scholarly journals Evaluation of Linearization Methods for Control of the Pendubot

2021 ◽  
Vol 11 (16) ◽  
pp. 7615
Author(s):  
Paweł Parulski ◽  
Patryk Bartkowiak ◽  
Dariusz Pazderski
Keyword(s):  
Feedback Linearization ◽  
Closed Loop ◽  
Input Saturation ◽  
Zero Dynamics ◽  
Closed Loop System ◽  
New Approach ◽  
Linearization Methods ◽  
Partial Feedback Linearization ◽  
Partial Feedback ◽  
Control Methodology

The aim of this paper is to test the usefulness of a new approach based on partial feedback linearization to control the Pendubot. The control problem stated in the article is to stabilize the Pendubot in the upright position. In particular, properties of the closed-loop system and the zero dynamics are investigated and illustrated by results of simulations. Next, the performance of a hybrid-like controller in the case of input saturation is evaluated by conduction extensive simulation trails. The experimental results suggest that the considered control methodology can be successfully applied for a real system.

Feedback Control of the Locomotion of a Tailed Quadruped Robot

2021 ◽  
Author(s):  
Yujiong Liu ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Feedback Linearization ◽  
Degrees Of Freedom ◽  
Closed Loop ◽  
Open Loop ◽  
The Body ◽  
New Paradigm ◽  
Quadruped Robots ◽  
Partial Feedback Linearization ◽  
Partial Feedback ◽  
Specific Control

Abstract The traditional locomotion paradigm of quadruped robots is to use dexterous (multi degrees of freedom) legs and dynamically optimized footholds to balance the body and achieve stable locomotion. With the introduction of a robotic tail, a new locomotion paradigm becomes possible as the balancing is achieved by the tail and the legs are only responsible for propulsion. Since the burden on the leg is reduced, leg complexity can be also reduced. This paper explores this new paradigm by tackling the dynamic locomotion control problem of a reduced complexity quadruped (RCQ) with a pendulum tail. For this specific control task, a new control strategy is proposed in a manner that the legs are planned to execute the open-loop gait motion in advance, while the tail is controlled in a closed-loop to prepare the quadruped body in the desired orientation. With these two parts working cooperatively, the quadruped achieves dynamic locomotion. Partial feedback linearization (PFL) controller is used for the closed-loop tail control. Pronking, bounding, and maneuvering are tested to evaluate the controller’s performance. The results validate the proposed controller and demonstrate the feasibility and potential of the new locomotion paradigm.

Trajectory tracking control of electric sail with input uncertainty and saturation constraint

2016 ◽  
Vol 39 (7) ◽  
pp. 1007-1016 ◽  
Author(s):  
Yu Wang ◽  
Bingxiu Bian
Keyword(s):  
Solar Wind ◽  
Trajectory Tracking ◽  
Closed Loop ◽  
Sliding Mode ◽  
Input Saturation ◽  
Asymptotically Stable ◽  
Closed Loop System ◽  
Saturation Constraints ◽  
Non Linear System ◽  
Input Saturation Constraints

The electric sail (ES) is a novel propellantless propulsion concept, which extracts the solar wind momentum by repelling the positively charged ions. Due to the difficulty of attitude adjustment by the large flexible structure and the uncertainty of ion density, velocity and electron temperature by solar wind, there exist thrust input uncertainty and saturation with time-varying bounds for ES. The trajectory tracking problem for ES in three-dimensional (3-D) space is studied, and the composite sliding mode control scheme with corresponding guidance strategy is proposed for the single-input–multiple-output (SIMO) non-linear system. The hierarchical sliding surfaces are constructed with an auxiliary design system to analyse the effect of input saturation constraints and decouple the SIMO non-linear system to reduce the control complexity. Also, the disturbance estimation based on a super-twisting algorithm is employed to decrease the switch chattering and improve the system robustness. It is proved that all the sliding mode surfaces are asymptotically stable, and all the signals of the closed-loop system are bounded with input saturation constraints. Furthermore, all the signals are converging to zero and the closed-loop system is asymptotically stable without saturation. Finally, the simulation demonstrates the proposed composite sliding mode control is fit for ES 3-D trajectory tracking.

Robust fault-tolerant control design for hypersonic vehicle with input saturation and actuator faults

2021 ◽  
pp. 095441002110412
Author(s):  
Zhong-Zhe Yue ◽  
Jing-Guang Sun
Keyword(s):  
Feedback Linearization ◽  
Fault Tolerant ◽  
Input Saturation ◽  
Lyapunov Stability Theory ◽  
Hypersonic Vehicle ◽  
Actuator Faults ◽  
Closed Loop System ◽  
External Disturbances ◽  
Longitudinal Tracking ◽  
Tangent Function

This study investigates the flight longitudinal tracking control problem of hypersonic vehicle in presence of the input saturation, external disturbances, model parametric uncertainties, and actuator faults. First, the velocity and altitude subsystem are established with disturbances based on the feedback linearization model. Second, two robust anti-saturation fault-tolerant controllers are designed for the velocity subsystem and altitude subsystem by the utilization of the tangent function, Nussbaum function, and adaptive nonlinear filter. Finally, Lyapunov stability theory is used to prove that the states of the closed-loop system are bounded. And, the effectiveness and robustness of the control strategy are proved by numerical simulations.

Discrete-time backstepping control with nonlinear adaptive disturbance attenuation for the inverted-pendulum system

2019 ◽  
pp. 014233121986777
Author(s):  
Fatih Adıgüzel ◽  
Yaprak Yalçın
Keyword(s):  
Discrete Time ◽  
Feedback Linearization ◽  
Inverted Pendulum ◽  
Backstepping Control ◽  
Disturbance Attenuation ◽  
Pendulum System ◽  
Inverted Pendulum System ◽  
Partial Feedback Linearization ◽  
Partial Feedback ◽  
Backstepping Controller

A discrete-time backstepping controller with an active disturbance attenuation property for the Inverted-Pendulum system is constructed in this paper. The main purpose of this study is to show that Immersion and Invariance (I & I) approach can be used to design a nonlinear observer for disturbance estimation and demonstrate its effectiveness considering a nonlinear system with an unstable equilibrium point, namely Inverted-Pendulum system, by utilizing the estimated values in backstepping control design. All designs are directly performed in discrete-time domain to obtain directly implementable observer and controller in discrete processors with superior performance compared to emulators. The Inverted-Pendulum system is not in strict feedback form therefore backstepping procedure cannot be directly applied. In order to enable backstepping construction, firstly a partial feedback linearization is performed and afterwards a novel discrete-time coordinate transformation is proposed. Prior to the construction of partial feedback linearizing and backstepping controller, a nonlinear disturbance estimator design is proposed with Immersion and Invariance approach. The estimated disturbance values used in the partial feedback linearization and construction of the backstepping controller. The global asymptotic stability of the estimator and local asymptotic stability of overall closed loop system are proved in the sense of Lyapunov. Performance of proposed direct discrete-time backstepping control with discrete I & I observer is compared with a backstepping sliding mode controller with another nonlinear disturbance observer (NDO) by simulations.

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