Vision-based haptic sensors have emerged as a promising approach to robotic touch due to affordable high-resolution cameras and successful computer-vision techniques. However, their physical design and the information they provide do not yet meet the requirements of real applications. We present a robust, soft, low-cost, vision-based, thumb-sized 3D haptic sensor named Insight: it continually provides a directional force-distribution map over its entire conical sensing surface. Constructed around an internal monocular camera, the sensor has only a single layer of elastomer over-molded on a stiff frame to guarantee sensitivity, robustness, and soft contact. Furthermore, Insight is the first system to combine photometric stereo and structured light using a collimator to detect the 3D deformation of its easily replaceable flexible outer shell. The force information is inferred by a deep neural network that maps images to the spatial distribution of 3D contact force (normal and shear). Insight has an overall spatial resolution of 0.4 mm, force magnitude accuracy around 0.03 N, and force direction accuracy around 5 degrees over a range of 0.03--2 N for numerous distinct contacts with varying contact area. The presented hardware and software design concepts can be transferred to a wide variety of robot parts.
翻译:以视觉为基础的视觉感应器由于负担得起的高分辨率相机和成功的计算机视觉技术而成为对机器人触碰的一种很有希望的方法,但是,它们提供的物理设计和信息尚未满足实际应用的要求。我们展示了一种强软、低成本、以视觉为基础的三维大拇指大小的三维感感应器,名为Insight:它不断在整个锥形感应表面提供方向力分布图。它围绕一个内部单色照相机,该感应器只有一层弹性的弹性反射器,在坚固的架子上铺设了一个单一的空间分辨率,以保证敏感度、稳健度和软接触。此外,我们观察是第一个使用对焦仪将光度立体和结构光的光结合起来的系统,以探测其易于替代的灵活外壳的三维变形。这种力量信息由一个深度神经网络推导出,将图像映射到3D接触力(正常和皮肤)的空间分布。在0.03 N左右,其总体空间分辨率为0.4毫米,力级精确度为0.3N,在5度左右的力量方向精确度左右。在0.03至2级的范围内,可以将大量的硬件和不同式设计区域转让。