Development of Multi-Axis Crank Linkage Motion System for Synchronized Flight Simulation with VR Immersion

This paper developed a rotatable multi-axis motion platform combined with virtual reality (VR) immersion for flight simulation purposes. The system could simulate the state of the flight operation. The platform was mainly comprised of three crank linkage mechanisms to replace an expensive six degrees of freedom (DoF) Stewart platform. Then, an independent subsystem which could rotate +/- 180 degrees was installed at the center of the platform. Therefore, this platform exhibited 4-DoF movement, such as heave, roll, pitch, and yaw. In the servo motor control unit, Visual Studio C# was applied as the software to establish a motion control system to interact with the motion controller and four sets of servo motors. Ethernet Control Automation Technology (EtherCAT) was utilized to communicate the commands and orders between a PC and each servo motor. The optimum controller parameters of this system were obtained using Simulink simulation and verified by experiment. The multiple sets of servo motors and crank linkage mechanisms were synchronized with flight VR imagery. For VR imagery, the software Unity was used to design the flying digital content. The controller was used to transmit the platform's spatial information to meet the direction of the pilot commands and to compensate the direction of the deviation in spatial coordinates. To achieve synchronized response and motion with respect to the three crank linkage mechanism platform and VR imagery on the tester's goggle view, the relation of the spatial coordinate of VR imagery and three crank linkage mechanisms was transformed to angular displacement, speed and acceleration which were used to command the motor drive system. As soon as the position of the VR imagery changed, the computer instantly synchronized the VR imagery information to the multi-axis platform and performed multi-axis dynamic motion synchronously according to its commanded information. The testers can thus immerse in the VR image environment by watching the VR content, and obtain a flying experience.