MMU推进器布置的冗余设计和分配算法

Redundant thruster configuration design and command allocation algorithm of manned maneuvering unit

美国和苏联现有的舱外载人机动装置(Manned Maneuvering Unit,MMU)推进系统设计均采用两套独立系统互为备份的方式,主系统故障后可以启动备用系统,但备用系统故障则无应对方案,因此制约航天员的安全性和舱外活动能力。文章在常规主备份推进模式基础上提出了应急推进模式,备份推进器发生故障后,根据失效发动机组相对位置关系采用不同应急策略,剩余有效推进器通过联合控制的方式保证航天员六自由度控制。经过可行性分析和仿真计算,证明了应急模式下MMU推进能力有一定降低,但能够为航天员返回提供动力,应急推进模式具有可行性。

Manned maneuvering units made by American and the Soviet Union both use two sets of independent propulsion systems, which are backup for each other. The backup propulsion system can take the place of the failure propulsion system,but there are no further safeguards for the backup system.The traditional scheme restricts the safety and extravehicular ability.Based on the conventional propulsion mode an emergency propulsion mode was proposed. Different strategies were carried out according to the positional relationship of the failured thrusters.The remaining effective thrusters to ensure the 6-DOF control were combined. Calculation and simulation results indicate that,the emergencypropulsion can complete the task of extravehicular activities with reduction of propulsion,and the scheme is feasible.