Development and implementation of a concurrent path following and body motion control system using a scale prototype vehicle

Abstract

The automotive industry’s future lies in developing autonomous vehicles, which rely on three fundamental components: perception, planning, and actuation. The actuation component, in particular, requires a robust and reliable control system to ensure the planned trajectory is executed with high fidelity. Furthermore, ad- vancements in active suspension technology, driven by cost reductions, have en- abled the individual adjustment and actuation of suspension components, thereby enhancing passenger comfort. A prototype vehicle is essential to validate these systems experimentally. To balance cost efficiency, ease of use and maintenance, and minimize risks to the en- vironment, a 1/8-scale miniature vehicle was developed. This scaled-down model incorporates all the necessary and existing systems of a full-sized vehicle, like all-wheel drive, four-wheel independent steering, disc brakes, and active suspen- sion, allowing for a wide range of system tests, regardless of their power demands, facilitated by wireless communication via the Robot Operating System (ROS). For control purposes, a Model Predictive Control (MPC) system was designed for path following, while a Linear Quadratic Regulator (LQR) was implemented for body motion control. In simulations, the MPC controller achieved a maxi- mum deviation of 0.3 meters from the planned path, while real-life tests on the prototype vehicle resulted in a deviation of 0.51 meters. During simulations, the active suspension system demonstrated a 48.38% improvement in pitch perfor- mance and a 50.92% improvement in roll performance. Real-world tests showed a 67. 54% improvement in pitch and a 2.44% improvement in roll performance. However, the performance of the MPC controller was adversely affected by system delays, as the controller operated on an external PC during both path-following experiments. This research focuses not only on controller design for vehicles but also tests this system on a scale of real vehicles to assess their performance and ensure that these systems can work on real passenger cars.