Japan Aerospace Exploration Agency (JAXA) has successfully launched and operated an unmanned supply cargo vehicle called the H-II Transfer Vehicle (HTV) six times as of 2017. Currently, a new-generation cargo vehicle called HTV-X is being developed. The first HTV-X flight is planned in JFY 2021. A new redundant design based on resilience engineering of HTV-X is being proposed. The new design policy, which stipulates that all redundant strings operate to manage degraded performance instead of switching one string due to failure, increases the complexity compared to conventional design. Therefore, various system behaviors, including such undesirable events as failure, must be evaluated and reflected in the system design. Generally, the control logic is validated using Simulink, but such issues as calculation time and event injection must still be overcome using Simulink. A system simulation environment that incorporates a native C code library generated by Matlab's auto-coding function has been developed to overcome these issues. This paper describes the validation results of the GNC algorithm design of HTV-X using a simulation environment with model-based technology for this conceptual study. It also presents the results of Monte Carlo simulation and cases of simulated failure.
展开▼
