| The electro-optical pod is an important part of weapon systems in the application of vehicle,airborne and ship-based equipment.It is a complex system integrated with optic,mechanism and electronic,which often undertakes the task of target searching and tracking,recognition of environment features,detection of war and guidance of fire assault.Nowadays,electro-optical pod is widely used in the airplane,in consequence,higher requirements of electro-optical pod are proposed to adapt to the fast developments of plane.With developments of UAVs especially mini-UAVs in the last years,electro-optical pods develop toward miniature,lightweight,function-integrated,and high pointing precision.Traditional transmission methods like gear drive,drain drive cannot achieve high servo performances because of their inherent nonlinear elements like friction,backlash and hysteresis,so they cannot meet weight requirements of electro-optical pod with high precision and lightweight.Cable drive,one of new transmission methods,has advantages of light weight,high precision,little friction and agility,so it may have a broad scope in the precise pointing mechanism.This paper focuses on the problems about engineering application of cable drive.An electro-optical pod with stabilization accuracy better than one micro radius and weight lighter than one kilogram was made through the investigation about modeling and controlling of electro-optical pod.The following studies are included in the thesis:1.In order to make clear about the theories of electro-optical pod,the characteristics and functions of stabilized platform was analyzed from stabilized methods,structural framework,inertial devices,then the requirements are analyzed combined with the design task,which built foundations of the following detailed designs.2.In order to learn the load requirements of transmission system,the load characteristics of two-axis cable drive system were analyzed.Two axes cable drive system was designed through detailed process to achieve the expected performances of cable-drive system.To meet the requirements of vibration and shock,the static and dynamic check of key components in the system were carried out.After the comprehensive design,a complete mechanical model was built.3.In order to achieve the function of servo control,both the hardware and software were designed.Power circuit,drive circuit and gyroscope signal processing circuit were emphatically analyzed.An operation control terminal was built to achieve the target of manipulation and control of electro-optical pod.4.In order to comprehensively understand characteristics of the system,a dynamic model of servo axis was built.While modeling,the effect of friction torque disturbance on the velocity-stabilized loop was mainly analyzed,then friction was compensated by a disturbance observer in simulation.5.In order to verify the simulation effects of modeling and disturbance observer,a hardware-in-loop simulation platform was built based on a precision turnplate.The experimental model was got by frequency sweep and model consistency from simulation to experiment was checked,then effects of friction compensation were estimated,finally the test on the stabilized precision was carried out to approve the performance of electro-optical pod.Results showed that the designed electro-optical pod could meet the initial requirements of stabilization accuracy.6.In order to further grasp the rules of static and dynamic characteristics in cable-driving mechanism,an experiment setup was built,further studies on the characteristics of cable drive were carried out,the performances including position precision,bandwidth were tested,a foundation on cable-driving mechanism in higher precision application would be laid by these processes. |
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