Path-tracking control of an autonomous 4WS4WD electric vehicle using its natural feedback loops

A four-wheel steered four-wheel driven electric vehicle (4WS4WD EV) has a steering motor and a driving motor for each wheel, for a total of eight motors. The existing path-tracking control solutions for this EV view its mathematical model as the system of equations ẋ = f(x, u), y = g(x, u), and apply various mathematically sophisticated control and estimation techniques on this system. In contrast, this paper performs a block-diagrammatic examination of the physical interactions represented by these equations, reveals the natural feedback loops present in the model, and exploits them to develop a simple solution that promises to be easier to tune. Simulations illustrate this solution.