Some Simulink® blocks, including those with sharp discontinuities, can produce poor linearization results. For example, when your model operates in a region away from the point of discontinuity, the linearization of the block is zero. Typically, you must specify custom linearizations for such blocks. You can specify the block linearization as:
A linear model in the form of a D-matrix.
A Control System Toolbox™ model object.
An uncertain state-space object or an uncertain real object (requires Robust Control Toolbox™ software).