Flapping-wing micro air vehicles (FWMAVs) have demonstrated remarkable bio-inspired agility, yet tailless two-winged configurations remain largely unexplored due to their complex fluid-structure and wing-body coupling. Here we present \textit{AirPulse}, a 26-gram butterfly-inspired FWMAV that achieves fully onboard, closed-loop, untethered flight without auxiliary control surfaces. The AirPulse robot replicates key biomechanical traits of butterfly flight, including low wing aspect ratio, compliant carbon-fiber-reinforced wings, and low-frequency, high-amplitude flapping that induces cyclic variations in the center of gravity and moment of inertia, producing characteristic body undulation. We establish a quantitative mapping between flapping modulation parameters and force-torque generation, and introduce the Stroke Timing Asymmetry Rhythm (STAR) generator, enabling smooth, stable, and linearly parameterized wingstroke asymmetry for flapping control. Integrating these with an attitude controller, the AirPulse robot maintains pitch and yaw stability despite strong oscillatory dynamics. Free-flight experiments demonstrate stable climbing and turning maneuvers via either angle offset or stroke timing modulation, marking the first onboard controlled flight of the lightest two-winged, tailless butterfly-inspired FWMAV reported in peer-reviewed literature. This work corroborates a foundational platform for lightweight, collision-proof FWMAVs, bridging biological inspiration with practical aerial robotics. Their non-invasive maneuverability is ideally suited for real-world applications, such as confined-space inspection and ecological monitoring, inaccessible to traditional drones, while their biomechanical fidelity provides a physical model to decode the principles underlying the erratic yet efficient flight of real butterflies.

翻译：扑翼微型飞行器（FWMAV）已展现出卓越的仿生敏捷性，然而，由于其复杂的流固耦合与翼身耦合，无尾双翼构型在很大程度上仍未得到充分探索。本文提出 \textit{AirPulse}，一种26克仿蝴蝶FWMAV，实现了完全机载、闭环、无系留的飞行，且无需辅助控制面。AirPulse机器人复现了蝴蝶飞行的关键生物力学特性，包括低展弦比机翼、柔顺的碳纤维增强机翼以及低频、大振幅扑动，这些特性诱导了重心和转动惯量的周期性变化，从而产生特征性的身体波动。我们建立了扑动调制参数与力-力矩生成之间的定量映射关系，并引入了扑动时序不对称节律（STAR）生成器，能够实现平滑、稳定且线性参数化的扑动不对称性，用于扑动控制。将这些与姿态控制器集成后，AirPulse机器人即使在强烈的振荡动力学环境下，也能保持俯仰和偏航稳定性。自由飞行实验表明，通过角度偏移或扑动时序调制，机器人能够实现稳定的爬升和转弯机动，这标志着在同行评审文献中报道的最轻双翼、无尾仿蝴蝶FWMAV首次实现了机载受控飞行。此项工作证实了一个用于轻量化、防碰撞FWMAV的基础平台，架起了生物灵感与实际空中机器人技术之间的桥梁。其非侵入式的机动性非常适合实际应用，例如传统无人机无法进入的受限空间检查和生态监测，而其生物力学保真度则为解码真实蝴蝶那看似不稳定却高效的飞行背后的原理提供了一个物理模型。