Research On Model Attitude Measurement Based On Optitrack Motion Capture System

During the free flight test,the control surface deflection angle,attitude angle,angle of attack and sideslip angle of the model in the wind tunnel are important indicators to represent the model attitude.However,the existing measurement methods for each index in wind tunnel have some defects,especially for the measurement of angle of attack and sideslip angle,when using the wind vane sensor to measure,the aerodynamic characteristics of the model will be affected.Therefore,in order to more accurately measure the model parameters in the wind tunnel,this paper studies the method of model attitude measurement based on optitrack motion capture system.In this paper,according to the requirements of wind tunnel test,a new optical motion capture system optitrack system is used to collect the information of aircraft model,and the information collected by the system is processed to realize the high-precision and low delay measurement of model rudder and model attitude,which has certain practical significance and engineering value.This paper first introduces the research background and development status at home and abroad,and then realizes the design of each part according to the design requirements1.The overall design of the measurement system.First,according to the system indicators and functional requirements,the overall framework of the system is designed,and then the acquisition module,data processing module and upper computer software module of the system are designed respectively.These modules realize the collection and processing of model information together,and finally complete the attitude calculation of the model.2.Data processing module design.After the data acquisition module collects the data of the mark points,it processes the collected data of the mark points,realizes the measurement of the model rudder deflection angle,the model attitude,the model angle of attack and sideslip angle,and verifies its accuracy through experiments.3.Compensate the experimental error.This paper analyzes the causes of the error in the test,realizes the compensation of the system installation error,and puts forward the scheme to reduce the vibration error.Finally,the test is carried out to verify the scheme.4.Upper computer software design.The function modules of the system are divided,and the software function modules of the upper computer(system login,parameter initialization,data analysis,data display)are designed,and each module is tested and verified.5.Wind tunnel test.After the realization of the attitude measurement system,the test is carried out in the wind tunnel,the verification of the measurement accuracy of the system and the test are completed,and the application of the measurement system in the free flight test is completed.