Robotic bin picking of small industrial parts with metallic luster is a challenging task. Especially, the bin picking for metallic bolts with high success rate is very challenging, since the metallic bolts are part of in nearly all industrial products. High accuracy 3D measurement for metallic bolts is difficult due to specular and diffuse reflection caused by a screw part of bolts. To achieve high success rate for bin picking of metallic bolts, we propose the following three approaches. First, we show that 4 steps phase shift can achieve three-order accuracy for 3D measurement by mathematical analysis and adopt it. Second, we propose a novel robust and fast posture estimation algorithm named SAC-LMI (Sample Consensus with Linear Matrix Inequality). The proposed algorithm SAC-LMI can compute posture of the metallic bolts with high accuracy by using 3D measured point cloud having many outliers. Finally, we adopt a simple 1-DOF handling device called RAPiD for robust bin picking against calibration error for camera-robot posture. Considering the three approaches shown above, we have developed a robotic bin picking system which provides 95% success rates in industrial bin picking.
In this research, a new concept named Dynamic Reconfiguration Manipulability (DRM) is proposed, gauging dynamical shape-changeability by using redundancy while a hand task is given primarily. Helping optimize designing and controlling robots, the DRM represents simultaneously how much acceleration each intermediate link can be generated and what direction the acceleration can be realized by normalized torque inputs. We have confirmed appropriateness and usefulness of the DRM by applying it to redundant manipulator PA10 produced by Mitsubishi Heavy Industries Ltd.
Because the mechanical and systematic requirements for robots used in nuclear power plants cannot often be satisfied with the industrial robots, special robots have been developed according to the specific needs. For saving time and cost of development, we have planned to prepare the general purpose manipulator with light-weight and environmental resistance which can be applied to maintenance work of nuclear power plants and which can correspond to system upgrading flexibly by an open system configuration.