Multi-Horizon and Multi-Rate Model Predictive Control for Integrated Longitudinal and Lateral Vehicle Control

Model predictive control (MPC) has been widely used for controlling multi-input multi-output (MIMO) systems. MIMO systems might consist of dynamics with different response speeds. Therefore, different horizons and prediction rates should be applied according to the response speed of each dynamic. However, multi-horizon and multi-rate prediction leads to mismatches of prediction points and results in prediction difficulties. In addition, multiple control rates should also be considered due to hardware constraints. This paper presents a multi-horizon and multi-rate MPC (MM-MPC) with zero-order hold interpolation for dealing with the mismatches of prediction points. Furthermore, by running MM-MPCs at different rates, a multi-control-rate system is constructed without ignoring the dynamic interaction between the dynamics. The presented methods were demonstrated through simulations. The results show that the presented MM-MPC can reach a better overall performance compared to conventional unified MPCs. In addition, the multi-control-rate system consisting of MM-MPCs with multiple execution rates reduces the average computation time without deteriorating the performance.