Question 1

Which discrete-time PID formulation is implemented, and how does it prevent integral saturation windup?

Accepted Answer

The control engine implements the ISA standard parallel algorithm with Tustin trapezoidal bilinear discretization. When the control output reaches physical actuator limits ($u_{min}$ or $u_{max}$), the integral accumulator is dynamically clamped using back-calculation feedback ($k_{bc} \cdot [u - v]$), completely eliminating large overshoot recovery delays.

Question 2

How are gain margins and phase margins calculated on interactive Bode and Nyquist plots?

Accepted Answer

The system computes the open-loop frequency response $L(j\omega) = C(j\omega) P(j\omega)$ across a logarithmic frequency sweep. It automatically locates the gain crossover frequency $\omega_{gc}$ (where $|L|=0	ext{ dB}$) to extract Phase Margin $\Phi_m = 180^\circ + \angle L(j\omega_{gc})$, and the phase crossover frequency $\omega_{pc}$ (where $\angle L=-180^\circ$) for Gain Margin $G_m$.

Question 3

Does the control valve simulator implement international IEC 60534 sizing equations?

Accepted Answer

Yes. The valve engine incorporates the standardized flow coefficient $C_v$ equations along with liquid pressure recovery factors $F_L$. If the vena contracta pressure drops below liquid vapor pressure ($P_v$), the simulator calculates cavitation index $\sigma$ and flags choked flashing flow regimes according to ISA-75.01.

Question 4

What physical line characteristics are modeled in the 4-20mA industrial current loop simulator?

Accepted Answer

The loop simulator models total series loop resistance (wire length, gauge AWG, and barrier resistance), power supply voltage compliance limits (e.g. 24 VDC), HART modem coupling impedances, and transmitter minimum operating voltages ($V_{tx,min} \approx 11	ext{--}12	ext{ V}$). Overburden conditions and NAMUR NE 43 fault saturation signals are displayed in real time.

Question 5

Are Evans root locus branch asymptotes and departure angles calculated analytically?

Accepted Answer

Yes. The root locus solver dynamically calculates open-loop pole/zero centroids $\sigma_a = \frac{\sum p_i - \sum z_i}{n - m}$, asymptote angles $	heta_a = \frac{(2k+1)180^\circ}{n - m}$, and breakaway points along the real axis via $\frac{dK}{ds} = 0$, allowing users to interactively observe closed-loop pole migrations as gain $K$ varies.

Control Systems & Robotics Simulators Hub & Curricular Syllabus (CS-300)

Department Syllabus Overview & Curricular Subfields

Referenced International Consensus Standards (12)

Interactive Engineering Simulators (6 Active Workbenches)

Industrial Closed-Loop PID Tuning & Anti-Windup →

Pneumatic Control Valve Flow Cv & Cavitation →

4-20mA Current Loop Transmitter & Line Resistance →

Differential Pressure Orifice Plate Flowmeter →

Bode Plot & Nyquist Diagram Frequency Stability →

Root Locus Plotter & Closed-Loop Stability Analysis →