Tiny “gnat robots,” weighing just a few milligrams, were first conjectured in the 1980s. How to stabilize one if it were to hover like a small insect has not been answered. Challenges include the requirement that sensors be both low mass and high bandwidth and that silicon-micromachined rate gyroscopes are too heavy. The smallest robot to perform controlled hovering uses a sensor suite weighing hundreds of milligrams. Here, we demonstrate that an accelerometer represents perhaps the most direct way to stabilize flight while satisfying the extreme size, speed, weight, and power constraints of a flying robot even as it scales down to just a few milligrams. As aircraft scale reduces, scaling physics dictates that the ratio of aerodynamic drag to mass increases. This results in reduced noise in an accelerometer’s airspeed measurement. We show through simulation and experiment on a 30-gram robot that a 2-milligram off-the-shelf accelerometer is able in principle to stabilize a 10-milligram robot despite high noise in the sensor itself. Inspired by wind-vision sensory fusion in the flight controller of the fruit fly Drosophila melanogaster , we then added a tiny camera and efficient, fly-inspired autocorrelation-based visual processing to allow the robot to estimate and reject wind as well as control its attitude and flight velocity using a Kalman filter. Our biology-inspired approach, validated on a small flying helicopter, has a wind gust response comparable to the fruit fly and is small and efficient enough for a 10-milligram flying vehicle (weighing less than a grain of rice).

中文翻译：

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用于 10 毫克机器人的无陀螺仪视觉惯性飞行控制和风传感系统

20 世纪 80 年代人们首次推测出重量只有几毫克的微型“小昆虫机器人”。如果它像一只小昆虫一样盘旋，如何稳定它尚未得到解答。挑战包括要求传感器既质量低又带宽高，以及硅微机械速率陀螺仪太重。执行受控悬停的最小机器人使用重达数百毫克的传感器套件。在这里，我们证明加速度计可能是稳定飞行的最直接方式，同时满足飞行机器人的极端尺寸、速度、重量和功率限制，即使它缩小到只有几毫克。随着飞机规模的缩小，比例物理决定了气动阻力与质量的比率增加。这导致加速度计的空速测量中的噪声降低。我们通过在 30 克重的机器人上进行仿真和实验表明，尽管传感器本身存在高噪声，但 2 毫克现成的加速度计原则上能够稳定 10 毫克重的机器人。灵感来自果蝇飞行控制器中的风视感官融合果蝇，然后我们添加了一个微型相机和高效的、受飞行启发的基于自相关的视觉处理，使机器人能够估计和拒绝风，并使用卡尔曼滤波器控制其姿态和飞行速度。我们的生物学启发方法在小型飞行直升机上得到验证，具有与果蝇相媲美的阵风响应，并且对于 10 毫克的飞行器（重量不到一粒米）来说足够小且高效。