  In recent times, object detection and pose estimation have gained significant
attention in the context of robotic vision applications. Both the
identification of objects of interest as well as the estimation of their pose
remain important capabilities in order for robots to provide effective
assistance for numerous robotic applications ranging from household tasks to
industrial manipulation. This problem is particularly challenging because of
the heterogeneity of objects having different and potentially complex shapes,
and the difficulties arising due to background clutter and partial occlusions
between objects. As the main contribution of this work, we propose a system
that performs real-time object detection and pose estimation, for the purpose
of dynamic robot grasping. The robot has been pre-trained to perform a small
set of canonical grasps from a few fixed poses for each object. When presented
with an unknown object in an arbitrary pose, the proposed approach allows the
robot to detect the object identity and its actual pose, and then adapt a
canonical grasp in order to be used with the new pose. For training, the system
defines a canonical grasp by capturing the relative pose of an object with
respect to the gripper attached to the robot's wrist. During testing, once a
new pose is detected, a canonical grasp for the object is identified and then
dynamically adapted by adjusting the robot arm's joint angles, so that the
gripper can grasp the object in its new pose. We conducted experiments using a
humanoid PR2 robot and showed that the proposed framework can detect
well-textured objects, and provide accurate pose estimation in the presence of
tolerable amounts of out-of-plane rotation. The performance is also illustrated
by the robot successfully grasping objects from a wide range of arbitrary
poses.
