scholarly journals Nonlinear Model Predictive Horizon for Optimal Trajectory Generation

Robotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 90
Author(s):  
Younes Al Younes ◽  
Martin Barczyk
Keyword(s):  
Nonlinear Model ◽  
Feedback Linearization ◽  
Optimization Problem ◽  
Closed Loop ◽  
Trajectory Generation ◽  
Loop Model ◽  
Loop Control ◽  
Feedback Linearization Control ◽  
Dynamic Obstacle ◽  
Reference Trajectories

This paper presents a trajectory generation method for a nonlinear system under closed-loop control (here a quadrotor drone) motivated by the Nonlinear Model Predictive Control (NMPC) method. Unlike NMPC, the proposed method employs a closed-loop system dynamics model within the optimization problem to efficiently generate reference trajectories in real time. We call this approach the Nonlinear Model Predictive Horizon (NMPH). The closed-loop model used within NMPH employs a feedback linearization control law design to decrease the nonconvexity of the optimization problem and thus achieve faster convergence. For robust trajectory planning in a dynamically changing environment, static and dynamic obstacle constraints are supported within the NMPH algorithm. Our algorithm is applied to a quadrotor system to generate optimal reference trajectories in 3D, and several simulation scenarios are provided to validate the features and evaluate the performance of the proposed methodology.

scholarly journals Feedback Linearization and Sliding Mode Control for VIENNA Rectifier Based on Differential Geometry Theory

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Xiang Lu ◽  
Yunxiang Xie ◽  
Li Chen
Keyword(s):  
Differential Geometry ◽  
Sliding Mode Control ◽  
Control Strategy ◽  
Feedback Linearization ◽  
Sliding Mode ◽  
Current Loop ◽  
Loop Control ◽  
Mode Control ◽  
Vienna Rectifier ◽  
Feedback Linearization Control

Aiming at the nonlinear characteristics of VIENNA rectifier and using differential geometry theory, a dual closed-loop control strategy is proposed, that is, outer voltage loop using sliding mode control strategy and inner current loop using feedback linearization control strategy. On the basis of establishing the nonlinear mathematical model of VIENNA rectifier ind-qsynchronous rotating coordinate system, an affine nonlinear model of VIENNA rectifier is established. The theory of feedback linearization is utilized to linearize the inner current loop so as to realize thed-qaxis variable decoupling. The control law of outer voltage loop is deduced by utilizing sliding mode control and index reaching law. In order to verify the feasibility of the proposed control strategy, simulation model is built in simulation platform of Matlab/Simulink. Simulation results verify the validity of the proposed control strategy, and the controller has a strong robustness in the case of parameter variations or load disturbances.

Design of an actuator fault-tolerant controller for an air vehicle with nonlinear dynamics

2018 ◽  
Vol 233 (10) ◽  
pp. 3534-3546 ◽  
Author(s):  
Sajad Roshanravan ◽  
Behnam Sobhani Gendeshmin ◽  
Saeed Shamaghdari
Keyword(s):  
Nonlinear Model ◽  
Optimization Problem ◽  
Closed Loop ◽  
Fault Tolerant ◽  
Control Design ◽  
Actuator Fault ◽  
Nonlinear Dynamic Model ◽  
New Approach ◽  
Air Vehicle ◽  
Novel Method

In this paper, a novel method is presented to design an autopilot for an air vehicle with a polynomial nonlinear model. This method employs the nonlinear model directly in the control design process without the need for local linearization about an operating point. It is shown that the control design problem can be formulated as a sum-of-squares optimization problem. This method guarantees exponential stability of the closed-loop nonlinear system by introducing a polynomial Lyapunov function. The nonlinear dynamic model of air vehicles can usually be represented in the polynomial form. Therefore, the proposed method can widely be applied to design an air vehicle autopilot. Besides using the proposed method along with the projection based and online redesign methods, a fault-tolerant controller is designed for the air vehicle. Furthermore, a new approach is developed by combination of these methods to fault-tolerant control system design. The proposed method is applied to design a fault-tolerant controller for a nonlinear pitch-axis model of an air vehicle subject to loss of effectiveness actuator fault. The simulation results show the efficiency of the proposed method.

scholarly journals Design and Analysis of Closed Loop Control of Multilevel SVPWM Inverter Fed PMSM Drive

2019 ◽  
Vol 8 (6S2) ◽  
pp. 809-816
Keyword(s):  
Permanent Magnet ◽  
Feedback Linearization ◽  
High Performance ◽  
Closed Loop ◽  
Permanent Magnet Synchronous Motor ◽  
Voltage Source ◽  
Closed Loop Control ◽  
Loop Control ◽  
Controlled Switching ◽  
Switching Devices

Permanent magnet synchronous machines have been universally used over induction machines in variable speed drives. For present trends and future developments, power electronics technology gives the extensive research of multilevel inverters that brings high safety voltages with low harmonic content in comparison with two-level inverter strategies. Multi level inverters implementation can be done by raising the number of power semi conductor controlled switching devices per phase to increase the number of inverter output voltage levels. By increasing the levels, power controlled switching devices and other components are increased, which makes the inverter complex and overpriced. From the above aspects, three-phase three-level inverter strategy is used for high performance and high voltage A.C drives. Multilevel inverter using a space vector pulse width modulation (SVPWM) strategy gives great advantages in high performance A.C drive applications. Various types of control strategies have been recommended for voltage source inverter fed A.C drives. In the proposed work, a PI controller is designed for the outer loop and non-linear controller using a state feedback linearization technique is designed for the inner loop. The closed loop control system for three-level inverter fed Permanent magnet synchronous motor drive employing SVPWM is extensively simulated using MATLAB.

Decentralized Robust Feedback Linearization Control Based on Integrity

2013 ◽  
Vol 411-414 ◽  
pp. 1687-1696
Author(s):  
Jin Li Chen ◽  
Ya Li Xue ◽  
Dong Hai Li
Keyword(s):  
Control System ◽  
Feedback Linearization ◽  
Closed Loop ◽  
Multivariable Systems ◽  
External Disturbances ◽  
Design Specifications ◽  
Feedback Linearization Control ◽  
System Uncertainties ◽  
Model Observer

Decentralized Robust Feedback Linearization (DRFL) approach based on integrity for multivariable systems is presented. It uses a model observer to compensate the non-modeled dynamics, system uncertainties, and external disturbances of a system. Firstly, the existence of DRFL controllers with integrity is examined. Then, stable regions of each DRFL controller parameters are calculated, and some parameters are obtained by placing suitable closed-loop poles, for meeting the design specifications for the whole control system. The proposed method is applied to an illustrative example. Results demonstrate that DRFL control is feasible and robust for complicated multivariable systems.

Friction-Compensating Feedback Linearization Control Applied to a Pneumatic Servo System

2014 ◽  
Vol 902 ◽  
pp. 219-224
Author(s):  
Mario R. Sobczyk S. ◽  
Ricardo M. Suzuki ◽  
Carlos A.C. Sarmanho Jr. ◽  
Eduardo A. Perondi
Keyword(s):  
Mathematical Model ◽  
Feedback Linearization ◽  
Control Algorithm ◽  
Closed Loop ◽  
Positioning System ◽  
Convergence Properties ◽  
Tracking Errors ◽  
Highly Nonlinear ◽  
Feedback Linearization Control ◽  
Pneumatic Servo System

This work proposes a feedback linearization control algorithm to be applied to a pneumatic positioning system. Such algorithm aims to compensate the undesirable effects due to the highly nonlinear dynamic behavior of such type of actuator. A mathematical model of the system is presented and the proposed controller is described. Besides, an analysis is provided of the convergence properties of the closed-loop tracking errors of the system when such controller is used. The main features of the proposed controller are illustrated by means of experimental results and respective discussions.

Square of Voltage Out-Loop Based Feedback Linearization Control of Voltage Source Converter (VSC) in SMES

2013 ◽  
Vol 732-733 ◽  
pp. 1216-1221 ◽  
Author(s):  
Xiao Kang Dai ◽  
Bu Han Zhang ◽  
Yi Chen
Keyword(s):  
Feedback Linearization ◽  
Magnetic Energy ◽  
Control Variable ◽  
Voltage Source ◽  
Voltage Source Converter ◽  
Loop Control ◽  
Variable Expression ◽  
Feedback Linearization Control ◽  
Dc Bus ◽  
Bus Voltage

To improve the response characteristic of the VSC in SMES (Superconducting Magnetic Energy Storage) with wide load disturbance, a new square of voltage out-loop based feedback linearization control strategy is proposed for the control of VSC. The input variable was controlled by a combining of square of voltage out-loop based direct voltage control and current inner-loop control to achieve fast stabilization of DC bus voltage and accurate tracking of power of PCC. Stability and dynamic response characteristics of the system were verified by simulation results. It is shown that the proposed strategy can improve the DC bus voltage transient response with load step change, with simplified control variable expression and reduced calculating burden.

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