ELECTRIFICATION AND CONTROL OF A SCALE VEHICLE

The target of this research work is the electrification of a 1:5 scale vehicle used in off-road races allowing complete control on its dynamic, bypassing the stock transmitter/receiver system, poor in compatibility. The original vehicle is equipped with a 2-stroke internal combustion engine (ICE). It features a fully adjustable suspension system closely resembling those found on full-scale cars, including springs, dampers, and anti-roll bars, for both axles. Adjustable settings include the variation of spring’s stiffness, damping response, suspensions hardpoints etc. Thanks to the vehicle reduced dimensions the setup could be quickly varied, unlike full-size cars, which requires significant effort and specific tools. Moreover, the size of the vehicle is significantly advantageous with regards to testing, since such a small vehicle does not require specialized test tracks and significant safety precautions. The electrification consists in the addition of a brushless DC motor, a planetary gearbox optimizing the speed/power range, an electric motor controller and a battery covering the role of power source provisioning, the selection criteria of these new components are provided. The layout of the assembly is designed to integrate the additional components. The manufacturing processes are well listed, e. g., the toothed gear slot creation to secure it to the planetary by means of a key, allowing the power transmission from the planetary to the ground, as well as the occurring chassis modifications made to accommodate the electric motor and the L-shaped mounts selection process. It is important to emphasize the reliance on Solidworks CAD models during this phase as they provide a comprehensive system overview, capable of being used for sizing, and verifying dimensions and volumes, which were otherwise challenging to measure. It is found that the new electric powertrain configuration is effective in space efficient. Several systems are used to monitor and control the powertrain speed, torque, and steering angle of the vehicle. The thesis lists and motivates the tests conducted for fine-tuning and controller optimization, moving among different control signals, both analogical than digital. The controller setting is done thanks to the ESCON Studio software. The signals are routed to the electric motor controller, what plays a crucial role in achieving a precise vehicle control, also giving an overview of the system status, resulting in consistent testing, reducing discontinuity sources weight, letting focus on the dynamic behavior. The early stage is a powertrain bench testing procedure in which an Arduino Portenta H7 board controls the system’s speed, in charge of Pulse Width Modulation (PWM) signal production. The sketches development, by means of the Arduino IDE software and wiring connections are discussed. The Arduino board is a powerful and versatile instrument, easy to use for different tasks or projects, even if suffering from a lack of data management as a drawback. The following step moves to an analogical signal coming from a potentiometer, having Arduino implied in the speed requested and obtained comparison. In this way the analog to digital signal conversion, performed by Arduino, is avoided. In the advanced, the powertrain is offline tested, being mounted on the vehicle. The speed control is achieved using the PWM signal coming from the stock wireless transmitter/receiver system. Lastly the control is performed by means of the real-time target machine Speedgoat. This system, o