The invention discloses a method for determining sensitive parameters of an air spring structure. The method comprises the following steps: constructing a digital model, performing finite element analysis on the digital model, summarizing key structure design parameters such as rubber layer thickness, material, cord thread attribute, cover plate thickness and the like, setting a parameter tolerance interval of the key structure design parameters, and constructing an output quantity and a random variable of an orthogonal function set approximation model by utilizing different generalized randompolynomials in a given parameter interval. On the basis of the obtained approximate explicit function expression; moment estimation is carried out on the model output quantity through Monte-Carlo simulation, on the basis of a sensitivity calculation result, the influence degree of independent changes of all parameters, simultaneous changes of different parameters and the like on the model outputquantity is analyzed, and therefore interaction between the parameters and structural characteristic sensitive parameters are determined. The problem that a traditional method is difficult to implement can be solved, repeated design can be avoided in the pre-design stage, the research and development period is greatly shortened, and the research and development cost is saved.

Method for determining sensitive parameters of air spring structure

The invention provides a method for predicting the dynamic stability characteristics of a full flight domain by coupling a non-stationary aerodynamic proxy-reduced-order model based on efficient adaptive sampling with a rigid body dynamic equation in a state space to solve a feature root of the feature matrix. The coupling dynamic stability characteristics of the aircraft in the entire flight domain can be acquired efficiently and accurately. The method can be used to calculate and analyze the multi-channel coupling dynamic stability characteristics of aerospace vehicles, and especially non-axisymmetric complex layout aircrafts. The method can greatly reduce the computational cost while ensuring the prediction accuracy, so that it is easy to carry out qualitative and quantitative researchon the dynamic stability characteristics of the aircraft in the whole flight domain, and the design direction that has guiding significance for the aircraft design is obtained.

Dynamic stability analysis method for full flight domain aircraft

The invention discloses a multi-parameter stability domain solving method for closed-loop stability analysis of a control system. According to the method, flight quality requirements of the control system are converted into constraint conditions of the distribution of closed-loop poles in a complex plane, and a hyper-ellipsoid region is adopted to describe the multi-parameter stability domain of amodel. Firstly, a protection mapping theory is adopted to respectively calculate the stability domain of each single parameter, and the box constraint form related to all model parameters is obtained; secondly, a multi-parameter hyper-ellipsoid is constructed according to boundary values of multi-parameter box constraints and is denoted as the initial hyper-ellipsoid; and the value of protectionmapping is regarded as an optimization objective, the model parameters are regarded as optimization variables, the scaling ratio of the multi-variable stability domain is determined through constructing an optimization problem of the multiple variables within the hyper-ellipsoid, and finally the multi-variable hyper-ellipsoid stability domain is determined. The method disclosed by the invention can quantitatively determine the variation range of the model parameters satisfying performance indexes under the condition that there are many model parameters, and has high engineering application values.

Multi-parameter stability domain solving method for closed-loop stability analysis of control system

The present invention discloses an unconventional layout aircraft rapid modeling method suitable for control of an iteration design. The method comprises the steps of: constructing a flight condition,determining a relation of parameters and a body model, and determining aircraft agent model effect variables; establishing an agent model integrated with the effect variables; and finally, verifyingthe consistency of the agent model and flight original data. The unconventional layout aircraft rapid modeling method suitable for control of the iteration design considers the influences of flight conditions and design parameters to integrate states, control variables, the flight condition influence quantity and design parameters into the agent model to construct a relation among the flight conditions, the design parameters and the body model, the reasonable modeling is ensured through verification of model consistency and dynamics feature consistency to meet the iteration design demand in the aircraft initial design phase. The modeling method is fast in computing speed, is suitable for control of the iteration design and has a good engineering application value.

Unconventional layout aircraft rapid modeling method suitable for control of iteration design

The invention discloses a hypersonic aircraft control-oriented multisystem associated modeling method. The method includes: from the perspective of hypersonic aircraft control system design, selectinga control required core system, and determining an association form of other systems associated with the core system to establish an association model; selecting an association characteristic evaluation index, respectively calculating an association index after association of each system with the core system, comparing the association index with the selected association characteristic evaluationindex, determining and retaining subsystems high in influence on hypersonic aircraft control system design, and constructing an association system through the determined association form.

Hypersonic aircraft control-oriented multisystem associated modeling method

The invention discloses a control association modeling method of an elastic mode of an aircraft. The method comprises the following steps that a mechanism model of the elastic structure mode of the aircraft is built, and dynamic response data of the elastic mode is obtained; based on a beam element, the form of an agent model of the elastic mode is determined; coefficient setting is conducted by using a system identification method, a control association model of the elastic mode is obtained, the effectiveness of the built agent model is further verified based on the goodness of fit, the influence of the elastic mode on the open-loop performance and close-loop performance of an aircraft body is analyzed, and the association relationship between the body characteristic and the elastic mode is analyzed. Therefore, the influence rule of the elastic mode on the overall system and the design of the control system is found, and a good technical support is provided for the actual engineering design.

Control association modeling method of elastic mode of aircraft

The invention discloses a configuration-varying aircraft model iterative design method based on protection mapping. The method mainly comprises the steps of describing criterion configuration of an aircraft, analyzing the matching relation between configuration variations and flight conditions, discovering the internal relation between the configuration variations and model dynamic characteristics, obtaining a simplified design model of the aircraft, analyzing model performance under the criterion configuration and obtaining optimal model parameters to realize optimal matching between the aircraft configuration and operating conditions. The method is beneficial for realizing model parameter setting in configuration-varying aircraft design; under complicated flight conditions, feasible model parameters are obtained adaptively based on the protection mapping theory according to expected open-loop and closed-loop performance requirements; through switching of the parameters, the designed model is made to cover a whole motion area, and meanwhile the stability of the configuration-varying aircraft can be ensured.

Configuration-varying aircraft model iterative design method based on protection mapping

The invention discloses an aerodynamic layout design method based on a variable-configuration aerospace vehicle. The aerodynamic layout design method comprises the steps that the low-speed datum layout and the high-speed datum layout of the variable-configuration aerospace vehicle are determined correspondingly; the geometrical shape of the variable-configuration aerospace vehicle is described ina parameterization mode through a state-type function method; a corresponding parameterization kinetic model is established through an engineering estimation method, models of different speed domainsare integrated based on the similarity criterion, and a corresponding agent model is established; the influence of the flight condition and aerodynamic layout change on the performance of a flight control system is determined through a sensitivity analysis method, and the stability boundary and system requirements of the variable-configuration aerospace vehicle are determined; and through full-speed-domain performance matching analysis, a variable-layout scheme of the variable-configuration aerospace vehicle is determined. By properly changing the wing configuration of the aerospace vehicle, it is guaranteed that the aerospace vehicle has the optimal aerodynamic layout at each mission stage, large envelope continuous flight under the minimum energy consumption is achieved, and the need ofintegrated design of the aerospace vehicle is met.

Lu Yuping

Papers

Control association modeling method of elastic mode of aircraft

Configuration-varying aircraft model iterative design method based on protection mapping

Aerodynamic layout design method based on variable-configuration aerospace vehicle

Hypersonic aircraft control-oriented multisystem associated modeling method