Optimal regulation of a cable robot in presence of obstacle using optimal adaptive feedback linearization approach

Robotica ◽  
2014 ◽  
Vol 33 (4) ◽  
pp. 933-952 ◽  
Author(s):  
M. H. Korayem ◽  
H. Tourajizadeh ◽  
A. Zehfroosh ◽  
A. H. Korayem
Keyword(s):  
Obstacle Avoidance ◽  
Feedback Linearization ◽  
Optimal Path ◽  
Linear Quadratic Regulator ◽  
Experimental Tests ◽  
Linear Quadratic ◽  
Optimal Regulation ◽  
Cable Robot ◽  
Optimal Controllers ◽  
Feedback Linearization Approach

SUMMARYOptimal path planning of a closed loop cable robot, between two predefined points in presence of obstacles is the goal of this paper. This target is met by proposing a new method of optimal regulation for non linear systems while Dynamic Load Carrying Capacity (DLCC) of the robot is supposed as the related cost function. Feedback linearization is used to linearize the system while Linear Quadratic Regulator (LQR) is employed to optimize the DLCC of the system based on torque and error constraints. Obstacle avoidance for both the end-effector and cables is also considered by the aid of designing an adaptive local obstacle avoidance controller. As a result of linearized nature of the proposed optimal regulation and obstacle avoidance, fast calculation for real time applications is possible. Therefore, formulation of the optimal feedback linearization, together with calculating the DLCC of the robot based on the presented constraints is derived. Finally, a simulation study is performed to study the optimal dynamics and also the maximum DLCC of the cable robot in presence of obstacles. Simulation results are eventually compared with experimental tests conducted on IUST Cable Suspended Robot (ICaSbot) to verify the validity and efficiency of the proposed optimal controllers.

A Feedback Linearization-Based Motion Controller for a UWMR with Experimental Evaluations

Robotica ◽  
2019 ◽  
Vol 37 (6) ◽  
pp. 1073-1089 ◽  
Author(s):  
Luis Montoya-Villegas ◽  
Javier Moreno-Valenzuela ◽  
Ricardo Pérez-Alcocer
Keyword(s):  
Feedback Linearization ◽  
Vision System ◽  
Experimental Tests ◽  
Experimental Result ◽  
The Novel ◽  
Tracking Accuracy ◽  
Motion Controller ◽  
Wheeled Mobile Robots ◽  
Feedback Linearization Approach ◽  
Error State

SummaryIn this paper, the feedback linearization approach is used to introduce a motion controller for unicycle-type wheeled mobile robots (UWMRs). The output function is defined as a linear combination of the error state. The novel scheme is firstly tested in numerical simulation and compared with its corresponding experimental result. Three controllers are taken from the literature and compared to the proposed approach by means of experiments. The gains of the experimentally tested controllers are selected to obtain identical energy consumption. The Optitrack commercial vision system and Pioneer P3-DX UWMR are used in real-time experimental tests. In addition, two sets of experimental results for different motion tasks are provided. The results show that the proposed controller presents the best tracking accuracy.

Optimal Control of a Wheeled Mobile Cable-Driven Parallel Robot ICaSbot with Viscoelastic Cables

Robotica ◽  
2019 ◽  
Vol 38 (8) ◽  
pp. 1513-1537 ◽  
Author(s):  
Moharam Habibnejad Korayem ◽  
Mahdi Yousefzadeh ◽  
Hami Tourajizadeh
Keyword(s):  
Feedback Linearization ◽  
Parallel Robot ◽  
System Stability ◽  
Control Input ◽  
Linear Quadratic ◽  
Combined System ◽  
Viscoelastic System ◽  
Control Effort ◽  
Cable Robot ◽  
Data Feedback

SUMMARYIn this paper, a new mobile cable-driven parallel robot is proposed by mounting a spatial cable robot on a wheeled mobile robot. This system includes all the advantages of cable robots such as high ratio of payload to weight and good stiffness and accuracy while its deficiency of limited workspace is eliminated by the aid of its mobile chassis. The combined system covers a vast workspace area whereas it has negligible vibrations and cable sag due to using shorter cables. The dynamic equations are derived using Gibbs–Appell formulation considering viscoelasticity of the cables. Therefore, the more realistic viscoelastic cable model of the robot reveals the system flexibility effect and shows the requirements needed to control the end-effector in the conditions with cable elasticity. The viscoelastic system stability is investigated based on the input–output feedback linearization and using only the actuators feedback data. Feedback linearization controller is equipped by two additional controllers, that is, the optimal controller based on Linear Quadratic Regulator (LQR) method and finite horizon model predictive approach. They are used to control the system compromising between the control effort and error signals of the feedback linearized system. The applied control input to the robot plant is the voltage signal limited to a specified band. The validity of modeling and the designed controller efficiency are investigated using MATLAB simulation and its verification is accomplished by experimental tests conducted on the manufactured cable robot, ICaSbot.

scholarly journals Research on Control Methods for the Pressure Continuous Regulation Electrohydraulic Proportional Axial Piston Pump of an Aircraft Hydraulic System

2019 ◽  
Vol 9 (7) ◽  
pp. 1376
Author(s):  
Peng Zhang ◽  
Yunhua Li
Keyword(s):  
Feedback Linearization ◽  
Control Method ◽  
Linear Quadratic Regulator ◽  
Piston Pump ◽  
Control Methods ◽  
Hydraulic Systems ◽  
Axial Piston Pump ◽  
Linear Quadratic ◽  
Delivery Pressure ◽  
Axial Piston

The objective of this paper is to design a pump that can match its delivery pressure to the aircraft load. Axial piston pumps used in airborne hydraulic systems are required to work in a constant pressure mode setting based on the highest pressure required by the aircraft load. However, the time using the highest pressure working mode is very short, which leads to a lot of overflow lose. This study is motivated by this fact. Pressure continuous regulation electrohydraulic proportional axial piston pump is realized by combining a dual-pressure piston pump with electro-hydraulic proportional technology, realizing the match between the delivery pressure of the pump and the aircraft load. The mathematical model is established and its dynamic characteristics are analyzed. The control methods such as a proportional integral derivative (PID) control method, linear quadratic regulator (LQR) based on a feedback linearization method and a backstepping sliding control method are designed for this nonlinear system. It can be seen from the result of simulation experiments that the requirements of pressure control with a pump are reached and the capacity of resisting disturbance of the system is strong.

Motion planning of spacecraft with obstacle avoidance under low uncertainty using the improved equal-collision-probability-curve and improved linear quadratic regulator strategy

2019 ◽  
Vol 233 (14) ◽  
pp. 5456-5467
Author(s):  
Wang Yi ◽  
Chen Xiaoqian ◽  
Bai Yuzhu ◽  
Cao Lu ◽  
Zhu Xiaozhou
Keyword(s):  
Motion Planning ◽  
Obstacle Avoidance ◽  
Linear Quadratic Regulator ◽  
Collision Probability ◽  
Planning Problem ◽  
Reference Trajectory ◽  
Linear Quadratic ◽  
Probability Curve ◽  
Proximity Operations ◽  
Low Uncertainty

In terms of the motion planning problem of spacecraft proximity operations with obstacle avoidance under low uncertainty, the improved equal-collision-probability-curve and improved linear quadratic regulator (IECPC-ILQR) strategy is proposed. Firstly, the novel function of the IECPC algorithm is developed to generate the avoidance control impulse. Subsequently, the ILQR is designed to track the reference trajectory. Furthermore, combining the improved ECPC algorithm with the ILQR controller, the composite controller of the IECPC-ILQR strategy is obtained and is implemented on the chaser spacecraft. Compared with the traditional ECPC algorithm, the IECPC-ILQR strategy can avoid collision in the presence of low uncertainty. Furthermore, the proposed avoidance strategy can obtain higher control precision while requiring the same fuel. Finally, numerical simulations verify the effectiveness of the proposed IECPC-ILQR strategy.

Coordination Control Strategy for Active and Reactive Power of DFIG Based on Exact Feedback Linearization under Grid Fault Condition

2011 ◽  
Vol 48-49 ◽  
pp. 335-344
Author(s):  
Meng Zeng Cheng ◽  
Zhen Lan Dou ◽  
Xu Cai
Keyword(s):  
Nonlinear Control ◽  
Power System ◽  
Control Strategy ◽  
Feedback Linearization ◽  
Transient Stability ◽  
Reactive Power ◽  
Control Method ◽  
Linear Quadratic Regulator ◽  
Linear Quadratic ◽  
Nonlinear Control Method

In this paper, a control strategy for operation of rotor side converter (RSC) of Doubly Fed Induction Generators (DFIG) is developed by injecting reactive power into the grid in order to support the grid voltage during and after grid fault events. The novel nonlinear control method is based on differential geometry theory, and exact feedback linearization is applied for control system design of DFIG. Then the optimal control for the linearized system is obtained through introducing the linear quadratic regulator (LQR) design method. Simulation results on a single machine infinite bus power system show that the proposed nonlinear control method can inject reactive power to fault grid rapidly, reduce the oscillation of active power and improve the transient stability of power system.

scholarly journals Sistem Kendali Penghindar Rintangan Pada Quadrotor Menggunakan Konsep Linear Quadratic

2017 ◽  
Vol 7 (2) ◽  
pp. 219
Author(s):  
Ariesa Budi Zakaria ◽  
Andi Dharmawan
Keyword(s):  
Control System ◽  
Response Time ◽  
Obstacle Avoidance ◽  
Rise Time ◽  
Pulse Width Modulation ◽  
Linear Quadratic Regulator ◽  
Linear Quadratic ◽  
Aerial Vehicle ◽  
Avoidance Control ◽  
Aircraft Type

Quadrotor is one of UAV (Unmanned Aerial Vehicle) rotary wing aircraft type. Quadrotor has been widely used for various needs to military or civilian. Quadrotor can be operated manually by remote or autonomously. One of the difficulties of quadrotor operations is to avoid the obstacles before autonomous flying towards destination point. Therefore, an obstacle avoidance control system is required on quadrotor systems. Linear Quadratic Regulator is a control system that produces an input value system from state value and feedback. State value is produced from translation and rotation. That input value then converted into pulse width modulation to control the speed of the brusless motor, and it's used to do obstacles avoidance manouver.This method might reduce overshoot on the system and make response time (rise time) arrived faster than other methods. The obstacle avoidance system requires small overshoot value and an appropriate response time to avoid frictions or collisions. The result of this research is the rise time to avoid obstacles that reached 4,7 second with flight speed of 0,6 m/s and turns for roll angle equal to 14,27 °, pitch equal to 13,26 °, and yaw equal to 9,87 ° while avoidance maneuvering obstacles.

Least Squares Tracking on the Euclidean Group

2000 ◽  
Author(s):  
Youngmo Han ◽  
F. C. Park
Keyword(s):  
Least Squares ◽  
Motion Control ◽  
Obstacle Avoidance ◽  
Analytic Solution ◽  
Linear Quadratic Regulator ◽  
Euclidean Group ◽  
Linear Quadratic ◽  
Complex Assembly ◽  
Compliant Motion ◽  
Control Framework

Abstract A large class of problems in robotics, e.g., tracking with obstacle avoidance, compliant motion control, and complex assembly, can be formulated as a least-squares tracking problem on the Euclidean group subject to constraints on the state and/or control. In this paper we develop a general, mathematically rigorous optimal control framework for this class of problems, and derive a simple closed-form analytic solution. Our formalism can be viewed as generalization to the Euclidean group of the linear quadratic regulator (LQR) subject to state equality constraints. Examples from force-guided complex assembly and tracking with obstacle avoidance are given.

scholarly journals Compound optimal control of harmonic drive considering hysteresis characteristic

2019 ◽  
Vol 10 (2) ◽  
pp. 383-391
Author(s):  
Quan Lu ◽  
Tieqiang Gang ◽  
Guangbo Hao ◽  
Lijie Chen
Keyword(s):  
Optimal Control ◽  
Feedback Linearization ◽  
Linear Quadratic Regulator ◽  
Optimal Controller ◽  
Mechanical Transmission ◽  
Reference Trajectory ◽  
Harmonic Drive ◽  
Tracking Accuracy ◽  
Linear Quadratic ◽  
Hysteresis Behavior

Abstract. Hysteresis behavior widely exists in the transmission process of harmonic drives. Eliminating the hysteresis effect is highly desired in the high-precision mechanical transmission, which results in challenges in the control design. This paper aims to improve the tracking accuracy of the motor-harmonic drive serial system. Firstly, a modified Bouc-Wen model based on uniform smooth approximating function is applied to describe the hysteresis behavior of the harmonic drive. By using coordinate transformation and accurate state feedback linearization, we then obtain the mathematical model of the serial system of the motor-harmonic drive. Finally, the reference trajectory is tracked by a compound optimal controller that is based on a linear quadratic regulator. Simulation results show that compared with the disturbance observer-based control (DOBC) using a linear observer, the new compound optimal controller in this paper presents a smoother control signal with the elimination of large amount of high-frequency oscillations. Furthermore, the relative error in the steady state tracking tends to approach to zero and no cyclic fluctuations appears. With the employing of optimal control, the output of the harmonic drive can trace more complex trajectory.

scholarly journals Riccati-less approach for optimal control and estimation: an application to two-dimensional boundary layers

2013 ◽  
Vol 731 ◽  
pp. 394-417 ◽  
Author(s):  
Onofrio Semeraro ◽  
Jan O. Pralits ◽  
Clarence W. Rowley ◽  
Dan S. Henningson
Keyword(s):  
Boundary Layer ◽  
Optimal Control ◽  
Linear Quadratic Regulator ◽  
Finite Amplitude ◽  
Two Dimensional ◽  
Dual Algorithm ◽  
Linear Quadratic ◽  
Perfect Agreement ◽  
Optimal Controllers ◽  
Dimensional Boundary

AbstractThe control of Tollmien–Schlichting waves in a two-dimensional boundary layer is analysed using numerical simulations. Full-dimensional optimal controllers are used in combination with a setup of spatially localized inputs (actuator and disturbance) and outputs (sensors). The adjoint of the direct-adjoint (ADA) algorithm, recently proposed by Pralits & Luchini (In Seventh IUTAM Symposium on Laminar–Turbulent Transition (ed. P. Schlatter & D. S. Henningson), vol. 18, 2010, Springer), is used to efficiently compute an optimal controller known as a linear quadratic regulator; the method is iterative and allows one to bypass the solution of the corresponding Riccati equation, which is infeasible for high-dimensional systems. We show that an analogous iteration can be made for the estimation problem; the dual algorithm is referred to as adjoint of the adjoint-direct (AAD). By combining the solutions of the estimation and control problem, full-dimensional linear quadratic Gaussian controllers are obtained and used for the attenuation of the disturbances arising in the boundary layer flow. The full-dimensional controllers turn out to be an excellent benchmark for evaluating the performance of the optimal control/estimation design based on reduced-order models. We show under which conditions the two strategies are in perfect agreement by focusing on the issues arising when feedback configurations are considered. An analysis of the finite-amplitude disturbances is also carried out by addressing the limitations of the optimal controllers, the role of the estimation, and the robustness to the nonlinearities arising in the flow of the control design.

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