Mechanism Optimal Design, Cueing And Control Of A Dynamic Seat

This dissertation deals with the analysis, optimization, force cueing and control of a 3 DOF dynamic seat, including inverse dynamic modeling and dynamic performance analysis, dynamic manipulability and optimization, force cueing algorithm and control strategy. The main research works can be described as follows:The force transmission rule on a moving part of the machine is studied and the inverse dynamic model in a linear form is derived by using the virtual work principle. The dynamic performance such as distributing of dynamic manipulability and maximum acceleration of the seat backpad mechanism is analyzed. Furthermore, a global condition index based on dynamic manipulability ellipsoid and general inertial ellipsoid is proposed. The mechanism of the seat backpad is optimized by this index. It can conclude that the optimized mechanism has better dynamic performance than its corresponding one in the distributing of dynamic manipulability and maximum acceleration.The pilot's perceptual models of the motion and body pressure in both dynamic seat and aircraft are built based on the pilot's dynamic model, respectively. Integrating the seat motion limit equation and flight input equation, the optimized force cueing algorithm is derived by the optimization method. It shows that this algorithm can get the best performance comparing with classical algorithm and adaptive algorithm, such as most rapid dynamic seat response and least motion force sensation error.The position loop controller is redesigned to improve the system response capability based on the control model of the seat chain. Then the position/force parallel control strategy is proposed based on position control, the position/force parallel control system is built to control the position and driven force of the motion chain of the dynamic seat synchronously. This control strategy is effective in the position and force control of the seat chain, which can achieve the requirement of force accuracy and position accuracy in the control of the dynamic seat. The performances of the force cueing algorithm and control strategy on the dynamic seat are investigated by experiments. The optimal force cueing algorithm can get the seat position cueing with the similar contour to the flight status, and the position/force parallel control strategy is effective in actual application on the dynamic seat. Furthermore, the position tracking tests show the position control performance in actual flight simulation, the flight simulation test shows that the dynamic seat is suitable for the real time flight simulation of the aircraft. The outcome of this dissertation has provided guidance for the control and development of other dynamic seats.