Bi-Layered Synchronized Optimization Control With Prescribed Performance for Vehicle Platoon

This paper studies synchronized optimization control for the cooperatively connected autonomous vehicle platoon formulation applicable in various driving scenarios and accommodates multiple vehicles dynamically entering or exiting the platoon. More specifically, the proposed algorithm consists of bi-layered synchronized optimization that enables the ultimate optimized control to attain the synchronized convergence property, and also importantly, ensures the satisfaction of safety performance requirements. The first layer of the proposed approach involves formulating the platoon dynamics and ensuring that the platoon operates within safe boundaries while optimizing its overall performance. To achieve this, the prescribed performance control is utilized to ensure that the state-variables remain within a predefined region throughout the synchronized optimization process. In the second layer, the control optimization takes into account the vehicle dynamics and actuators of either heterogeneous or homogeneous individual vehicles, improving performance and coordination within the platoon. In each optimization layer, the optimized backstepping is utilized, and the norm-normalized sign function is appropriately incorporated with the decomposition design to establish the learning framework with the outcome that attains the synchronized properties simultaneously. The adaptive dynamic programming and gradient-constrained method are utilized in the learning design to iteratively optimize system control while keeping the learning parts within the admissible policy region. Importantly, it is rigorously shown that this particular development and methodology attains the noteworthy time-synchronized stability property and outcome that all vehicle agents arrive at the desired relative position at the same time with synchronized convergence. Additionally, it is also shown that the methodology of our specific algorithmic strategy significantly also attains the desired outcomes of 'string stability' (jointly with the above-mentioned desired outcomes of 'time-synchronized stability'). To evaluate its effectiveness, comparative studies with different methods are carried out to showcase the significantly better desired outcomes attained with this methodology of synchronized optimization. Further evaluations in scenarios involving dynamic entry and exit of multiple vehicles demonstrate the corresponding capability and effectiveness in achieving the desired objectives.