If robots could reliably manipulate the shape of 3D deformable objects, they could find applications in fields ranging from home care to warehouse fulfillment to surgical assistance. Analytic models of elastic, 3D deformable objects require numerous parameters to describe the potentially infinite degrees of freedom present in determining the object's shape. Previous attempts at performing 3D shape control rely on hand-crafted features to represent the object shape and require training of object-specific control models. We overcome these issues through the use of our novel DeformerNet neural network architecture, which operates on a partial-view point cloud of the object being manipulated and a point cloud of the goal shape to learn a low-dimensional representation of the object shape. This shape embedding enables the robot to learn to define a visual servo controller that provides Cartesian pose changes to the robot end-effector causing the object to deform towards its target shape. Crucially, we demonstrate both in simulation and on a physical robot that DeformerNet reliably generalizes to object shapes and material stiffness not seen during training and outperforms comparison methods for both the generic shape control and the surgical task of retraction.
翻译:如果机器人可以可靠地操纵 3D 变形物体的形状,他们可以在从家用护理到仓库安装到外科协助等不同领域找到应用。 弹性、 3D 变形物体的分析模型需要多种参数来描述确定对象形状时存在的潜在自由度。 以往执行 3D 形状控制的尝试依靠手动制作的特性来代表对象形状, 需要训练特定对象的控制模型。 我们通过使用我们的新颖的变异Net 神经网络结构克服了这些问题, 它运行在被操纵对象的局部视野云上, 以及目标形状的点云中, 学习对象形状的低维表示。 这种形状的嵌入使机器人能够学会定义视觉变异控制器, 使机器人的末效器发生改变, 使对象向目标形状变形。 显而易见的是, 我们在模拟中以及在一个物理机器人上都展示了这些变异性, 变异性网络可以对被操纵对象形状和材料的坚硬度进行瞄准, 而在训练中和外形比较方法中看不到。