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Microelectronics Reliability
journal homepage: www.elsevier.com/locate/microrel
Low cost sensor network for obstacle avoidance in share-controlled smart
wheelchairs under daily scenarios
Jiangbo Pu
1
, Youcong Jiang
1
, Xiaobo Xie, Xiaogang Chen, Ming Liu, Shengpu Xu
⁎
Institute of Biomedical Engineering, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, PR China
ARTICLE INFO
Keywords:
Sensor network
LiDAR
Ultrasonic sensors
Smart wheelchairs
Obstacle avoidance
Falling prevention
ABSTRACT
Intelligent wheelchairs working in various environments need to sense the neighborhood around itself and
prevent dangerous situation such as collision and falling down from stairs. In this paper, we develop a low cost
and real time intelligent wheelchair shared control system for people with disabilities at the rehabilitation center
or at home. Our system is composed of an electric wheelchair, an RGB camera, an infrared camera, 4 ultrasonic
sensors, a laser LiDAR (light detection and ranging equipment), and a personal computer. Based on the in-
telligent sensor network and sensor priority control algorithms, it can detect different obstacles with various
dangerous levels, send out voice and graphical alarm, and suggest a safe path to avoid them. The combination
usage of the RGB camera and the IR camera enables our system to work under normal lighting conditions and
under low lighting conditions. The reliability of individual type of sensors and the whole system was examined
by simulated scenarios and user questionnaire. Experiment results reveal that the system is reliable and effective.
The key components in our system are low cost and easy to be installed on various electric wheelchairs and
common PCs. It will be a useful tool for further developing smart wheelchairs with shared control frameworks.
1. Introduction
Electrical wheelchairs are one of the most popular assistant tools for
enhancing the quality of the elderly and disabled people's life. The
wheelchair is electrically powered and is commonly used to provide
mobility and to improve the independence for handicapped people.
However, conventional electrical wheelchairs, which are usually just
operated by a joystick, are not always suitable to meet the need. Many
disabled people find it necessary to provide auxiliary assistance to drive
the wheelchair, for example, the obstacle avoidance assistance tech-
nique. Further, intelligent wheelchairs with sensors and automatic
auxiliary assistance algorithms would require less attention from the
users to drive [1–7]. Therefore, it can be meaningful to the application
which combines the wheelchair and the brain-computer interface (BCI)
that usually consumes much attention of the user [2,5,6,8–12]. Also, in
BCI wheelchairs, the less commands that the user is needed to send, the
less fatigue that the user may suffer [5,10].
Currently, advanced sensor technology and mobile computing make
it possible to build an intelligent wheelchair. Researches focused on
intelligent wheelchairs have already received significant attentions.
While some researchers have focused on improving the autonomous
function of the wheelchairs' mobility [3,4,11,13], others focused on
sharing the mobile control with the user [2,8,10]. Shared control fra-
meworks take both advantage of computer assistance and users' in-
telligence, which can help the wheelchair driver in dangerous situa-
tions, extending the capabilities for handicapped people. Shared
controlled paradigms are also easy to cooperate with many other con-
trol paradigms like brain computer interfaces and virtual/mixed reali-
ties, especially, the shared control of wheelchairs can help to reduce the
attention mental resources. Otherwise, the users need to continuously
pay attention to the brain computer interface and are easy to be fatigue
[5,10].
To implement shared control paradigm, several requirements
should be fulfilled. Obstacle avoidance should be operated in real time
to fit in real world dynamic environments. Thus, many researches took
low computational consuming algorithms into action [6,14]. Daily
scenarios should be considered since the beginning of design. Overall
user safety, usability and comfortability are critical [6]. Low cost and
easy installation to existing wheelchair can also help more handicapped
people benefiting from the intelligent wheelchair [15]. There have been
a number of studies reporting various designs to fulfill requirements
above. RGB/RGB-D cameras, laser range finder (or LiDAR), 3D laser
scanners, ultrasonic sensors and accelerometers were successfully used
in
many projects separately or in different combinations [3,16–19].
https://doi.org/10.1016/j.microrel.2018.03.003
Received 1 March 2018; Received in revised form 4 March 2018; Accepted 4 March 2018
⁎
Corresponding author.
1
Jiangbo Pu and Youcong Jiang contributed equally.
E-mail address: xushengpu@126.com (S. Xu).
Microelectronics Reliability 83 (2018) 180–186
0026-2714/ © 2018 Elsevier Ltd. All rights reserved.
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