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A nonlinear output feedback control method is presented, which achieves asymptotic altitude and attitude trajectory tracking of a quadrotor system in the presence of model uncertainty and unknown external disturbances. To address a practical scenario where velocity measurements are not available, a bank of dynamic filters is utilized, which acts as a velocity observer in the closed-loop system. A...
Current traffic rule handling in autonomous driving relies on non-scalable methods such as explicitly hard-coding sets of logical statements to evaluate rules. This is sufficient for early prototypes but is not scalable for larger systems designed to work in arbitrary locations. Such methods can also become problematic when traversing different geographical entities with changing traffic rules. Additionally,...
This paper proposes a novel nonlinear controller for path following control of underactuated autonomous underwater vehicle (AUV) in the horizon plane. In order to overcome the drawback of dependence on the accurate dynamic model that are present in a number of path following control strategies described in the literature, the unknown environmental disturbances and unmodeled dynamics are viewed as...
This paper presents an intelligent sliding mode formation control using recurrent fuzzy wavelet neural networks (RFWNN) for a group of uncertain, networked heterogeneous Mecanum-wheeled omnidirectional platforms (MWOPs). The dynamic behavior of each uncertain MWOP is modelled by a reduced three-input-three-output second-order state equation and the multi-MWOP system is modeled by a directed graph...
This study proposes a new sliding mode control strategy based on a fuzzy reaching law to enhance the yaw angle control of a Tail-sitter UAV. First of all, the simplified yaw angle dynamic model is analyzed, then the fuzzy reaching law is designed considering both the chattering reduction and position tracking; finally, the sliding mode control law is designed for the Tail-sitter UAV's yaw angle system...
This paper presents an approach to enable general tracking of extended objects of multiple sensors. Expert information in each input providing sensor module is mapped into simple model parameters and allows the fusion center to use a generalized version of such information. The model type and parameters are presented and a classical Kalman based fusion is extended with a method for integrated extent...
In this paper, we develop an adaptive nonlinear controller based on dynamic inversion and neural network for quadrotor UAVs in the presence of uncertainties in UAV and actuator dynamics. The basic control law is first designed by using conventional PID control, and then the nonlinear dynamic inversion control is provided for the purpose of stabilization and robustness. The neural network is used to...
Superconducting quantum systems are promising candidates for quantum information processing due to their scalability and design flexibility. However, real quantum systems usually suffer from decoherence caused by environment disturbance. This effect, together with parametric error and un-modelled dynamics, usually leads to uncertainties in system models, which will destroy the system's excellent quantum...
A sliding mode controller is proposed for the robust control of both the position and attitude of a quadrotor. The design is tested in simulation. The performance is compared with a proportional plus derivative controller. The robustness of the design is also tested for parametric uncertainty. The effect of disturbances is also investigated. It is found that the sliding mode controller provides good...
The research of a quadrotor delivering hanged payload is meaningful in many applications, but it's also a very challenging task because the payload will significantly change the dynamics of the quadrotor. Since the states of payload is hard to measure and the mass may change, the control strategy depending on precise models may not work. Thus, we propose the Active Disturbance Rejection Control strategy...
A novel robust adaptive control scheme is developed based on the characteristic modeling and discrete-time sliding mode control theory, for the attitude control of a hypersonic vehicle with parameter uncertainties and time-variation. The characteristic model of the hypersonic vehicle is derived considering the control objective and the vehicle feature firstly. Then a discrete-time sliding mode control...
This paper considers the distributed containment problem for multiple Euler-Lagrange systems with multiple dynamic leaders in the presence of unknown uncertainties and external disturbances under a directed topology graph. First, we propose a finite-time sliding-mode estimator to obtain accurate estimation of the weighted average of the accelerations, velocities, and positions of the leaders, where...
Increasing the level of autonomy facilitates a vehicle in performing long-range operations with minimum supervision. This paper shows that the ability of Autonomous Underwater Vehicles (AUVs) to fulfill mission objectives is directly influenced by route planning and task assignment system performance. This paper proposes an efficient task-assign route-planning model in a semi-dynamic network, where...
LPV models are extremely appealing, as they allow describing the dynamics of many physical systems that are of interest in various engineering applications. For such systems, dedicated control approaches have been proposed, which rely on the measurement of the scheduling variables and exploit such information for improving the closed-loop performance with respect to fixed-structure, possibly robust,...
A robust adaptive terminal controller is proposed for attitude system of near space vehicle. Firstly, NSV dynamic model is presented, which includes nonlinear, uncertainty and disturbance. Secondly, an second order sliding mode disturbance observer is used to estimate the unknown disturbance. Then, in order to overcome the chattering problem in traditional sliding mode, the design process of second-order...
this paper presents a disturbance rejection control methodology for the course keeping of a fully-submerged hydrofoil craft. The course keeping dynamics of the fully-submerged hydrofoil craft with parameter perturbation is firstly analyzed. Then an extended disturbance observer (EDO) is developed to make real time estimate of the disturbance as well as the model uncertainties. A nonsingular terminal...
A novel attitude control scheme is proposed for a rolling aerial vehicle (RAV) with large uncertainties. Firstly, the RAV highly coupled nonlinear system is separated into attitude loop and angular loop via backstepping technique. The nominal states are calculated based on the procedure of trajectory linearization control (TLC). Then, extended state observers (ESO) are applied to estimate the uncertainties...
This paper focuses on a robust cooperative output tracking problem of networked power integrator systems. The dynamics of each system is considered as a nonlinear high-order power integrator whose linearized model is uncontrollable around its origin. It is proven via Lyapunov Theory that under some mild assumptions and graph structural properties, all agents' outputs in the network can be synchronized...
For the longitudinal dynamics of hypersonic vehicles with multiple uncertainties and time varying delays, a design method of robust controllers is proposed to control the velocity and height channels of the hypersonic vehicles model. To reduce the effects of the multiple uncertainties, the controller is designed including a full state feedback controller and a robust compensator. The robust stability...
Hybrid underwater glider (HUG) combines behaviors of autonomous underwater gliders and those of traditional autonomous underwater vehicles. HUG can dive along a saw-tooth trajectory in the gliding mode and autonomously cruise in the level-flight mode. In the study of HUG dynamics, the mathematical model and the physical parameters of the vehicle are assumed to be deterministic. The simulation results...
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