Time-varying linear control for tiltrotor aircraft

A review of mathematical modelling techniques for advanced rotorcraft configurations

Real-time simulation model for helicopter flight task analysis in turbulent atmospheric environment

Study of helicopter autorotation landing following engine failure based on a six-degree-of-freedom rigid-body dynamic model

This paper presents an integrated flight control system with rotor-state feedback for helicopter approaching to the ship deck. First, a high-order nonlinear flight dynamics model coupled with the r...

Rotor-State Feedback Control to Alleviate Pilot Workload for Helicopter Shipboard Operations

https://cyberleninka.org/article/n/390219.pdf

A Mathematical Model for Helicopter Comprehensive Analysis

A flight dynamics model of the tilt rotor aircraft was established based on the research into the aerodynamic of the rotors,wing,fuselage,nacelle,empennage and control system.Quasi-steady element theory was used to analyze the lift,drag,moment and the flapping motion of the rotors.The lift line theory was used to research the aerodynamics of others,and then an investigation was conducted on the XV-15 tilt rotor aircraft.The results can be helpful to realize the characteristics of tilt rotor aircraft,also be useful to flight control design.

Flight dynamics characteristic of tilt rotor aircraft

A method based on the set-membership identification theory for the parameter identification of a helicopter fully coupled flight dynamics model is presented.In view of the fact that the helicopter flight dynamics model is seriously coupled and that it is difficult to obtain explicit function relationships between the identification model and the parameters to be identified,an indirect identification algorithm is created in this method for the set-membership identification in the form of a state-space differential equation.The concept of generalized noise is introduced to implement the set-membership identification of a complex model which has numerous identification parameters that are seriously coupled and greatly differentiated in sensitivity.Then a two-step method for the set-membership identification of a helicopter fully coupled flight dynamics model is established.A comparison with the flight test data of helicopter BO-105 demonstrates that the identification model using this method has good coherence with the data.Compared with the traditional method which is based on statistic theory,the new method can enhance identification accuracy,speed and robustness.

Identification Method for Helicopter Fully Coupled Flight Dynamics Model in Hover Condition

A method to predict the aerodynamic characteristics of a rotor at high advanced ratio is proposed which takes into consideration the particularity of the compound high speed helicopter rotor with a severe reverse flow region.The method is then used to calculate the aerodynamic performance of an H-34 rotor with various combinations of advanced ratios and rotor angles of attack and the results are compared with wind tunnel test data.The article further analyzes the effect of reverse flow region on the performance of the H-34 rotor at various high advanced rotor ratios as well as on the angle of attack,the lift and drag coefficients of the blade sections.The results show that the larger the area of the reverse flow region,the greater is its influence on the rotor performance and angle of attack,lift and drag coefficients of the blade sections.Furthermore,the angle of attack of a blade section exhibits rapid change on the boundary of the reverse flow region.There are obvious differences between the angle of attack,the lift and drag coefficients of the blade sections inside and outside the reverse flow region.

Effect of Reverse Flow Region on Characteristics of Compound High Speed Helicopter Rotor

Since the coupling of longitudinal and lateral motions of the helicopter is very severe,high frequency noise of rotor and random error of test cause data contamination,it is still difficult to identify full coupled dynamic model of the helicopter.A method that can improve identification accuracy of full coupled dynamic model is presented.Based on BO-105 flight test data with frequency sweep,a multi-step identification algorithm is constructed and proper cost function is selected to solve ill problem of information matrix caused by severe coupling,large differentiation of sensitivity and large amount of identification parameters in full coupled dynamic model.The results show this method can identify full coupled dynamic model of the helicopter effectively.

Chen Renliang

Papers

A Mathematical Model for Helicopter Comprehensive Analysis

Flight dynamics characteristic of tilt rotor aircraft

Identification Method for Helicopter Fully Coupled Flight Dynamics Model in Hover Condition

Effect of Reverse Flow Region on Characteristics of Compound High Speed Helicopter Rotor

Identification method of longitudinal and lateral coupled dynamic model for helicopter