Design Of Small Celcstial Body Probe Trajectory Tracking Control And Visual Simulation System

Small-body exploration,as a hot topic in the field of deep space exploration,is an important research direction for the future development of human space activities.The probe is subjected to a variety of unknown perturbations while operating in the deep space environment,which greatly affects the accuracy and robustness of the probe orbit tracking control.In this paper,the trajectory tracking control method is studied for the problems of poor accuracy and slow response of the system caused by the nonlinearity and unknown disturbance of the detector.Meanwhile,a virtual engine based view simulation platform is designed for the problems of high cost and difficulty of small object detection mission experiments and the difficulty of the navigation tracking algorithm relying only on mathematical models and mathematical simulation to reflect its characteristics,and the platform is developed with small object flight view simulation,motion simulation and sequence image acquisition as the main research tasks.The main research contents of the paper include:(1)To address the problems of unknown disturbances and difficult parameter measurements during the flight of small object detectors,a sliding-mode iterative learning-based trajectory tracking control method for small object detectors is proposed.Firstly,a neural network adaptive observer is designed to estimate the disturbance of the system and compensate for it;then,an iterative learning controller is designed to eliminate the periodic disturbances such as non-spherical gravity among the unknown disturbances,and the non-periodic disturbances caused by its own parameter uptake are eliminated by the sliding mode feedback controller,and a control dead zone is introduced in the controller to achieve the purpose of reducing fuel loss.The simulation results show that the controller constructed in this paper has the advantages of good robustness,fast dynamic response and high control accuracy.(2)In view of the problems of poor accuracy and weak realism of the existing 3D model of small objects,the 3D solid model of small objects is established and optimized.First,on the basis of the existing 3D model with the help of weighted least squares method to achieve the model triangle mesh light smooth,so that the experience presented in the subsequent software is more realistic.Then,bilinear interpolation is applied to the model’s texture mapping to enhance the details of the texture image.Finally,with the help of stereo mapping,spherical mapping,and UVW parameter adjustment,the two-dimensional texture image is accurately attached to the threedimensional model.The resulting 3D model database has the characteristic of high realism,which meets the high standards required for 3D models in small celestial body detection experiments and verifications.(3)The development of a high-precision deep-space small-object detection virtual view simulation platform was carried out to address the problems of difficulty and high cost of small-object detection process experiments.First,using a virtual engine,the orientation of small celestial bodies and detectors is set,and a virtual deep space environment is constructed,with auxiliary functions such as collision detection designed to provide the environmental foundation for real-time visual scene simulation.Next,the virtual simulation of the detector’s attitude control during flight is considered,which is implemented using the quaternion method and rotation matrix method.Additionally,multiple control scripts are written,including environmental lighting and image acquisition,to simulate the detector’s motion and enable small celestial body imaging acquisition.Finally,communication with the deep space exploration GNC system is achieved through interface protocols,allowing for real-time data transmission.The simulation platform provides an experimental platform for the subsequent validation of trajectory tracking,navigation,and guidance methods.