Most of the previous research works consider hu-
mans as dynamic obstacles using different techniques
and sensing modalities. Nevertheless, considering hu-
mans as dynamic obstacles to simply avoid them is
certainly sufficient from the safety point of view, but
can cause annoyances for humans. Indeed, proxemics
theory, one of the most popular principles in Human
Robot Spatial Interaction (HRSI), advises to select
appropriate interaction distances between robots and
humans (Lindner and Eschenbach, 2017). The robot
should keep a certain distance from a human while
navigating, preferably greater than 1.2m not to vio-
late the Personal Space (PS).
Currently, many researches are devoted to design
navigation approaches with safety control in com-
plex environments. For instance, Choi et al. (Choi
et al., 2017) proposed Gaussian process motion re-
gression based robot navigation, which predicts fu-
ture trajectory of human with two Microsoft Kinect
sensors in dynamic environments. In (Song et al.,
2017), a shared-control scheme based navigation is
proposed via combining active obstacle avoidance
and passive-compliant motion behavior prediction for
human, where walking-assistant robot avoids colli-
sion and allows safe guidance for human using leg
detector by 2D laser sensor. In (Zimmermann et al.,
2018), the robot trajectory planning is done by esti-
mating 3D human pose in RGB-D images while exe-
cuting tasks in cluttered environments occupied with
different features of the obstacles.
Numerous solutions have been presented for hu-
man detection and tracking in a human populated
environment based on 2D Laser range sensors (Lin-
der et al., 2016; Song et al., 2017). The core idea
of human detection is a binary classifier trained on
leg appearance features that is reflected by beams of
2D laser sensor. First, the reflected 2D laser data
(points) is segmented according to Euclidian distance
(jump distance) between continuously neighboring
2D points. These segments are then classified as a
human leg if it scores approximation values of 2D ge-
ometrical structure features, which are characterized
by pre-defined fourteen parameters such as number of
reflected points, width, linearity, circularity, radius as
described by (Arras et al., 2007). Nevertheless, even
if these methods achieve great performances in air-
port and hospital environment, they are not applicable
in logistics warehouses environment due to the high
number of false detection as reported in this study.
On the other hand, human detectors based on 3D vi-
sion show high performances in industrial environ-
ment (Munaro et al., 2016) and intralogistics ware-
houses (Linder et al., 2018).
For these reasons, the main goal of this research is
to design a human-aware navigation framework that
makes the robot behaviour more sociable (as shown in
Figure 1). It implies being able to distinguish between
human and non-human obstacles, which is currently
the case in the state-of-the-art. We investigate the
constraints of human detection algorithm implemen-
tation taking into account different point of view, from
the computational costs, to the safety and proxemics
theory requirements. The proposed framework is de-
signed to be optimal in logistics warehouses environ-
ments with their specific properties and constraints.
Then, the functionality of the framework is proved
in an experiment based on autonomous Summit XL
mobile robot in a logistics warehouses simulated en-
vironment relying on the well known Robot Operat-
ing System (ROS) (Quigley et al., 2009). To illus-
trate, one of the powerful ROS toolbox is Navigation
Stack
1
which detects obstacles through 2D laser sen-
sor in real time. Then, inflation layer is created with
around obstacles by inflation radius value to avoid the
collision. The idea is to use a small inflation radius
value that allow pick and place mobile robot to close
enough to its targets that are installed in selective
racks. Additionally, coworkers safety area is manip-
ulated as a circular obstacle fused in laser scan data.
The final achievement of this research is a global ar-
chitecture keeping a balance between real-time con-
straints leading to investment and operational costs
and societal issues to make the human working con-
ditions more comfortable.
This paper is structured as follows: Section 2
describes the proposed sensor interaction algorithm
for human-aware mobile robot navigation in logistics
warehouses. Section 3 presents experimental results
demonstrating the advantages of the proposed frame-
work. Finally, conclusions are drawn in Section 4.
2 HUMAN-AWARE NAVIGATION
FRAMEWORK
2.1 Mobile Robot Navigation
ROS is a compilation of tools, libraries, and utili-
ties which facilitate the design of complex robot tasks
through powerful algorithms implementation such as
Navigation Stack which is composed of several algo-
rithms (ROS nodes). These nodes are communicating
via publish/subscribe message-oriented middleware.
For each ROS node, information is sent/received via
a given topic as a structured data message. Conse-
quently, a variety of information patterns can be ex-
1
ROS navigation, http://wiki.ros.org/navigation.
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