  We present the grasping system and design approach behind Cartman, the
winning entrant in the 2017 Amazon Robotics Challenge. We investigate the
design processes leading up to the final iteration of the system and describe
the emergent solution by comparing it with key robotics design aspects.
Following our experience, we propose a new design aspect, precision vs.
redundancy, that should be considered alongside the previously proposed design
aspects of modularity vs. integration, generality vs. assumptions, computation
vs. embodiment and planning vs. feedback. We present the grasping system behind
Cartman, the winning robot in the 2017 Amazon Robotics Challenge. The system
makes strong use of redundancy in design by implementing complimentary tools, a
suction gripper and a parallel gripper. This multi-modal end-effector is
combined with three grasp synthesis algorithms to accommodate the range of
objects provided by Amazon during the challenge. We provide a detailed system
description and an evaluation of its performance before discussing the broader
nature of the system with respect to the key aspects of robotic design as
initially proposed by the winners of the first Amazon Picking Challenge. To
address the principal nature of our grasping system and the reason for its
success, we propose an additional robotic design aspect `precision vs.
redundancy'. The full design of our robotic system, including the end-effector,
is open sourced and available at
http://juxi.net/projects/AmazonRoboticsChallenge/
