Research On Synchronous Control Of Spatial Sleeve Deployment Mechanism

As one of the important components of the deployment structure of very large aperture space telescopes,the space sleeve deployment mechanism has the characteristics of high deployment rigidity,high deployment accuracy,large load capacity and long spreading distance.However,at present,the control system of the space sleeve expandable mechanism is more complicated,and the single driving and receiving device of the expandable mechanism has the problem of insufficient motion stability,and the synchronous control system of the variable diameter internal drive device is the key to achieving smooth unfolding movement of the space sleeve expandable mechanism.Therefore,this paper proposes a double closed-loop synchronous control scheme for variable diameter internal drive device suitable for space sleeve expandable mechanism,and conducts in-depth research on its control system.Firstly,the structure of the space sleeve expandable mechanism is analyzed,and according to the structural characteristics and working principle of the space sleeve expandable mechanism,the theoretical model of the motion state of the variable diameter internal drive device is constructed,and the control requirements of the variable diameter internal drive device are clarified when the working condition is extended in the sleeve,and then a double closed-loop control system is established.Secondly,in order to improve the controllability of the space sleeve expandable mechanism and make its unfolding process more stable,the motion control strategy of the variable diameter internal drive device is studied.The wheel drive mechanism consists of two groups of drive units,so it is necessary to ensure the smooth motion of the single group of drive units and the control synchronization of the two groups of drive units at the same time.Combined with the characteristics of fuzzy algorithm and PID algorithm,a singlegroup drive unit control system based on fuzzy PID algorithm is designed,and the speed following and anti-interference of the control system are verified by comparative simulation,so as to achieve accurate control of the speed of a single group drive unit of the variable diameter internal drive device.In addition,three synchronous control strategies are applied to the double closed-loop control system of variable diameter internal drive device and simulated to verify the feasibility of cross-coupling synchronous control system,which lays a theoretical foundation for the construction of the control system of the subsequent test platform.Then,through the hardware configuration and motion principle of the space sleeve expandable mechanism,the program design and development of the whole machine control system of the variable diameter internal drive device are carried out.The modular idea is introduced in the design of the control system,which mainly includes five modules: main control program,drive unit subprogram,preload unit subprogram,coordinated control subprogram and automatic control subprogram.After the independent design of each module,it is combined with each other through the main control program to form the overall software of the control system.Finally,a prototype test platform was built for the space sleeve deployable mechanism.Continuous transition tests were carried out at different speeds,and the motion was relatively stable and without obvious fluctuations.The data shows that the error of the driving arm angle is between 0.30%-0.35%,0.25%-0.29%,0.51%-0.58%,and the error of preload change does not exceed 0.62 N,0.49 N and 0.42 N,respectively,which meets the control requirements of the variable diameter internal drive device and provides strong support for the smooth development and application of the space sleeve expandable mechanism.