Research On Mechanism Design And Attitude Control Of Bionic Flapping Wing Aircraft

Biomimetic flapping-wing aircrafts are characterized by strong maneuverability,good aerodynamic performance,high flight efficiency,low flight noise,and good camouflage,making them ideal for military reconnaissance,disaster relief,and environmental monitoring.Currently,there is a greater focus on the research of miniature biomimetic flapping-wing aircrafts.These aircrafts mimic small flying organisms such as insects,but their short endurance time and small payload capacity make them difficult to apply in practical scenarios.In contrast,the existing large biomimetic bird-like flappingwing aircrafts suffer from poor aerodynamic performance and limited control capability.To address these issues,this thesis presents the design of a large wingspan biomimetic flapping-wing aircraft,including its mechanical structure and attitude controller,and conducts flight testing.Firstly,the functional requirements and performance indicators of the large wingspan biomimetic flapping-wing aircraft were determined based on an analysis of its application scenarios.The aircraft was then divided into two parts: the mechanical system and the control system.The mechanical system was further divided into four parts:flapping wings,drive mechanism,fuselage,and tail wings,each of which was designed in detail.Both integrated and separate wing structures were designed and tested,and the separate wing structure was ultimately selected.Two types of wing drive mechanisms,gear transmission and servo transmission,were analyzed,and the servo transmission was selected.Next,the attitude control requirements of the large wingspan biomimetic flappingwing aircraft were analyzed,and components and sensors were selected for the attitude controller.The hardware schematic of the attitude controller was designed using a modular design approach,which was divided into seven modules: MCU minimum system module,power module,power interface module,attitude sensor module,wireless communication module,servo drive module,and human-computer interaction module.Suitable packaging was selected for each component,and a PCB circuit board was designed,fabricated,and debugged.The software design was then based on the hardware design of the attitude controller,using a front-end and back-end software architecture.Software programs were designed for the five modules of the hardware circuit.A coordinate system for the biomimetic flapping-wing aircraft was established,and two attitude updating calculation methods,direction cosine method and quaternion method,were analyzed.The quaternion method was selected for attitude updating calculation,and two attitude control methods,nonautonomous control algorithm and semi-autonomous control algorithm,were designed.Finally,a prototype of the large wingspan biomimetic flapping-wing aircraft was produced,and in-field fixed and suspended flight tests and out-of-field straight,pitch,and turn flight tests were conducted.The test results showed that the prototype designed in this thesis is feasible.