Synthesizing Diverse and Physically Stable Grasps with Arbitrary Hand Structures by Differentiable Force Closure Estimator
Code is available at https://github.com/tengyu-liu/diverse-and-stable-grasp
arxiv link: https://arxiv.org/abs/2104.09194
Abstract
Existing grasp synthesis methods are either analytical or data-driven. The former one is oftentimes limited to specific application scope. The latter one depends heavily on demonstrations, thus suffers from generalization issues; e.g., models trained with human grasp data would be difficult to transfer to 3-finger grippers. To tackle these deficiencies, we formulate a fast and differentiable force closure estimation method, capable of producing diverse and physically stable grasps with arbitrary hand structures, without any training data. Although force closure has commonly served as a measure of grasp quality, it has not been widely adopted as an optimization objective for grasp synthesis primarily due to its high computational complexity; in comparison, the proposed differentiable method can test a force closure within 4ms. In experiments, we validate the proposed method's efficacy in 8 different settings.
Results
3D View of Synthesized Example
Please follow this link to view the final state of the synthesis trajectory in the above video.
3D View Before/After Refinement
The following table contains the 3D views of corresponding examples depicted in Fig 6.
Click on each image to view them in 3D.
3D View Grasp of Different Hand
Click on each image to view them in 3D.
Additional Results
We present more experimental results here that cannot fit into our RA-L paper due to space limitations.
Synthesizing Specific Grasp Type
As mentioned in Section IV-B, the choice of contact points on the hand surface primarily determines the grasp type. Hence, specific grasp types can be synthesized by mandating the choice of contact point.
(a)(d)(g)(j) show the query contact points in red, each followed by two synthesized examples using the queried contact points.