# Process Control and Instrumentation

The exhaustive list of topics in Process Control and Instrumentation Problems in which we provide Help with Homework Assignment and Help with Project is as follows:

• Representative process control problems -Liquid Surge Tank, Blending Process.
• Incentives for Chemical Process Control.
• Classification of variables and design elements of a control system.
• Modeling Considerations:
• Rationale for process modeling.
• General modeling principles; balance equations - mass, energy, momentum; Thermodynamics and reaction kinetics; degrees of freedom analysis.
• State variables, State equations; input-output models.
• Lumped and distributed parameter systems.
• Steady state and dynamic behavior.
• Examples – liquid serge tank, isothermal chemical reactor.
• Dynamic behavior of Chemical Processes:
• Solving algebraic equations and integration of ODEs.
• Concept of nonlinearity; linearization of nonlinear processes; deviation variables.
• Concept of Laplace Transform (LT); the LT of basic functions - step, impulse, pulse, ramp, exponential, integral, derivative, time delay; initial and final value theorems.
• Solution of differential equation using LT techniques - Partial fraction expansion, direct division.
• Transfer function of Single Input Single Output (SISO) process; Transfer function matrix of Multi Input Multi Output (MIMO) process.
• Properties of transfer function; Poles and Zeros of a transfer function; stability issues, unstable and non-minimum phase behavior.
• Dynamic response of a first order process, first order plus dead time process, second order process, pure capacitive process, pure dead time, higher order process; inverse response; Padé approximation.
• Interacting and non-interacting processes.
• Development of Empirical model - Model development using linear and nonlinear regression, fitting first and second order models using step test results.
• Frequency response analysis - Bode and Nyquist plot.
• Feedback controller:
• Feedback control.
• Elements of Control loop - controller, measuring device, final control element, transmission lines, transducers, transmitters, block diagram.
• Concept of servo and regulatory problems.
• Selection of measured, manipulated and controlled variables.
• Types of controller - P, PI, PID, on-off.
• Effects of proportional, integral and derivative actions.
• Notion of stability - characteristic equation, Routh-Hurwitz criteria, root-locus analysis.
• Design of feedback controller - performance criteria, controller tuning methods, Cohen-Coon method, 1/4th 12 decay ratio method, direct synthesis methods, gain and phase margins, Ziegler-Nichols method, Bode & Nyquist stability criteria, robustness analysis.
• Compensation for large dead time and inverse response, Smith Pr
• Other control strategies:
• Feed forward controller - design with steady state model, design with dynamic model, combination of feed forward-feedback structure.
• Cascade control structure - analysis and design.
• Ratio control, split range control, selective control, override control, auctioneering control.
• Concepts of adaptive and inferential control.
• Multi loop multivariable control:
• Process and control loop interaction.
• Singular Value Decomposition (SVD), Relative Gain Array (RGA), I/O pairing.
• Sensitivity to model uncertainty; failure sensitivity.
• Decoupling and design of non-interacting control loops.
• Example - Design of controller and control structure for a 4 input x 4 output Distillation Column.
• Instrumentation:
• Final Control Elements - Valve characteristics, thyristors.
• Measuring Devices for flow, temperature, pressure and level.
• Instrumentation symbols.
• Process Flow Diagram (PFD) and Piping & Instrumentation Diagram (P&ID).