Dynamic Optimization Of Six-rotor UAV In Heavy-duty Long-haul

The multi-rotor UAV platform is widely used in many fields such as fire protection,logistics,plant protection,public security and aerial photography,which provides a stable and reliable platform.With the increasing demands of production and living,designers have developed multi-rotor UAV with heavy loads and long-duration.This type of UAV is driven by the diesel engine which greatly increases the load and the voyage.However,the vibration caused by engine is larger than that caused by electric motor.Therefore,the structural design of the multi-rotor UAV with heavy loads and long-duration is perfomed,then the optimization of the structure is carried out.The main contents of this paper are as follows:(1)Firstly,a series of vibration measurement experiments are carried out on a six-rotor UAV platform to analysis the vibration characteristics of the UAV.The vibration response of the multi-rotor UAV is measured and collected under different flight conditions,including the UAV start-up phase,hover phase,yaw phase and landing phase,then the vibration characteristics in different conditions are obtained.(2)Then,based on vibration theory,the vibration suppression elements are designed in this work.The dynamic model of rotor-engine system of multi-rotor UAV is established,and the structural design was completed by means of ANSYS that is a s finite element software.The stiffness of the vibration suppression elements is optimized,and then the intensity check is carried out to meet the strength requirement requirements.(3)Finally,the APDL language is used to parametrically model the six-rotor UAV to further exploit the vibration suppression performance of the UAV structure,and the optimization function of ANSYS is used to optimize the the vibration suppression performance of the UAV by changing the structural parameters of the UAV.performance.The optimized design results show that load capacity of the UAV is improved by optimizing the mass of the UAV.Meantime,the vibration amplitude of the interest point is significantly reduced,obtaining the expected vibration reduction effect.