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Steps to design closed loop control system

Short answer

Design steps: 1) Define specifications (error, overshoot, timing). 2) Select sensor/actuator. 3) Model plant (e.g., m·dv/dt=-b·v+u+d). 4) Choose controller structure (P/PI/PD/PID). 5) Set sampling period T ≪ plant time constant. 6) Determine gains via stability analysis or tuning. 7) Simulate and verify. 8) Implement, test, and retune on hardware.

With a neat diagram write the steps for designing a closed loop control system.

Designing a closed-loop controller means choosing a controller and its parameters so that the measured output follows the reference with the required accuracy, speed and stability.

Block diagram

 r -->(+)-e->[Controller]-u->[Actuator]->[Plant]--+--> y
       ^ -                          d --^           |
       |                                            |
       +----------------[Sensor]<-------------------+

Design steps

  1. State the objective and specifications: the controlled variable, set-point range, allowed steady-state error, overshoot, rise and settling time.
  2. Choose sensor and actuator: select a sensor to measure the output and an actuator to drive the plant; check range, resolution and speed.
  3. Model the plant: write the differential (or difference) equation from physics or from a step-response test, e.g. m·dv/dt = -b·v + u + d.
  4. Choose the controller structure: P, PI, PD or PID, depending on needed error, speed and damping.
  5. Choose the sampling period (for a digital controller), much shorter than the plant's time constant.
  6. Find the gains from the stability conditions (no unbounded output, no oscillation) using analysis or tuning rules.
  7. Simulate the closed loop and check the specifications and disturbance rejection.
  8. Implement in software (ISR at period T) or hardware, test on the real plant, and re-tune.

✓ Answer checked by Claude Opus 5.5 (high effort)

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