Srinivasan M V, Zhang S W, Chahl J S, Barth E, Venkatesh S
Centre for Visual Science, Research School of Biological Sciences, Australian National University, Canberra, ACT.
Biol Cybern. 2000 Sep;83(3):171-83. doi: 10.1007/s004220000162.
Freely flying bees were filmed as they landed on a flat, horizontal surface, to investigate the underlying visuomotor control strategies. The results reveal that (1) landing bees approach the surface at a relatively shallow descent angle; (2) they tend to hold the angular velocity of the image of the surface constant as they approach it; and (3) the instantaneous speed of descent is proportional to the instantaneous forward speed. These characteristics reflect a surprisingly simple and effective strategy for achieving a smooth landing, by which the forward and descent speeds are automatically reduced as the surface is approached and are both close to zero at touchdown. No explicit knowledge of flight speed or height above the ground is necessary. A model of the control scheme is developed and its predictions are verified. It is also shown that, during landing, the bee decelerates continuously and in such a way as to keep the projected time to touchdown constant as the surface is approached. The feasibility of this landing strategy is demonstrated by implementation in a robotic gantry equipped with vision.
研究人员拍摄了自由飞行的蜜蜂降落在平坦水平表面上的过程，以探究其潜在的视觉运动控制策略。结果表明：（1）着陆的蜜蜂以相对较小的下降角度接近表面；（2）它们在接近表面时倾向于使表面图像的角速度保持恒定；（3）瞬时下降速度与瞬时前进速度成正比。这些特征反映了一种出奇简单而有效的实现平稳着陆的策略，即随着接近表面，前进速度和下降速度会自动降低，并且在触地时都接近零。无需明确知晓飞行速度或离地面的高度。开发了该控制方案的模型并验证了其预测结果。研究还表明，在着陆过程中，蜜蜂持续减速，并且在接近表面时以保持预计触地时间恒定的方式减速。通过在配备视觉的机器人龙门架上实施，证明了这种着陆策略的可行性。
