SCI	Spinal Cord Injury
CP	Cerebral Palsy
WHO	World Health Organization
SW	Smart Walker
SWs	Smart Walkers
HRI	Human–Robot Interaction
HREI	Human–Robot–Environment Interaction
REI	Robot–Environment Interaction
COOL Aide	CO-Operative Locomotion Aide
ROS	Robotic Operating System
IMU	Inertial Measurement Unit
LiDAR	Light Detection and Ranging Sensor
HD	High Definition
LRF	Laser Range Finder
CPU	Central Processing Unit
$F_{xRight}$	Force along the x-axis on the right load cell
$F_{xLeft}$	Force along the x-axis on the left load cell
$F_{yRight}$	Force along the y-axis on the right load cell
$F_{yLeft}$	Force along the y-axis on the left load cell
$F_{zRight}$	Force along the z-axis on the right load cell
$F_{zLeft}$	Force along the z-axis on the left load cell
$Fs{p}_{xRight}$	Force along the x-axis on the right supporting point
$Fs{p}_{xLeft}$	Force along the x-axis on the left supporting point
$Fs{p}_{yRight}$	Force along the y-axis on the right supporting point
$Fs{p}_{yLeft}$	Force along the y-axis on the left supporting point
$Fs{p}_{zRight}$	Force along the z-axis on the right supporting point
$Fs{p}_{zLeft}$	Force along the z-axis on the left supporting point
GCE	Gait Cadence Estimator
WFLC	Weighted-Fourier Linear Combiner
$F_{CAD}$	Resulting force used to estimate user’s gait cadence
$F_{CAD}^{\prime }$	Filtered $F_{CAD}$ force
FLC	Fourier Lineal Combiner
FS	Filtering System of forces along y-axis
$F_{y\Phi }$	Representation of whether $F_{yLeft}$ or $F_{yRight}$
$F_{yLeft}^{\prime }$	Filtered $F_{yLeft}$
$F_{yRight}^{\prime }$	Filtered $F_{yRight}$
$F_{y\Phi }^{\prime }$	Representation of whether $F_{yLeft}^{\prime }$ or $F_{yRight}^{\prime }$
$F_{y\Phi LP}$	Resulting $F_{y\Phi }$ signals after low-pass filter
$F_{y\Phi CAD}$	Cadence signals obtained from the FLC
M	Order of the FLC filter
$\mu$	Adaptive gain of the FLC filter
F	Final force applied to the walker by the user
$\tau$	Final torque applied to the walker by the user
$F_{yLeftLP}$	Resulting signal from the low-pass filter for $F_{yLeft}$
$F_{yLeftCAD}$	Resulting signal from the FLC for $F_{yLeft}$
v	Linear velocity generated with an admittance controller
$\omega$	Angular velocity generated with an admittance controller
$L\left(s\right)$	Second order system for linear velocities generation
m	Virtual mass of the walker
$b_l$	Damping ratio for $L\left(s\right)$
$k_l$	Elastic constant for $L\left(s\right)$
$A\left(s\right)$	Second order system for angular velocities generation
J	Virtual moment of inertia of the walker
$b_a$	Damping ratio for $A\left(s\right)$
$k_a$	Elastic constant for $A\left(s\right)$
SLAM	Simultaneous Localization and Mapping
AMCL	Adaptive Monte Carlo Localization Approach
TEB	Time Elastic Band
ROI	Region of interest in the camera image
HOG	Histogram of Oriented Gradients
SVM	Support Vector Machine
STD	Stop Distance Parameter
SD	Slow Distance Parameter
WR	Width Rate
MET	Maximum Exerted Torque
$x_{n}av$	X position of nearest path point
$y_{n}av$	Y position of nearest path point
$x_{s}w$	X position of the walker
$y_{n}av$	Y position of the walker
${\theta }_{sw}$	Orientation of the walker
${\theta }_{usr}$	Orientation of user’s intention of movement
${\theta }_{nav}$	Orientation of nearest path point
d	Euclidean distance from the walker position to the next pose
$La$	Base of first right-angled triangle
$Lb$	Base of second right-angled triangle
${\theta }_a$	Auxiliary angle for first right-angled triangle
${\theta }_b$	Auxiliary angle for first right-angled triangle
$Wi{n}_{width}$	Scaling factor of triangle-shaped window
${\theta }_{nxt}$	Orientation of next path pose
${\theta }_{diff}$	Relative orientation of the triangle-shaped window center