Immersion and invariance-based filtered transformation with application to estimator design for a class of DC-DC converters

2018 ◽  
Vol 41 (5) ◽  
pp. 1323-1330 ◽  
Author(s):  
Milad Malekzadeh ◽  
Alireza Khosravi ◽  
Mehdi Tavan

This paper addresses the problem of state and parameter estimation for a class of uncertain DC-DC such converters as DC–DC boost, buck and buck-boost converters. Using the advantages of Immersion and Invariance technique with input-output filtered transformation, a proper immersion and auxiliary dynamic filter is constructed in the proposed estimator. Uniform global asymptotic convergence of the estimator is proven for the system with parametric uncertainties. In the presence of both output and state dynamics perturbations, the performance of the proposed estimator has been theoretically analyzed and verified by means of simulation results. In addition, the effectiveness of this scheme is validated via experimental test for DC-DC boost converter.

2021 ◽  
Vol 3 (9) ◽  
Author(s):  
Mohammadreza Kasaei ◽  
Ali Ahmadi ◽  
Nuno Lau ◽  
Artur Pereira

AbstractBiped robots are inherently unstable because of their complex kinematics as well as dynamics. Despite many research efforts in developing biped locomotion, the performance of biped locomotion is still far from the expectations. This paper proposes a model-based framework to generate stable biped locomotion. The core of this framework is an abstract dynamics model which is composed of three masses to consider the dynamics of stance leg, torso, and swing leg for minimizing the tracking problems. According to this dynamics model, we propose a modular walking reference trajectories planner which takes into account obstacles to plan all the references. Moreover, this dynamics model is used to formulate the controller as a Model Predictive Control (MPC) scheme which can consider some constraints in the states of the system, inputs, outputs, and also mixed input-output. The performance and the robustness of the proposed framework are validated by performing several numerical simulations using MATLAB. Moreover, the framework is deployed on a simulated torque-controlled humanoid to verify its performance and robustness. The simulation results show that the proposed framework is capable of generating biped locomotion robustly.


2004 ◽  
Vol 14 (04) ◽  
pp. 1439-1445 ◽  
Author(s):  
S. S. GE

In this letter, we reconsider the problem of controlling chaos in the well-known Lorenz system. Firstly, the difficulty in controlling the Lorenz system is discussed in the general strict-feedback form. Then, singularity-free adaptive control is presented for the Lorenz system with three key parameters unknown by exploiting the physical property of the system using decoupled backstepping design. The proposed controller guarantees the asymptotic convergence of the output and the boundedness of all the signals in the closed-loop system. Simulation results are conducted to show the effectiveness of the approach.


Author(s):  
T. Sundar ◽  
S. Sankar

<p>This Work deals with design, modeling and simulation of parallel cascaded buck boost converter inverter based closed loop controlled solar system. Two buck boost converters are cascaded in parallel to reduce the ripple in DC output. The DC from the solar cell is stepped up using boost converter. The output of the boost converter is converted to 50Hz AC using single phase full bridge inverter. The simulation results of open loop and closed loop systems are compared. This paper has presented a simulink model for closed loop controlled solar system.  Parallel cascaded buck boost converter is proposed for solar system.</p>


2013 ◽  
Vol 744 ◽  
pp. 466-469 ◽  
Author(s):  
Bo Yang ◽  
Hui Zhao ◽  
Bo Dai

A new biaxial decoupled resonant micro-accelerometer is researched. The new biaxial resonant micro-accelerometer consists of four same tuning forking resonators, four pair of decoupled beams, four lever mechanisms and a proof mass. The decoupling between two orthogonal axes is realized by the decoupling beams, which will benefit to isolate two axes acceleration detection. The simulation is implemented to verify the basic principle by the Ansys. The simulation results prove that the effective frequencies of two acceleration sensitive modes are 3.699 kHz and 3.718 kHz separately. Two pair of resonator modes which are 23.893 kHz, 23.946 kHz, 26.974 kHz and 26.999 kHz separately have about 3kHz difference in frequency in order to prevent the mutual interference. And the interference modes are isolated with effective mode apparently. The input-output characteristic simulation results indicate the y-axis scale factor is 57.1Hz/g and the coupling output in the x-axis is 0.0148Hz/g, while the x-axis scale factor is 56.1Hz/g and the coupling output in the y-axis is 0.0073Hz/g, which proves that the new biaxial resonant micro-accelerometer is practicable and has an excellent decoupled performance.


1986 ◽  
Vol 18 (8) ◽  
pp. 1061-1076 ◽  
Author(s):  
F Harrigan ◽  
I McNicoll

There is a growing body of evidence which suggests that, used in conjunction with a suitable estimation method, the incorporation of good quality exogenous data can enhance the accuracy of simulated or updated regional input—output matrices. However, there has been little attempt to measure explicitly the accuracy of simulation results in relation to the data used in their estimation. Within the context of programming estimation procedure, comparable measures of the ‘quantity’ of exogenous data and the accuracy of simulation are developed in this paper. Subsequently, this framework is demonstrated using Scottish and Washington input—output tables.


Author(s):  
K W Lee ◽  
S N Singh

The article presents a new non-certainty-equivalent adaptive (NCEA) longitudinal autopilot for the control of a missile based on the immersion and invariance theory. The interest here is to control the angle of attack of the missile in the presence of large parametric uncertainties. For the derivation of the control law, a backstepping design procedure is used. At each step of the design, certain filtered signals are generated for the synthesis of a stabilizing control signal and a parameter estimator. Using Lyapunov stability analysis, it is shown that in the closed-loop system, trajectory control of the angle of attack is accomplished, and the trajectories of the system are attracted to certain manifold in the space of state variables and parameter errors. For stability in the closed-loop system, an explicit analytical relation involving the controller gains is obtained. It may be pointed out that recently an adaptive autopilot based on the immersion and inversion theory has been designed, but it has stringent requirements because for its synthesis, the derivatives of the Mach number and angle of attack must be known, and a large number of parameters must be updated. The derived control system of this article is synthesized using only the state variables, and its identifier is of lower order. A traditional certainty-equivalent adaptive autopilot is also presented for comparison. Simulation results are obtained which show that the designed NCEA control system can accomplish angle of attack control despite large parametric uncertainties; and it can give better tracking performance than the traditional controller.


Author(s):  
Shengtao Li ◽  
Xiaomei Liu ◽  
Xiaoping Liu

Transient stability is the key problem for reliable and secure planning under the new deregulated market conditions. By using immersion and invariance (I&I) method, a nonlinear coordinated generator excitation and steam-valve controller is designed to improve transient stability of power systems. The proposed coordinated I&I controller can assure power angle stability, voltage, and frequency regulations, when a large disturbance occurs on the transmission line or a small perturbation to mechanical power. Compared with the Lyapunov method, the proposed method does not need to construct a Lyapunov energy function. Some numerical simulations are used to validate the proposed controller. Simulation results show that the nonlinear coordinated I&I controller has better control performance than the existing coordinated passivation controller (CPC).


2018 ◽  
Vol 225 ◽  
pp. 04010
Author(s):  
Pydikalva Padmavathi ◽  
Sudhakar Natarajan

A novel high gain voltage lift technique based transformer free non isolated boost converter is proposed with single switch operating at constant frequency in this paper. This performance of this converter is very good and high efficient compared to the conventional boost converters. The high gain is obtained by applying voltage lift cell to the quadratic boost converter. The simple structure, easy controlling and lower voltage stress. The operating principle with theoretical analysis and simulation results of proposed converter for various loads at 10 kHz frequency are discussed in this paper to compare the performance of this novel boost converter.


Sign in / Sign up

Export Citation Format

Share Document