scholarly journals Analytical and Experimental Analyses of Nonlinear Vibrations in a Rotary Inverted Pendulum

2021 ◽  
Author(s):  
Mohammadjavad Rahimi dolatabad ◽  
Abdolreza Pasharavesh ◽  
Amir Ali Akbar Khayyat
Keyword(s):  
Analytical Solution ◽  
Numerical Solution ◽  
Closed Loop ◽  
Inverted Pendulum ◽  
Multiple Scales ◽  
Nonlinear Oscillations ◽  
Wide Frequency Range ◽  
Perturbative Method ◽  
Full State Feedback ◽  
Rotary Inverted Pendulum

Abstract Gaining insight into possible vibratory responses of dynamical systems around their stable equilibria is an essential step, which must be taken before their design and application. The results of such a study can significantly help prevent instability in closed-loop stabilized systems through avoiding the excitation of the system in the neighborhood of its resonance. This paper investigates nonlinear oscillations of a Rotary Inverted Pendulum (RIP) with a full-state feedback controller. Lagrange’s equations are employed to derive an accurate 2-DoF mathematical model, whose parameter values are extracted by both the measurement and 3D modeling of the real system components. Although the governing equations of a 2-DoF nonlinear system are difficult to solve, performing an analytical solution is of great importance, mostly because, compared to the numerical solution, the analytical solution can function as an accurate pattern. Additionally, the analytical solution is generally more appealing to engineers because their computational costs are less than those of the numerical solution. In this study, the perturbative method of multiple scales is used to obtain an analytical solution to the coupled nonlinear motion equations of the closed-loop system. Moreover, the parameters of the controller are determined, using the results of this solution. The findings reveal the existence of hardening- and softening-type resonances at the first and second vibrational modes, respectively. This led to a wide frequency range with moderately large-amplitude vibrations, which must be avoided when adjusting a time-varying set-point for the system. The analytical results of the nonlinear vibration of the RIP are verified by experimental measurements, and a very good agreement is observed between the results of both approaches.

Closed-Loop Dynamic Analysis of a Rotary Inverted Pendulum for Control Design

2011 ◽  
Vol 134 (2) ◽  
Author(s):  
Hashem Ashrafiuon ◽  
Alan M. Whitman
Keyword(s):  
Analytical Solution ◽  
Closed Loop ◽  
Inverted Pendulum ◽  
Sliding Mode ◽  
Approximate Analytical Solution ◽  
Multiple Scale ◽  
Horizontal Line ◽  
Weakly Nonlinear ◽  
Loop Dynamics ◽  
Rotary Inverted Pendulum

This paper presents an approximate analytical solution for the weakly nonlinear closed-loop dynamics of the sliding phase of a sliding mode controlled rotary inverted pendulum based on the multiple scale method. A locally stable nonlinear sliding mode control law with starting configurations above the horizontal line is presented for the rotary inverted pendulum. The analytical expressions derived from the nonlinear solution of the reduced-order closed-loop dynamics provide both qualitative and quantitative insight into the closed-loop response leading to proper selection of parameters that guarantee stabilization and improve controller performance. The approximate analytical solution is verified through comparison with the exact numerical solution. The control performance predicted by the analytical solution is experimentally demo.

Modified PD Control of Rotary Inverted Pendulum

2009 ◽  
Author(s):  
Naserodin Sepehry ◽  
Mahnaz Shamshirsaz
Keyword(s):  
Feedback Control ◽  
Inverted Pendulum ◽  
Break Point ◽  
State Feedback Control ◽  
Pd Controller ◽  
Loop Transfer Function ◽  
Full State ◽  
Full State Feedback ◽  
Rotary Inverted Pendulum ◽  
Space Method

The inverted pendulum, a classical mechatronic application, exists in many different forms. In despite that many works have been done to balance the pendulum link on end of this device using feedback control but few studies have been developed to control this rotary inverted pendulum using PD controller. In classical methods, using PD, PI or PID control, difficulties appear due to one of the coefficients becomes zero in closed loop transfer function denominator and consequently the system becomes unstable. In this study, an arbitrary pole is placed in order to create a break point in root locus, so by this way a PD controller can be designed for this new system. Also, disturbance rejection has been investigated by state space method in this paper. The results of this modified PD controller are compared with full state feedback control and optimal control, so the method used in this study has been validated.

scholarly journals Performance Comparisons Of Hybrid Fuzzy-LQR And Hybrid PID-LQR Controllers On Stabilizing Double Rotary Inverted Pendulum

2020 ◽  
Vol 1 (2) ◽  
pp. 71-80
Author(s):  
Jamilu Kamilu Adamu ◽  
Mukhtar Fatihu Hamza ◽  
Abdulbasid Ismail Isa
Keyword(s):  
Inverted Pendulum ◽  
Fuzzy Logic Controller ◽  
Linear Quadratic Regulator ◽  
State Feedback Control ◽  
Linear Quadratic ◽  
Trajectory Tracking Control ◽  
Stabilization Control ◽  
Full State Feedback ◽  
Lqr Controller ◽  
Rotary Inverted Pendulum

Double Rotary Inverted Pendulum (DRIP) is a member of the mechanical under-actuated system which is unstable and nonlinear. The DRIP has been widely used for testing different control algorithms in both simulation and experiments. The DRIP control objectives include Stabilization control, Swing-up control and trajectory tracking control. In this research, we present the design of an intelligent controller called “hybrid Fuzzy-LQR controller” for the DRIP system. Fuzzy logic controller (FLC) is combined with a Linear Quadratic Regulator (LQR). The LQR is included to improve the performance based on full state feedback control. The FLC is used to accommodate nonlinearity based on its IF-THEN rules. The proposed controller was compared with the Hybrid PID-LQR controller. Simulation results indicate that the proposed hybrid Fuzzy-LQR controllers demonstrate a better performance compared with the hybrid PID-LQR controller especially in the presence of disturbances.

scholarly journals Bifurcation analysis of a composite cantilever beam via 1:3 internal resonance

2020 ◽  
Vol 28 (1) ◽  
Author(s):  
M. Sayed ◽  
A. A. Mousa ◽  
D. Y. Alzaharani ◽  
I. H. Mustafa ◽  
S. I. El-Bendary
Keyword(s):  
Steady State ◽  
Analytical Solution ◽  
Numerical Solution ◽  
Bifurcation Analysis ◽  
Multiple Scales ◽  
Approximate Analytical Solution ◽  
Feedback Signal ◽  
Beam Model ◽  
Signal Gain ◽  
Periodic Attractors

Abstract In this paper, we study a multiple scales perturbation and numerical solution for vibrations analysis and control of a system which simulates the vibrations of a nonlinear composite beam model. System of second order differential equations with nonlinearity due to quadratic and cubic terms, excited by parametric and external excitations, are presented. The controller is implemented to control one frequency at primary and parametric resonance where damage in the mechanical system is probable. Active control is applied to the system. The multiple scales perturbation (MSP) method is implemented to obtain an approximate analytical solution. The stability analysis of the system is obtained by frequency response (FR). Bifurcation analysis is conducted using various control parameters such as natural frequency (ω1), detuning parameter (σ1), feedback signal gain (β), control signal gain (γ), and other parameters. The dynamic behavior of the system is predicted within various ranges of bifurcation parameters. All of the stable steady state (point attractor), stable periodic attractors, unstable steady state, and unstable periodic attractors are determined efficiently using bifurcation analysis. The controller’s influence on system behavior is examined numerically. To validate our results, the approximate analytical solution using the MSP method is compared with the numerical solution using the Runge-Kutta (RK) method of order four.

scholarly journals Calculation of the critical delay for the double inverted pendulum

2020 ◽  
pp. 107754632092690
Author(s):  
Csenge A Molnar ◽  
Tamas Balogh ◽  
Islam Boussaada ◽  
Tamas Insperger
Keyword(s):  
State Feedback ◽  
Closed Loop ◽  
Inverted Pendulum ◽  
Dimensional Space ◽  
Computational Effort ◽  
Closed Loop System ◽  
Characteristic Roots ◽  
Full State ◽  
Full State Feedback ◽  
Delayed State Feedback

Single and double inverted pendulum systems subjected to delayed state feedback are analyzed in terms of stabilizability. The maximum (critical) delay that allows a stable closed-loop system is determined via the multiplicity-induced-dominancy property of the characteristic roots, that is the dominant (rightmost) roots are associated with higher multiplicity under certain conditions of the system parameters. Other methods such as tracking the changes of the D-curves with increasing delay and the Walton–Marshall method are also demonstrated for the example of the single pendulum. For the double inverted pendulum subjected to full state feedback, the number of control gains is four, and application of numerical methods requires therefore high computational effort (i.e. optimization in a four-dimensional space). It is shown that, with the multiplicity-induced-dominancy–based approach, the critical delay and the associated control gains can be determined directly using the characteristic equation and its derivatives.

scholarly journals A real-time HIL control system on rotary inverted pendulum hardware platform based on double deep Q-network

2021 ◽  
Vol 54 (3-4) ◽  
pp. 417-428
Author(s):  
Yanyan Dai ◽  
KiDong Lee ◽  
SukGyu Lee
Keyword(s):  
Control System ◽  
Reinforcement Learning ◽  
Inverted Pendulum ◽  
Learning Algorithm ◽  
Deep Understanding ◽  
Control Engineering ◽  
Experience Replay ◽  
Real Hardware ◽  
Rotary Inverted Pendulum ◽  
Reinforcement Learning Algorithm

For real applications, rotary inverted pendulum systems have been known as the basic model in nonlinear control systems. If researchers have no deep understanding of control, it is difficult to control a rotary inverted pendulum platform using classic control engineering models, as shown in section 2.1. Therefore, without classic control theory, this paper controls the platform by training and testing reinforcement learning algorithm. Many recent achievements in reinforcement learning (RL) have become possible, but there is a lack of research to quickly test high-frequency RL algorithms using real hardware environment. In this paper, we propose a real-time Hardware-in-the-loop (HIL) control system to train and test the deep reinforcement learning algorithm from simulation to real hardware implementation. The Double Deep Q-Network (DDQN) with prioritized experience replay reinforcement learning algorithm, without a deep understanding of classical control engineering, is used to implement the agent. For the real experiment, to swing up the rotary inverted pendulum and make the pendulum smoothly move, we define 21 actions to swing up and balance the pendulum. Comparing Deep Q-Network (DQN), the DDQN with prioritized experience replay algorithm removes the overestimate of Q value and decreases the training time. Finally, this paper shows the experiment results with comparisons of classic control theory and different reinforcement learning algorithms.

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