@article{1138, author = {Mudassir Shabbir and Waseem Abbas and Yasin Yazıcıoğlu and Xenofon Koutsoukos}, title = {Computation of the Distance-Based Bound on Strong Structural Controllability in Networks}, abstract = {In this article, we study the problem of computing a tight lower bound on the dimension of the strong structurally controllable subspace (SSCS) in networks with Laplacian dynamics. The bound is based on a sequence of vectors containing the distances between leaders (nodes with external inputs) and followers (remaining nodes) in the underlying network graph. Such vectors are referred to as the distance-to-leaders vectors. We give exact and approximate algorithms to compute the longest sequences of distance-to-leaders vectors, which directly provide distance-based bounds on the dimension of SSCS. The distance-based bound is known to outperform the other known bounds (for instance, based on zero-forcing sets), especially when the network is partially strong structurally controllable. Using these results, we discuss an application of the distance-based bound in solving the leader selection problem for strong structural controllability. Further, we characterize strong structural controllability in path and cycle graphs with a given set of leader nodes using sequences of distance-to-leaders vectors. Finally, we numerically evaluate our results on various graphs.}, year = {2023}, journal = {IEEE Transactions on Automatic Control}, volume = {68}, number = {3}, pages = {1768-1775}, month = {03/2023}, issn = {1558-2523}, url = {https://ieeexplore.ieee.org/document/9738436}, doi = {10.1109/TAC.2022.3160682}, }