Distributed Nash Equilibrium Seeking With Limited Cost Function Knowledge via a Consensus-Based Gradient-Free Method

Distributed Nash equilibrium seeking: A gossip-based algorithm

The distributed optimal coordinated control problem of heterogeneous linear multi-agent systems is studied in this paper. Specifically, each agent in the system under consideration has a local private cost function, which is assumed to be strongly convex with a Lipschitz continuous gradient. The agents aim to achieve output consensus on the optimal solution of a global cost function, which is the sum of local cost functions. The communication topology among agents is assumed to be a weight-unbalanced and strongly connected directed graph. To solve such a control problem, a tracking-based approach is suggested and utilized, where an auxiliary system is designed to seek the optimal solution. Based on the output regulation technique, distributed tracking control inputs are proposed for the agents, which ensure that the outputs of the agents track the trajectories generated by the auxiliary system. Under the assumptions on the local cost functions, the communication topology and system matrices, it is proved that with the proposed control scheme, the outputs of all agents can achieve consensus on the optimal solution. Finally, two numerical simulation examples are presented to illustrate the effectiveness of the proposed tracking control scheme.

On Nash-solvability in pure stationary strategies of finite games with perfect information which may have cycles

In this paper, the distributed Nash equilibrium seeking problem of aggregative games, with players been presented by uncertain nonlinear systems over directed graphs, is investigated. The problem aims at designing a distributed algorithm for each player such that the player's state is bounded, while the player's output converges to the Nash equilibrium point. A dynamic compensator is firstly proposed by utilizing gradient-based protocol and average consensus strategy. Then the distributed Nash equilibrium seeking problem is converted into a tracking problem. Finally, the resulting tracking problem is addressed by developing a novel output feedback controller. It is shown that the concerned distributed Nash equilibrium seeking problem can be solved by the distributed algorithm composed of the dynamic compensator and the output feedback controller.

The paper mainly talks about the distributed optimal issue under the continuous-time high-order multi-agent system with event-triggered communication. Every agent possesses its local convex cost function only known by itself. and our aim is to minimize the sum of all the local cost functions and make the agents convergent to the optimal point through the communication between the agents. Utilizing the knowledge of convex analysis and graph theory, we propose a distributed protocol with event-triggered communication under a undirected graph for the high-order multi-agent system. Through Lyapunov method, the agents gradually converging to the optimal point is testified. In addition, we provide an example to validate the proposed protocol.

Distributed Nash Equilibrium (NE) seeking for networked games has been widely investigated in recent years. In particular, convergence speed and communication cost are two of the critical concerns for the design of the seeking algorithms. To achieve fast convergence while saving communication resources, this paper investigates the appointed-time distributed NE seeking problem for networked games under a discrete-time communication scenario. By utilizing the idea of motion planning, a new continuous-time distributed NE seeking algorithm, which ensures convergence to NE at the prescribed time, is proposed based on sampled-data information exchange. Compared with the existing related works, the established algorithm has advantages on both the communication cost and convergence speed (i.e., appointed-time convergence). Finally, the effectiveness of the proposed method is verified via numerical simulations.

This paper studies the distributed generalized Nash equilibrium seeking problem for aggregative games with coupling constraints, where each player optimizes its strategy depending on its local cost function and the estimated strategy aggregation. The information transmission in distributed networks may go beyond bandwidth capacity and eventuate communication bottlenecks. Therefore, we propose a novel communication-efficient distributed generalized Nash equilibrium seeking algorithm, in which the communication efficiency is improved by event-triggered communication and information compression methods. The proposed algorithm saves the transmitted rounds and bits of communication simultaneously. Specifically, by developing precise step size conditions, the proposed algorithm ensures provable convergence, and is proven to achieve (0,δ)-differential privacy with a stochastic quantization scheme. In the end, simulation results verify the effectiveness of the proposed algorithm.

This letter addresses the problem of economic dispatch for network systems where the local cost functions are coupled through their decision variables. Using Lyapunov based techniques, a continuous-time algorithm is developed which guarantees finite-time convergence to the optimal solution. This makes it possible to predetermine the system convergence time based on the initial conditions. Unlike many previous studies, the local cost functions in this letter can be nonconvex and coupled through their decision variables. It is only required that their sum is strongly convex. To verify the effectiveness of the proposed results, an illustrative example is studied.

This paper considers the problem of multi-agent distributed optimization. In this problem, there are multiple agents in the system, and each agent only knows its local cost function. The objective for the agents is to collectively compute a common minimum of the aggregate of all their local cost functions. In principle, this problem is solvable using a distributed variant of the traditional gradient-descent method, which is an iterative method. However, the speed of convergence of the traditional gradient-descent method is highly influenced by the conditioning of the optimization problem being solved. Specifically, the method requires a large number of iterations to converge to a solution if the optimization problem is ill-conditioned. In this paper, we propose an iterative pre-conditioning approach that can significantly attenuate the influence of the problem's conditioning on the convergence-speed of the gradient-descent method. The proposed pre-conditioning approach can be easily implemented in distributed systems and has minimal computation and communication overhead. For now, we only consider a specific distributed optimization problem wherein the individual local cost functions of the agents are quadratic. Besides the theoretical guarantees, the improved convergence speed of our approach is demonstrated through experiments on a real data-set.

This article investigates a second-order multi-agent distributed optimisation algorithm on matrix-weighted networks. To address the limitations of traditional methods on matrix-weighted networks, a novel second-order distributed optimisation algorithm is proposed. By constructing auxiliary variables, the algorithm eliminates the requirement for velocity information updates. Under the proposed control protocol, algebraic and graph-theoretic conditions for achieving optimisation consensus are established based on matrix theory and Barbalat's lemma. Specifically, the given parameter conditions and local cost functions are convex; the second-order consensus at the global optimal solution is achieved when the Laplacian matrix's null space spans the consensus subspace or the matrix-weighted graph contains a positive spanning tree. Finally, a numerical experiment is conducted to validate the effectiveness of proposed algorithms.

The problem of seeking Nash equilibrium (NE) based on aggregative games under quantization constraints is full of challenges. Although the NE seeking algorithm in continuous-time systems has been studied, this problem in discrete-time systems still needs to be solved urgently. To address this problem, three distributed algorithms are first proposed under three quantization cases, adaptive, random, and time-varying quantizations, based on doubly stochastic communication topology networks. Then, the actions of players would eventually converge to NE under the conditions of vanishing step size and strong monotonicity are proved. Moreover, the convergence rate of the three quantization cases are analyzed, respectively. Finally, numerical experiments are implemented on plug-in hybrid electric vehicles (PHEVs) to validate the effectiveness of the proposed distributed algorithms. Comparing the convergence rates of the three proposed algorithms, the convergence effect of the adaptive quantization is better than that of the other two quantization cases.

In this article, the prescribed-time distributed Nash equilibrium (NE) seeking problem for multicoalition games with heterogeneous general linear players is investigated. In such games, there exist multiple coalitions that consist of heterogeneous players. The players have to seek the NE of the entire coalition while being limited to access only their individual cost functions. The proposed algorithm involves a two-layer structure composed of the NE seeking part and the tracking control part. To address the challenge of global information dependency, the leader-following-based estimates are designed. The NE seeking part is designed based on the distributed estimates and concurrently performed over the weight-balanced digraphs. Subsequently, by introducing the time-varying parametric Lyapunov equation, the strategies of the players are driven to the NE solution within a manually prescribed settling time, and the prescribed-time convergence is proved. Finally, the proposed algorithm is executed on the heterogeneous coalitions made up of quadrotor unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs) in a group formation scenario. Both the simulation and the experiment results are presented to show the effectiveness of the algorithm.

In this paper, we consider the problem of multi-agent systems where each agent aims to establish a line formation in a distributed manner. In constructing an efficient line formation, finding a line with the closest total distance from every agent is essential. We propose a formation control using least squares estimation (LSE) performed by each agent with only the local information that consists of the corresponding agent’s and neighbors’ positions. Each agent calculates the local cost function, which is the squared distance from the LSE line to the related agent’s and its neighbors’ positions. Our goal is to minimize the global cost function, which is the sum of these local cost functions. To achieve this, we employ distributed optimization to the global cost function of the overall system using the subgradient method performed by each agent locally. We evaluate our proposed method using numerical simulation, and the result complies with our goal of this paper

This paper considers distributed nonconvex optimization with the cost functions being distributed over agents. Noting that information compression is a key tool to reduce the heavy communication load for distributed algorithms as agents iteratively communicate with neighbors, we propose three distributed primal–dual algorithms with compressed communication. The first two algorithms are applicable to a general class of compressors with bounded relative compression error and the third algorithm is suitable for two general classes of compressors with bounded absolute compression error. We show that the proposed distributed algorithms with compressed communication have comparable convergence properties as state-of-the-art algorithms with exact communication. Specifically, we show that they can find first-order stationary points with sublinear convergence rate <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathcal {O}(1/T)$</tex-math></inline-formula> when each local cost function is smooth, where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$T$</tex-math></inline-formula> is the total number of iterations, and find global optima with linear convergence rate under an additional condition that the global cost function satisfies the Polyak–Łojasiewicz condition. Numerical simulations are provided to illustrate the effectiveness of the theoretical results.

In this paper, we consider distributed Nash equilibrium (NE) seeking in potential games over a multi-agent network, where each agent can not observe the actions of all its rivals. Based on the best response dynamics, we design a distributed NE seeking algorithm by incorporating the non-smooth finite-time average tracking dynamics, where each agent only needs to know its own action and exchange information with its neighbours through a communication graph. We give a sufficient condition for the Lipschitz continuity of the best response mapping for potential games, and then prove the convergence of the proposed algorithm based on the Lyapunov theory. Numerical simulations are given to verify the result and illustrate the effectiveness of the algorithm.