| This thesis presents the development of a hardware-in-the-loop simulation platform for Mars explorer guidance and navigation system.A six degree of freedom(DOF)motion platform was developed to simulate the relative motion of the explorer for the landing phase,the key components of the motion platform,including mechanical structure,structural mechanics and motion control technique,are studied.The main contributions of this thesis are follows:Firstly,we propose a novel 6-DOF motion platform with serial structure,and carry out the structural mechanics analysis of the proposed motion platform,which ensures the reliability and safety of the motion simulation platform.Secondly,this paper investigates the motion controller design problem for the motion platform,and establishes the mathematical model of servo system of rotary motion and linear motion respectively.Then the control laws of velocity and position loop using the frequency domain correction and PID correction are developed.Comparative simulations we carried out demonstrate the accuracy of the proposed method.Next,in order to deal with changing equivalent load torque of eccentric load during rotation,this paper proposes to apply a model reference adaptive control law.To address the problem of nonlinear characteristics caused by the gap,a fuzzy adaptive PID control law is used to enhance the steady state performance of the controller.Simulation results have shown that the proposed algorithms outperforms classical PID based control approach.Finally,this paper studies the realization of motion simulation platform control system.We introduce the 6-DOF motion simulation system and the working principle.The selection of the key components of the motion platform,such as the motor,transmission and measurement system,was discussed.In addition,the proposed adaptive control algorithm is verified on the simulation platform,which demonstrates the performance of the proposed algorithms in terms of flexibility and accuracy. |
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