Hardware-In-The-Loop Pid-Based Speed Regulation of A Dc Motor Under Variable Mechanical Load

This study presents a Hardware-in-the-Loop (HIL) closed-loop speed regulation of a physical DCmotor using a LabVIEW-based PID controller. In DC motors, maintaining the desired speed under changingmechanical loading is an important control problem in electromechanical systems, where variations in loadtorque result in speed deviations and transient disturbances. To overcome these issues, mathematical modellingand software simulation are useful for controller development; experimental evaluation with a hardware setup isnecessary to account for practical effects associated with motor dynamics, sensing, actuation, and mechanicalloading. An optical quadrature encoder provides real-time shaft speed feedback, and a variable friction brake isemployed to introduce controlled mechanical load disturbances. A discrete-time mathematical motor model isincorporated as a supporting simulation tool for controller development and analysis, while the physical DCmotor remains the experimental plant. The system is evaluated under various mechanical-load conditions withspeed references. Motor-speed response, tracking error, controller output, and actual performance metrics areanalysed to assess reference tracking and disturbance-rejection behaviour. The proposed setup provides anexperimentally oriented platform for investigating closed-loop DC motor speed regulation under controlledphysical loading and establishes a basis for systematic controller tuning, experimental validation, and furtherdevelopment of HIL-based electromechanical control systems.