Measurement Method And Equipment Development Of Moment Of Inertia Considering Flexibility Effect

The development of control systems for aircraft such as rotor UAV drones places high demands on the measurement of mass properties.And the flexible effect of the system under test affects the effectiveness of traditional measurements.In this paper,based on the measurement of a certain type of rotor UAV,the problem of the measurement method considering the flexible effect is studied from the coupling of the measured object flexibility and the dynamic measurement system and the inclination angle constraint caused by the gravity.Based on the quality measurement of a certain type of rotor UAV,an integrated measurement system is designed.The main research are as follows:Established the dynamics of moment inertia measurement system considering flexible coupling effect and analyzed the influence of flexibility effect on the measurement results of moment of inertia.Take the simplify sytem as a model,a simplified dynamic model of the system is established,and the natural frequency of the simplified system is solved,and the equivalent dynamic equation is solved.The actual measurement of moment of inertia is analyzed,and the data acquisition model of moment of inertia is established.Based on the solution of equivalent dynamic equation,an algorithm for solving the equivalent dynamic solution based on dichotomy is proposed,which improves the computation efficiency and accuracy.Combined with the data acquisition model of the moment of inertia,optimal stiffness coefficient of torsion bar is determinated,the influence of periodic acquisition times on measurement accuracy of photoelectric is analyzed,the influence of the installation position of the photoelectric on the measurement accuracy is analyzed,The influence of initial twist angle on measurement accuracy is analyzed.A measurement model of moment inertia considering the constraint of inclination angle is established,and the part and global optimal measuring angles are studied.In view of the limitation that flexible objects can not be till measured in large angle,the optimal attitude measurement method under angle constraint is proposed.First,the single axis optimal attitude of the moment of inertia considering the flexible effect is solved.The moment of inertia and the inertial product optimal measurement equation is established by the inertial ellipsoid method.The moment of inertia and the inertial product of the object under the single axis are solved,and the optimal attitude angle is simulated and analyzed by the Monte Carlo method.Then the global optimal attitude of moment of the inertia considering the flexible effect is studied.The global optimal moment of inertia and the inertial product are obtained by the global optimization algorithm,and the simulation is carried out.A measurement system for the mass properties of a certain type of rotor UAV is designed.The working principle and mathematical model of the measuring equipment are analyzed and studied.The mass centroid measurement scheme of three point weighing method,and the moment of inertia measurement scheme of the torsion pendulum method are determined,and the measurement scheme is realized through the lifting mechanism.The geometric shape and technical index of the product are analyzed,and the overall design scheme of the system hardware and system software is determined,and the measurement process is optimized.Solid Works is used to complete the design of the mechanical structure,and the software for measuring is developed,and the algorithm is designed.An accurate measurement of a certain type of rotor UAV is realized.The measurement accuracy of the system is analyzed,evaluated and verified.The error analysis of the measurement system is carried out to ensure the feasibility of the design scheme.The function and measurement accuracy of the measuring system are tested.Finally,the mass properties measurement system meets the design requirements.In general,this paper has completed the modeling and characteristic analysis of the moment of inertia system considering the flexible coupling effect,and studies the optimal measurement angle of the inertia tensor considering the angle constraint,which provides an important reference for the measurement of the mass properties of a certain flexible object.