Speed Control of a DC Motor under Voltage Saturation and Load Disturbance: A Simulation Comparison of P, PI and PID Controllers with Anti-Windup

Speed control of a DC motor is a standard task in cyber-physical systems, yet the behaviour of simple controllers under actuator saturation is often shown only in idealised linear form. This paper compares proportional (P), proportional-integral (PI) and proportional-integral-derivative (PID) speed controllers for a simulated armature-controlled DC motor with a ±24 V voltage limit and a load-torque step. The P controller leaves a steady-state error of 0.091 rad/s on a 1 rad/s reference, whereas integral action removes it (error below 0.001 rad/s). With back-calculation-free clamping anti-windup, the PI controller overshoots by 1.0 %; without anti-windup the overshoot grows to 32.6 %. Adding a derivative term on the measurement reduced the speed dip after the load step by 42 % but did not reduce overshoot in this setting. The study is a simulation with assumed parameters and illustrates design trade-offs rather than a hardware validation. This is a simulation study; all results are outputs of the deposited Python code with assumed parameters. Source code is attached.