Modeling And Simulation Of A Five-DOF Wind Tunnel Test Model Support Platform

It is an important and indispensable part of the development of new types of aircraft for the wind tunnel test. Development of each new aircraft needs carry out a large number of tests in a wind tunnel. Aircraft achieves wind tunnel tests that can not be separated from the model support system, and it has high pertinency between the support system and experimental results. For the general performance requirements of aircraft can be simulated in the simple wind tunnel simulation test, but it can not meet the requirements of the aircraft simulation with high performance requirements. Because it not only requires the ability to do complex movements under the guidance of the test, but also reasonable configuration options can be achieved in a variety of constraints.The traditional wind tunnel test model supporting device commonly used serial mechanism. The number of degrees of freedom of the serial mechanism depends on the number of the corresponding mobile axis and the rotary shaft. At present, most of the wind tunnel test device of this kind is limited to no more than3degrees of freedom of movement. Compared with the serial mechanism, the parallel mechanism have many advantages such as high stiffness, stable structure, high bearing capacity, high speed, small movement inertia and high efficiency. This paper proposes one kind of wind tunnel test model the support platform with5degrees of freedom. This platform is not only able to guide the objects around the virtual center to realize the three-dimensional rotating about a fixed point, and the advantages of the serial mechanism and parallel mechanism were taken into account.This artical is started to expand from the determination of its configuration to analyze and simulate in the following aspects, which include forward and inverse kinematic, Jacobian matrix, workspace and flexible component. So the results which we have got provide the academic gist for the determination of velocity, acceleration, dynamic analysis and prototype of the platform.Firstly, the thesis takes the necessary of support device of the wind tunnel test as conditions to analysize the most representative hybrid mechanisms at home and abroad, based on the thought of taking full advantage of serial mechanism and parallel mechanism and getting rid of their respective deficiencies. Secondly, according to the thought, the author determines support platform configuration and analyzes the operating principle of support platform with5degrees of freedom; Based on closed-loop vector methord, the constraint equation of the branched-chain of the platform are be created to perform the location fo the platform; according to the kinematics equation which have be got, we can get the Jacobian matrix of the test platform by means of direct differentiation method and differential transformation method on account of mathematics model of the inverse position; Workspace analysis of the support platform was got by boundary search method in view of constraint conditions of the model supporting platform branched. So we can get the spectrum of the structure parameter influence on the workspace by MATLAB software. Finally, considering the light weight and the slender members show that the rigid bodies do not have flexible performance at high velocity, the flexible performance of the members may lead to the elastic deformation of members, and even the motion error of system and elastic vibration. So, In order to make this model support platform has fairly good dynamics performance, achieves optimal performance and a higher analysis precision of the prototype, some parts of the model support platform have been turned into flexible bodies by ADAMS software and ANSYS software, based on the establishing principle of flexible multibody systems.