# Article

**Keywords:**

Filippov systems; differential algebraic equations (DAEs); Filippov systems with DAEs; soft drink process

**Summary:**

We will study discontinuous dynamical systems of Filippov-type. Mathematically, Filippov-type systems are defined as a set of first-order differential equations with discontinuous right-hand side. These systems arise in various applications, e.g. in control theory (so called relay feedback systems), in chemical engineering (an ideal gas--liquid system), or in biology (predator-prey models). We will show the way how to extend these models by a set of algebraic equations and then study the resulting system of differential-algebraic equations. All MATLAB simulations are performed in modified version of the program developed by Petri T. Piiroinen and Yuri A. Kuznetsov published in ACM Trans. Math. Software, 2008.