Development of a small-scale electric vehicle for evaluation of torque vectoring and MPC path tracking

Sammanfattning

In this thesis, a small-scale electrical vehicle with independently driven rear wheels isdeveloped to implement and test torque vectoring and MPC using microcontrollers.The project investigated how torque distribution affects stability, maneuverabilityand trajectory tracking during representative driving maneuvers. A scale RC carchassis was purchased and equipped with custom mechanical components, electricmotors, electronic speed controllers, battery, microcontrollers and an internal measuringunit to form a closed-loop control platform. The control system combinedMPC using the TinyMPC library for path tracking with a PID-controller basedtorque vectoring strategy to influence yaw behavior. The system was evaluatedthrough simulations and practical testing, where vehicle trajectories were extractedfrom video recordings using image processing.The results showed that torque vectoring generated noticeable but moderate handlingimprovements. However, performance was limited by hardware constraints,simplified modeling, incomplete PID-controller tuning, limited torque authority andsensor limitations. Nevertheless, the project demonstrates that torque vectoringcan improve controllability on a low-cost small-scale electric vehicle platform, aswell as validating that MPC can be implemented on limited hardware, such as microcontrollers.It also shows that further development is required for more robustand quantitatively reliable results. Recommended improvements include systematiccontroller tuning, improved state estimation, onboard data logging, slip-anglecontrol implementation, PWM-to-torque mapping, and more capable actuators.