IEEE Trans Cybern. 2022 May;52(5):2750-2762. doi: 10.1109/TCYB.2020.3022175. Epub 2022 May 19.
Robotic grasping ability lags far behind human skills and poses a significant challenge in the robotics research area. According to the grasping part of an object, humans can select the appropriate grasping postures of their fingers. When humans grasp the same part of an object, different poses of the palm will cause them to select different grasping postures. Inspired by these human skills, in this article, we propose new grasping posture prediction networks (GPPNs) with multiple inputs, which acquire information from the object image and the palm pose of the dexterous hand to predict appropriate grasping postures. The GPPNs are further combined with grasping rectangle detection networks (GRDNs) to construct multilevel convolutional neural networks (ML-CNNs). In this study, a force-closure index was designed to analyze the grasping quality, and force-closure grasping postures were generated in the GraspIt! environment. Depth images of objects were captured in the Gazebo environment to construct the dataset for the GPPNs. Herein, we describe simulation experiments conducted in the GraspIt! environment, and present our study of the influences of the image input and the palm pose input on the GPPNs using a variable-controlling approach. In addition, the ML-CNNs were compared with the existing grasp detection methods. The simulation results verify that the ML-CNNs have a high grasping quality. The grasping experiments were implemented on the Shadow hand platform, and the results show that the ML-CNNs can accurately complete grasping of novel objects with good performance.
机器人抓取能力远远落后于人类技能,这在机器人研究领域构成了重大挑战。根据物体的抓取部分,人类可以选择手指的适当抓取姿势。当人类抓取物体的同一部分时,手掌的不同姿势会导致他们选择不同的抓取姿势。受这些人类技能的启发,在本文中,我们提出了具有多输入的新抓取姿势预测网络(GPPN),该网络从物体图像和灵巧手的手掌姿势获取信息,以预测适当的抓取姿势。GPPN 进一步与抓取矩形检测网络(GRDN)相结合,构建多级卷积神经网络(ML-CNN)。在这项研究中,设计了力封闭指数来分析抓取质量,并在 GraspIt!环境中生成力封闭抓取姿势。在 Gazebo 环境中捕获物体的深度图像,以构建 GPPN 的数据集。在这里,我们描述了在 GraspIt!环境中进行的模拟实验,并通过变量控制方法研究了图像输入和手掌姿势输入对 GPPN 的影响。此外,还将 ML-CNN 与现有的抓取检测方法进行了比较。模拟结果验证了 ML-CNN 具有较高的抓取质量。在 Shadow 手平台上进行了抓取实验,结果表明 ML-CNN 可以准确完成对具有良好性能的新物体的抓取。