Skip to main content
. 2025 Jul 14;12:1488869. doi: 10.3389/frobt.2025.1488869

TABLE 1.

Nomenclature.

Symbol Definition
ei Position error of the end-effector along the i -axis in the task-space
e Position error vector of the end-effector in the task-space
e˙i Velocity error of the end-effector along the i -axis in the task-space
e˙ Velocity error vector of the end-effector in the task-space
emaxi Sensitivity threshold of the position error of the end-effector along the i -axis in the task-space for the MTJ controller
e˙maxi Sensitivity threshold of the velocity error of the end-effector along the i -axis in the task-space for the MTJ controller
h Vector of feedback linearization estimator term in the MTJ controller
I Identity matrix
J Linear Jacobian matrix
K Coefficient matrix of the feedback linearization estimator in the MTJ controller
KD Derivative coefficient matrix of the MTJ controller
KI Integral coefficient matrix of the MTJ controller
KP Proportional coefficient matrix of the MTJ controller
li Length of tendon i in the continuum robotic arm
L Vector of tendon lengths in the continuum robotic arm
L˙ Vector of tendon length change rates in the continuum robotic arm
p Position vector of a point on the backbone of the continuum robotic arm
s Backbone reference length parameter
T Transpose of the vector or matrix
Ti Tension of tendon i
T Vector of generalized forces in joint space (tendon tensions)
T+ Vector of generalized forces in joint space (tendon tensions) after passing the null-space projection operator
t Time
X Task-space variables vector (end-effector position vector)
X˙ Task-space velocities vector (end-effector velocity vector)
η Non-trivial solution to the linear algebraic system
ζ Null-space adjustment vector ( ζR6 )
F Vector of generalized forces in the task-space
Pseudo-inverse of a non-square matrix