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When a helicopter is required to hover with minimum deviations from a desired position without measurements of a persistent wind disturbance, a robustly stabilizing control action is vital. In this paper, the stabilization of the position and translational velocity of a nonlinear helicopter model affected by a wind disturbance is addressed. The wind disturbance is assumed to be a sum of a fixed number...
Electrically Controlled Rotor (ECR) is a new concept rotor system which was brought forward at the beginning of the 21st century. A control strategy of the ECR system is given out in this paper. An adaptive blade pitch control strategy of the ECR system is proposed, which is based on the adaptive filter with least mean aquare (LMS) algorithm. A secondary path on-line identification method with random...
The dynamic equations of a quadrotor unmanned aerial vehicle (UAV), namely Qball-X4, are analyzed and built, trajectory tracking control design based on an inner/outer loop control structure is proposed in this paper. The method of analytic geometry is used in dead-reckoning, discrete Kalman filter has been applied to trajectory tracking for improving the accuracy of estimated location. Integrated...
This article presents one solution to a quadrotor control problem that is based on a discrete automaton. This automaton combines classical PID and more sophisticated LQ controllers to create a hybrid control system. This closed loop control concept is expanded with an open loop controller that enables the aircraft to perform aggressive flying maneuvers. The combination of open and closed loop controllers...
This paper presents the solution to the tracking control problem for an underactuated scaled autonomous helicopter using variable structure control via output measurements. First, it is designed a state-feedback second order sliding mode controller to stabilize height and rotation positions. Controller is designed from a reduced model of the helicopter and the resulting control law is tested in its...
This paper focuses on a critical component of the situational awareness, the control of autonomous vertical flight for an unmanned aerial vehicle. Autonomous vertical flight is a challenging but important task for tactical unmanned aerial vehicles to achieve high level of autonomy under adverse conditions. With the situational awareness strategy, we proposed a two stage flight control procedure using...
A helicopter agent has to plan trajectories to track multiple ground targets from the air. The agent has partial information of each target's pose, and must reason about its uncertainty of the targets' poses when planning subsequent actions. We present an online, forward-search algorithm for planning under uncertainty by representing the agent's belief of each target's pose as a multi-modal Gaussian...
In this paper a quadrotor aircraft is developed with the signals of attitude angle and angular rate being filtered by using frequency analysis. A PD sliding mode controller is designed to stabilize the attitude and position while a tracking-differentiator is employed to obtain the estimate of the required velocity. Experiments are conducted to demonstrate the developed quadrotor can be appropriately...
In this paper we present an application of a recently developed strategy for robust distributed controller design for formations and show a way of including performance requirements in the design. The proposed synthesis method guarantees stability for all possible formations and arbitrary fast changes in the communication topology. The number of agents in the formation can also be chosen arbitrarily...
This paper presents a helicopter dynamic model controlled by a nonlinear output feedback controller. Particular emphasis is placed on the mathematical modeling of the main rotor dynamics, i.e., modeling the individual dynamics of the blades and the dynamics of the main rotor stabilizing bar. Since the derived model is highly nonlinear, an output feedback controller that uses a nonlinear observer is...
The contribution of this paper is the development of a nonlinear position controller for a quadrotor VTOL aircraft using feedback linearization with dynamic extension. The developed controller completely decouples and linearizes the nonlinear dynamical model of the aircraft. The use of dynamic extension has resulted into a fourteenth dimensional controller for the the twelve dimensional state system...
We present the current results of our ongoing research in achieving efficient control of a flying robot for a wide variety of possible applications. A lightweight small indoor helicopter has been equipped with an embedded system and relatively simple sensors to achieve autonomous stable flight. The controllers have been tuned using genetic algorithms to further enhance flight stability. A number of...
Hovering performance of unmanned helicopter is of key importance in flight.This paper presents an autonomous control system to achieve the excellent hovering performance for a miniature unmanned helicopter. First, the response data of system is collected during special flight test and a linear time-invariant model is extracted by frequency identification technique.Then, the control system is designed...
In this paper, we present a new control approach for a quadrotor mini-helicopter using the full state backstepping technique. The controller can set the helicopter track three Cartesian position and the yaw angle to their desired trajectories and stabilize the pitch and roll angles by varying the input signals of DC-motors. The quadrotor has been presented into three interconnected subsystems. The...
In this paper, we deal with the problem of local positioning and orientation of a rotorcraft in indoor flight using a simple vision system. We apply two different approaches to obtain a navigation system for the flying machine. The first approach is based on the perspective of n-points and the second one follows the plane-based pose technique. Our aim is to obtain a good estimate of variables that...
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