Papers by Keyword: Flight Control

Abstract: This paper presents the flight dynamics simulation and analysis of a tilt-rotor vertical takeoff and landing (VTOL) aircraft on transition phase, that is conversion from vertical or hover to horizontal or level flight and vice versa. The model of the aircraft is derived from simplified equations of motion comprising the forces and moments working on the aircraft in the airplane's longitudinal plane of motion. This study focuses on the problem of the airplane's dynamic response during conversion phase, which gives an understanding about the flight characteristics of the vehicle. The understanding about the flight dynamics characteristics is important for the control system design phase. Some simulation results are given to provide better visualization about the behaviour of the tilt-rotor. The simulation results show that both transition phases are quite stable, although an improved stability can give better manoeuver and attitude handling. Improvement on the simulation model is also required to provide more accurate and realistic dynamic response of the vehicle.

Abstract: A vertical takeoff and landing aircraft (VTOL) like a helicopter has come to be used in environmental investigations and inspections at dangerous places. However, there is a possibility that the VTOL like a helicopter crash if the rotor stopped. Then, computational simulation in the case that a six-rotor craft can safely continue to fly even though one of six rotors stop was carried out. Then the experimental six-rotor craft was developed and the validity of our control method was examined by the flying experiment.

Abstract: This paper performed the longitudinal nonlinear PID Controller parameter optimization of general aircraft autopilot based on the longitudinal channel model and genetic algorithm. Proportion, integration and differential gain of nonlinear PID Controller is nonlinear function of controlling error. The objection function involves time integration of error’s absolute value, output of controller and system overshoot. The longitudinal controlling rate optimization of general aircraft autopilot is realized by minimizing the objection function value. Simulation results show that controller designed by the present method is better than traditional PID controller.

Abstract: For quadrotor unmanned air vehicles (UAVs) nonlinear control problems under disturbance conditions, a nested loop control approach is presented to realize robust control. The robust control approach is proposed to solve the stabilization and navigation problems in the quadrotor. The robust control strategy is composed of two controllers. A nonlinear backstepping controller is designed for the inner loop to stabilize the attitude angle. A PID controller based on BP neural network is designed for the outer loop in order to generate the reference path for the inner loop. Numerous simulations and flight test experiments have been made to study the performance of controller based on the independently developed quadrotor UAV. The results illustrate that the proposed controller has good stability, maneuverability and robustness.

Abstract: The Wing-in-Ground Effect vehicles (WIG-craft, Wingships) or Ekranoplanes as they are called in Russia are developing in several countries and the problem of perfect flight control is very important for these vehicles' successful application either for commercial or military. An accident-free flight at very low altitude above the rough underlying surface, mainly above the disturbed sea surface, and also take-off and landing require special systems of motion control that are different from those used on planes. The requirements for such motion control systems and the new criteria for their improvement are offered. The aim of this investigation is to define the way for operational performance improvement of the vehicles of advanced design. The experience and achievements in this field of high technology are described.

Abstract: Helicopter is a strong coupling and instability nonlinear system, of which the inherent flight qualities are poor. Helicopter model following control technology can make four control channels of helicopter with excellent tracking and decoupling characteristics. This paper applied the control method of model following control combining eigenststructure assignment to the helicopter control system. The results of simulation show that the helicopter flight qualities meet the requirements of ADS-33, the helicopter has excellent tracking and decoupling characteristics. Thus it proves that this control method is of great effectiveness.

Abstract: Quadrotor helicopter is light and very agile aerial robots which attracted much attention of scientists. A practical implementation of a quadrotor helicopter based on STM32 is described in this article, applying MPU6050 and other inertial sensors. The hardware structures and software flow chart of flight control are both presented. The discussions with the key problems during the process of implementation are also made.

Abstract: A frequency identification modeling method for a small UAV helicopter and its control system design is presented. A modified frequency identification method for a state-space model of helicopter is presented. The overall concept is to extract a complete set of non-parametric input-to-output frequency responses that fully characterizes the coupled helicopter dynamics, conduct a nonlinear search based on secant method for a linear state-space model that matches the frequency-response data set. The accuracy of the identified model is verified by flight experiments. A path following controller is presented for an unmanned helicopter with two-loop control frame. The outer-loop is used to obtain the expected attitude angles through reference path and speed with guidance-based path following control, and the inner-loop is used to control the attitude angles of helicopter tracking the expected ones with loop shaping method. Finally, an 8 trajectory tracking simulation is conducted to illustrate the efficiency of the proposed control method.

Abstract: This paper describes an unconventional overall design of eight-rotor aerial robot. An INS/GPS based Kalman Filter solution is introduced in attitude estimate to meet the high precision and reliability requirement. In order to coordinate the contradiction between high load and high frequency, we present a new control method for multi-rotor aerial robot, witch take decoupling control on lift rotors and attitude control rotors. Results of simulation and flight test show that our design on aerial robot is effective.

Abstract: This paper carried out the control system design of a DFV based on dynamical characteristic analysis, and flight experiments were carried out to validate the performance of the control system. Firstly, the characteristics such as outstanding and control difficulty were pointed out, and then the control strategy such as three forms of translation is proposed. In the end, the controller was realized and tested by a series of experiments, and the excellent performance was demonstrated by the experimental results.