Nonlinear electromechanical modeling and cascaded sliding mode control of a wheeled self-balancing robot

• Developed a nonlinear electromechanical model of a self-balancing robot • Incorporated DC motor electrical dynamics with inductance and voltage constraints • Designed cascaded sliding mode control robust to disturbances and uncertainties • Analysed stability under communication and sensor delays via simulations • Demonstrated reliable performance with low-cost actuators and sensors This study addresses the stabilisation of wheeled self-balancing robots under practical constraints imposed by low-cost hardware, where communication and sensing delays critically degrade control performance. A comprehensive nonlinear electromechanical model is developed by integrating the dynamics of an inverted pendulum with the electrical and mechanical characteristics of DC motors, thereby capturing the full actuator-plant interaction. Based on this, a cascaded sliding mode control scheme is proposed to regulate the pitch angle directly through motor voltages. The controller is designed to enhance robustness against modeling uncertainties and external disturbances, while explicitly accounting for actuator and sensor delays. Extensive numerical simulations are conducted to evaluate closed-loop stability and control torque behaviour under varying delay profiles and hardware limitations such as motors with reduced capacity. The results demonstrate that it maintains stable balancing performance despite significant time delays and degraded hardware quality, which highlights its suitability for cost-efficient robotic design. The modeling framework and delay study presented here provide a general methodology for assessing the robustness of nonlinear electromechanical systems subject to communication and sensor delays, as well as actuation constraints.