The control model and the control objectives of a multi-object ACC system are presented. The multi-object ACC problem is looked at as a constrained optimal control problem incorporating the dynamics of the traffic scene, the driver's desire to cruise at a certain velocity, the lane assignment of the other road users, the objective of respecting certain minimum distances to other road users and to adapt the velocity to the flow of the other road users. Additionally, overtaking a preceding vehicle on the right can be avoided. The choice of the relevant object is implicitly determined by the cost function and the optimization criteria. Constraints imposed by physical limitations as well as by comfort and safety considerations can be included and a receding horizon control strategy is applied.
The multi-object ACC problem is looked at as a constrained finite time optimal control (CFTOC) problem with a mixed logical dynamical (MLD) system description. With an efficient way to represent and evaluate the explicit solution to the corresponding multi-parametric mixed integer quadratic program, it is possible to include all desired control objectives in the problem formulation and still obtain an explicit solution suitable for real-time operation. Simulation results of this multi-object ACC control approach are presented and the controller is compared to a reference ACC controller. With the efficient controller representation the multi-object ACC controller is implemented on the ECU of a standard production platform vehicle to confirm the simulation results in real traffic.