Decentralised nonlinear control with disturbance rejection for on-ramp metering in highways

The decentralised (localised) control of the traffic in a highway, which is treated as a series of subsystems with bounded interconnections, is considered. Using variable structures, a new nonlinear controller estimates the instantaneous magnitude of these interconnections and then generates a bounded continuous control law. The new controller offers the following two main advantages over previous solutions: (i) it addresses some phenomena that simpler models do not characterise and (ii) it takes into account the practical restrictions of the problem by, for example, complying with the boundedness constraint on the control effort.