Study On Deduction And Evaluation Method Of Space Station Short-term Operation Plan

In 2022,China will build a long-term operational space station in near-Earth orbit.Simulation and evaluation technology is one of the key technologies to ensure stable and safe operation and effective event implementation.Based on the actual needs of China’s space station project,this paper focuses on the simulation,evaluation,and adjustment methods of the short-term operation plan.The main results are as follows.A simulation method composed of several strategies for short-term operation plan under contingency circumstances is proposed.Based on the stochastic,discrete point-in-time variability of the operation plan state,a discrete event simulation model of the combined strategy,including event postponement,execution state update by batch,and selective scheduling,is constructed.Firstly,based on the characteristics of the contingency and the resolution time of event execution constraints,a contingency deferral strategy and a constraint deferral strategy are separately proposed.Then,an event status update strategy in a single batch is proposed in which the batches are divided based on timing relationships.Finally,an event selective scheduling strategy considering the event execution time and executable flags is proposed.The test results show that the proposed simulation method can obtain feasible solutions that satisfy the constraints under contingency situations.A multi-perspective evaluation method for short-term operation plan based on Monte Carlo method is proposed.Based on simulation volatility analysis,several measurable metrics are defined,and a solution performance evaluation method based on Monte Carlo method is proposed.By using the combination of sub-round variance calculation and variance reduction methods,an accurate and stable performance evaluation is achieved with a small number of simulations.Then,based on the stability characteristics of the scheme under the number,an event execution range definition strategy is proposed,and the delayed and cancellation situation of each event are specifically analyzed.The test results show that the proposed evaluation method can reduce the absolute accuracy of the evaluation metrics to less than 0.8 with a 90%confidence level under a small simulation number and obtain reliable performance assessment and task execution scoping results.A robustness adjustment method for short-term operation plan under contingency circumstances is proposed.Based on the analysis of plan robustness,an optimization model with event execution offset as the constraint and event execution rate as the target is constructed.By introducing the evaluation process into the method,the integration of simulation,evaluation and adjustment of short-term operation plan is achieved.The test results show that the method can improve the event execution rate from 89.9% to 98.3% when satisfying the constraints.A software is developed based on the study of the simulation and performance evaluation methods,providing technical support for engineering departments to carry out related work.