different control approaches are utilized to blend the electric motor torque with hydraulic brake torque; motor ABS, torque decomposition, and optimal slip-tracking control strategies. The results for the anti-lock braking system simulations can be summarized as follows: (1) Motor ABS strategy improves the stopping distance compared to the standard anti-lock braking system. (2) In case the motors are not solely capable of providing the required braking torque, torque decomposition strategy becomes a good solution. (3) Optimal slip-tracking control strategy improves the stopping distance remarkably compared to the standard anti-lock braking system, motor anti-lock braking system, and torque decomposition strategies for all architectures. The vehicle-stability controller simulation results can be summarized as follows: (1) higher affective wheel inertia of the on-board and hub motor architecture dictates a higher need of wheel torque in order to generate the tire force required for the desired yaw rate tracking. A higher level of torque causes a higher level of tire slip. (2) Optimal slip-tracking control strategy reduces the tire slip trends drastically and distributes the traction/braking action to each tire with the control-allocation algorithm specifying the reference slip values. This reduces reference tire slip-tracking error and reduces vehicle sideslip angle. (3) Tire slip trends are lower with the hub motor architecture, compared to the other architectures, due to more precise slip control.

Heliostat Attitude Control Strategy in the Solar Energy Research Facility of Valparaiso University

2019 ◽  
Vol 141 (5) ◽  
Author(s):  
Shahin S. Nudehi ◽  
G. Scott Duncan ◽  
Luke J. Venstrom
Keyword(s):  
Solar Energy ◽  
Control Strategy ◽  
Attitude Control ◽  
Tracking Error ◽  
Feedback Gain ◽  
Research Facility ◽  
Energy Research ◽  
Nonlinear Dynamic Model ◽  
Concentrated Solar Energy ◽  
Tracking Strategy

In this paper, a continuous tracking strategy for the heliostat in the James S. Markiewicz Concentrated Solar Energy Research Facility at Valparaiso University is developed. A model of the nonlinear dynamics of the heliostat motion is developed and the open-loop control strategy is presented. Asymptotic stability of the heliostat control using the Lyapunov and LaSalle’s theorems was proven. Simulations using the nonlinear dynamic model are presented and interpreted to identify the feedback gain that maximizes the time response of the heliostat without introducing oscillations in its motion. Finally, the control strategy is put to the test during summertime operation. The data presented show that the tracking strategy has an root mean square (RMS) tracking error of 0.058 mrad, where the error is defined as the difference between the desired and actual heliostat positions. Images of the aperture of a high-temperature solar receiver over 8 h of testing are also presented to qualitatively demonstrate the success of the tracking strategy.

scholarly journals Adaptive variable structure control of input delay non-minimum phase hypersonic flight vehicles

2017 ◽  
Vol 14 (1) ◽  
pp. 172988141668561
Author(s):  
Dedong Huang ◽  
Xiaoxiang Hu ◽  
Xunliang Yan
Keyword(s):  
Control Strategy ◽  
Tracking Error ◽  
Variable Structure Control ◽  
Variable Structure ◽  
Input Delay ◽  
Structure Control ◽  
Hypersonic Flight ◽  
Flight Vehicles ◽  
Output Tracking Control ◽  
Tracking Model

An adaptive variable structure control strategy is proposed for the output tracking control of input delay non-minimum hypersonic flight vehicles. The problem is challenging because of the complex nonlinearity of hypersonic flight vehicles and the existence of input delay. The nonlinear model of hypersonic flight vehicles is partially linearized, and a state tracking model is constructed based on the ideal internal dynamics of hypersonic flight vehicles. A filtered tracking error is introduced to handle the input delay. A variable structure control strategy is proposed for the stability of filtered tracking error system, and an adaptive law is established for the unknown perturbations. Finally, the effectiveness of the proposed control method is shown by the simulation results.

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