Design, Simulation of PMDC Motor Speed Controller in Geotechnical Uses

Abstract

Field geotechnical operations demand drive systems capable of holding shaft velocity within tight bounds despite soil resistance that shifts unpredictably across strata. This paper addresses that requirement by designing, simulating, and comparing three closed-loop speed-control strategies for a Permanent Magnet DC (PMDC) motor: a classically tuned Proportional-Integral-Derivative (PID) regulator, a Mamdani Fuzzy Logic Controller (FLC) built on a compact 3×3 rule surface, and a sigmoid-blended hybrid that draws on both. The PMDC plant is derived analytically from armature-circuit and rotor-dynamics first principles and reproduced in MATLAB/Simulink with a full H-Bridge stage driven by an STM 32F103C8T6 microcontroller. Actual MATLAB/Simulink simulation results for the PID controller are presented, showing mot or voltage, speed, armature current, torque, and PWM waveforms. The proposed hybrid controller further limits the disturbance-induced speed dip to 31 RPM recovered in 0.60 s, with overshoot of 4.1 %, settling time of 1.12 s, and residual error of 0.3 %, satisfying the ±25 % velocity tolerance of ISO 22476-1 for cone penetration testing.