IEEE Robotics & Automation Magazine - March 2021 - 86

laser scan format (pointcloud_to_laserscan); reading the
joystick commands (joy), interpreting them as speed commands, and applying speed and acceleration limits to them
(yocs_velocity_smoother); and connecting the Raspberry Pi
4 with the Kobuki platform (kobuki_node) and the Arduino Nano (rosserial).

remotely, to deactivate the safety layer module. The speed
commands mux module implements this multiplexing.

(1)

External Body and Sanitization Requirements
Any piece of equipment, particularly a robot that interacts
with isolated COVID-19 patients, should be sanitizable in a
safe and rapid way. Otherwise, the robot becomes a propagating agent of the virus. This requirement was taken into
account in the design of Pudu's external body.
Pudu's body consists of a cylindrically shaped base, a post
connecting the base and the tablet computer, and two handles
used to lift the robot (see Figures 1, 2, and 5). The body is
composed mainly of smooth surfaces. The materials used to
build the body fulfill the health requirements. The external
parts are built using aluminum composite plates, which are
resistant to the cleaning products used in hospitals and are
not penetrable by water [according to the American Society
for Testing and Materials (ASTM) test method E331-00
(R2016)]. The two handles are made of high-density polyethylene, which is resistant to alcohols and acidic and alkaline
elements but is less resistant to chlorinated solvents. This
material is also impermeable to water [according to ASTM
D570 (2)].

For situations in which the robot needs to move in restricted spaces (e.g., between very close beds), the user can choose,

Deployment and Early Results
Since August 2020, Pudu robots have been used in two hospitals in the Santiago Metropolitan Region: the first was the
Clinical Hospital of the University of Chile; the second was

Assistive Teleoperation
Assistive teleoperation is implemented by the safety layer
module (see Figure 4), which controls the robot's linear speed
to avoid collisions. The robot's angular speed is never limited,
given the robot's circular footprint.
The module takes the laser scan generated by the pointcloud_to_laserscan as input and determines the distance to
the closest obstacle in the direction of the robot's movement,
d min . This distance is compared with two predefined safety
thresholds: d safety
max , which determines the distance at which the
safety module should start modifying the robot's linear speed,
and d safety
min , which defines the distance at which the robot must
stop. Then, the robot's linear speed is modified as
v

out
linear

Z
v in
if d min 2 d safety
linear
max ,
]
safety
]
=
0
if d min 1 d min ,
[
safety
d
min - d min
in
]] v linear e safety
otherwise.
safety o
d max - d min
\

Xbox
Controller

rosserial
Servo

Arduino
Connection

Receives Angle
for Neck Position

joy
Controller
Driver

Controller Command
to Speed Command

LEDs
Receive Battery
Status and Robot
Status

yocs_velocity_smoother

RealSense
Camera
realsense2_camera
Camera
Driver

depth_image_proc
Depth Image
to Point Cloud

Speed
Command Smoother
Kobuki

pointcloud_to_laserscan

Receives Speed
Commands

Safety Layer

Point Cloud to Laser Scan

kobuki_node
Speed
Command to Base

Speed Commands Mux

ROS

Hardware

Figure 4. Pudu's software architecture. All of the modules in cyan are ROS packages. LEDs: light-emitting diodes.

86

*

IEEE ROBOTICS & AUTOMATION MAGAZINE

*

MARCH 2021



IEEE Robotics & Automation Magazine - March 2021

Table of Contents for the Digital Edition of IEEE Robotics & Automation Magazine - March 2021

Contents
IEEE Robotics & Automation Magazine - March 2021 - Cover1
IEEE Robotics & Automation Magazine - March 2021 - Cover2
IEEE Robotics & Automation Magazine - March 2021 - Contents
IEEE Robotics & Automation Magazine - March 2021 - 2
IEEE Robotics & Automation Magazine - March 2021 - 3
IEEE Robotics & Automation Magazine - March 2021 - 4
IEEE Robotics & Automation Magazine - March 2021 - 5
IEEE Robotics & Automation Magazine - March 2021 - 6
IEEE Robotics & Automation Magazine - March 2021 - 7
IEEE Robotics & Automation Magazine - March 2021 - 8
IEEE Robotics & Automation Magazine - March 2021 - 9
IEEE Robotics & Automation Magazine - March 2021 - 10
IEEE Robotics & Automation Magazine - March 2021 - 11
IEEE Robotics & Automation Magazine - March 2021 - 12
IEEE Robotics & Automation Magazine - March 2021 - 13
IEEE Robotics & Automation Magazine - March 2021 - 14
IEEE Robotics & Automation Magazine - March 2021 - 15
IEEE Robotics & Automation Magazine - March 2021 - 16
IEEE Robotics & Automation Magazine - March 2021 - 17
IEEE Robotics & Automation Magazine - March 2021 - 18
IEEE Robotics & Automation Magazine - March 2021 - 19
IEEE Robotics & Automation Magazine - March 2021 - 20
IEEE Robotics & Automation Magazine - March 2021 - 21
IEEE Robotics & Automation Magazine - March 2021 - 22
IEEE Robotics & Automation Magazine - March 2021 - 23
IEEE Robotics & Automation Magazine - March 2021 - 24
IEEE Robotics & Automation Magazine - March 2021 - 25
IEEE Robotics & Automation Magazine - March 2021 - 26
IEEE Robotics & Automation Magazine - March 2021 - 27
IEEE Robotics & Automation Magazine - March 2021 - 28
IEEE Robotics & Automation Magazine - March 2021 - 29
IEEE Robotics & Automation Magazine - March 2021 - 30
IEEE Robotics & Automation Magazine - March 2021 - 31
IEEE Robotics & Automation Magazine - March 2021 - 32
IEEE Robotics & Automation Magazine - March 2021 - 33
IEEE Robotics & Automation Magazine - March 2021 - 34
IEEE Robotics & Automation Magazine - March 2021 - 35
IEEE Robotics & Automation Magazine - March 2021 - 36
IEEE Robotics & Automation Magazine - March 2021 - 37
IEEE Robotics & Automation Magazine - March 2021 - 38
IEEE Robotics & Automation Magazine - March 2021 - 39
IEEE Robotics & Automation Magazine - March 2021 - 40
IEEE Robotics & Automation Magazine - March 2021 - 41
IEEE Robotics & Automation Magazine - March 2021 - 42
IEEE Robotics & Automation Magazine - March 2021 - 43
IEEE Robotics & Automation Magazine - March 2021 - 44
IEEE Robotics & Automation Magazine - March 2021 - 45
IEEE Robotics & Automation Magazine - March 2021 - 46
IEEE Robotics & Automation Magazine - March 2021 - 47
IEEE Robotics & Automation Magazine - March 2021 - 48
IEEE Robotics & Automation Magazine - March 2021 - 49
IEEE Robotics & Automation Magazine - March 2021 - 50
IEEE Robotics & Automation Magazine - March 2021 - 51
IEEE Robotics & Automation Magazine - March 2021 - 52
IEEE Robotics & Automation Magazine - March 2021 - 53
IEEE Robotics & Automation Magazine - March 2021 - 54
IEEE Robotics & Automation Magazine - March 2021 - 55
IEEE Robotics & Automation Magazine - March 2021 - 56
IEEE Robotics & Automation Magazine - March 2021 - 57
IEEE Robotics & Automation Magazine - March 2021 - 58
IEEE Robotics & Automation Magazine - March 2021 - 59
IEEE Robotics & Automation Magazine - March 2021 - 60
IEEE Robotics & Automation Magazine - March 2021 - 61
IEEE Robotics & Automation Magazine - March 2021 - 62
IEEE Robotics & Automation Magazine - March 2021 - 63
IEEE Robotics & Automation Magazine - March 2021 - 64
IEEE Robotics & Automation Magazine - March 2021 - 65
IEEE Robotics & Automation Magazine - March 2021 - 66
IEEE Robotics & Automation Magazine - March 2021 - 67
IEEE Robotics & Automation Magazine - March 2021 - 68
IEEE Robotics & Automation Magazine - March 2021 - 69
IEEE Robotics & Automation Magazine - March 2021 - 70
IEEE Robotics & Automation Magazine - March 2021 - 71
IEEE Robotics & Automation Magazine - March 2021 - 72
IEEE Robotics & Automation Magazine - March 2021 - 73
IEEE Robotics & Automation Magazine - March 2021 - 74
IEEE Robotics & Automation Magazine - March 2021 - 75
IEEE Robotics & Automation Magazine - March 2021 - 76
IEEE Robotics & Automation Magazine - March 2021 - 77
IEEE Robotics & Automation Magazine - March 2021 - 78
IEEE Robotics & Automation Magazine - March 2021 - 79
IEEE Robotics & Automation Magazine - March 2021 - 80
IEEE Robotics & Automation Magazine - March 2021 - 81
IEEE Robotics & Automation Magazine - March 2021 - 82
IEEE Robotics & Automation Magazine - March 2021 - 83
IEEE Robotics & Automation Magazine - March 2021 - 84
IEEE Robotics & Automation Magazine - March 2021 - 85
IEEE Robotics & Automation Magazine - March 2021 - 86
IEEE Robotics & Automation Magazine - March 2021 - 87
IEEE Robotics & Automation Magazine - March 2021 - 88
IEEE Robotics & Automation Magazine - March 2021 - 89
IEEE Robotics & Automation Magazine - March 2021 - 90
IEEE Robotics & Automation Magazine - March 2021 - 91
IEEE Robotics & Automation Magazine - March 2021 - 92
IEEE Robotics & Automation Magazine - March 2021 - 93
IEEE Robotics & Automation Magazine - March 2021 - 94
IEEE Robotics & Automation Magazine - March 2021 - 95
IEEE Robotics & Automation Magazine - March 2021 - 96
IEEE Robotics & Automation Magazine - March 2021 - 97
IEEE Robotics & Automation Magazine - March 2021 - 98
IEEE Robotics & Automation Magazine - March 2021 - 99
IEEE Robotics & Automation Magazine - March 2021 - 100
IEEE Robotics & Automation Magazine - March 2021 - 101
IEEE Robotics & Automation Magazine - March 2021 - 102
IEEE Robotics & Automation Magazine - March 2021 - 103
IEEE Robotics & Automation Magazine - March 2021 - 104
IEEE Robotics & Automation Magazine - March 2021 - 105
IEEE Robotics & Automation Magazine - March 2021 - 106
IEEE Robotics & Automation Magazine - March 2021 - 107
IEEE Robotics & Automation Magazine - March 2021 - 108
IEEE Robotics & Automation Magazine - March 2021 - 109
IEEE Robotics & Automation Magazine - March 2021 - 110
IEEE Robotics & Automation Magazine - March 2021 - 111
IEEE Robotics & Automation Magazine - March 2021 - 112
IEEE Robotics & Automation Magazine - March 2021 - 113
IEEE Robotics & Automation Magazine - March 2021 - 114
IEEE Robotics & Automation Magazine - March 2021 - 115
IEEE Robotics & Automation Magazine - March 2021 - 116
IEEE Robotics & Automation Magazine - March 2021 - 117
IEEE Robotics & Automation Magazine - March 2021 - 118
IEEE Robotics & Automation Magazine - March 2021 - 119
IEEE Robotics & Automation Magazine - March 2021 - 120
IEEE Robotics & Automation Magazine - March 2021 - 121
IEEE Robotics & Automation Magazine - March 2021 - 122
IEEE Robotics & Automation Magazine - March 2021 - 123
IEEE Robotics & Automation Magazine - March 2021 - 124
IEEE Robotics & Automation Magazine - March 2021 - 125
IEEE Robotics & Automation Magazine - March 2021 - 126
IEEE Robotics & Automation Magazine - March 2021 - 127
IEEE Robotics & Automation Magazine - March 2021 - 128
IEEE Robotics & Automation Magazine - March 2021 - Cover3
IEEE Robotics & Automation Magazine - March 2021 - Cover4
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2023
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2023
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2023
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2023
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2022
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2022
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2022
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2022
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2021
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2021
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2021
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2021
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2020
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2020
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2020
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2020
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2019
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2019
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2019
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2019
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2018
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2018
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2018
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2018
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2017
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2017
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2017
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2017
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2016
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2016
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2016
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2016
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2015
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2015
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2015
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2015
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2014
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2014
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2014
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2014
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2013
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2013
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2013
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2013
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2012
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2012
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2012
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2012
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2011
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2011
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_june2011
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_march2011
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_december2010
https://www.nxtbook.com/nxtbooks/ieee/roboticsautomation_september2010
https://www.nxtbookmedia.com