scholarly journals Disturbance Observer-Based Control for Trajectory Tracking of a Quadrotor

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1624
Author(s):  
Sang Wook Ha ◽  
Bong Seok Park
Keyword(s):  
Trajectory Tracking ◽  
Closed Loop ◽  
Control Method ◽  
Control Strategies ◽  
Hierarchical Control ◽  
Loop System ◽  
Nonlinear Controller ◽  
Closed Loop System ◽  
External Disturbances ◽  
Dynamic Surface

This paper presents a new control approach for the trajectory tracking of a quadrotor in the presence of external disturbances. Unlike in previous studies using hierarchical control strategies, a nonlinear controller is designed by introducing new state transformations that can use Euler angles as virtual control inputs. Thus, the proposed method can eliminate the timescale separation assumption of hierarchical control strategies. To estimate the external disturbances involved in the translational and rotational dynamics of the quadrotor, disturbance observers are developed. Using state transformations and estimates of external disturbances, we design a robust nonlinear controller based on the dynamic surface control method. The stability of the closed-loop system is analyzed without separation into two subsystems. From the Lyapunov stability theory, it is proven that all error signals in the closed-loop system are uniformly ultimately bounded and can be made arbitrarily small. Finally, simulation results are presented to demonstrate the performance of the proposed controller.

Fuzzy fault-tolerant containment control for multi-agent systems with unknown nonlinear dynamics

2021 ◽  
pp. 014233122110430
Author(s):  
Malika Sader ◽  
Fuyong Wang ◽  
Zhongxin Liu ◽  
Zengqiang Chen
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Fault Tolerant ◽  
Nonlinear Function ◽  
Loop System ◽  
Multi Agent Systems ◽  
Closed Loop System ◽  
Containment Control ◽  
Agent Systems ◽  
Multi Agent

This paper studies the containment control problem for a class of nonlinear multi-agent systems (MASs) with actuator faults (AFs) and external disturbance under switching communication topologies. To address this problem, a new fuzzy fault-tolerant containment control method is developed via utilizing adaptive mechanisms. Furthermore, a sufficient condition is obtained to guarantee the stability of the considered closed-loop system by the dwell time technique combined with Lyapunov stability theory. Unlike the traditional method to estimate the weight matrix, the fuzzy logic system is used to estimate the norm of weight vectors. Thus, the difficulty that the unknown nonlinear function cannot be compensated for when the actuator produces outage or stuck fault is solved. Compared with the existing controllers for nonlinear MASs, the proposed controller is more suitable for the considered problem under the influence of AFs that are detrimental to the operation of each agent system. Besides which, the closed-loop system is proven to be stable by using the developed controller, and all followers converge asymptotically to the convex hull formed by the leaders. Finally, an example based on a reduced-order aircraft model is presented to verify the effectiveness of the designed control scheme.

Mode Decoupling Controller for Feedback Model Updating

2004 ◽  
Author(s):  
Hunsang Jung ◽  
Youngjin Park ◽  
K. C. Park
Keyword(s):  
Closed Loop ◽  
Model Updating ◽  
Control Method ◽  
Loop System ◽  
Mode Shapes ◽  
Closed Loop System ◽  
Sensitivity Matrix ◽  
Data Set ◽  
Conventional Methods ◽  
The Stability

A novel concept of feedback loop design for modal test and model updating is proposed. This method uses the closed-loop frequency information for parameter modifications to overcome the problems associated with the conventional methods employing the modal sensitivity matrix. To obtain new modal information from the closed-loop system, controllers should be effective in changing modal data while guaranteeing the stability of the closed-loop system. The present paper proposes a mode-decoupling controller that can alter a target mode while guaranteeing the stability of the closed-loop, and that can be constructed by using the measured open-loop, mode shapes. A simulation based on time domain input/output data is performed to evaluate the feasibility of the proposed control method, which is subsequently corroborated via experiments. Experimental data obtained on a beam via the proposed mode-decoupling controller have been applied to estimate thicknesses of a beam. The results show that the proposed approach outperforms conventional methods with a far less number of data set for the estimation of system parameters.

scholarly journals Adaptive Robust Quadratic Stabilization Tracking Control for Robotic System with Uncertainties and External Disturbances

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jinzhu Peng ◽  
Yan Liu
Keyword(s):  
Closed Loop ◽  
Robot Manipulator ◽  
Variable Structure ◽  
Robotic System ◽  
Loop System ◽  
Closed Loop System ◽  
Hybrid Scheme ◽  
External Disturbances ◽  
Control Approach ◽  
Quadratic Stabilization

An adaptive robust quadratic stabilization tracking controller with hybrid scheme is proposed for robotic system with uncertainties and external disturbances. The hybrid scheme combines computed torque controller (CTC) with an adaptive robust compensator, in which variable structure control (VSC) andH∞optimal control approaches are adopted. The uncertain robot manipulator is mainly controlled by CTC, the VSC is used to eliminate the effect of the uncertainties and ensure global stability, andH∞approach is designed to achieve a certain tracking performance of closed-loop system. A quadratic stability approach, which allows separate treatment of parametric uncertainties, is used to reduce the conservatism of the conventional robust control approach. It can be also guaranteed that all signals in closed-loop system are bounded. The validity of the proposed control scheme is shown by computer simulation of a two-link robotic manipulator.

Fault Tolerant Control and Classification for Longitudinal Vehicle Control

2003 ◽  
Vol 125 (3) ◽  
pp. 320-329 ◽  
Author(s):  
Bongsob Song ◽  
J. Karl Hedrick ◽  
Adam Howell
Keyword(s):  
Closed Loop ◽  
Fault Tolerant ◽  
Optimization Technique ◽  
Tracking Error ◽  
Fault Detection And Diagnosis ◽  
Loop System ◽  
Fault Classification ◽  
Closed Loop System ◽  
Dynamic Surface ◽  
Performance Loss

In this paper, a new method of analyzing for the performance loss caused by faults in the systems is presented, and applied to the design of a fault tolerant longitudinal controller for a transit bus. Based on the amount of performance loss measured by a quadratic function, fault impact assessment is developed for both single and multiple faults. More specifically, ellipsoidal approximation of the tracking error bounds via dynamic surface control (DSC) is obtained via convex optimization technique for the nonlinear closed-loop system. Relying on the fault impact to the closed loop system and its isolatability on a fault detection and diagnosis system, the fault classification is proposed to provide a switching logic in the framework of a switched hierarchical structure. Finally, simulation results of the fault tolerant controller and corresponding fault classification are shown for multiple multiplicative faults.

Output Feedback Algorithm for Nonlinear Systems with Compensation of Bounded Disturbances and Measurement Noises

2019 ◽  
Vol 20 (1) ◽  
pp. 3-15 ◽  
Author(s):  
I. B. Furtat ◽  
P. A. Gushchin ◽  
A. A. Peregudin
Keyword(s):  
Output Feedback ◽  
Closed Loop ◽  
Sufficient Conditions ◽  
Loop System ◽  
Partial Recovery ◽  
Closed Loop System ◽  
External Disturbances ◽  
Control Schemes ◽  
Measurement Noises ◽  
Feedback Algorithm

The output feedback algorithm for dynamic plants with compensation of parametric uncertainty, external disturbances and measurement noises is synthesized. The plants are described by a nonlinear system of differential equations with vector input and output signals. Unlike most existing control schemes in this paper the dimensions of the measurement interference and the output signal are equal, the sources of the signals of disturbances and disturbances are different, parametric and external disturbances can be present in any equation of the plant model. For simultaneous compensation of disturbances and measurement noises it is proposed to consider two channels. On the first channel a part of the measurement noises will be estimated which will allow partial recovery the information about the plant noisy output. On the second channel the disturbances will be compensated. Thus, at least two independent measurement channels are required for simultaneous compensation of disturbances and measurement noises. Sufficient conditions for calculating the parameters of the algorithm in the form of solvability of the linear matrix inequality are obtained. It is shown that the equation of a closed-loop system obtained on the basis of the proposed algorithm depends on the disturbances and the smallest component of the measurement noise. However, if the smallest component cannot be identified a priory, the results of the transients depend on the component of the noise that will be selected in the synthesis of the control system. Thus, unlike most existing control schemes, where the equation of a closed-loop system depends on disturbance and noise, the resulting algorithm provides better transients, because they do not depend on the entire noise vector, but only on its smallest (one) component. The simulations for a third-order nonlinear plant and the synchronization of an electrical generator connected to the power grid are presented. Numerical examples illustrate the effectiveness of the proposed scheme and the robustness with respect to random components in the noises and disturbances.

scholarly journals Design of Dynamic Nonlinear Control Techniques for Flexible-Link Manipulators

2008 ◽  
Vol 144 ◽  
pp. 250-256
Author(s):  
V. Gavriloiu ◽  
V. Yurkevich ◽  
K. Khorasani
Keyword(s):  
Closed Loop ◽  
Control Strategies ◽  
Output Feedback Control ◽  
Loop System ◽  
Phase Behaviour ◽  
Flexible Link ◽  
Closed Loop System ◽  
Flexible System ◽  
Advantages And Disadvantages ◽  
Control Objective

In this paper, we develop robust dynamical controllers for addressing the problems of tracking and regulation of flexible-link manipulators. The design of dynamical controllers is based on construction of a two-time scale dynamical motion of the closed-loop system. The main control objective is to achieve stability of the closed-loop system while ensuring boundedness of all the control signals as well as sufficiently small tip-position tracking requirement. In order to achieve a minimum phase behaviour for utilizing output feedback control strategy, a new redefined output is proposed. Instead of using the joint angles as outputs in the rigid-link case, a new output is chosen for the flexible-link case which will provide and guarantee stability of the closed-loop flexible system. Simulations results are provided for flexible-link manipulators using the proposed control strategies. A comparative analysis is also included to demonstrate and illustrate the advantages and disadvantages of the considered control methodologies.

An Approach to Telerobotic Manipulations

1997 ◽  
Vol 119 (3) ◽  
pp. 431-438 ◽  
Author(s):  
H. Kazerooni ◽  
C. L. Moore
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Sufficient Conditions ◽  
Human Robot Interaction ◽  
Loop System ◽  
Robotic Manipulation ◽  
Closed Loop System ◽  
Robot Interaction ◽  
Minimum Number ◽  
The Stability

This article introduces three areas of study: 1 telefunctioning; 2 a control method for producing telefunctioning; and 3 an analysis of human-robot interaction when telefunctioning governs the system behavior. Telefunctioning facilitates the maneuvering of loads by creating a perpetual sense of the load dynamics for the operator. Telefunctioning is defined as a robotic manipulation method in which the dynamic behaviors of the slave robot and the master robot are functions of each other; these functions are the designer’s choice and depend on the application. (In a subclass of telefunctioning currently referred to as telepresence, these functions are specified as “unity” so that the master and slave variables (e.g., position, velocity) are dynamically equal.) To produce telefunctioning, this work determines a minimum number of functions relating the robots’ variables, and then develops a control architecture which guarantees that the defined functions govern the dynamic behavior of the closed-loop system. The stability of the closed-loop system (i.e., master robot, slave robot, human, and the load being manipulated) is analyzed and sufficient conditions for stability are derived.

Passivity-Based Stabilization of Underactuated Mechanical Systems

2013 ◽  
Vol 421 ◽  
pp. 16-22
Author(s):  
Shan Shan Wu ◽  
Wei Huo
Keyword(s):  
Closed Loop ◽  
Control Method ◽  
Controller Design ◽  
Design Method ◽  
Mechanical Systems ◽  
Matching Condition ◽  
Loop System ◽  
Closed Loop System ◽  
Underactuated Mechanical Systems ◽  
Stabilization Control

A new stabilization control method for underactuated linear mechanical systems is presented in this paper. By proper setting the desired closed-loop system, the matching condition for controller design is reduced to one equation and an adjustable parameter (damping coefficient) is introduced to the controller. Stability of the closed-loop system is proved based on passivity. As an application example, stabilization control of 2-DOF Pendubot is studied. The system is linearized at its equilibrium point and the proposed controller design method is applied to the linearized system. The procedure of solving matching condition and design controller for the Pendubot is provided. The simulation results verify feasibility of the proposed method.

Sign in / Sign up

Export Citation Format

Share Document