Development and testing of a steer-by-wire platform, using a four-wheel steering control system

Abstract

The rapid electrification of the automotive industry has created new opportunities for integrated vehicle control, including steer-by-wire and four-wheel steering systems. Small-scale prototypes can provide a cost-effective platform for developing and evaluating control strategies aimed at improving vehicle stability and maneuverability. The purpose of this project was to design, assemble, and evaluate a small-scale electric vehicle prototype equipped with electronically actuated four-wheel steering to investigate vehicle dynamics and path-following control. A modular chassis was developed using 3D-printed components, integrating two DC propulsion motors, two steering servos, and a Teensy 4.1 microcontroller. A Proportional–Integral (PI) control strategy was implemented in simulation to regulate wheel speed and steering angle. Due to hardware-related and time constraints, the physical implementation was limited to individual PI-based wheel speed regulation. Testing demonstrated that the PI controllers successfully maintained the target average wheel speed of 80 RPM with a small mean error. However, the physical tests revealed that instantaneous speed variations, amplified by sensor noise and mechanical tolerances in the 3D-printed assemblies, introduced lateral instability and deviations from a straight path. Ultimately the project delivered a simulation using a PI control strategy and a hardware platform for further four-wheel steering research.