SPACECRAFT DOCKING SIMULATION USING HARDWARE-IN-THE-LOOP SIMULATOR WITH STEWART PLATFORM

A ground-based hardware-in-the-loop （HIL） simulation system with hydraulically driven Stewart platform for spacecraft docking simulation is presented. The system is used for simulating docking process of the on-orbit spacecraft. Principle and structure of the six-degree-of-freedom simulation system are introduced. The docking process dynamic of the vehicles is modeled. Experiment results and mathematical simulation data are compared to validating the simulation system. The comparisons of the results prove that the simulation system proposed can effectively simulate the on-orbit docking process of the spacecraft.

Dynamic Diagrams Post Processing Software Tools for Simulation Analysis of Spacecraft Docking Dynamics

Realistic 3D-animation is used in all motion simulation systems of mechanisms and other mechanicals systems. It provides a high-quality illustration of time processes, but it has a weak capability for analysis of their dynamics, for simultaneous display of contact interaction and functioning of mechanisms of different motion types. A spacecraft docking is characterized by a complex contact interaction of docking assemblies with mechanisms and devices of different motion types. Integration and time synchronization of the animation, plots and numerical values greatly facilitates the understanding of dynamics features of these processes. Usage of simple wireframe graphical models allows displaying all contact points. A changing of the set of graphical elements focuses attention on major events of a simulated process. Graphical models developed with consideration of these features and used for spacecraft docking simulation analysis are called dynamic diagrams and described in this paper.

Shock Characteristics and Protective Design of Equipment During Spacecraft Docking Process

The shock loads generated by spacecraft during docking can cause functional failure and structural damage to aerospace electronic equipment and even lead to catastrophic flight accidents.There is currently a lack of systematic and comprehensive research on the shock environment of spacecraft electronic equipment due to the diversity and complexity of the shock environment.In this paper,the validity of the finite element model is verified based on the sinusoidal vibration experiment results of the spacecraft reentry capsule.The method of shock dynamic response analysis is used to obtain the shock environment of electronic equipment under different shock loads.The shock response spectrum is used to describe the shock environment of aerospace electronic equipment.The results show that the resonance frequency error between the sinusoidal vibration experiment and the model is less than 4.06%.When the docking relative speed of the reentry capsule is 2 m/s,the shock response spectrum values of one of the equipment are 30 m^(2)/s,0.67 m/s,and 0.059 m,respectively.The wire rope spring on the mating surface can provide vibration isolation and shock resistance.An increase in spring damping coefficient results in a decrease in the amplitude and time of the vibration generated.An increase in spring stiffness reduces the input of shock load within a certain range.These research results can provide guidance for the design and evaluation of shock environmental adaptability of aerospace electronic equipment.

Influence of Monitoring Method and Control Complexity on Operator Performance in Manually Controlled Spacecraft Rendezvous and Docking

This study focuses on the influence of the monitoring method and control complexity on the operator performance in manually controlled spacecraft rendezvous and docking （RVD）. Two one-factor experiments were designed on a simulated RVD system. One examined the video guidance and periscope monitoring methods, and the other examined three control complexity levels using one-axis RVD control, two-axis RVD control, and three-axis RVD control. Eighteen male volunteers aged 22-35 participated in the experiments. The results show that the RVD operating time increases with control complexity. Based on the operators＇ findings, the two-axis control is the easiest. The monitoring method has no significant influence on failure rate with the low complexity using one-axis RVD control.

Safe Autonomous Docking of Spacecraft:A RRT-combined Output-constrained Recursive Control Method

In addressing the challenges of short-range spacecraft docking in the presence of obstacles and disturbances,it is critical to integrate guidance and motion control to ensure autonomous and reliable operation.Traditional methods that separate these two layers often struggle with accurately tracking predefined paths,increasing the risk of collisions.In light of this,a proposed scheme integrating guidance and control in an organic manner has been put forth.This scheme employs the rapidly-exploring random trees(RRT)algorithm within the guidance layer to generate a collision-avoidance trajectory for the control layer,efficiently navigating the spacecraft towards its target.Then the control layer implements a second-order output-constrained controller by adding a power integrator and a novel barrier Lyapunov function(BLF)together,to guarantee that the tracking error of the predefined trajectory remains bounded and the system asymptotically converges to the target.To account for tracking errors,obstacle radii are expanded during path planning through a dilation constant.Based on theoretical derivation and simulation experiments,the effectiveness and advancement of the proposed method are validated.