IEEE Robotics & Automation Magazine - September 2018 - 85

Design and Architecture
Mechatronic Design
The mechatronic setup, referred to as RoDyMan like the project name, is a 21-degrees-of-freedom (DoF) humanoid robot
(see Figure 1). An omnidirectional mobile platform allows the
robot to move. An actuated mechanism gives the ability to
enlarge the support polygon during the execution of dynamic
and rapid movements of the upper body. The battery pack
and uninterruptible power supply unit used to provide power
to all of the devices are housed within the mobile platform
and provide the weight to stabilize the platform. Two standard
personal computers (PCs) are also located in the base. One is
a QNX-based PC used to control the motors in real time and
for the implementation of safety procedures. The second is a
Linux-based PC used for perception and high-level planning
and control algorithms.
The upper-body limbs of the robot are two SCHUNK LWA
4P arms with 6 DoF each. The seventh joint of each arm,
required to add human-like kinematics, is provided by a
SCHUNK PRL-100 integrated into the shoulder. To the best of
our knowledge, the SCHUNK were the only arms on the market to have both dimensions similar to human arms and also
the control directly on the controller area network bus without
an external controller box. Nevertheless, experimental results
show that the high friction and the low-joint velocities exhibited by these arms represent a limitation on the execution of
particular and complex tasks like tossing. However, this solution represents only a first prototype, and the design of new
arms, with advanced dynamical characteristics, is within the
RoDyMan project plan.
Moreover, the dynamic model of the whole structure is
derived in a symbolic form. The linear matrix inequality (LMI) method in [13] was employed to obtain the
identification of the dynamic parameters by absorbing
the physical constraints within the optimization procedure. Experimental results have shown that friction,
mostly the static part, is the dominant component in the
measured torque. Therefore, friction identification has
first been performed separately, and then the friction
parameters have been used as constraints within the LMI
optimization procedure.
The RoDyMan platform is completed by two motors to
actuate the torso and one for the pan-tilt neck. To provide
enhanced dexterous manipulation skills, two anthropomorphic SCHUNK Servo-electric 5-Finger SVH hands can be
applied at the end-effector tip of the two arms. However,
these hands are very delicate, and they are replaced with
suitable three-dimensional (3-D)-printed tools for those
tasks requiring nontrivial weights in action, such as the
pizza-peel task. From the perception point of view, the platform is equipped with two laser scanners in the base for
odometry operation. Two force sensors can be mounted
on the wrist to measure the interaction forces between the
end effector and the environment, while the interaction
forces exerted on the robot structure can also be obtained

using proper estimators [14]. Finally, the head is equipped
with a stereo camera system, a red-green-blue depth
(RGB-D) sensor, and a time-of-flight camera to obtain
precise depth estimation.
High-Level Software Architecture
To carry out the expected activities involving complex manipulation actions, control architecture is designed to handle
high-level planning tasks. A sketch of the control architecture
is shown in Figure 2.
The human-robot interaction (HRI) interface module is
used to specify high-level tasks as inputs for the system (e.g.,
the pizza tossing). The supervisor module is responsible for
the task decomposition process and for splitting the highlevel actions received by the HRI interface into lower-level
actions, which considers both the state of the robot and the
information generated by the perception module. After the
decomposition process, each lower-level action can be executed. Examples of high-level tasks include grasp, search, or
toss for objects and sequences of nonprehensile manipulation primitives.
To suitably perform the task decomposition process, the
supervisor module is provided with multiple hierarchical
tasks, similar to hierarchical task networks, which can be

Figure 1. The RoDyMan platform handling the peel with two
arms and two proper grippers at the end effectors. The displayed
tool is a real pizza peel employed by chefs to cook the dough in
the oven. A blue silicon disk, usually employed by acrobatic pizza
chefs for training, is employed in the experiments.

september 2018

IEEE ROBOTICS & AUTOMATION MAGAZINE

IEEE Robotics & Automation Magazine - September 2018

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