iqcToolbox: An Open-Source Robustness Analysis Toolbox based on Integral Quadratic Constraints

We present iqcToolbox, an open-source robustness analysis toolbox based on integral quadratic constraint (IQC) theory. To better enable collaborative contributions, this MATLAB toolbox is modularly designed and avoids dependencies on other closed-source toolboxes, excepting the Control System Toolbox. In contrast to existing robustness analysis packages, iqcToolbox is capable of analyzing discrete-time time-varying systems as well as continuous-time systems. iqcToolbox also allows the specification of time-varying IQC multipliers, and we demonstrate how the incorporation of time-varying systems in the toolbox can generate new uncertainties (such as eventually time-invariant parameters), express new disturbance signal sets (such as constant or periodically updated signals), and enable new analysis tools (such as worst-case reachability analysis). Both the expressivity and modularity of our core analysis objects provide a rich and stable framework for extensions by current and future developers.