We consider the problem of open-goal planning for robotic cloth manipulation. Core of our system is a neural network trained as a forward model of cloth behaviour under manipulation, with planning performed through backpropagation. We introduce a neural network-based routine for estimating mesh representations from voxel input, and perform planning in mesh format internally. We address the problem of planning with incomplete domain knowledge by means of an explicit epistemic uncertainty signal. This signal is calculated from prediction divergence between two instances of the forward model network and used to avoid epistemic uncertainty during planning. Finally, we introduce logic for handling restriction of grasp points to a discrete set of candidates, in order to accommodate graspability constraints imposed by robotic hardware. We evaluate the system's mesh estimation, prediction, and planning ability on simulated cloth for sequences of one to three manipulations. Comparative experiments confirm that planning on basis of estimated meshes improves accuracy compared to voxel-based planning, and that epistemic uncertainty avoidance improves performance under conditions of incomplete domain knowledge. Planning time cost is a few seconds. We additionally present qualitative results on robot hardware.
翻译:我们考虑的是机器人布料操作的开放目标规划问题。我们系统的核心是一个神经网络,它是一个经过训练,作为正在操纵的服装行为前方模型,通过背面反射进行规划。我们采用了基于神经网络的例行程序,根据 voxel 输入来估计网状图示,并在内部以网状格式进行规划。我们通过明确的缩略图不确定信号来解决利用不完全的域知识进行规划的问题。这个信号是从预测前方模型网络的两种情况之间存在的差异中计算的,并用来避免在规划期间出现隐蔽的不确定性。最后,我们引入了处理对一组独立候选人的掌握点进行限制的逻辑,以适应机器人硬件所施加的可获取性限制。我们评估了该系统对一至三次操作序列的模拟布料的估计、预测和规划能力。比较实验证实,根据估计的网状进行规划可以提高比基于 voxel 的规划的准确性,而缩略图避免在不完全的域知识条件下提高性能。规划成本为几秒钟。我们提出了关于机器人硬件的定性结果。