Yugeng Xi

Yuanqiang Zhou, Dewei Li, Yugeng Xi et al.

For the application of MPC design in on-line regulation or tracking control problems, several studies have attempted to develop an accurate model, and realize adequate uncertainty description of linear or non-linear plants of the processes. In this study, we employ the data-driven learning technique to iteratively approximate the dynamical parameters, without requiring a priori knowledge of system matrices. The proposed MPC approach can predict and optimize the future behaviors using multiorder derivatives of control input as decision variables. Because the proposed algorithm can obtain a linear system model at each sampling, it can adapt to the actual dynamics of time-varying or nonlinear plants. This methodology can serve as a data-driven identification tool to study adaptive optimal control problems for unknown complex systems.

Jiwei Li, Pierluigi Nuzzo, Alberto Sangiovanni-Vincentelli et al.

We develop an assume-guarantee contract framework for the design of cyber-physical systems, modeled as closed-loop control systems, under probabilistic requirements. We use a variant of signal temporal logic, namely, Stochastic Signal Temporal Logic (StSTL) to specify system behaviors as well as contract assumptions and guarantees, thus enabling automatic reasoning about requirements of stochastic systems. Given a stochastic linear system representation and a set of requirements captured by bounded StSTL contracts, we propose algorithms that can check contract compatibility, consistency, and refinement, and generate a controller to guarantee that a contract is satisfied, following a stochastic model predictive control approach. Our algorithms leverage encodings of the verification and control synthesis tasks into mixed integer optimization problems, and conservative approximations of probabilistic constraints that produce both sound and tractable problem formulations. We illustrate the effectiveness of our approach on a few examples, including the design of embedded controllers for aircraft power distribution networks.