Distributed model predictive control of nonlinear systems with asynchronous communication

网络化和复杂系统在自动化领域的重要性与日俱增。实际相关的例子是智能电网和供水网络，它们可以用具有大量动态耦合子系统的模块化分布式系统来描述。因此，这类系统的现代控制方法必须能够处理模块化和可扩展性。特别是，分布式模型预测控制（DMPC）将网络的各个组件的中心问题分解为子问题，这些子问题由本地代理并行解决。在之前的DFG项目中，开发了一个用于非线性网络系统的模块化和计算效率高的DMPC框架，并在开源工具箱GRAMPC-D中实现。最先进的DMPC优化方法，如ADMM（乘法器交替方向法）在网络上同步执行局部优化和通信步骤。这种同步的主要缺点是网络必须等待网络中最慢的代理。文献和自己的初步工作的初步结果表明，子系统的异步处理可以大大提高效率，同时能够显著减少网络上的通信。受这些结果的启发，本项目研究了非线性系统中DMPC的异步协调以及相应的通信方面，并最终扩展了现有的开源工具箱GRAMPC-D，以异步和模块化的方式处理非线性网络系统。

Networked and complex systems are of growing importance in the field of automation. Practically relevant examples are smart grids and water supply networks that can be described by modular, distributed systems with a large number of dynamically coupled subsystems. Accordingly, modern control methods for this kind of systems must be able to cope with modularity and scalability. In particular, distributed model predictive control (DMPC) splits the central problem in subproblems for the individual components of the network that are solved in parallel by local agents. In a previous DFG project, a modular and computationally efficient DMPC framework for nonlinear networked systems was developed and implemented in the open-source toolbox GRAMPC-D.State-of-the-art optimization methods for DMPC such as ADMM (Alternating Direction Method of Multipliers) perform the local optimizations and communication steps synchronously over the network. This synchronization has the major drawback that the network has to wait for the slowest agent of the network. First results in the literature and own preliminary work show that an asynchronous handling of the subsystems can massively improve the efficiency and at the same time is able to significantly reduce the communication over the network. Motivated by these results, this project investigates the asynchronous coordination of DMPC for nonlinear systems and the corresponding communication aspects and eventually extends the existing open-source toolbox GRAMPC-D to handle nonlinear networked systems in an asynchronous and modular fashion.