Table of Symbols

The symbols used in this document are summarized in the Table of Symbols along with their units. The symbols are listed in alphabetical order.

Symbol	Description	Units
$\mathit{AbsTol}$	Absolute Tolerance	–
${C_{\text{s}}}$	Control Variable in the frequency domain	–
$c$	Damping coefficient of the spring	–
${c_{\text{t}}}$	Control Variable in the time domain	–
${D_{\text{s}}}$	Derivative control in the frequency domain	–
${E_{\text{s}}}$	Process Error in the frequency domain	–
${e_{\text{t}}}$	Process Error in the time domain	–
${F_{\text{s}}}$	Laplace Transform of a function	–
${f_{\text{t}}}$	Function in the time domain	–
${H_{\text{s}}}$	Transfer Function in the frequency domain	–
${K_{\text{d}}}$	Derivative Gain	–
${K_{\text{p}}}$	Proportional Gain	–
$k$	Stiffness coefficient of the spring	${\text{s}}$
$\mathit{L⁻¹[F(s)]}$	Inverse Laplace Transform of a function	–
$m$	Mass	${\text{kg}}$
${P_{\text{s}}}$	Proportional control in the frequency domain	–
${R_{\text{s}}}$	Set-Point in the frequency domain	–
${r_{\text{t}}}$	Set-Point	–
$\mathit{RelTol}$	Relative Tolerance	–
$s$	Complex frequency-domain parameter	–
$t$	Time	${\text{s}}$
${t_{\text{sim}}}$	Simulation Time	${\text{s}}$
${t_{\text{step}}}$	Step Time	${\text{s}}$
${Y_{\text{s}}}$	Process Variable in the frequency domain	–
${y_{\text{t}}}$	Process Variable	–

Table of Symbols

Software Requirements Specification for PD Controller