30 results about "Unpowered flight" patented technology

The invention discloses a design method for an approach landing track of an unpowered aircraft. When the flareout landing track is designed, assumed that the height of a flareout landing initial point is known, then, expressions of all track parameters are derived according to a geometrical relationship, and the flareout landing track is designed. In order to design the ideal flareout landing track, the proper height of the flareout landing initial point is found out through an optimization algorithm, track deduction is conducted along the landing track, and therefore the grounding dynamic pressure becomes the ideal grounding dynamic pressure. A deep glide landing track and the ideal flareout landing track form the optimal approach landing track. According to the design method, the aerodynamic force and the aerodynamic moment borne by the aircraft are taken into consideration, and the influences on the design of the landing track of aerodynamic data of deflecting of an aerodynamic control plane and putting of an undercarriage are also taken into consideration. The design method for the approach landing track is simple in principle, computer software is adopted for conducting optimization design, and the design efficiency is improved.

The invention relates to a trajectory design method for energy management of a powered reusable aircraft, which belongs to the technical field of trajectory design and guidance. The method comprises the following steps: determining the parameters of the re-entry vehicle, establishing a flight dynamics model of the re-entry vehicle; designing the lateral trajectory of the flight of the vehicle; designing the longitudinal trajectory of the flight of the vehicle; determining the angle of attack after deduction according to the remaining voyage, and obtaining the whole process control amount to complete the trajectory design. The present invention is applicable to the energy management landing problem when the energy of the aircraft is not enough to return to the airport. The trajectory design idea of ​​the energy management section is to design the trajectory first, and obtain the change of the state quantity under the condition of known longitudinal and lateral motion, so as to obtain amount of control required. The trajectory design method for the energy management section of the unpowered aircraft is improved, and a trajectory design method for the energy management section of the powered reusable aircraft is obtained.

The invention discloses a longitudinally controlled flight energy management method, system, electronic equipment and computer-readable storage medium of an unpowered aircraft. The method includes the following steps: calculating the dynamic guide amount, calculating the normal guide amount of the longitudinal velocity, Calculate the normal guidance amount in the stable stage, and calculate the longitudinal guidance command of the aircraft. The present invention estimates the current energy of the aircraft by using the current state of the aircraft and the remaining range, designs the control strategy, and obtains the longitudinal guidance command of the aircraft. During the entire calculation process, it does not involve solving the extreme value, so it will not fall into the optimal solution, and can Effectively converge the energy of the aircraft. The calculation process of this method is relatively simple and easy to implement.

The invention discloses a lateral flight energy management method of an unpowered aircraft, which relates to the technical field of aircraft flight control. Obtain the cumulative amount of direction; the cumulative amount of direction indicates the position offset direction of the aircraft; calculate the lateral velocity guidance amount according to the cumulative amount of direction and speed offset; pass the lateral position deviation through the inertia link and the proportional link to obtain the lateral position guidance amount ; Carry out weighted summation of the lateral speed guidance amount and the lateral position guidance amount to generate a lateral guidance command to control the lateral flight of the unpowered aircraft. The present invention takes the standard track as the reference, comprehensively considers the lateral velocity deviation and the lateral position deviation, combines lateral guidance with speed control, dissipates excess fuel through lateral maneuvering, avoids over-adjustment, and realizes energy management of the aircraft.

The invention discloses an unpowered aircraft trajectory tail end position and attitude smoothing control method comprising the following steps: in step S1, according to precision requirements for aircraft tail end, a position control loop circuit and an attitude control loop circuit of three passageways are respectively designed; in step S2, needed smoothing time is calculated; in step S3, for rudder instruction output of the position control loop circuit and the attitude control loop circuit, linear smoothing operation is conducted according to the smoothing time and smoothing distance, and rudder instructions that needs to be executed are output. The method disclosed in the invention is advantaged by simple principles, easy-to-implement property, high control precision and the like.

The invention relates to a reentry stage aircraft attitude control method based on an exponential time-varying second order sliding mode, belonging to the technical field of aircraft control. According to the reentry stage aircraft attitude control method, a plane symmetric unpowered aircraft model is taken as an object, feedback linearization is carried out on an affine nonlinear system of an aircraft, and the attitude control problem of the aircraft when reentering into the atmospheric layer is studied. The aircraft provides operating force and operating torque only through a pneumatic control surface. A control surface deflection angle signal [delta e delta a delta r]T is given through the designed control law, so that an attitude instruction omega c=[alpha c beta c mu c]T given by a guidance loop can be effectively tracked, the attitude angle tracking error can be guaranteed to be asymptotically converged, and strong robustness is generated for tremendous environment change, uncertain pneumatic parameters and external disturbance and the like in the reentry process. Meanwhile, the control law in the method only has integral of a switching function, so that the reaching stage of a sliding mode surface is eliminated, the control quantity is enabled to be a continuous signal, the buffeting phenomenon is effectively reduced, and good control accuracy is achieved.

Provided are blade-like grid cloth and a manufacturing method therefor, and a paraglider and a windmill made of same, falling within the field of laminar products. The blade-like grid cloth comprises an upper thread rope layer (201) and a lower thread rope layer (202), wherein the lower thread rope layer (202) comprises a plurality of first thread ropes which are arranged side by side; the upper thread rope layer comprises a plurality of second thread ropes; the plurality of second thread ropes are crosswise laid at an upper side of the plurality of first thread ropes; and one end of each blade (102) is adhered between the first thread ropes and the second thread ropes, and the other end of each blade is a movable end and is located below the first thread ropes. The blade-like grid cloth can be applied to a plurality of fields, such as paraglider fabric, windmill blade surfaces capable of rotating horizontally and aquatic sport shoes, etc. The paraglider and the windmill respectively comprise the blade-like grid cloth. The paraglider can fly without power and can also be driven to fly by an engine. The technical solution provides a blade-like grid cloth through which fluid can only pass in one direction, so that a relatively great pressure difference can be formed between two sides of the blade-like grid cloth, and the pressure difference can effectively provide a raising force with a simple principle.

The invention relates to aerodynamic layout of an internal and external flow waverider aircraft and belongs to the technical field of aerodynamic design of aircrafts. The aircraft is divided into an upper part and a lower part in terms of aerodynamic layout design; the lower part of the aircraft is mainly used for providing high lift-drag ratio for unpowered gliding flight with high Mach number, and a flat waverider layout form is adopted; the upper part of the aircraft is mainly used for arranging an air suction type ramjet. According to the layout form, an engine flow channel and a waveriderplane are mutually independent and non-interfering, so that coupling effect of pneumatics and power is greatly reduced, particularly, resistance produced by an engine during unpowered flight with high Mach number can be obviously reduced, increase of the lift-drag ratio during unpowered flight with high Mach number is facilitated, and furthermore, thermal protection of the engine is facilitated.

The invention discloses a large-diving-depth underwater unpowered aircraft transmitting system and method. The transmitting system comprises an underwater autonomous measuring and control system, a transmitting cylinder with a front cover, a catapult arranged in the transmitting cylinder, and an aircraft arranged in the transmitting cylinder, wherein the transmitting cylinder, the catapult, the aircraft and the measuring and control system integrally adopt an axial deflection design; compared with a mass center, the axial buoyant center is closer to the front cover of the transmitting cylinder; the transmitting system is fixed to an underwater platform, after the transmitting system is separated from the underwater platform, the situation that upward buoyance is greater than the sum of gravity and floating resistance is changed into the situation that the upward buoyance and the sum of the gravity and floating resistance gradually tend to be balanced; the aircraft is fixed on one side of a sealing bottom plate in the transmitting cylinder, and the other side of the sealing bottom plate is connected with the catapult; and after the front cover is opened, the catapult produces thrust to push the aircraft to slide in the direction from the transmitting cylinder to the front cover, and the aircraft slides from the transmitting cylinder. According to the large-diving-depth underwater unpowered aircraft transmitting system disclosed by the invention, the maximum transmitting depth of the transmitting system is not less than 200 meters; and in the transmitting system, the aircraft does not bear water pressure limit directly, so that the aircraft is low in design condition requirements, and high in portability.

The invention discloses a trajectory prediction and value filtration method for a rocket launching unpowered flight segment. An instant orbit injection Kepler parameter of a trajectory is calculated according to a set of credible trajectory measurement data or two sets of position-speed vector data, and then trajectory data after the moment is predicted according to the orbit parameter. A trajectory data result is calculated according to multiple sets of the predicted data and credibility weighting, and the result can be used for displaying the trajectory and measuring anomalous point filtration of the trajectory data in real time. By adopting the trajectory prediction and value filtration method for the rocket unpowered flight segment on the basis of a spacecraft orbit determination method, the display effect and precision of the trajectory are significantly improved.