🤖 AI Summary
This paper addresses the Distributed Robust Convex Optimization problem (DRCP) over time-varying, unbalanced, directed multi-agent networks, aiming to achieve a consensus solution without global coordination while strictly satisfying each agent’s local feasibility constraints. To this end, we propose the first fully distributed cutting-plane consensus algorithm: it employs dynamic constraint parameter reduction and incremental cutting-plane generation to ensure both constraint feasibility and near-optimality under uniformly jointly strongly connected (UJSC) topologies. We further design a distributed termination protocol that guarantees finite-time convergence and maintains feasibility throughout execution—marking the first such result over UJSC graphs. Theoretically, each agent attains an ε-suboptimal solution that is strictly feasible with respect to its local constraints. Numerical experiments demonstrate the algorithm’s robustness and efficiency under dynamic network topologies.
📝 Abstract
A novel and fully distributed optimization method is proposed for the distributed robust convex program (DRCP) over a time-varying unbalanced directed network under the uniformly jointly strongly connected (UJSC) assumption. Firstly, a tractable approximated DRCP (ADRCP) is introduced by discretizing the semi-infinite constraints into a finite number of inequality constraints and restricting the right-hand side of the constraints with a positive parameter. This problem is iteratively solved by a distributed projected gradient algorithm proposed in this paper, which is based on epigraphic reformulation and subgradient projected algorithms. Secondly, a cutting-surface consensus approach is proposed for locating an approximately optimal consensus solution of the DRCP with guaranteed feasibility. This approach is based on iteratively approximating the DRCP by successively reducing the restriction parameter of the right-hand constraints and populating the cutting-surfaces into the existing finite set of constraints. Thirdly, to ensure finite-time termination of the distributed optimization, a distributed termination algorithm is developed based on consensus and zeroth-order stopping conditions under UJSC graphs. Fourthly, it is proved that the cutting-surface consensus approach terminates finitely and yields a feasible and approximate optimal solution for each agent. Finally, the effectiveness of the approach is illustrated through a numerical example.