Research studies on quadrotors have recently drawn significant interest from academia and industry. Faults and failures handling are the major weaknesses of conventional quadrotor platforms; therefore, an innovative actuation mechanism was introduced to allow tilting the rotors. Tilting rotors of multirotor platforms provide high dexterity for flying between adjacent obstacles and assist the platforms in dealing with various failure scenarios. This paper reviews the state of the research on tilt-quadrotor platforms. Several platforms, software and hardware architectures, were discussed in the literature. Most of the latest developments were focused on conventional quadrotor modelling, combined with rotor tilting dynamics. On the other hand, controlling such platform was mainly studied using two types of controllers: Feedback Linearisation technique and Control Allocator. Recovery strategy in case of fault or failure has been covered extensively for conventional quadrotors, but very limited known work for tilt-quadrotor. This review concludes that the system dynamic modelling is relatively well covered compared to exploring new control techniques for more stringent requirements. However, recovery strategies as the main advantage of tilt-quadrotor platforms are not explored extensively and require more research attention.

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倾斜四旋翼飞行器、建模、控制和故障恢复的最新技术

四旋翼飞行器的研究最近引起了学术界和工业界的极大兴趣。故障和故障处理是传统四旋翼平台的主要弱点；因此，引入了一种创新的驱动机制来允许倾斜转子。多旋翼平台的倾转旋翼为相邻障碍物之间的飞行提供了高度的灵活性，并协助平台应对各种故障场景。本文回顾了倾斜四旋翼平台的研究现状。文献中讨论了多个平台、软件和硬件架构。大多数最新发展都集中在传统的四旋翼建模上，结合转子倾斜动力学。另一方面，主要研究使用两种类型的控制器来控制此类平台：反馈线性化技术和控制分配器。常规四旋翼飞行器已广泛涵盖故障或故障情况下的恢复策略，但倾斜四旋翼飞行器的已知工作非常有限。该审查得出的结论是，与针对更严格要求探索新的控制技术相比，系统动态建模的覆盖范围相对较好。然而，作为倾斜四旋翼平台主要优势的恢复策略并未得到广泛探索，需要更多的研究关注。