Hover Control of a PVTOL Using Nonlinear Regulator Theory

In the last few years, there has been a great deal of interest in the design of control laws to the purpose of achieving trajectory trackdng in nonlinear control systems. The simplest approach to this problem is so-called "inversion-based" control. Here, state feedback is used to modify the internal dynamics of the system so that part of it becomes identical to the system "zero dynamics" (and therefore cancels with the latter and does not contribute to the input-output behavior), while the other part becomes linear and input-output-wise equivalent to a string of r integrators (where r is the relative degree of the system). On the system