Aircraft flat-spin recovery using sliding-mode based attitude and altitude control

2020 ◽  
pp. 095441002096467
Author(s):  
Salahudden ◽  
Vijay S Dwivedi ◽  
Prasiddha N Dwivedi ◽  
Dipak K Giri ◽  
Ajoy K Ghosh
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
The Body ◽  
Primary Control ◽  
System A ◽  
Horizontal Flight ◽  
Barbalat’S Lemma ◽  
Control Command ◽  
Altitude Control ◽  
Loop Form

In the present paper, a control command to recover steady-straight-level flight from flat-oscillatory-stable-left-spin is developed using a sliding-mode based attitude and altitude control. Direct spin recovery, using a spin solution by bifurcation results, to low angle-of-attack is achieved in finite-time without any separation in dynamics. The exponential convergence of errors is discussed by invoking Barbalat’s Lemma theorem. Thereafter settling time is obtained thereby making the system a finite-time stable to reach the sliding surface. The novelty of this work lies in the proposed control strategy, wherein expressions for all four primary control inputs are obtained in a closed-loop form without any approximation and altitude margin required for flat-spin recovery is investigated based on a heuristic approach for a fixed controller gains. Additionally, results of this research indicate the proposed controller first stops the spin by controlling the attitude of the aircraft thereby rotation stops about the body axis and then reaches the commanded altitude to attain the horizontal flight.

Adaptive smooth second-order sliding mode control method with application to missile guidance

2015 ◽  
Vol 39 (6) ◽  
pp. 848-860 ◽  
Author(s):  
Zheng Wang
Keyword(s):  
Sliding Mode Control ◽  
Finite Time ◽  
Control Method ◽  
Sliding Mode ◽  
Second Order ◽  
Control Law ◽  
Smooth Control ◽  
Mode Control ◽  
Control Command ◽  
Second Order Sliding Mode

This paper proposes an adaptive smooth second-order sliding mode control law for a class of uncertain non-linear systems. The key point of this control law is ensuring a smooth control signal considering parametric uncertainty and disturbances with unknown bounds. The proposed control method is obtained by introducing a continuous function under the integral and using adaptive gains. The switching function and its derivative are forced to zero in finite time. This is achieved using a smooth control command and without the prior knowledge of upper bound parameters of uncertainties. The finite-time stability is proved based on a quadratic Lyapunov approach and the reaching time is estimated. This structure is used to create a homing guidance law and the efficiency is evaluated via simulations.

scholarly journals Finite Time Consensus Control for Nonlinear Heterogeneous Multi-agent Systems With Disturbances

2021 ◽  
Author(s):  
Lianghao Ji ◽  
Donglin Lv ◽  
Shasha Yang ◽  
Xing Guo ◽  
Huaqing Li
Keyword(s):  
Finite Time ◽  
Sliding Mode ◽  
Pinning Control ◽  
Control Methods ◽  
Multi Agent Systems ◽  
Consensus Control ◽  
Agent Systems ◽  
First Order ◽  
System A ◽  
Multi Agent

Abstract This paper discusses the finite time consensus (FTC) issue of nonlinear heterogeneous multi-agent systems (HMASs) by combining integral sliding-mode control (SMC), event-triggered control (ETC) and pinning control methods. The SMC is constructed separately for first-order and second-order agents to assure that the system is not interfered by the nonlinearities and disturbances when the state trajectory of the system moves on the sliding surface. To stimulate the FTC of system, a novel control protocols are designed and a fully distributed ETC with adjustable trigger frequency only rely on the local information is introduced. Moreover, the Zeno behavior is eliminated and the range of pinning gain of each agent under directed topology is determined. Meanwhile, we also give the conditional criteria for the system to achieve FTC. Eventually, the correctness of the obtained conclusion is illustrated by several simulation examples.

An ayurvedic tablet formulation for ulcer protection

2020 ◽  
Vol 10 (4) ◽  
pp. 35-38
Author(s):  
Shiva Kumar K ◽  
Purushothaman M ◽  
Soujanya H ◽  
Jagadeeshwari S
Keyword(s):  
Pharmacological Activity ◽  
The Body ◽  
Gastric Ulcers ◽  
Antiulcer Activity ◽  
Herbal Drugs ◽  
Human Beings ◽  
Synthetic Drugs ◽  
Scientific Investigations ◽  
System A ◽  
The World

Gastric ulcers or the peptic ulcer is the primary disease that affects the gastrointestinal system. A large extent of the population in the world are suffering from the disease, and the age group of people those who suffer from ulcers are 20-55years. Herbs are known to the human beings that are useful in the treatment of diseases, and there are a lot of scientific investigations that prove the pharmacological activity of herbal drugs. Practitioners have been using the herbal material to treat the ulcers successfully, and the same had been reported scientifically. Numerous publications have been made that proves the antiulcer activity of the plants around the world. The tablets were investigated for the antiulcer activity in two doses 200 and 400mg/kg in albino Wistar rats in the artificial ulcer those are induced by the ethanol. The prepared tablets showed a better activity compared to the standard synthetic drug and the marketed ayurvedic formulation. The tablets showed a dose-dependent activity in ulcer prevention and treatment. Many synthetic drugs are available for the ulcer treatment, and the drugs pose the other problems in the body by showing the side effects and some other reactions. This limits the use of synthetic drugs to treat ulcers effectively. Herbs are known to the human beings that are useful in the treatment of diseases, and there are a lot of scientific investigations that prove the pharmacological activity of herbal drugs.

Continuous Finite-Time Integral Sliding Mode Control for Attitude Stabilization

2020 ◽  
Vol 67 (10) ◽  
pp. 2084-2088
Author(s):  
Lei Wang ◽  
Zhuoyue Song ◽  
Xiangdong Liu ◽  
Zhen Li ◽  
Tyrone Fernando ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Finite Time ◽  
Sliding Mode ◽  
Integral Sliding Mode Control ◽  
Integral Sliding Mode ◽  
Attitude Stabilization ◽  
Mode Control ◽  
Time Integral

scholarly journals Research on predictive sliding mode control strategy for horizontal vibration of ultra-high-speed elevator car system based on adaptive fuzzy

2021 ◽  
Vol 54 (3-4) ◽  
pp. 360-373
Author(s):  
Hong Wang ◽  
Mingqin Zhang ◽  
Ruijun Zhang ◽  
Lixin Liu
Keyword(s):  
Sliding Mode Control ◽  
High Speed ◽  
Sliding Mode ◽  
Mode Switching ◽  
Parameter Uncertainties ◽  
Horizontal Vibration ◽  
Adaptive Fuzzy ◽  
Mode Control ◽  
System A ◽  
Ultra High Speed

In order to effectively suppress horizontal vibration of the ultra-high-speed elevator car system. Firstly, considering the nonlinearity of guide shoe, parameter uncertainties, and uncertain external disturbances of the elevator car system, a more practical active control model for horizontal vibration of the 4-DOF ultra-high-speed elevator car system is constructed and the rationality of the established model is verified by real elevator experiment. Secondly, a predictive sliding mode controller based on adaptive fuzzy (PSMC-AF) is proposed to reduce the horizontal vibration of the car system, the predictive sliding mode control law is achieved by optimizing the predictive sliding mode performance index. Simultaneously, in order to decrease the influence of uncertainty of the car system, a fuzzy logic system (FLS) is designed to approximate the compound uncertain disturbance term (CUDT) on-line. Furthermore, the continuous smooth hyperbolic tangent function (HTF) is introduced into the sliding mode switching term to compensate the fuzzy approximation error. The adaptive laws are designed to estimate the error gain and slope parameter, so as to increase the robustness of the system. Finally, numerical simulations are conducted on some representative guide rail excitations and the results are compared to the existing solution and passive system. The analysis has confirmed the effectiveness and robustness of the proposed control method.

scholarly journals Finite-Time Adaptive Higher-Order SMC for the Nonlinear Five DOF Active Magnetic Bearing System

Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1333
Author(s):  
Sudipta Saha ◽  
Syed Muhammad Amrr ◽  
Abdelaziz Salah Saidi ◽  
Arunava Banerjee ◽  
M. Nabi
Keyword(s):  
Sliding Mode Control ◽  
Finite Time ◽  
Sliding Mode ◽  
A Priori ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Mode Control ◽  
Adaptive Laws ◽  
Effective Performance ◽  
Unknown Disturbances

The active magnetic bearings (AMB) play an essential role in supporting the shaft of fast rotating machines and controlling the displacements in the rotors due to the deviation in the shaft. In this paper, an adaptive integral third-order sliding mode control (AITOSMC) is proposed. The controller suppresses the deviations in the rotor and rejects the system uncertainties and unknown disturbances present in the five DOF AMB system. The application of AITOSMC alleviates the problem of high-frequency switching called chattering, which would otherwise restrict the practical application of sliding mode control (SMC). Moreover, adaptive laws are also incorporated in the proposed approach for estimating the controller gains. Further, it also prevents the problem of overestimation and avoids the use of a priori assumption about the upper bound knowledge of total disturbance. The Lyapunov and homogeneity theories are exploited for the stability proof, which guarantees the finite-time convergence of closed-loop and output signals. The numerical analysis of the proposed strategy illustrates the effective performance. Furthermore, the comparative analysis with the existing control schemes demonstrates the efficacy of the proposed controller.

scholarly journals Zur exakten Behandlung von kollektiven Rotationen Teil A: Theorie / On the Exact Treatment of Collective Rotations Part A: Theory

1973 ◽  
Vol 28 (2) ◽  
pp. 206-215
Author(s):  
Hanns Ruder
Keyword(s):  
Coordinate System ◽  
Perturbation Expansion ◽  
Rotational Energy ◽  
The Body ◽  
System A ◽  
N Body Problem ◽  
Definition Of ◽  
Fixed System ◽  
Body Fixed Coordinate System ◽  
Groundstate Energy

Basic in the treatment of collective rotations is the definition of a body-fixed coordinate system. A kinematical method is derived to obtain the Hamiltonian of a n-body problem for a given definition of the body-fixed system. From this exact Hamiltonian, a consequent perturbation expansion in terms of the total angular momentum leads to two exact expressions: one for the collective rotational energy which has to be added to the groundstate energy in this order of perturbation and a second one for the effective inertia tensor in the groundstate. The discussion of these results leads to two criteria how to define the best body-fixed coordinate system, namely a differential equation and a variational principle. The equivalence of both is shown.

Sign in / Sign up

Export Citation Format

Share Document