| In recent years,helicopters have shined in both military and civilian fields.In the military field,they can not only carry out ordinary transportation tasks but also undertake combat missions such as ground strikes.The civilian fields also have outstanding short-term air transport capabilities and disaster search and rescue capabilities.Benefit from the uniqueness of helicopter flight performance.However,because the usual working environment of a helicopter is very harsh,the strong vibration and aerodynamic interference generated by its blades rotating at high speed make it very difficult to control the helicopter.China usually uses helicopter wind tunnel tests to study helicopter performance,aerodynamic characteristics,noise and vibration characteristics,etc.,to complete the development of helicopter flight control systems.The paper introduces the basic principles of helicopter rotor pitch conversion in flight control,summarizes the research and development status of helicopter flight control systems at home and abroad,and draws on the experience of current excellent flight control system research and development,combined with its own test conditions and learning capabilities,Designed a helicopter model rotor variable pitch control system.The main work of the paper is as follows:(1)Considering that the helicopter model rotor control has strong interference,the auto-interference rejection + PI double closed-loop control method is used to control the motor that realizes the pitch conversion.The speed loop of the motor is controlled by the auto-interference rejection method,and the current loop is controlled by the PI method.The simulation model is established and compared with the simulation results of the motor using PI to control the speed loop current loop.In the case of the same interference from the outside world,the control method of auto-immunization and PI is significantly better than the method of using only PI control.(2)According to the requirements of the subject,the overall plan of the system is designed.The PC + motion controller is adopted as the control plan of the system.The upper computer is one of the cores of the system control,which is mainly the control command input and system status monitoring.The upper computer and the lower computer work together to form the software part of the model rotor variable pitch control system.The system has the characteristics of modularization,easy to upgrade and maintain.(3)Build an experimental platform,verify the entire system one by one according to the functional requirements of the subject,and observe the stability and reliability of the system at the same time.According to the experimental data,the correctness of the system control scheme and the test indicators are also in line with expectations.In summary,this paper studies and designs a helicopter model rotor variable pitch control system in a modular manner,and the experimental test results meet the control requirements of the subject. |
