Department of Mechanical Engineering, Virginia Tech, 1075 Life Science Circle, Blacksburg, VA, 24061, United States of America.
Bioinspir Biomim. 2018 Jun 26;13(4):046011. doi: 10.1088/1748-3190/aac788.
The noseleaf and pinnae of horseshoe bats (Rhinolophus ferrumequinum) have both been shown to actively deform during biosonar operation. Since these baffle structures directly affect the properties of the animals biosonar system, this work mimics horseshoe bat sonar system with the goal of developing a platform to study the dynamic sensing principles horseshoe bats employ. Consequently, two robotic devices were developed to mimic the dynamic emission and reception characteristics of horseshoe bats. The noseleaf and pinnae shapes were modeled as smooth blanks matched to digital representations of a horseshoe bat specimens noseleaf and pinnae. Local shape features mimicking structures on the pinnae and noseleaf were added digitally. Flexible baffles with local shape feature combinations were manufactured and paired with actuation mechanisms to mimic pinnae and noseleaf deformations in vivo. Two noseleaves with and without local shape features were considered. Each noseleaf baffle was mounted to a platform called the dynamic emission head to actuate three surface elements of the baffle. Similarly, 12 pinna realizations composed of combinations of three local shape features were mounted to a platform called the dynamic reception head to deform the left and right pinnae independently. Motion of the noseleaf and pinnae were synchronized to the incoming and outgoing sonar waveform, and the joint time-frequency properties of the noseleaf and pinnae local feature combinations and pairs of pinnae and noseleaf thereof were characterized across spatial direction. Amplitude modulations to the outgoing and incoming sonar pulse information across spatial direction were observed for all pinnae and noseleaf local shape feature combinations. Peak modulation variance generated by motion of the pinnae and combinations of the noseleaf and pinnae approached a white Gaussian noise variance bound. It was found the dynamic emitter generated less modulation than either the combined or reception scenarios.
马蹄蝠的鼻甲和耳屏都在生物声纳操作过程中表现出主动变形。由于这些挡板结构直接影响动物生物声纳系统的特性，这项工作模拟了马蹄蝠的声纳系统，旨在开发一个研究马蹄蝠动态感知原理的平台。因此，开发了两种机器人设备来模拟马蹄蝠的动态发射和接收特性。鼻甲和耳屏的形状被建模为与马蹄蝠标本的鼻甲和耳屏的数字表示相匹配的光滑空白。通过数字方式添加了模拟耳屏和鼻甲上结构的局部形状特征。制造了带有局部形状特征组合的柔性挡板，并与致动机构配对，以模拟体内耳屏和鼻甲的变形。考虑了两个带有和不带有局部形状特征的鼻甲。每个鼻甲挡板都安装在一个称为动态发射头的平台上，以致动挡板的三个表面元件。同样，由三个局部形状特征组合组成的 12 个耳屏实现被安装在一个称为动态接收头的平台上，以独立地变形左右耳屏。鼻甲和耳屏的运动与入射和出射声纳波形同步，并且表征了鼻甲和耳屏局部特征组合以及相应的左右耳屏之间的联合时频特性在空间方向上的变化。观察到所有耳屏和鼻甲局部形状特征组合在空间方向上对出射和入射声纳脉冲信息的幅度调制。耳屏和鼻甲组合以及耳屏和鼻甲的运动产生的峰值调制方差接近白高斯噪声方差边界。结果发现，动态发射器产生的调制比组合或接收情况都要少。
