List of Symbols and Acronyms

Symbols

	Closed-loop polynomial
	Desired closed-loop polynomial
	Sampling interval
	Laplace transform for output disturbance
	Laplace transform for input disturbance
	Laplace transform for measurement noise
	Transfer function model
	Imaginary unit,
	Proportional control gain
, ,	Scheduling parameters
	Backward shift operator,
	Sensitivity function
	Input sensitivity function
	Complementary sensitivity function
	Desired complementary sensitivity function
	Derivative control gain
	Derivative control filter time constant
	Integral control time constant
	Closed-loop time constant
	Control signal
	Minimum and maximum limits for
	Steady-state value for a control signal
	Actual control signal ()
	Operating condition of
	Bandwidth or natural frequency in PID controller design (rad/s)
	Operating condition of
	Damping coefficient in PID controller design
	Output signal
	Steady-state value of the output signal
	Actual output signal ()

Acronyms

FFT	Fast Fourier transform
FSF	Frequency sampling filter
IPD	Alternative PID controller structure with proportional control and derivative control on output only
PID	Proportional, integral and derivative
PWM	Pulse Width Modulation