Design Of An Integrated Test Equipment For Helicopter Parallel Actuator

In the actual process of flight, as the actuating mechanism of the helicopter automatic flight control system, the actuator bears aerodynamic force and torque from the hydraulic booster, and the aerodynamic force and torque appears to dynamic changing loads. Performance of actuator system directly affects the whole performance of the flight control system and the helicopter. The actuator load-test equipment, also called the load simulator, is a kind of hardware-in-loop simulation test equipment. It is designed to simulate the hinge torque on the output shaft in laboratory and to check the actual working performance of the actuator.Based on studying the current situation of the load simulator and a background of a specific engineering application, this paper designs an equipment that can apply torque to the helicopter four-channel (collective, pitch, roll, course) actuator automatically using the electric load system which is widely used nowadays.The main works in this thesis are:(1) Comparing the advantage and shortage of each method, the article chooses electric load system to apply torque to the actuator, and then analyzing reasons and methods of the elimination of surplus torque.(2) Combined with literature studying, market research and theoretical knowledge, the loading scheme is determined, and the hardware components and software system are chosen. The system uses an AC servo motor to apply torque to the actuator. The system control platform is based on PXI and uses LabVIEW 2013 software as the development platform.(3) Designing a proper mechanical structure, determining the shaft diameters, choosing the proper coupling and torque sensor, organizing the join of mechanical parts to ensure the coaxial tolerance of the load platform, then analyzing the stress to the key parts with ANSYS Workbench.(4) According to the mathematical model, a simulation model of the system is built by the simulink block of software Matlab. Using the feedforward compensation and the PID control system to reduce the surplus torque and enhance the loading precision. The simulation result shows that the testing equipment meets the requirements.(5) The software structure is divided into four modules:system setup, test control, test detection and printing. LabVIEW 2013 is used for graphical programming.(6) Commissioning the mechanical structure to suite the assembly requirements, and test the whole system to fulfill the expected targets.Using LabVIEW 2013 as the development platform, the automatic test system has a friendly man-machine interface, powerful function, and can calibrate accuracy by the manual mode. The results of simulation and the physical experiment show that the precision of both torque and position control are high, and the equipment can meet the measurement requirements.