32 results about "Longitudinal model" patented technology

The invention discloses a fixed-wing unmanned aerial vehicle finite time formation fault-tolerant control method based on a neural network, and the method comprises the steps: firstly, carrying out the formation control through a virtual leader-follower structure, and carrying out the information interaction through a distributed formation method, based on this, designing a corresponding communication topological graph and calculating a corresponding adjacency matrix and a Laplacian matrix; then, aiming at a longitudinal model of the fixed-wing unmanned aerial vehicle, simplifying a dynamic model into a strict feedback form based on a reasonable assumed condition, and considering a failure fault of elevator deflection; on the basis of a backstepping method, sliding mode control is combined, an unknown nonlinear function of a model is processed through a radial basis function neural network, and the failure fault of the elevator is estimated in a self-adaptive mode, so that fault-tolerant control within finite time is achieved. The problem that formation fault-tolerant control is difficult due to the fact that the longitudinal model of the fixed-wing unmanned aerial vehicle serves as a high-order nonlinear system is solved, and the system has high robustness and can be stable within finite time.

The invention discloses a method for analyzing stiffness influence lines of shear of shear keys of joints of an immersed tube tunnel. The method includes 1), constructing a longitudinal model of the immersed tube tunnel; 2), computing sedimentation delta and the vertical stiffness k of an optional spring; 3), computing the average stiffness and stiffness variation ratios alpha of n springs within a total-length range, and drawing a stiffness variation distribution graph; 4), replacing the longitudinal model of the immersed tube tunnel by an indefinite-length elastic foundation beam model under an integral heating working condition; 5), enabling the indefinite-length elastic foundation beam model to be equivalent to an indefinite-length beam model supported by the average stiffness under the effect of concentrated force q1; 6) solving a relation between the concentrated force q1 and force q; 7), solving a shear value at an optional section-side position by the aid of the concentrated force q1; 8), drawing a stiffness influence line of the shear of the shear key at an inspected joint position. The stiffness support in a certain miniature section [-X<0>, X<0>] under uniformly distributed load of the force q is changed into k<2> by the infinite-length elastic foundation beam model. The method has the advantages that the stiffness influence lines are multiplied by the foundation stiffness variation distribution graph to obtain the values of the shear of the shear keys of the joints, and the shear is caused due to variation of the foundation stiffness.

The invention relates to a noise compensation method for a two-optical-comb measuring system. The method comprises: two continuous laser devices and two optical combs generate beat frequency signals at adjacent longitudinal models at the same side to obtain relative beat frequency signals fb1 and fb2 between two optical comb longitudinal modes; the relative beat frequency signals fb1 and fb2 are processed to obtain a carrier phase noise of an interference signal and time jittering of a periodic envelope in a two-optical-comb measuring system; and according to the carrier phase noise of the interference signal and time jittering of the periodic envelope in the two-optical-comb measuring system, noises of an original interference signal in the two-optical-comb measuring system are correctedto realize noise compensation. The compensation precision is high; the precision needed by the two-optical-comb measuring system application is met; the dependence on the high-precision light source is reduced substantially; and the system cost, size and weight are reduced.

The invention relates to a fine anti-interference tracking controller of a flexible hypersonic vehicle. A method for constructing the fine anti-interference tracking controller comprises the following steps of: (1) building a longitudinal model of the flexible hypersonic vehicle; (2) building a multisource interference system model of the flexible hypersonic vehicle based on the longitudinal model in the step (1): firstly, building a control-oriented nominal model; then regarding an elastic mode as interference and building an elastic mode interference model; and finally, building a multisource interference system model by combining the above two models and considering measurement errors, parameter uncertainty, external interference, etc.; (3) designing a nonlinear disturbance observer to estimate the elastic mode interference based on the multisource interference system model in the step (2); and (4) constructing the fine anti-interference dynamic reverse composite tracking controller based on the nonlinear disturbance observer in the step (3). The fine anti-interference tracking controller has the advantages of high anti-interference performance, rapid tracking speed, high control accuracy, etc., and applies to high accuracy tracking control of the height and the speed of the flexible hypersonic vehicle.

The invention discloses a modeling method for a multi-cell LPV system of an elastic hypersonic aircraft. The method comprises the following steps: establishing an elastic hypersonic aircraft nonlinearlongitudinal model, obtaining corresponding aerodynamic parameters, analyzing the relationship between the elastic deformation of an aircraft and a rigid body of the aircraft, and establishing a mathematical model; establishing a three-input three-output multi-cell LPV system model and a two-input two-output multi-cell LPV system model for the nonlinear longitudinal model of the hypersonic aircraft based on Jacobian linearization and tensor product transformation; to be specific, selecting a scheduling variable, and performing Jacobian linearization at a balance point to obtain a continuous LPV model; discretizing the continuous LPV model and storing the discretized continuous LPV model in a tensor; performing high-order singular value decomposition on the tensor to extract a core LTI vertex system; and constructing a continuous weight function of a core LTI vertex system. According to the method, the multi-cell LPV model capable of reflecting the elasticity of the hypersonic flight vehicle is established, the characteristics of the large flight envelope of the hypersonic flight vehicle are covered, the modeling calculation amount is reduced, and meanwhile the modeling precision is kept.

The invention provides a robust compensation control method of a high-speed aircraft and the high-speed aircraft, and relates to the technical field of high-speed aircraft control. The method comprises the steps of acquiring the flight parameters of a detected high-speed aircraft; inputting the flight parameters into a robust controller which comprises an optimal controller for realizing the expected tracking performance of a nominal system and a robust compensator for inhibiting the influence of equivalent disturbance on a closed-loop control system; importing the optimal controller and the robust compensator into a preset high-speed aircraft longitudinal model to obtain a target control variable, and controlling the high-speed aircraft according to the target control variable. The robustcompensation control method of the high-speed aircraft and the high-speed aircraft are provided. An optimal controller for realizing the expected tracking performance of a nominal system and a robustcompensator for inhibiting the influence of equivalent disturbance on a closed-loop control system are used for controlling the high-speed aircraft, and the tracking performance of the high-speed aircraft can be improved.

The invention discloses a state-limited hypersonic vehicle elevator fault-tolerant control method. Aiming at the longitudinal model of the hypersonic vehicle, an adaptive fault-tolerant controller is proposed under the premise of considering the internal coupling of the system to realize the state constraints. The complexity brought about by aerodynamic uncertainties, external disturbances and elastic modes is considered throughout the controller design process. First, a sliding mode control method is introduced to deal with the coupling of the system in the first step of the backstepping process. Next, barrier Lyapunov functions are applied in the subsequent backstepping process to ensure that the angle of attack and pitch rate are limited. Moreover, due to the introduction of the dynamic surface method, the problem of differential explosion is avoided. Finally, a fault-tolerant controller structure is designed for unknown faults of the elevator. The invention can simultaneously deal with the coupling problem and the state limit problem of the system, thereby improving the accuracy of the control system.

The invention relates to a track dip angle inversion controlling method of an aircraft based on a control force limitation situation. The track dip angle inversion controlling method comprises the following four steps of: step 1, constructing a longitudinal model of an aircraft and converting a state of the aircraft; step 2, carrying out an inversion control design based on saturated control input; step 3, verifying tracking performance and regulating parameters; and step 4, finishing the design. The invention aims at a longitudinal plane dynamic model of the aircraft, utilizes an input saturation error dynamic amplification method by defining an auxiliary analysis system to realize an inversion control method based on the saturated control input, and is applied to the control of a track dip angle of the aircraft. The invention has better practical value and a wide application prospect in an aerospace automatic control technical field.

A hypersonic vehicle trajectory tracking control method based on output information, comprising the following steps: Step 1: Using an input-output linearization technique, transform the longitudinal model of the hypersonic vehicle into a system containing lumped disturbances (the sum of external disturbances and parameter uncertainties) ) input and output model; Step 2: According to the input and output model established in Step 1, design a fixed time dilation state observer to estimate the state of the unknown disturbance and the input and output model; Step 3, based on the fixed time dilation state observer and the output value of the system , design the fixed-time continuous terminal sliding mode surface, and further obtain the fixed-time continuous terminal sliding mode trajectory tracking control scheme of the hypersonic aircraft system; the method of the invention can make the system output track the reference trajectory in the fixed time. The invention is suitable for the field of hypersonic aircraft control.

The invention discloses an online vehicle quality estimation method based on model iteration, aiming to solve the shortcomings of low estimation accuracy, poor robustness and few applicable conditions in the existing vehicle quality estimation technology. By obtaining engine torque, longitudinal vehicle speed, longitudinal acceleration, lateral acceleration, yaw rate, and steering wheel angle from the vehicle CAN bus and sensors, combined with recursive least squares and Kalman filter algorithms, using longitudinal model quality estimation methods or lateral The model quality estimation method estimates the vehicle quality according to the model arbitration method under different working conditions, and iteratively updates each other. The present invention refers to many vehicle-mounted signals, considers the longitudinal and lateral aspects, achieves the effect of mutual correction, and has the advantages of strong robustness, wide range of applicable conditions and high precision. It provides a relatively reliable vehicle quality signal input for the electronic control system of the automobile chassis.

The invention discloses an optical network unit device for mutual-excitation multi-wavelength dynamic scheduling in a passive optical network (PON), belonging to the technical field of optical communication. The optical network unit device comprises an uplink data transmitter, a downlink data receiver and an optical circulator, wherein the output end of the optical circulator is connected with the uplink data transmitter so as to transmit downlink data optical signals, and the input end of the optical circulator is connected with the uplink data transmitter so as to transmit uplink data optical signals; and the uplink data transmitter comprises two FP multi-longitudinal model lasers with the same model intervals, an adjustable band-pass filter, two optical circulator, an optical splittingand coupling device and a control module. Based on the mutual-excitation working mode of two FP multi-longitudinal model lasers, the invention can dynamically generate uplink optical carrier with adjustable multi-wavelength, flexibly and effectively share all uplink wavelength resources, improve the utilization rate of the uplink wavelength resources, has simple structure and low cost, and meet the development requirement on rapid increase of user uplink access capability.

The invention provides an alternate adjustment calibration method applied to head-up equipment, and the method comprises the following steps: S1, collecting the position of a calibration plate through a camera, and obtaining the internal parameters of the camera; S2, calculating external parameters of the camera; S3, calculating a distortion coefficient; S4, establishing the distortion coefficient into a transverse model and a longitudinal model; and S5, performing operation through an alternate adjustment optimization iterative algorithm, and optimizing internal parameters and external parameters with minimum errors. Modeling is carried out by carrying out nonlinear optimization on radial and tangential distortion models of a camera lens. The parameters of the visual system is further corrected by adopting an alternating adjustment algorithm. The problem that non-linear distortion cannot be corrected is solved. The method has the characteristics of high precision and easy realization.

The invention provides an optical fiber phase compensator and a use method of the optical fiber phase compensator. A laser of a single longitudinal mode laser device of the optical fiber phase compensator is divided into two beams through an optical fiber coupler, one beam is input into a first wavelength division multiplexer and transmitted to a transmission optical fiber along with a transmission optical signal, one end of the transmission optical fiber is wound around piezoelectric ceramics (PZT), the other end of the transmission optical fiber is connected with a second wavelength division multiplexer, an output single longitudinal mode laser signal is reflected by a second optical fiber reflecting mirror and returned through the transmission optical fiber, interference between the optical fiber coupler and the local single longitudinal model laser signal is generated, an interference optical signal enters a feedback control circuit, a control signal controls the PZT flexible range, an upper optical fiber optical path of the PZT is changed, and phase compensation is conducted on the transmission optical signal. The use method comprises the steps that a stable phase point of the optical fiber phase compensator is firstly set and automatic phase compensation is conducted by the PZT; when the adjustment limitation of the PZT is reached, reset is conducted. The stable phase transmission distance of one-level compensation reaches 25 km and a cascade optical fiber phase compensator can be formed through multiple levels.

It is a single-longitudinal model solid purplish blue laser composed of single-longitudinal model exocoel frequency multiplier Nd:YAG laser, plane lens, lambda / 2 quartz wavepad, focus lens, titanium diamond laser. It is characterized by the following: the titanium diamond laser adopts three-lens right angle ring chamber structure composed of high reverse back cavity lens, forty-five degree incidence reflection lens, titanium diamond crystal and output cavity lens. The titanium diamond laser output is divided into two paths, wherein, one goes in through first blind plate and out through frequency crystal, the other one goes in through frequency multiplier crystal and second blind plate and out through frequency crystal.

The invention discloses an obstacle-avoiding and anti-disturbance flight control method for a fixed-wing unmanned aerial vehicle based on preset performance. Interaction between lateral motion and longitudinal motion, establish a UAV longitudinal model with external interference and define performance functions; based on UAV longitudinal model, design altitude controller, speed and track inclination angle based on preset performance functions Controller; design a disturbance observer, design an attitude angle controller and an attitude angle rate controller based on the disturbance observer; select the Lyapunov function of the control system, select the control parameters according to the Lyapunov stability theory, and ensure the boundedness of the system signal . The invention can ensure the safe flight of the fixed-wing unmanned aerial vehicle, and can also make the height tracking error meet the given performance, and realize the robust anti-disturbance tracking flight control of the fixed-wing unmanned aerial vehicle under external interference.