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In this paper, we focus on the hover/high-speed-cruising transition flight control of a ducted fan unmanned aerial vehicle (UAV), in which saturation on control surfaces is taken into consideration. To achieve full-envelope flight control, we propose an adaptive cascaded structure on the velocity tracking control for the nonlinear aircraft system. By introducing adaptive neural network, the closed-loop system tracks a prescribed reference system with all the nonlinear tracking errors well canceled. In the meanwhile, to tackle the control surface saturation, we propose a control effectiveness enhancement (CEE) algorithm in attaining sufficient control moment to the ducted fan vehicle. Under the proposed cascaded adaptive control scheme in conjunction with the CEE algorithm, the state tracking performance is proved to be bounded when encountering surface saturation. Finally, comparison experiments in terms of the forward and backward flight transition are conducted on the ducted fan UAV. The results are satisfactory and convincing in exhibiting the flight transition course that demonstrates the effectiveness of the proposed method.

To handle the problems of point cloud data quantity explosion and urgent need for real-time access to massive point cloud data in collecting and storing phase, this paper proposes an index technology with internal and external storage interactions, which is based on extended 3D grid in memory layer and B-tree in external storage layer. The experiment shows that it is efficient to retrieve massive point cloud data by using this double-layer index structure.

The autopilot of aerobridge has attracted considerable attention recently since human error and high labor costs. To estimate the pose of an aerobridge, this paper proposes a navigation algorithm with the aid of pairwise distances and inertial measurements. We first locate the joints of the aerobridge with the distance measurement. Then the pose of the aerobridge is calculated using its kinematic in closed-form and the associated covariance is derived. A dual quaternion based multiplicative extended Kalman filter is designed to fuse inertial measurements with the estimated pose, which produces a smooth pose. To verify the precision of this algorithm, a simulation is constructed based on Robotics Toolbox and the experiment results are positive.

In this paper, we generalize the Extended Kalman Filter algorithm on Lie Groups for the attitude propagation and update of the unmanned helicopters. The data noises obtained by sensors are assumed to be independent as Gaussian distributions, and the posterior distribution of the estimated state is also Gaussian distribution. The attitude of the drone can be obtained from the accelerometers, the gyroscopes, and the magnetometers. These three sensors need to be fused to obtain the optimal estimated value. Among them, the method of multiple sub-samples is used to compensate for the error generated by the long sampling period of the gyroscope, and we use a Chi-square detection method to determine whether the observation information is valid during the updating process.

In this paper, we address the hover-to-cruise transition control problem for high-speed level flight of a ducted fan UAV. Firstly, the nonlinear aircraft dynamic system is derived and relevant key aerodynamic characteristics are presented. Then, we divide the dynamic system into known parts and uncertain parts. In order to track a reference system formed by the known parts, we propose a neural-network-based control strategy to learn the error dynamics and cancel the tracking error with proved stability. Finally, simulations and experiments are conducted to perform the transition process at fixed altitude and constant horizontal acceleration, with satisfactory results accomplishing the designed flight course.

In this paper, it is supposed that the linearized water wave equation (LWWE) can describe the movement of water waves. Utilizing the identification algorithm we put forward in this paper, the depth of water, the elevation of the wave surface, and the velocity potential can be calculated from the measured velocity of surface water waves at the same time. We show the estimability by proving the mapping from the depth of water, the elevation of wave surface and the velocity potential to the measurement is injective. Moreover, we verify our proposed algorithm, which is on the basis of the classical gradient descent method, with some numerical simulations.

This paper presents new techniques for construction of dynamic output feedback controllers with a static anti-windup compensator for a class of saturated systems with sector-bounded and slope-restricted nonlinearities. To handle the slope restriction, a so-called differential compensator is incorporated into the traditional nonlinear controller. Considering its sector-bounded property and convex-hull representation, respectively, two LMI-based synthesis methods are proposed to address the problems of the estimates of the region of attraction (ROA) and ${{{\mathcal{L}}}_2}$ performance analysis of the closed-loop system. A numerical example illustrates the effectiveness of the proposed approaches.

In this paper, we propose an algorithm of identification in order to simultaneously estimate the velocity of water waves and the water depth in coastal region. We assume that the motion of water waves is described by linearized water wave equation (LWWE) and the surface wave elevation is measurable. Based on the gradient descent method, we design an algorithm of identification to recover simultaneously both the velocity of water waves and the water depth. Numerical simulations are carried out to show the effectiveness of the algorithm.

The robust controller is designed for certain BTT missile which is equipped with grid fin. In order to design the controller of BTT missile, the aerodynamic force of grid fin is analyzed when the grid fin rotates in flying, then the aerodynamic force and aerodynamic moment along with movement equations are linearized based on the small perturbation linear theory, the beginning state of the cruise is chosen as the feature point, and then the dynamical coefficient are calculated, then the longitudinal and lateral perturbation equations are established. The dynamic responses of each motion deviation under the longitudinal and lateral free disturbance are obtained through solving the perturbation equations. The transfer functions and the dynamic responses under the step deflection of grid fin are derived, then the dynamic characteristics of the missile can be obtained. The results indicate that the grid fin can provide favorable stability. The H ∞ controller of pitch and lateral bank channels are designed based on dynamic characteristics analysis, the simulation results indicate that the system dynamic performance can satisfy the requirement, and H ∞ controller has a fine robustness for the parametric variation.

In order to simulate the in-orbit movement of formation satellites, the unmanned helicopter is utilized to set up the microgravity environment relative navigation ground simulation platform. The platform can provide the movement of six degrees of freedom and can simulate the formation satellite flying in three-dimensional space. The test platform includes host computer system, communication system, UAVs formation control system, satellite attitude simulation system, and so on. Sensors are equipped with laser radar and visible light cameras. Formation control and navigation of multi-body can be achieved under complex network environment. The platform can be used for the test of satellite autonomous formation simulation, joint fleet navigation, and so on. The algorithm of multi-body formation, multi-source and multi-target tracking based on sensor network, multi-body navigation and remote control can be verified on this platform.

In order to realize the localization demand of mobile robot, the motion model and observation model of mobile robot were analyzed, and the mobile robot real-time localization algorithm of given map environment based on extended Kalman filtering was described. Besides, the algorithm was simulated. The landmark model of map was built in the process of simulation, and the landmark that was observed under control action was used to correct the location of mobile robot, by which the positioning of robot was realized. The result of simulation shows that the positional accuracy of this algorithm is very high. In addition, the construction method of real-time map of mobile robot was described on extended Kalman filtering under unknown environment based on this. Experimental result shows that this algorithm can identify the location of landmark accurately so as to give reference for the real-time positioning and mapping construction of mobile robot.

In this paper, Universal Kriging (UK) technology combined with Model Predictive Control (MPC) algorithm is exploited to estimate the unknown situation of oil dispersion for just one unmanned aerial vehicle (UAV) to predict and track the objective boundary automatically. The advantage of the Kriging method is that it is an optimal interpolator in the sense that the estimates are unbiased and the minimum variance is known, so that it can relatively accurately construct the environment map. In addition, the advantage of the MPC is its constraint handling capacity. These two uncorrelated technologies, however, can be combined to realize some special functions. The simulation based on an advection diffusion equation demonstrates the proposed method is feasible and effective.

This paper presents a hierarchical inner-outer loop-based approach to the longitudinal and lateral control of a small unmanned helicopter in the presence of parameter uncertainties and exogenous disturbances. The outer loop employs robust H ∞ output feedback to attenuate the wind disturbance and track the reference trajectory, while the inner loop controller is proposed to solve the parameter uncertainties problems using robust H ∞ static output feedback. The obtained control method takes advantage of the feature of hierarchical structure ensuring the stability of the flight attitude. Finally, the validity of the proposed control strategy is verified through simulation results.

This paper considers the robust static output feedback control of a miniature helicopter with parameter uncertainties and wind gust disturbances. A sufficient H 2 /LMI condition is derived for suboptimal controllers of uncertain system. Then by iterative LMI algorithm, the robust static output feedback controller is designed for the helicopter system with uncertainties. In the end, simulation results are given to validate the control method.

This paper considers the environmental boundary tracking problem where the objective is to steer a mobile robot to track the desired environmental boundary. Based on the kinematic model of the mobile robot, we design a kinematic control law for the robot to track the desired boundary. Kinematic control law needs perfect velocity tracking, which doesn't always hold for a mobile robot. So, dynamic control law is designed for the nonholonomic mobile robot to track a designated reference velocity, so as to track the desired environmental boundary. The stability of the designed control laws is verified by Lyapunov theory and Barbalat's Lemma and illustrated by simulation results.

A linear physical model with uncertainties is used to describe the lateral dynamics of a miniature helicopter. The structured parameters with uncertainties are identified through a lot of experiments. Then a robust H ∞ static output feedback (RHSOF) control is presented to guarantee the stability of the system and the influence of the unmodeled dynamics and disturbance in a given level. At last, simulation results validates the designed control law.

This paper examines the fault tolerant control problem for a generic class of incipient failure modes that grow in severity as a function of component loading. Assuming that a prognostic model is available to evaluate the risk of incipient fault modes growing into catastrophic failure conditions, then fundamentally the fault adaptive control problem is to adjust component loads to minimize risk of failure, while not overly degrading nominal performance. A methodology is proposed for posing this problem as a finite horizon constrained optimization, where constraints correspond to maximum risk of failure and maximum allowable deviation from nominal performance. Simulation results are given for an example system with an active redundant DC motor configuration. The fault mode simulated in this system is temperature dependent motor winding insulation degradation.

This paper attempts to make a conceptual illustration of fault prognosis-enhanced reconfiguration control. The definition of fault propagation and the proposed control adaptation algorithm ensuring the mission completion are discussed in this paper, along with some illustrative examples on prognosis-enhanced reconfiguration control of servomechanisms.

In this paper, decentralized controllers are developed to drive a swarm of mobile agents with high-order (n > 2) nonlinear dynamics in strict feedback form into a moving target region while avoiding collisions among themselves. It is important to consider coordination of multiple high-order agent dynamics which generalize the existing simple single-integrator/double-integrator ones because, in practice, we may need to incorporate actuator dynamics into the vehicle dynamics in order to achieve better performance, thus increasing the order of the system dynamics. The control design is based on a fusion of two kinds of new potential functions (target potential functions and collision avoidance potential functions), backstepping technique and Lyapunov synthesis. The presence of parametric uncertainties is handled by adaptive control techniques. The framework does not depend on a fixed ordering of agents, and is robust to individual agent failures. Therefore, flexibility and scalability are improved. Simulation results illustrate the performance of the proposed approach.

This paper addresses the boundedness of L2-L∞ norm of polytopic system with time-varying delay. Delay-dependent sufficient conditions are presented such that the L2-L∞ norm of polytopic system is less than a prescribed scalar in terms of linear matrix inequalities. Numerical example is presented.

The core of the abstraction-refinement verification is the analysis of the counterexample and refinement of the abstract model, which are the most expensive parts of the verification procedure. In this paper, we present a method that aims at reducing the complexity as much as possible. Our method combines the qualitative analysis with the reachability analysis. Qualitative analysis checks the feasibility of pair-wise transitions without the explicit numerical reachability computation. While reachability analysis employs bidirectional analysis strategy to minimize the region to be refined. Experiment shows that the integration of these strategies and techniques make the verification more efficient.

In this paper, we present an autonomous helicopter with vision based navigation called South China University of Technology unmanned aerial vehicle (SCUAV). A GPS/INS system has been designed and implemented for getting stable navigation information. A Kalman filtering has been used in this system for data fusion. A real-time computer vision system is presented in this paper as the complement of the GPS/INS system. The vision algorithm is designed and implemented in this paper, which is integrated with algorithms for tracking a known landmark and estimating the helicopter positions. A method of image processing is designed for tracking and recognizing known land marks. At the end of the paper, we will present the experiment results to demonstrate our efficacious algorithm.

In this paper the concept and model of hybrid systems are introduced. Invariant sets introduced by LaSalle is proposed, and the concept is extended to invariant sets in hybrid systems which include disturbance. It is shown that the existence of invariant sets by arbitrary transition in hybrid systems is determined by whether there exist a common Lyapunov function in the systems. Based on the Lyapunov function, an efficient transition method is proposed to ensure the existence of invariant sets. An algorithm is concluded to compute the transition mode, and the invariant set can also be computed as a convex problem. The efficiency and correctness of the transition algorithm are demonstrated by an example of hybrid systems.

A small unmanned helicopter is constructed in South China University of Technology. It has already gained some rudimental capability of autonomously flying. In this paper we introduce the further design of its multi-variable control strategy, a robust gain-scheduling algorithm. The feasibility of the proposed design is proven via simulation results.