Design Of The Three Degree-of-freedom Platform For The Flight Simulator

Flight simulator motion system can provide real aircraft pilots the same or similar motor and sensory. Flight simulator with motion system can realistically simulate attitude of flight, which can be the ground and air momentary overload. Pilot of the aircraft can profoundly feel the immediate movehieve better training results.Nowadays, flight simulator motion platform system is achieved primarily through the motion platform. According to the general requirements of certain type of flight simulator, this paper adopt three degrees of freedom motion platform system with anti-torsion beam structure that can replicate the aircraft's three degrees of freedom which are roll, pitch and heave. Although the motion platform has been widely used, but it only relies on the experience of engineers to carry out, without theoretical instruction. In particular, the motion platform'kinematics, dynamics and control strategies are all on the lack state. This pater analysises these aspects of the three degrees of freedom motion platform. It is important significance to flight simulationmotion system in engineering practice.3-DOF motion platform is a complicated nonlinear system in substance and has multiple variables. And it's kinematics and dynamics analysis is the precondition of the parallel manipulator's structure design and hydraulic system design. In this paper the kinematics analysis is carried out by coordinate transformation and differentiation firstly. Then build a single rigid body dynamics model based on the Newton-Euler method without considering each folding and leg's mass and inertia. This paper also design hydraulic power mechanism base on the kinematics and dynamics. And give the hydraulic cylinder's load matching curve in the basic working conditions.The control strategy of 3-DOF motion platform is another important research field, and the final performance of 3-DOF the motion platform is immediately determined by the control system. This paper build the transfer function mathematical expression of asymmetry cylinder controlled by symmetry valve system. Then design a simple PID regulator for the control system, and make a preliminary analysis on the characteristics of the control system.To validate the feasibility of building the prototype, a virtual prototype of it is established using SimMechanics and then integrated simulation with simulink to verify the kinematics and dynamics. The virtual prototype can simulate the real 3-DOF motion platform exactly, and the results show that the kinematics analysis, dynamics analysis and control system analysis of the parallel robot are correct. All these analysis about the parallel robot are useful for researching the actual tank turret and fire control system test bench.