56results about How to "Improve flight quality" patented technology

A vertical stabilizer (38) is supported by and projects upwardly and rearwardly from the tail portion (14) of a helicopter fuselage (12). A tail rotor (TSR) is mounted on the vertical stabilizer (38) for rotation about a horizontal axis (C). The tail rotor (TSR) is positioned laterally outwardly from one side of the vertical stabilizer (38). The vertical stabilizer (38) has an upper end, a lower end and a rear edge recess (44) located between the upper end and the lower end. The recess (44) has a laterally convex rear edge (50). The tail portion (14) of fuselage (12) has a rear end extension (40) that extends rearwardly from the vertical stabilizer (38) and narrows in width as it extends rearwardly. The rear end extension (40) of the fuselage (12) provides vertical area to replace vertical area that was removed by placement of the recess (44) in the vertical stabilizer (38). A corner (82) is formed where the rear edge of the vertical stabilizer (50) meets the upper edge (80) of the rear end extension (40) of the fuselage (12). The corner (82) is laterally convex and vertically concave. The upper end of the vertical stabilizer (38) is wider than the vertical stabilizer is in the region of the rear edge recess (44). The upper end of the vertical stabilizer (38) forms a corner (84) with the rear edge recess (44). This corner (84) is laterally convex and vertically concave. The rear end extension (40) of the tail portion (14) of the fuselage (12) has a forward portion including sides that are convex in the vertical direction and a rear end portion that is substantially straight in the vertical direction. The rear end extension (40) of the tail section (14) of the fuselage (12) is both laterally and longitudinally convex.

The present invention provides a three-axis full-authority control method for flying-wing unmanned aerial vehicles based on adaptive augmentation control theory. First, a feed-forward decoupling compensation controller is designed to offset angular rate coupling; for the decoupled linear model, based on The angular rate feedback design adaptive augmented controller solves the problem that the feedforward decoupling controller cannot completely offset the coupling amount, and there are still nonlinear coupling and unmodeled dynamic problems in the model; compared with the attitude control scheme, the angular rate control The scheme speeds up the dynamic response speed of the inner loop and improves the damping characteristics, and extends the control surface to the entire available range; the present invention adds an adaptive control part on the basis of the traditional PID control method, which can make the system dynamic in the presence of uncertainty The consistency performance of the closed-loop system is maintained under the condition of unknown parameters and parameters, and the robustness and anti-interference ability of the system are improved.

The invention provides a trajectory tracking control method for a quadrotor aircraft based on nonlinear guidance, and belongs to the technical field of aircraft control. The present invention first establishes a straight-line path coordinate system, an arc path polar coordinate system, and an inertial coordinate system for the quadrotor aircraft; then calculates the required height, desired heading angle, desired pitch angle, and desired lateral Acceleration; the altitude controller of the quadrotor aircraft obtains the height required for tracking the trajectory, the attitude angle controller obtains the desired heading angle, the pitch angle controller obtains the desired pitch angle, the roll angle controller obtains the desired lateral acceleration, and finally the quadrotor The aircraft flies according to a predetermined trajectory under the control of the altitude controller, the attitude controller, the pitch controller and the roll controller. The invention solves the problems that the tracking control of the existing four-rotor aircraft cannot guarantee uniform flight and the response delay is large. The invention can be used for trajectory tracking control of quadrotor aircraft.

An airplane able to change the shape of wing is composed of an airplane body and two wings consisting of fixed wing with one end fixed to airplane body, slide wing installed in the skeleton of said fixed wing and with a roller moving in a spiral slot on a cylindrical body, and the cylindrical body and shape memory alloy bar, which are fixed to each other and installed in the skeleton of said fixed wing. Said shape memory alloy bar is used as the drive source for changing wing shape.