144 results about "Near space" patented technology

The invention discloses a nonlinear self-adaption control method of near-space hypersonic vehicle (NHV), which belongs to a flight control method in the technical field of aerospace. The control method mainly comprises three control law parts: a nominal nonlinear generalized predictive control law (NGPC), a B-spline recursive functional linkage network (BRFLN) self-adaption control law, and a robust control law of gain self-adaption adjustment. The invention integrates the simplicity of the NGPC method and the effectiveness of dynamic uncertainty of the BRFLN learning, targets the immeasurable dynamic uncertainty and fast interference of an attitude system in the flight of the NHV, brings favorable learning effect, and realizes the nonlinear accurate control to the attitude angle.

The invention discloses a near-space missile-borne strap-down inertial navigation system transfer alignment method based on a star sensor. The method comprises the following steps: 1) establishing a missile-borne strap-down inertial navigation system transfer alignment state equation by taking an inertial coordinate system (launching point coordinate system for short) on a carrier launching point as a navigation coordinate system and a strap-down inertial navigation system (SINS) on a missile to be launched as sub-inertial navigation; 2) calculating navigation information and observed quantity of the missile-borne strap-down inertial navigation system; 3) establishing a measurement equation; 4) by depending on the state equation and the measurement equation established, estimating a mathematics platform misalignment angle, a speed error, a position error and an installation error of the missile as well as flexural deflection of the carrier through a sparse grid integral kalman filter, and correcting a sub-inertial navigation system, thus finishing a transfer alignment process.

A near space propeller comprises propeller blades and propeller hub. Two propeller blades are connected through the propeller hub to form an integral structure; and the propeller blades have the following structure: chord length of 160-180mm and angle of attack beta of 31-34 degree at 0.3 elongation position; chord length of 140-160mm and angle of attack beta of 25-28 degree at 0.35 elongation position; chord length of 115-135mm and angle of attack beta of 18-21 degree at 0.45 elongation position; chord length of 95-110mm and angle of attack beta of 16-18 degree at 0.6 elongation position; chord length of 85-95mm and angle of attack beta of 14-16 degree at 0.7 elongation position; chord length 65-75mm and angle of attack beta of 13-14 degree at 0.75 elongation position; and chord length of 45-55mm and angle of attack beta of 12-13 degree at 0.9 elongation position.

The invention discloses a near space moving target positioning method based on an unmanned aerial vehicle, which belongs to the technical field of unmanned aerial vehicle target positioning. The method comprises the following steps: firstly, an infrared target detector loaded on the unmanned aerial vehicle is used for acquiring a target angle measurement value, in combination of an unmanned aerial vehicle navigation system, the position and the attitude information of the unmanned aerial vehicle are outputted, and the angle value of the connection line between the target and the unmanned aerial vehicle in an earth-rectangular coordinate system is calculated; then, according to the calculated angle value, the least-squares solution of the target in the earth-rectangular coordinate system is solved; and finally, the solved rectangular coordinates are converted to the longitude, the latitude and the height. The method can realize high-precision positioning of the near space target when a laser range finder or a radar can not be used normally, and can be applied to multi-unmanned aerial vehicle formation cooperative positioning.

The invention discloses a moving target detection method and an imaging method for a near space slow platform SAR (Synthetic Aperture Radar). In the detection method disclosed by the invention, the characteristics of low platform speed and smaller ground static clutter Doppler broadening of the near space slow platform SAR are utilized, and separation of a moving target from static clutter is realized by designing a Doppler filter in a Doppler domain, so that the problem of difficulty in separating dynamic and static clutters of the SAR in moving target imaging is solved. According to the imaging method disclosed by the invention, moving target echo is extracted after separation of dynamic and static clutters and moving target detection, one-order keystone conversion is combined with a variable-resolution Doppler frequency modulation estimation method, and range walk correction is completed under the condition that the speed of the moving target is unknown, so that the problem of difficulty in range walk correction of the moving target echo is solved. The methods have the advantages that rapid moving targes can be detected and imaged; and the methods are suitable for detecting and imaging slow moving targets.

The invention discloses a wind tunnel test data correction method for a near-space high-aspect ratio flexible spacecraft. The wind tunnel test data correction method comprises a basic state data correction of wind tunnel test, a horizontal tail installation angle adjustment and a data correction of wind tunnel test pilot. The wind tunnel test data correction method combines the prior test conditions for wind tunnel tests in China and completes the correction of the wind tunnel test data of rigid body shape by means of aeroelastic and fluid mechanics analysis. The wind tunnel test data correction method can provide accurate aerodynamic data for near-space high-aspect ratio flexible spacecraft control rate design and flight simulation and ensure that the aircraft can stably flight under the condition of large deformation near the space.

The invention discloses an air-space-ground integrated network system architecture based on a near space platform and a design method, and belongs to the technical field of wireless communication, andthe design method comprises the following steps: S1, introducing a near space platform aircraft; S2, formulating a communication link frequency band planning scheme; S3, simplifying protocol design.When communication link selection is carried out, the communication link selection is carried out based on the principle of minimizing propagation time delay and routing hops according to the geographical location relationship and the service type of two users carrying out communication. According to the invention, the near space platform aircraft is introduced into the network system architecture; a satellite network and a ground network are fused; global coverage is realized; the communication service quality of a non-ground network coverage area is effectively improved, extremely high robustness is achieved, the rerouting rate, the switching rate, the system delay overhead, the system access capacity and the like can be remarkably improved by designing a simplified protocol process, a frequency band planning scheme and a link selection scheme, and the method is worthy of application and popularization.

The invention provides a device for measuring RCS (Radar Cross Section) jet disturbance force and disturbance moment of a near space aircraft. The device comprises six simple component force sensors, six elastic hinge connecting rods and three adaptive connecting rods, wherein the measurement directions of the three simple component force sensors are distributed along the axis Z of the Cartesian coordinate system and the three simple component force sensors are used for respectively measuring the force along the direction of the coordinate axis Z, the moment along the direction of the coordinate axis Y, and the moment along the direction of the coordinate axis X; the measurement directions of the two simple component force sensors are distributed along the axis X and the two simple component force sensors are used for measuring the force along the direction of the coordinate axis X and the moment along the direction of the coordinate axis Z; the measurement direction of one simple component force sensor is distributed along the axis Y and the one simple component force sensor is used for measuring the force along the direction of the coordinate axis Y; the elastic hinge connecting rods are arranged uprightly, one end of each elastic hinge connecting rod is fixedly arranged at one of the simple component force sensors, and the other end of each elastic hinge connecting rod is fixedly arranged at an upper floating plate directly or indirectly through one adaptive connecting rod. The device is capable of simultaneously measuring the three-component force and three-component moment of the whole RSC under a working state.

The invention provides a near space atmosphere environment detector and an operating method thereof. The detector comprises a load grade system and a booster grade system; the booster grade system comprises a rocket body structure, a booster grade control subsystem and a booster grade power mechanism; the booster grade control subsystem is used for detecting the attitude and motion information of the rocket body structure when the load grade system is separated, and then controls the operation of the booster grade power mechanism according to the attitude and motion information of the rocket body structure, and therefore backward-thrust braking is provided to make the rocket body structure land in the vertical direction; the load grade system comprises a payload bay carried with an environment detection instrument, a load grade control subsystem and a load grade power mechanism; the load grade control subsystem is used for controlling the load grade power mechanism to operate in dependence on detected attitude, height, motion and guidance information, control of flying trajectories of the payload bay, the load grade control subsystem and the load grade power mechanism is achieved, and at least two times of skip flying is achieved.

The invention relates to an aircraft trajectory predicting method, in particular to a method for predicting a skipping trajectory of a hypersonic glide warhead in near space and belongs to the technical field of target tracking. The method aims to solve the problem that by the adoption of an existing method, the prediction precision of the trajectory of a maneuvering target is low. The method comprises the steps that firstly, a trajectory equation of the hypersonic glide warhead is established; secondly, a kalman filter tracking the movement curve of the hypersonic glide warhead is designed; thirdly, according to the position, the speed and the acceleration of the hypersonic glide warhead at the tracking end moment and the trajectory equation, the attack angle and the roll angle of the hypersonic glide warhead in fight are estimated, the hypersonic glide warhead in the near space flies by a constant attack angle and a constant roll angle in a subsequent flight time period, recursive calculation for the trajectory at a next moment is conducted through the trajectory equation, and then a trajectory prediction value of the hypersonic glide warhead after a time period is obtained.

The invention relates to a modified variable-structure grid interaction multi-model filtering method, and provides a modified variable-structure grid interaction multi-model filtering method for tracking a hypersonic-speed target of near space. By the modified variable-structure grid interaction multi-model filtering method for tracking the hypersonic-speed target of the near space, the problem that the existing single-model filtering algorithm, the existing fixed-structure interaction type multi-model algorithm and the traditional variable-structure interaction multi-model algorithm cannot be used for quickly tracking a hypersonic-speed maneuvering target of the near space precisely is solved. According to the technical scheme, the modified variable-structure grid interaction multi-model filtering method for tracking the hypersonic-speed target of the near space comprises the following steps of (1) establishing an inertial reference coordinate system and establishing a state equation of maneuvering movement of the target in the inertial reference coordinate system; (2) using a current statistics model of the maneuvering target as a central model and using constant-speed turning models as a left turning model and a right turning model; (3) determining a measurement model of a target tracking system on the basis of the inertial reference coordinate system; and (4) performing state estimation and error covariance matrix fusion. The modified variable-structure grid interaction multi-model filtering method for tracking the hypersonic-speed target of the near space is used for the field of aircrafts.

A pod (100) for flights to and/or from space or near-space, comprising a pressurized body (10) for hosting passengers, said pressurized body having a substantially ring-like shape provided around a central axis (7) and having a central opening, wherein said pressurized body comprises one or more windows.

The invention discloses a high resolution imaging system. The system comprises an optical camera, an airborne data processing system and image transmission equipment of real-time transmission. A shell top of the imaging system is provided with a light shield mask. The optical camera is formed by four lens arrays. Each lens adopts a linear array CCD. The airborne data processing system carries out splicing processing on an image obtained by each camera so as to acquire a high resolution image with a large field of view scope. Therefore, under the condition that a total number of detection pixels of a focal plane array detector is not increased, the resolution of the imaging system is improved and a detection blind area of the detector, which is brought by a filling factor, is eliminated. The image transmission equipment transmits the image to a ground receiving system in real time so as to process and transmit to a user so that real-time monitoring of a ground target is realized.

The invention discloses a near space low-speed platform SAR (Synthetic Aperture Radar) imaging method, which specifically comprises the following steps: acquiring target echo; rearranging data; performing pulse compression in range dimension; performing variable-aperture back projection imaging; and performing data splicing and outputting an imaging result. The solution of the invention is that a wide view field and common aperture working mode is adopted, and large-scene imaging is realized on the basis of a gradient aperture back projection method; the space-variant problem of range migration is solved by using the back projection method; a gradient aperture is used in the azimuth direction, so that the space-variant and image distortion problems caused by different resolutions in the azimuth direction of an image in case of different view angles are solved; and finally near space low-speed platform SAR large-scene imaging is realized.

Aiming at the problem of signal accumulation detection of a hypersonic velocity maneuvering target in a near space in a radar scanning period, the invention discloses a hypersonic velocity target TBD detection method for polynomial Hough conversion, and aims to search movement of a matching target in a radial dimension by using polynomial with velocity and acceleration as parameters, associate by using orientation wave gates in a direction, map the energy on a target track to a parameter space for polynomial Hough conversion, and detect by comparing the maximum energy value of the parameter space with a constant false alarm threshold. According to the method disclosed by the invention, the problem of two-dimensional parameter searching is degraded to the problems of one-dimensional distance search and small-range association in orientation by setting the orientation wave gates, the order times of polynomial search are reduced by setting range gates, and thus the calculation quantity is greatly reduced; meanwhile, in addition to functions of a conventional Hough conversion TBD method, the method disclosed by the invention is also applicable to signal accumulation detection under conditions of strong target movement, fuzzy distance measurement, multiple targets and the like.

The invention provides an information acquisition system based on a near space floating platform. The information acquisition system comprises the near space floating platform, a putting device, multiple miniature unmanned aerial vehicles and a satellite, wherein the near space floating platform is used for carrying the putting device to a designated position, the putting device is used for bearing the multiple miniature unmanned aerial vehicles, the putting device is further used for reaching the designated position and the putting the multiple miniature unmanned aerial vehicles, the multiple miniature unmanned aerial vehicles are used for landing to the surrounding positions of a ground target respectively, then performing information acquisition and sending the acquired information to the satellite. The near space floating platform adopted by the information acquisition system has stronger loading capacity, and the unmanned aerial vehicles can be accurately and snugly put around a target place and can reliably perform information acquisition and transmission.

The invention relates to an active expansion ball for in-situ detection of a near space atmosphere environment. The active expansion ball comprises a ball drop package shell (1), an expanded ball film(2), an inflation mechanism (3) and a measuring unit (4). The expanded ball film (2) is internally provided with the inflation mechanism (3) and the measuring unit (4), the expanded ball film (2) issealed, and the sealed expanded ball film (2) is subjected to air exhaust and folding and is inlaid in the ball drop package shell (1); when the active expansion ball is subjected to separated ball throwing, the inflation mechanism (3) is used for air inflation for the folded expanded ball film (2) to form an overpressure ball, and the ball drop package shell (1) is unfolded by the expanded ball film (2) after air inflation and is separated from the expanded ball film (2); and the built-in measuring unit (4) is employed for in-situ measurement of the atmosphere environment.

The invention belongs to the technical field of radio transmission, and discloses a near space high-altitude platform space-polarization diversity MIMO channel modeling method. The method comprises the steps of determining Loo channel parameters by utilizing a Markov state transfer model; calculating a polarization-space correlation coefficient by using channel measurement data and a theoretical model, and substituting the polarization-space correlation coefficient into a large/small-scale fading model simulated by the Loo model to generate the correlation; and combining large-scale fading andsmall-scale fading portions of each sub-channel to obtain a high-altitude platform space-polarization diversity MIMO channel model. Compared with the existing high-altitude platform MIMO channel model, the high-altitude platform space-polarization diversity MIMO channel model comprehensively considers advantages and disadvantages of the theoretical model and a measurement based scattering model,comprehensively evaluates influences imposed by the polarization correlation and spatial correlation on the channel model and can accurately describe large-scale and small-scale fading characteristicsunder the high-altitude platform environment and the correlation between the sub-channels.

The invention discloses a near space circular synthetic aperture radar rapid back-direction projection imaging method. In view of the problem of near space circular synthetic aperture radar rapid imaging, the method replaces a phase error in coherent imaging method with a pixel amplitude error as the evaluation criterion of imaging precision, approximately expands through low order of Green function which is based on chebyshev nodes and lagrange interpolation according to the principle of minimum mean square error, switches the problem of calculation of sub aperture projection to the problem of calculation of limited number of approximate expansion coefficients, and reduces as much as possible the number of expansion coefficients under the condition of meeting the focusing accuracy so that algorithm computational complexity is reduced, and then accomplishes the imaging from coarse focusing to fine focusing by applying recursive computation. Compared with the existing circular SAR back-direction projection imaging method, the near space circular synthetic aperture radar rapid back-direction projection imaging method has the advantages that computing speed is greatly improved, big scene imaging is achieved and imaging accuracy is much higher.

The invention discloses an ascent-stage trajectory of a two-stage to-orbit aerospace vehicle and a design method. By dividing primary and secondary ascent stages, an ascent-stage trajectory form is determined; firstly, the position of a separation point is determined; secondly, a secondary trajectory is designed; and thirdly, a primary trajectory is designed. The ascent-stage trajectory of the two-stage to-orbit aerospace vehicle and the design method have the advantages of simple algorithm and efficient calculation and can be widely used for designing ascent-stage trajectories of aerospace vehicles and near space hypersonic airplanes.