| In recent years,China's strategic emerging industry development plan has included the offshore engineering equipment industry into the high-end equipment manufacturing industry,which has made clearly the significance of the marine strategy.At the same time,with the modernization of China's naval military forces,research on surface equipment is becoming increasingly important.Among them,the stable platform system plays a vital role in isolating ship disturbances and providing a highly stable working environment for shipboard equipment.Aiming at the requirements of miniaturization,low cost,and high dynamics of unmanned ships,this dissertation designs a stable platform system based on a series-parallel structure,and conducts in-depth research on the mechanical structure,kinematic analysis and control system of the stable platform,which are described as folows:Firstly,the actuator of the stable platform is designed.By comparing and analyzing several typical transmission mechanisms,the series-parallel articulated structure is selected according to the working state information of the shipboard equipment;the structural dimension parameters are determined based on the kinematics theory,and the 3D simulation model of the platform is established using UG software to verify the parameter design.Based on the theory of structural mechanics and further combined with the relationship between the link and the swing angle of the platform,the finite element method is utilized to analyze the key components such as the upper end shaft,the lower end shaft,the pin,and the motor support,which verify the accuracy of the structural design.Secondly,the dynamic and kinematic analysis of the stable platform is performed and verified by ADAMS simulation.In terms of dynamics,the force of the connecting rod is analyzed,and the corresponding driving torque is obtained under the maximum applied load,which provides a theoretical reference for determining the parameters of the driving motor.In terms of kinematics,the inverse solution of the position of the stable platform is derived by means of the coordinate transformation method.The function relationship between the rotation angle of the actuator and the stable platform is further calculated to provide a basis for the control algorithm.The ADAMS software is used to simulate and analyze the system performance,motion parameters and load peaks,which demonstrate the rationality of the designed structure.Then,the stable platform control system is designed.In order to realize the complex motion strategy control of series parallel structure,a high-performance microprocessor with floating-point computing capability is used as the control core,and a hardware system with high response,low delay and low cost is realized in combination with the design of real-time parallel multi-drive algorithm;At the same time,multiple nine-axis high-precision inertial measurement modules are used to detect the real-time position and attitude of the stable platform motion state.Combining the dynamic information of angular velocity and acceleration,a closed-loop control system with real-time multi-source information feedback is formed.Finally,experimental analysis is performed on the stable platform.For the ship's rolling,pitching,swaying and swaying states,the performance test and control accuracy experiment are carried out separately.Aiming at the control compensation problem,the inertia measurement unit combined with the inclinometer is used to verify the static accuracy.Under the rated load,the stability accuracy of lateral,pitch and sway is no more than 1°,and the stability accuracy of sway is less than 2mm.ADAMS and MATLAB are used to verify the dynamic accuracy of the stable platform,and follow-up verification is performed using the physical platform.The experimental results further show that the design platform has the advantages of good dynamic real-time performance,high accuracy,fast response speed,and strong robustness.It can provide a stable working environment for shipboard equipment. |
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