Design Of Control System Of Posture Alignment Mechanism In Cylinder Cabin

With the continuous development of the aeronautics and space undertakings and military industry in China,the requirements on assembly efficiency and accuracy of cylinder cabins has becoming higher and higher.At present,enterprises mainly adopt manual assembly mode which features with low efficiency and insufficient accuracy and the status quo of low level of automatic assembly needs to be increased.In this dissertation aiming at the assembly requirements of cylinder cabins,a set of posture alignment systems for cylinder cabins are designed,the posture alignment mechanism of cylinder cabins is analyzed,and the motion planning and control strategy of the posture alignment mechanism are studied.Firstly,research on the posture alignment mechanism of cylinder cabins has been carried out,during which the principle of the posture alignment mechanism is analyzed,the global reference coordinate system and the coordinate systems for fixed cabins and to-be-assembled cabins are established,what’s more,the relationship between the cabin posture and the motion of the posture alignment mechanism is deduced according to the transformation relationship among the coordinate systems.Moreover,the dynamic model of posture alignment mechanism is derived using the Newton-Euler equation,the hardware system of the posture alignment platform is designed and the type of posture alignment mechanism hardware is selected.On the other hand,the software system of posture alignment platform is designed.According to the process flow of cabin posture alignment,the software operation flow and the troubleshooting tree,which is for troubleshooting the posture alignment mechanism,of posture alignment mechanism are designed.Secondly,study on the trajectory of posture alignment of cylinder cabins is carried out.After the initial position and target position of the cabin are determined,the trajectory of posture alignment is fitted based on the quintic polynomial and the relevant boundary constraints,and the posture alignment time of the cabin isdetermined in light of the speed and acceleration constraints of the posture alignment mechanism.After that,the effectiveness of trajectory planning method is verified by simulating the cabin posture alignment trajectory.Finally,the control strategy of the posture alignment mechanism of cylinder cabin is studied,during which the control model of driving shafts of the posture alignment mechanism is analyzed,and specific to the posture alignment stage,the PID control strategy is used to design the position servo system controller.In order to reduce the contact force in the docking process,impedance control is introduced into the docking stage.In addition,based on the basic principles of mechanism kinematics and impedance control,the uni-axis impedance control model of mechanism is built in MATLAB,and the influence of impedance parameters on the control effect is analyzed.What’s more,the virtual prototype model of the posture alignment mechanism is built in ADAMS,and the united simulation of ADAMS and MATLAB is carried out via software interface,which verifies the correctness of the impedance control algorithm,thus completing the design of the control strategy of the posture alignment mechanism of the cylinder cabin.The control system designed in this dissertation can realize the automatic posture alignment and docking of cylinder cabin.The trajectory planning method of cabin posture alignment is designed to ensure the stable and impact free motion of cabin in the process of posture alignment.The control strategy can meet the requirements of high precision posture alignment and flexible docking.