Van der Pol’s controlled 2D oscillator

There are two reasons for 2D auto-oscillations to be of such interest for analysis. Firstly, mechanical systems based on such a model are widely used. Secondly, unlike 1D van der Pol’s oscillator, a 2D model as a mathematical object has much more characteristics: in addition to potential and dissipative forces, more complicated forces can be taken into account, which characterize different specific behaviors of the oscillator.