Adaptive control methods are developed for stability and tracking control of flight systems in the presence of parametric uncertainties. This paper offers a design technique of adaptive sliding mode control (ASMC) for finite-time stabilization of unmanned aerial vehicle (UAV) systems with parametric uncertainties. Applying the Lyapunov stability concept and finite-time convergence idea, the recommended control method guarantees that the states of the quad-rotor UAV are converged to the origin with a finite-time convergence rate. Furthermore, an adaptive-tuning scheme is advised to guesstimate the unknown parameters of the quad-rotor UAV at any moment. Finally, simulation results are presented to exhibit the helpfulness of the offered technique compared to the previous methods.

Adaptive sliding mode control for finite-time stability of quad-rotor UAVs with parametric uncertainties.

This article proposes a novel control strategy based on a broad fuzzy neural network (BFNN) which is subjected to contact with the unknown environment. Compared with the conventional fuzzy neural network (NN), a prominent feature can be achieved by taking the advantage of the broad learning system (BLS) to explicitly tackle the problem of how to choose a sufficient number of NN units to approximate the unknown dynamic model. Aiming at providing a soft compliant contact scheme without the requirement of the environment model, an adaptive impedance learning is developed to establish the optimal interaction between the robot and the environment. Meanwhile, the problems related to the state constraints are addressed by incorporating a barrier Lyapunov function (BLF) into the design of a trajectory tracking controller. The proposed method can achieve desired tracking and interaction performance while guaranteeing the stability of the closed-loop system. In addition, simulation and experimental studies are performed to verify the effectiveness of BFNN under optimal impedance control with a two degree-of-freedom (DOF) manipulator and a Baxter robot, respectively.

Optimal Robot–Environment Interaction Under Broad Fuzzy Neural Adaptive Control

This paper considers the finite-time chaos synchronization of Chua chaotic oscillators based on the secure communication scheme in wireless sensor networks. The modified Chua oscillators are added to the base station and sensor nodes to generate the chaotic signals. Two methods are proposed for the finite-time synchronization of the modified Chua systems with uncertain parameters. In the first method, by using the Lyapunov stability theory, control law is suggested to achieve finite-time chaos synchronization. In order to increase the robustness of the controller, in the second method, a sliding mode controller is applied to the wireless sensor network. Synchronization between the base station and each of the sensor nodes is realized by multiplying a selection matrix by the specified chaotic signal, which is broadcasted by the base station to the sensor nodes. The mathematical proofs confirm that the proposed control law is correct and finally, the simulation results are presented to show the efficiency o...

Finite-time chaos synchronization and its application in wireless sensor networks

On the guidance, navigation and control of in-orbit space robotic missions: A survey and prospective vision

In this paper, fixed-time synchronization of two fractional order chaotic systems in the presence of uncertainties and exogenous disturbances using a fuzzy adaptive sliding mode controller has been investigated. In the proposed approach, the upper bound of the synchronization time is completely independent of the difference between the initial conditions of the master and slave systems and just depends on the design parameters of the switching surface and controller. Adaption laws are proposed for selecting controllers and switching surface parameters to have a proper control and reduce control dependence on estimation of disturbances upper bound. Furthermore, to remove chattering phenomenon a fuzzy logic system is used. The fixed-time stability and controller design are driven based on Lyapunov stability theorem and simulations results are provided to show the effectiveness of proposed method.

Robust fixed-time synchronization of fractional order chaotic using free chattering nonsingular adaptive fractional sliding mode controller design

This paper proposes an adaptive robust finite-time control method based on a global sliding surface for the synchronization of a class of chaotic systems. New chattering-free control laws are designed to guarantee the removal of the reaching mode and realize the existence of the sliding mode around the designed surface right from the first moment. The proposed adaptive-tuning controllers eliminate the requirement of knowledge about disturbance bounds. Using the suggested control technique, superior master–slave synchronization is achieved, the chattering problem is fully solved, and the amplitudes of the control signals are noticeably decreased. Demonstrative simulation results for a Lu chaotic system are presented to indicate the efficiency and usefulness of the proposed scheme. In the end, using a state-feedback controller, we obtain a four-dimensional system with two interesting features. First, some hyperchaotic solutions are proposed, and then a continuous bifurcation diagram showing chaos for a wide...

Haipeng Ren

Papers

Robust finite-time synchronization of a class of chaotic systems via adaptive global sliding mode control: