dt	Sample period (s)
Fn,t	Normal or tangential force error (N)
${\overline{F}}_{n,t}$	Nominal Normal or tangential force (N)
Fr	Reference force (N)
$\overline{F_r}$	Nominal reference force (N)
Fn	Normal force acting on wire saw (N)
Kn, K, Kp	Coefficient
Kw	Gain of commanded wire saw velocity
P	Tension force (N)
Vc	The command wire velocity (m/s)
$\overline{V_c}$	Nominal command wire velocity (m/s)
Vmax	Maximum wire saw velocity (m/s) or part feed rate (mm/min)
Vmin	Minimum wire saw velocity (m/s) or part feed rate (mm/min)
Vs	Wire saw velocity (m/s)
${\dot{V}}_{x,s}$	Wire saw (m/s) of part feed rate (mm/min) dynamic variation
$\overline{V_{x,s}}$	Nominal wire velocity (m/s) or part feed rate (mm/min)
Vx	Part feed rate (mm/min)
α, β	Coefficient
$\Delta E_n$	Incremental normal force error (N)
$\Delta F_n$	Incremental normal force (N)
$\Delta F_r$	Incremental reference force (N)
$\Delta V_{x,s}$	Incremental part feed rate (mm/min) or wire velocity (m/s)
$\Delta V_c$	Incremental command wire velocity
$\tau$	Time constant (s)
${\tau }_1, {\tau }_1$	Time constants of closed-loop overdamped system (s)