Design And Research About Wire-driven Parallel Suspension Systems Used In Forced Oscillation Experiment In Low-speed Wind Tunnels For Obtaining Dynamic Derivatives

Based on the research of obtaining static derivatives by wire-driven parallel suspension systems, the exposition of the research subject "Design and Research about Wire-Driven Parallel Suspension Systems Used in Forced Oscillation Experiment in Low-Speed Wind Tunnels for Obtaining Dynamic Derivatives" focuses on the research of the related problems of using the wire-driven parallel suspension system to obtain dynamic derivatives. The problems are summarized as following:(1) The motion of5single-degree-of freedom oscillations can be realized;(2) The dynamic derivatives can be identified accurately. Analysis and simulation of the mechanism of oscillation motion that the system should be realized are done; theoretical analysis of the problem of identifying dynamic derivatives also is done.Firstly, the working principle of the wire-driven parallel mechanism is introduced, and the mathematical model is built to analyze the kinematics problem. In the premise of satisfaction of the requirements of oscillation motion, the inverse kinematics of the position, velocity and acceleration are simulated to get the relationship between the changes of the model’s pose and the changes of the wires; meanwhile, modeling and simulation of the stiffness of system are done to make the system run normally.Secondly, for controlling the pose of the model accurately, the vibration of the wires and the natural frequency of the system are analyzed based on the dynamic model to get the relationship between the driving torque and the pose of the model. To reduce the aerodynamic interference and improve the accuracy of control, a feedforward compensation control scheme which is based on PD is designed and the tensions of the wires are optimized.At last, the method of the identification of dynamic derivatives based on the aerodynamic force and torque is researched. The systems of the detection of model’s pose and the measuring of aerodynamic as well as the principle of figuring the aerodynamic are introduced; and the example of using aerodynamic force and torque to obtain dynamic derivatives which is under small attack angle and small disturbance is made.