Abstract The main purpose of this survey paper is to review the field of convergence between the liquid-propellant rocket-propulsion and automatic-control disciplines. A comprehensive collection of academic works and some industrial developments are summarised and discussed, making the link to the current context of launcher reusability. The main control problem in liquid-propellant rocket engines (LPRE), the target of this survey, generally consists in tracking set-points in combustion-chamber pressure and mixture ratio, their main operating quantities. This goal is attained via the adjustment of flow-control valves while complying with operating constraints. Each aspect of control systems, ranging from modelling to the actual control techniques, is reviewed and subsequently related to the rest of aspects. The comparison of the different approaches points to the general use of linearised models about concrete operating points for deriving steady-state controllers, which in most cases are of PID type. Other more sophisticated approaches present in the literature, incorporating some nonlinear, hybrid or robust techniques, improve certain aspects of performance and robustness. Nevertheless, no fully nonlinear or hybrid frameworks, which may allow the control of a wider throttling domain, have been published. In addition, control during the thermally and structurally demanding transient phases is usually in open loop, and hence with low correction margins. This sort of control enhancements, probably together with more sophisticated monitoring architectures, would serve to extend the life of LPRE, a significant factor in their reusability. Therefore, this survey intends to draw a path for the future control design trends which will certainly be more suitable for reusable LPRE.

中文翻译：

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液体火箭发动机自动控制方法综述

摘要 本调查论文的主要目的是回顾液体推进剂火箭推进与自动控制学科之间的融合领域。对学术著作和一些工业发展的综合集合进行了总结和讨论，从而与发射器可重用性的当前背景建立了联系。本次调查的目标液体推进剂火箭发动机 (LPRE) 的主要控制问题通常包括跟踪燃烧室压力和混合比的设定点，它们的主要操作量。这个目标是通过在遵守操作限制的同时调整流量控制阀来实现的。控制系统的每个方面，从建模到实际控制技术，都经过审查，随后与其他方面相关联。不同方法的比较表明了关于具体操作点的线性模型的普遍使用，用于推导稳态控制器，在大多数情况下是 PID 类型。文献中出现的其他更复杂的方法，结合一些非线性、混合或鲁棒技术，提高了性能和鲁棒性的某些方面。尽管如此，还没有发布可以允许控制更广泛的节流域的完全非线性或混合框架。此外，在热和结构要求瞬态阶段期间的控制通常是开环的，因此具有较低的校正裕度。这种控制增强，可能与更复杂的监控架构一起，将有助于延长 LPRE 的寿命，这是它们可重用性的一个重要因素。所以，